the german cockroach ( blattella germanica ) is a small species of cockroach , typically about 1.1 to 1.6 cm ( 0.43 to 0.63 in ) long .

in colour it varies from tan to almost black , and it has two dark , roughly parallel , streaks on the pronotum running anteroposteriorly from behind the head to the base of the wings .

although blattella germanica has wings , it can barely fly , although it may glide when disturbed .

of the few species of cockroach that are domestic pests , it probably is the most widely troublesome example .

it is very closely related to the asian cockroach , and to the casual observer the two appear nearly identical and may be mistaken for each other .

however , the asian cockroach is attracted to light and can fly rather like a moth , while the german cockroach can not .

german cockroach

german cockroach <EOT> german cockroach diseases german cockroach life cycle german cockroach nests german cockroach nymphs german cockroach vs . american cockroach

insect management guide for cockroaches . least toxic methods of cockroach control . german cockroach management in low income housing

the german cockroach is the most common species of the cockroach . german cockroaches can breed at a rate of up to six generations per year . the german cockroach can fit through an opening as small as 3 / 8 inch in width .

german cockroaches can be found all over the world . they are the most common cockroach in the united states . each german cockroach can live about 100 - 200 days .

the german cockroach eats almost anything but prefers starchy foods like potatoes , rice and cereal .

i saw one small german cockroach in my home and now i am worried . how long before they overrun my home ? keep reading to learn how fast german cockroach reproduction occurs .

the german cockroach , which originally came from africa , is the smallest of the pest species .

differential development and reproduction of the german cockroach ( dictyoptera : blattellidae ) on three laboratory diets .

the american cockroach is the largest cockroach found in houses . despite its name , the american cockroach is not native to north america , but was likely introduced via ships from africa in the 1600s .

prof essional roach baits , pesticide dusts , aerosols or residual spray concentrates can be used to eliminate german cockroach infestations .

differential development and reproduction of the german cockroach ( dictyoptera : blattellidae ) on three laboratory diets . - pubmed - ncbi

wondering how to get rid of german cockroaches ? the best advice for german cockroach control is to practice good sanitation . to prevent german cockroaches from infesting the space , vacuum often , keep a spotless kitchen , seal all entrances around utility pipes and ventilate crawl spaces to prevent moisture buildup . if there is evidence of a cockroach infestation , contact a licensed pest professional to inspect and treat the german cockroach problem .

robinson , w . 1999 . worries over german cockroach resistance fades . pest control 67 ( 7 ) : 40 - 42

the smallest cockroach known is attaphila fungicola , measuring 1mm wide and 3mm long . this cockroach lives in the nest of leaf cutter ants .

the german cockroach is the cockroach of concern , the species that gives all other cockroaches a bad name . it occurs in structures throughout florida , and is the species that typically plagues multifamily dwellings . in florida , the german cockroach may be confused with the asian cockroach , blattella asahinai mizukubo . while these cockroaches are very similar , there are some differences that a practiced eye can discern .

figure 4 . third instar nymph of german cockroach blattella germanica ( linnaeus ) . photograph by james castner , university of florida .

rust mk , owens jm , reierson da . 1995 . understanding and controlling the german cockroach . oxford university press , oxford .

nalyanya g . , gore j . c . , linker h . m . , schal c . german cockroach allergen levels in north carolina schools : comparison of integrated pest management and conventional cockroach control .

robinson , w . 1996 . resistance remediation in the german cockroach . resistant pest management 8 ( 1 ) : 34 - 35 .

wang c . , bennett g . w . comparative study of integrated pest management and baiting for german cockroach management in public housing .

figure 1 . adult female german cockroach , blattella germanica ( linnaeus ) , with ootheca . photograph by james castner , university of florida .

figure 6 . adult male german cockroach , blattella germanica ( linnaeus ) . photograph by p . g . koehler , university of florida .

figure 7 . adult female german cockroach , blattella germanica ( linnaeus ) . photograph by p . g . koehler , university of florida .

tsai , y . , k . cahill . 1970 . parasites of the german cockroach ( blattella germanica l . ) in new york city .

figure 2 . oothecae ( egg cases ) of the german cockroach , blattella germanica ( linnaeus ) . photograph by james castner , university of florida .

the german cockroach is also the most sociable of the pest species and is often found in large groups , especially near warm areas like water heaters .

check out the tips in this video to help you prevent and treat cockroach infestations .

find more facts about and information on cockroach pest control at the official npma website .

ithe german cockroach is the hardest pest cockroach to get rid of and is the most troublesome in sydney . it can be found anywhere in the home but is probably most common in the kitchen , frequently inside cupboards , drawers and electrical appliances .

robinson , w . 1996 . how the german cockroach has adapted to the household environment . pest control 64 ( 7 ) : 43 , 44 , 46 .

2004 . " german cockroach - blattella germanica " ( on - line ) . north carolina museum of natural sciences . accessed october 18 , 2008 at urltoken .

the world ' s smallest cockroach is only 0 . 3mm long and lives in ant nests

cornwell pb . 1968 . the cockroach , volume i . hutchinson of london , london .

survey - to control german cockroaches , it is important to do a thorough inspection . a cockroach survey ( trapping ) is sometimes necessary to determine the extent of an infestation , as even a thorough inspection will not reveal all cockroach harborages or foraging areas .

the german cockroach is one of the most common roaches found in apartment houses , restaurants , and hotels . german cockroaches ( eggs included ) , are brought inside or hitchhike on man ' s belongings , luggage , boxes or packages . a large german roach population will produce a foul odor . these roaches prefer moisture , food , and warmth . sanitation measures are critical in controlling german roaches . german roaches can be a serious health hazard in restaurants .

fasulo tr . ( 2002 ) . stored product pests and german cockroach . bug tutorials . university of florida / ifas . cd - rom . sw - 165 .

chai r . y . , lee c . y . insecticide resistance profiles and synergism in field populations of the german cockroach ( dictyoptera : blattellidae ) from singapore .

if you have ever seen a particularly long cockroach , then you may have seen a female carrying its egg case on its abdomen . the egg case , an ootheca , of a german cockroach typically carries 30 to 40 eggs . the german cockroach will carry this egg case up to nearly the time when the eggs are ready to hatch , and once the new baby roaches hatch , they are initially bright , white nymphs .

the german cockroach is found throughout the world in association with humans . they are unable to survive in locations away from humans or human activity . the major factor limiting german cockroach survival appears to be cold temperatures . studies have shown that german cockroaches were unable to colonize inactive ships during cool temperatures and could not survive in homes without central heating in northern climates . the availability of water , food , and harborage also govern the ability of german cockroaches to establish populations , and limit growth .

droppings german cockroach droppings may appear as small , dark , “pepper - like” material left on countertops or in drawers . fecal staining may appear as dark spots or smears :

egg capsules since german cockroach females carries their egg case until 1 to 2 days before depositing it , empty egg cases may be found in areas that the females frequent .

snell , e . and w . h robinson . 1991 . bait stations and german cockroach management programs . pest control technology 19 ( 8 ) : 55 - 57 .

robinson , w . 1996 . more good news from the field ( german cockroach resistance ) . pest control technology 24 ( 6 ) : 56 , 61 , 62 .

watch this video to learn more about the most common cockroach species that can infest your home .

koehler pg , strong ca , patterson rs . 1994 . rearing improvements for the german cockroach ( dictyoptera : blattellidae ) . journal of medical entomology 31 : 704 - 710 .

zhai , j . and w . h robinson . 1992 . chemical control of the german cockroach . pest control technology 20 ( 3 ) : 40 , 41 , 44 .

since the german cockroach is considered an aesthetic pest , the action threshold for this insect depends upon the tolerance of the people living in the infested dwelling . however , most people associate cockroach infestations with poor sanitary conditions and typically go to excessive lengths to eradicate them from their houses .

the german cockroach is a widely distributed urban pest . it is also the most common cockroach species in houses , apartments , restaurants , hotels , and other institutions . this is true not only in pennsylvania but also throughout the united states and in most parts of the civilized world .

figure 3 . first instar nymphs emerging from the oothecae ( egg case ) of a german cockroach , blattella germanica ( linnaeus ) . photograph by james castner , university of florida .

the german cockroach ranges in size from about one - eighth of an inch in length when it hatches , to a little over one - half of an inch as an adult .

zhai , j . and w . robinson . 1996 . antennal and leg grooming in two strains of the german cockroach ( orthoptera : blattellidae ) . med . entomol . zool .

mccandless , l . 2005 . " cu scientists unravel mating clues of the german cockroach " ( on - line ) . cornell chronicle . accessed november 14 , 2008 at urltoken .

lifespan as adults , german cockroaches can survive anywhere from 100 to 200 days .

figure 5 . newly molted adult german cockroach , blattella germanica ( linnaeus ) . within a few hours the cuticle will harden and darken . photograph by james castner , university of florida .

robinson , w . h and j . zhai . 1992 . insecticide rotation and german cockroach control . pest control technology 20 ( 12 ) : 24 , 28 , 30 . 31 .

robinson , wm . h and j . zhai . 1992 . insecticide rotation and german cockroach control . pest control technology 20 ( 12 ) : 24 , 28 , 30 , 31 .

german cockroaches produce odorous secretions that can affect the flavor of various foods . when cockroach populations are high , these secretions may result in a characteristic odor in the general region of the infestation . disease - producing organisms such as bacteria , protozoans , and viruses have been found on cockroach bodies .

when beginning your german roach control program , sanitation is one of the first things to consider . german roaches only need a small amount of food to sustain them .

nature has provided german roaches the means to ensure their survival in a splendid way . german roaches protect their eggs to help ensure hatching and reproduce at astounding rates .

german cockroaches are one of the most common cockroach species found in households . german cockroaches undergo three distinct life phases : egg , nymph and adult . their entire life cycle spans approximately 100 days , although this is dependent on factors such as temperature , diet and injuries .

asian cockroaches , a pest of the southeastern united states , are often mistaken for the german cockroach . similar in appearance , the main differences between the two cockroaches are evident in their behavior .

durier v , rivault c . 2003 . improvement of german cockroach ( dictyoptera : blatellidae ) population control by fragmented distribution of gel baits . journal of economic entomology 96 : 1254 - 1258 .

phantom aerosol may be used with roach baits and will enhance your german roach control .

breeding season german cockroaches breed continuously year round , though breeding slows during colder months .

advion arena roach bait advion cockroach bait arena can be used to control cockroach populations indoors and outdoors with the active ingredient indoxacarb , an insecticide that acts through ingestion by cockroaches . advion roach bait arena ( 60 ctn )

the german cockroach was once the no . 1 pest in residential and commercial buildings . that changed with the introduction of cockroach baits , which resulted in one of the great success stories in insecticide development . cockroaches became almost a second tier pest , and remained so for more than a decade . but have you noticed ? they’re back ! it’s time for pest management service technicians to review some of the critical aspects of german cockroach biology and habits that can make it one of our more challenging pests .

zhai , j . and w . h robinson . 1992 . measuring cypermethrin resistance in the german cockroach ( orthoptera : blattellidae ) . j . econ . entomol . 85 : 348 - 351 .

] . the german cockroach has been reported to have developed resistance to 42 unique insecticide active ingredients in 219 documented cases worldwide and is ranked as the world’s no . 2 insecticide resistant urban pest [

day , e . august 1996 . " german cockroach . " ( on - line ) . virginia cooperative extension , virginia polytechnic institute and state university . accessed october 14 , 2008 at urltoken .

valles , s . 2008 . " german cockroach " ( on - line ) . university of florida institute of food and agricultural sciences – featured creatures . accessed october 10 , 2008 at urltoken .

highly magnified footage of these experiments clearly shows a glucose - averse cockroach reacting to a dose of the sugar .

in addition to being a nuisance , the german cockroach has been implicated in outbreaks of illness and allergic reactions in many people . cockroaches have been reported to spread at least 33 kinds of bacteria , six kinds of parasitic worms and at least seven other kinds of human pathogens . they can pick up germs on the spines of their legs and bodies as they crawl through decaying matter or sewage and then carry these into food or onto food surfaces . medical studies have shown that german cockroach allergens cause allergic reactions and can exacerbate asthma attacks , especially in children . this makes german cockroach control incredibly vital .

reproduction & life cycle the female german cockroach produces an egg capsule every 3 to 4 weeks , with each capsule containing 25 - 45 eggs . rather than depositing the sack , the female carries the capsule with her and protects it until it hatches . this is another reason the german cockroach is so difficult to get rid of - its nymphs are well protected . these young nymphs will begin breeding again in as little as 36 days . adult german cockroaches can live up to 365 days .

female german cockroaches carry the oothecae attached to their abdomens until about two days prior to hatching and then deposit them in a protected location . oothecae may be seen protruding from the abdomens of german cockroach females . nymphs emerge from the oothecae as tiny insects . they gradually darken into dark brown or black cockroaches with parallel lines visible upon the pronotum . german cockroach nymphs are wingless and incapable of reproduction . nymphs molt six to seven times and can develop completely within 100 days under optimal conditions .

not applying insecticides effectively . whether baits , liquids , dusts , or other formulations , cockroach insecticides need to be applied in cracks , crevices , voids , and other sites where german cockroaches are aggregating .

zungoli , p . a . and w . h robinson . 1984 . feasability of establishing an aesthetic injury level for german cockroach pest management programs . environ . entomol . 13 : 1453 - 58 .

a flashlight would be a handy tool to inspect evidences of german roaches the following places .

wings : while adult german cockroaches have wings , they rarely fly , preferring to run .

robinson , w . 1996 . antennal grooming and movement behavior in the german cockroach , blattella germanica ( l . ) . proc . internat . conf . insect pests urban environment 1996 : 361 - 369 .

not rescheduling problem apartments . when cockroach populations become large , service needs to be repeated every few weeks to succeed .

the largest winged cockroach in the world is megaloblatta blaberoides from costa rica ( wingspan of 7 . 3 inches ) .

maxforce® forte contains fipronil 0 . 03 % along with gel that delivers quick results for treatment of cockroach . . .

the german cockroach is a highly pestiferous insect that produces asthma - inducing allergens , and is closely associated with areas of human habitation . as such , the german cockroach is transported through human activities , such as food and equipment dispersal . in connected apartments and buildings , german cockroaches can also move between units , making control difficult in heavy infestations . it has previously been shown that the bacterial flora transmitted by german cockroaches presents a serious epidemiological problem for human health and well - being , especially to those living in low - income housing . because german cockroaches are able to vector antibiotic - resistant bacteria , its presence must be controlled to reduce the threat of bacterial contamination in hospitals and swine farms .

for effective control , cockroaches must prefer to eat the bait product over surrounding , non - toxic foods . that means cleaning the dishes in the sink , removing trash in a timely fashion , properly storing food , cleaning spills quickly , and identifying potential water sources ( such as leaky pipes ) . cleaning and sanitation has been shown to be effective at reducting german cockroach population numbers , and reducing cockroach allergen levels . reduce clutter to reduce possible cockroach harborages .

the german cockroach , blattella germanica ( l . ) , is a common indoor cockroach species . infestations of this pest are associated with poor sanitation , particularly in and around food - handling facilities , and also tend to be associated with lower socioeconomic status . cockroach infestations lead to food damage and contamination because cockroaches can vector human and domesticated animal pathogens . cockroach feces , saliva and cast skins contain allergens that may trigger allergic reactions and psychological distress in sensitive individuals [ 46 ] . cockroaches are among the most problematic urban pests in initiating asthmatic and allergic reactions in children [ 47 ] .

farmer , b . r . and w . h robinson . 1984 . harborage limitation as a component of a german cockroach pest management program . proc . entomol . soc . wash . 86 : 269 - 73 .

teachers can find additional information on german cockroaches to share with students at the official npma website .

the adult stage begins with the last successful molting . at this point , german cockroaches are approximately 15 mm in length and are winged . adult german cockroaches are nocturnal insects that hide during the day and scavenge at night . despite their fully developed wings , german cockroaches very rarely fly .

3 . german cockroaches spend most of their lives hidden and protected . for every cockroach in view in daytime , hundreds can be hidden inside wall and ceiling voids , behind cabinets , inside appliances , and the like . a german cockroach’s favorite location is inside a narrow crevice with its antennae extended out . typical “prime” locations are the cracks between cabinets and walls , the flange under the kitchen sink , and the space between door corners and jambs .

zhai , j . and w . h robinson . 1996 . instability of cypermethrin resistance in a field population of the german cockroach ( orthoptera : blattidae ) . j . econ . entomol . 80 : 332 - 336 .

gondhalekar a . d . , scherer c . w . , saran r . k . , scharf m . e . implementation of an indoxacarb susceptibility monitoring program using field - collected german cockroach isolates from the united states .

zhai , j . and w . h robinson . 1991 . pyrethroid resistance in a field population of german cockroach , blattella germanica ( l . ) . jpn . j . sanit . zool . 42 : 241 - 244 .

ajjan , i . and w . h robinson . 1996 . measuring hydramethylnon resistance in the german cockroach , blattella germanica ( l . ) . proc . internat . conf . insect pests urban environment 1996 : 135 - 144 .

robinson , w . 1999 . the changing pest status of the german cockroach in the urban environment . proceedings of the fifty second new zealand plant protection conference , new zealand plant protection society inc . , 1999 : 16 - 21

german cockroaches breed continually . in a lifetime , a female cockroach is capable of producing almost 400 eggs . populations grow quickly in optimal conditions . a typical thriving population is comprised of 75 percent nymphs and 25 percent adult roaches .

german cockroaches do not have a specific home range . they usually dwell in homes and in garbage .

if insecticides have been used in a building , there is a possibility that the german cockroach simply scattered to another area . these harborages need to be located and treated . it may not be possible to eliminate all the german cockroaches in a building completely if a consistent supply of cockroaches is carried into the premises via packages or food shipments .

what are the most common areas in the home where cockroaches are found ? dr . jim fredericks discusses the most popular cockroach hangouts .

robinson , w . h and j . zhai . 1993 . insecticide program to manage a cypermethrin - resistant population of the german cockroach , blattella germanica ( l . ) . resistance pest managt . 5 ( 1 ) : 21 - 23

miller , d . m . , koehler , p . g . 2000 . novel extraction of german cockroach ( dictyoptera : blattellidae ) fecal pellets enhances efficacy of spray formulation insecticides . j . econ . entomol . 93 : 107 - 111

orkin can provide the right solution to keep german cockroaches in their place…out of your home , or business .

if you think you might have german roaches , then don’t wait ! call bug zapper pest control for a free inspection . let our trained technicians accurately identify possible german roaches and help you find the best solution .

temprid is a combination product suitable as residual spray for the control of american cockroaches and german . . .

miller , d . m . , koehler , p . g . 2000 . trail following in the german cockroach , blattella germanica ( l . ) ( dictyoptera : blatellidae ) . . j . econ . entomol . 93 : 1241 - 1246

thoms , e . m . and w . h robinson . 1987 . potential of the cockroach oothecal parasite prosevania punctata ( hymenoptera : evaniidae ) as a biological control agent for the oriental cockroach ( orthoptera : blattidae ) . environ . entomol . 16 : 938 - 944 .

german cockroaches will feed on almost anything , including soap , glue and toothpaste . german cockroaches are good hitchhikers and often find their way into new structures via grocery bags , cardboard boxes , drink cartons and secondhand appliances .

the german cockroach is the most successful of the species infesting buildings in pennsylvania . there are several reasons for this cockroach’s persistence and the difficulty of controlling it . german cockroaches produce a larger number of eggs per capsule and they undergo the shortest time from hatching until sexual maturity , resulting in a rapid population growth . a greater number of nymphs hatch successfully because the female carries the egg capsule during the entire time the embryos are developing within the eggs . also , and most importantly , german cockroaches are smaller than most other cockroaches and can conceal themselves in many places inaccessible to individuals of the larger species .

5 . german cockroaches protect their egg cases . the female german cockroach carries her egg case for as long as a month , dropping it just before it hatches . while she is carrying the egg case , the female german cockroach is less active and tends to stay hidden away in cracks and crevices and protected voids . for this reason , when applying residual insecticides , it is especially important to ( 1 ) treat deep inside cracks , crevices , and voids , and ( 2 ) schedule follow - up treatments from a few weeks to a month later in problem locations to control newly - emerged nymphs .

tekko pro stops the reproduction and reduces the survival of the german roach with two different modes of action . it effects the molting process , making the german roach vulnerable to survival and it stops it at the larvae state .

besides physiological resistance to bait insecticides , german cockroaches have developed behavioral resistance to various phagostimulants of bait formulations , typically d - glucose and d - fructose [ 65 , 66 , 67 ] . the glucose aversion in field german cockroach populations resulted in the failure of attracting cockroaches to toxic baits and protected them from receiving lethal doses of insecticides [ 65 , 66 ] .

the german cockroach has three life stages typical of insects with incomplete metamorphosis : the egg , nymph , and adult . the entire life cycle is completed in about 100 days . however , factors such as temperature , nutritional status , and strain differences may influence the time required to complete a life cycle . german cockroaches breed continuously with many overlapping generations present at any one time . under ideal conditions , population growth has been shown to be exponential . actively growing field populations are comprised of 80 percent nymphs and 20 percent adults . the german cockroach is omnivorous , eating table scraps , pet food , and even book bindings .

for german roach control in restaurants we recommend the use of insecticides , aerosols , dusts , and insect growth regulators instead of baits . there is too much competing food sources for effective control of german roaches in restaurants with bait .

many times , german roaches in restaurants require insecticides as opposed to baiting . using baits in german roach control requires that their is no competing food sources . in restaurants , it is almost impossible to eliminate all competing food sources .

robinson , w . h 1988 . bait stations in cockroach pest management programs . pest control 56 ( 8 ) : 56 , 57 , 60 .

general the german cockroach is the most common roach found in apartments , houses , hotels , and restaurants . german cockroaches and their eggs are usually transported into buildings on a person ' s belongings , luggage , or boxes . it only takes one small egg capsule and you have an infestation six months later . this species is also one of the most challenging to get rid of .

dust should only supplement any insecticide of bait control program for german roach control , not as a stand alone solution .

adult german roaches can live up to one year . they adapt quickly to changing environments , and evolve to survive .

as they are quite abundant , german cockroaches are not considered a species of concern in any part of their range .

german cockroaches live in warm and damp places , like kitchens , bathrooms , and places where people eat and drink .

4 - eliminating harborages german roaches prefer a tight crack or crevice , or a dark wall void in which to hide out of sight during daylight areas . eliminate as many harborages as you can and german roaches will hit the road .

german cockroaches adulterate food or food products with their feces and defensive secretions , physically transport and often harbor pathogenic organisms , may cause severe allergic responses , and in extremely heavy infestations have been reported to bite humans and feed on food residues on the faces of sleeping humans . in addition , some scientists suggest that german cockroach infestations may cause human psychological stress and that the stigma associated with infestations alters human behavior . for example , people with infested houses do less entertaining , and avoid the kitchen at night for fear of encountering a cockroach .

eliminating nesting sites by improving sanitation and reducing clutter and the elimination of food and water sources is imperative to eliminate german cockroach infestations and will help protect you from future infestations . you can also help prevent infestations by sealing any areas where roaches could enter from other units in multi - unit buildings and by checking items such as shipping boxes , school bags and grocery bags for cockroach hitchhikers before bringing them into your home .

the german cockroach is a small , noctural , dime / penny sized , fast moving cockroach that can quickly escape into cracks and crevices in the wall . adults are elongated , light carmel - colored brown , with two longitudinal black stripes running along the pronotum . adult females may be seen carrying an egg case ( shown to the right ) . nymphs are darker brown / black colored , smaller , and oval shaped .

miller , d . m . , meek , f . 2004 . cost and efficacy comparison of ipm strategies with monthly spray insecticide applications for german cockroach ( dictyoptera : blattellidae ) control in public housing . . j . econ . entomol . 97 : 559 - 569 .

miller , d . m . , koehler , p . g . , nation , j . l . 2000 . fecal extract trails enhance trap catch in german cockroach ( dictyoptera : blattellidae ) monitoring stations . j . econ . entomol . 93 : 865 - 870 .

the process of natural selection would strongly favour any chance genetic change that caused a cockroach to avoid the bait and therefore death . since individuals with the trait would have a greater chance of surviving and reproducing , their descendants with the trait would in time replace those that lacked the trait in the cockroach population .

tee h . , lee c . sustainable cockroach management using insecticidal baits : formulations , behavioral responses and issues . in : dhang p . , editor .

in addition to robotic intervention , there are several steps that people can take to reduce or eliminate cockroach populations . we ' ll look at these next .

the german cockroach can move well within a building . they also can travel from a neighboring apartment or location to another and can pass through small openings like light switch plates . many times they are brought in with grocery items , grocery bags , cartons , handbags , and luggage .

there are about 4 , 600 species of cockroach and fewer than 30 of these are considered pests . ( there are about 5 , 400 species of mammals )

avert dry flowable cockroach bait remains effective for more than one year after initial treatment . the dry formula reaches void areas that gels and bait stations cannot reach .

zhai , j . and w . h robinson . 1991 . cockroach distribution in urban buildings . pest control technology 19 ( 2 ) : 36 - 39 .

cypermethrin insecticides are the most popular for killing german cockroaches . mop up can also be used when mopping kitchen floors and is used primarily in restaurant roach control . the best professional baits for german roaches are invict gold cockroach gel and maxforce magnum . demon insecticide is the best residual spray and can best be used in conjunction with baygon aerosols . if you prefer to use professional dusts , delta dust and drione dust are the best dusts for roach control . for more help in ridding yourself of this pest , refer to german roach elimination .

ajjan , i . and w . robinson . 1996 . measuring hydramethylon resistance in the german cockroach , blattella germanica ( l . ) . in k . wildey and w . robinson , eds . proceedings international conf . on urban pests , prague , edinburgh , pp . 135 - 144

adult german cockroaches are light - brown and have two stripes on their pronotum , which is the “shield” just behind their head .

7 . german cockroaches regularly disperse to new areas . older , larger nymphs are most likely to disperse , followed by adult males and then adult females without egg cases . small nymphs are least mobile . during an outbreak of german cockroaches , technicians need to expand their search for cockroaches into adjacent rooms above and below , even into sites that are not typically infested with german cockroaches .

egg carrying patterns and rapid reproduction rates allow german roaches to quickly infest a home . don’t take chances with your family’s health .

empty cabinets and clean them out . another common food source for german roaches are the crumbs and food spills inside kitchen cabinets .

store food in sealed containers . german roaches are small enough to slip into the cardboard packaging that many foods are stored in .

females carry an egg capsule containing 30 - 48 eggs at the end of their abdomen . when the eggs are close to hatching , the females attach the capsule in a dark corner where the young can emerge safely . one female german cockroach can produce up to 20 , 000 young annually .

an allergy to cockroaches could set off adult or pediatric asthma . cockroach allergens can be environmental triggers for asthma . learn more about the health implications of cockroaches here .

the information for roaches should help not only identify pests but also help to differentiate types of roaches that are given common or incorrect names . to many people , any large roach , roaches that live primarily outdoors or any cockroach that is not a german cockroach is considered a woods roach . the wood roach is a distinct species of roach , not a group of bugs . however , many pest control experts do consider roaches that are not german roaches to belong to a generic " large roach " or " outdoor roach " because their primary source is the outdoors . " water bugs " is a term many people use to describe german cockroaches . there are no roach pests that are technically water bugs . when our customers say that water bugs are a problem in their home , we can usually assume that they have an infestation of german roaches .

in three to four months , those baby roaches will develop into fully grown adults . the lifespan of a cockroach is usually one year , and in any female roach’s lifetime , she can produce anywhere between 200 to 300 offspring or 6 generations a year . the number of eggs a single cockroach can produce will vary from species to species . potentially , and with optimal conditions , one female german cockroach and her offspring could produce 300 , 000 roaches in a year . this means that if you are not careful , a relatively small roach infestation can quickly develop into a much larger problem that needs to be dealt with quickly .

what do they eat ? german cockroaches are scavengers , capable of feeding on most any food source available . the pests will eat :

6 . german cockroach egg capsules are not susceptible to insecticides . most insecticides do not have the ability to penetrate the egg case , even if directly applied to the case . the unaffected egg cases will hatch days after treatment . this is another reason to schedule follow - up treatments in heavy infestations .

miller , d . m . , koehler , p . g . , patterson , r . s . 1997 . use of german cockroach ( blattella germanica ) fecal extract to enhance toxic bait performance in the presence of alternative food sources . j . econ . entomol . 90 : 483 - 487 .

feeding habits the german cockroach will eat practically anything and will live very close to food and water sources . they eat sweets , starches , grease , and meat products ; but will also feed on beer , leather , book bindings , hair , glue , dried skin , dead animals and plant material .

pest control effort ! failure to practice good housekeeping is the primary reason for outbreaks of german roaches . like most pests , german roaches require 3 things to thrive - food , water , and harborage . if you can eliminate even one of these things through proper sanitation ,

to inspect for the presence of german cockroaches , one can use pheromone sticky traps ( commonly found in hardware / supermarket stores ) to attract and trap german cockroaches . however , the use of these traps requires vigilant inspection over time ( traps are only as useful as the person that monitors them ) . for an easy - to - make homemade trap for a possible german cockroach infestation , take a baby food jar and coat the inside - upper walls with vasoline . put a small amount of beer and bread inside the baby food jar , and place jar along the wall underneath the kitchen sink . the smell of fermentation and yeast from this attractive mixture will lure nearby cockroaches , and when the cockroach falls into the jar it won’t be able to run up the vasoline !

another study suggests that cockroaches have a collective intelligence made up of the decisions of individual roaches . european scientists developed a robot called insbot that was capable of mimicking cockroach behavior . the researchers applied cockroach pheromones to the robot so real roaches would accept it . by taking advantage of roaches ' tendencies to follow each other , insbot was able to influence the behavior of entire groups , including convincing roaches to leave the shade and move into lighted areas . scientists theorize that similar robots could be used to herd animals or to control cockroach populations .

" in the cockroach case , sugar actually tastes bitter - an effective way for natural selection to quickly produce cockroaches that won ' t accept the sugar baits that hide poison . "

farmer , b . r . and w . h robinson . 1984 . is caulking beneficial for cockroach control . pest control 52 ( 6 ) : 28 , 30 , 32 .

this kit contains invict roach bait with gentrol point source igr for the best combination for german roach control , it kills the adult population and prevents new births . invict gold cockroach gel rapidly kills roaches with its bait matrix of 11 food attractants as a lure . it is known to maximize roach control and fight against bait aversion .

whether mother roaches care for their young also varies from one species to another . some mothers hide or bury their ootheca and never see their offspring . others care for their offspring after birth , and scientists believe that some offspring have the ability to recognize their mothers . the number of young that one roach can bear also varies considerably . a german cockroach and her young can produce 300 , 000 more roaches in one year . an american cockroach and her young can produce a comparatively small 800 new roaches per year .

robinson , w . h . 1985 . german cockroaches , facts or fiction . pest control 53 ( 10 ) : 70 , 75 - 76 .

the mating behavior of german cockroaches is driven by pheromones given off by females , which are detected by the antennae of males . german cockroaches breed continuously with many overlapping generations present at any one time . as a result of continuous breeding and promiscuity , population growth has been shown to be exponential .

male german cockroaches , on average , live 100 to 150 days . females live much longer , with an average lifespan of 190 to 200 days .

thoms , e . m . and w . h robinson . 1987 . distribution and movement of the oriental cockroach around urban apartment buildings . environ . entomol . 16 : 731 - 737 .

) . conventional cockroach control programs have used spray formulations containing carbamates , ops , organochlorines and pyrethroids . consequently , high levels of resistance to these insecticides have been documented in many field populations [

german cockroaches , believed to have originated in southeast asia , are the most widely distributed urban pests . they have been introduced to all parts of the globe including north america , australia , africa , and the oceanic islands . this ubiquity makes german cockroaches cosmopolitan , with the only deterrent being cold temperatures .

male adult german cockroaches are slender and a little smaller than the females , who are a little larger and wider in the abdomen . when female adult german roaches are ‟gravid , ” or pregnant , they have an egg capsule , or ootheca , that can be seen protruding about one quarter - inch from the end of the abdomen . the egg capsule contains about 40 german cockroach eggs , more or less , that will be carried with her until about 24 hours before the new roaches are ready to hatch . she then drops the egg capsule in a concealed location . when the new roaches open it and crawl out , they are on their own .

german cockroach females , unlike most other roaches , carry the egg capsule protruding from their abdomen until their capsules ready to split open . during the last three or four days prior to dropping her egg case , the female german cockroach does not forage for food or water . the case is then placed in a secluded location , with the nymphs emerging sometimes within the hour or as long as a week . a female may produce four to six cases during her lifetime , each containing 30 to 40 eggs . eggs hatch in 28 to 30 days , and nymphs develop in 40 to 125 days . female roaches live about 200 days , with males living not quite as long . the german roach produces more eggs and has more generations per year ( three to four ) than other roaches , and only a few individuals are needed to develop into troublesome infestations .

robinson w . h and j . zhai . 1990 . pyrethroid resistance in german cockroaches . pest control technology 18 ( 10 ) : 26 - 28 .

although german cockroaches are capable of living outdoors , they are often found in homes where food is widely available . learn more in the orkin pest library urltoken

" it shakes its head and refuses to imbibe that liquid , at the end , you can see the [ glucose ] on the side of the head of the cockroach that has refused it . "

the saliva , droppings and decomposing bodies of cockroaches contain allergen proteins which are known to trigger allergies and increase the severity of asthma symptoms . for more on cockroaches , check out the cockroach pest guide .

thoms , e . m . and w . h robinson . 1986 . the oriental cockroach : new insights on an old foe . pest control 54 ( 7 ) : 30 - 32 , 36 .

at rentokil , our british pest control association ( bpca ) certified technicians are able to provide customised , targeted treatments to guarantee complete control of your cockroach problem and help to prevent a re - infestation .

german cockroaches have three developmental stages : egg , nymph , and adult . females develop 4 to 8 capsules containing 30 to 48 eggs each in their lifetime . capsules hatch about 28 days after they begins to form . a few weeks thereafter , a new egg capsule begins to form . the egg stage varies in duration from 14 to 35 days . german cockroaches have 6 to 7 nymphal stages occurring over a period of 6 to 31 weeks . they express incomplete metamorphosis : zygotes develop within eggs and hatch directly into nymphs , which then grow into adult cockroaches . the complete life cycle of the cockroach is roughly 100 to 200 days for females , during which 10 , 000 descendants of a single cockroach can be produced .

the most common and effective igr used for german roach control is gentrol igr , which comes in an aerosol , concentrated liquid , and point - source tablet .

due to resistance to most insecticides on the market , professional roach baits are by far the most effective products to use when german cockroach extermination is needed . there is an insecticide concentrate that can be used against these resistant roaches but it is labeled for use only in commercial kitchens - and it has a very high odor . commercial kitchens should either bait or use orthene

the best way to get rid of german roaches is place out a high quality roach bait like invict gold to kill the adult german roaches and an insect growth regulator ( igr ) like gentrol point source igr to stop the reproduction of roaches . we have both products in a kit , invict gold roach kit for savings .

adult german cockroaches are 1 / 2 to 5 / 8 inch long and tan to light brown ( fig . 1 ) . although they have fully developed wings , they do not fly . nymphs are similar in appearance to adults except that they are smaller and lack wings . the german cockroach is best identified by its small size and by two dark parallel lines running from the back of the head to the wings . it is usually found in kitchens ( near dishwashers , stoves , and sinks ) and in bathrooms of homes .

german roach infestations are usually are generally found in kitchens and bathrooms . if the population is large enough , they will spill over to other rooms . these roaches are mostly active at night . if german roaches are seen active during the day , it most likely is due to overcrowding in their hiding places or a shortage of food and water supply . cracks and crevices are their harborage areas ; they spend about 75 % of their time in such harborages . first instar nymphs require a crack of about 1 / 32 " whereas , adults require an inch width . german cockroach nymphs are smaller than most other cockroaches ; thus , they are able to conceal themselves in many places and remain protected .

non toxic and low toxic alternatives for german cockroach control are available . sticky traps can be used to monitor or reduce population size . improving sanitation by eliminating food and water sources and clutter can have a significant impact on reducing the chances of infestation population size . finally , exclusion practices such as sealing cracks and crevices will reduce harborage space and also negatively impact population size .

german cockroaches prefer to live in warm , humid places close to food and moisture sources . they are frequently found in residential and commercial kitchen environments , and bathrooms .

zhai , j . and w . h robinson . 1991 . the walking behavior of german cockroaches . pest control technology 18 ( 7 ) : 44 - 46 .

jacobs , s . 2007 . " german cockroaches " ( on - line ) . entomology notes , pennsylvania state university . accessed october 15 , 2008 at urltoken .

bao , n . and w . h robinson . 1990 . morphogenetic effects of hydroprene on genitalia of the oriental cockroach ( dictyoptera : blattidae ) . j . econ . entomol . 83 : 1415 - 1421 .

if a german roach infestation is found , treatment will be applied in areas where roaches have been or may be hiding . knowledge about the german cockroach is vital for effective treatment . for example , young roaches often feed on the fecal droppings of the adult cockroaches in “aggregation” areas , while the adults are out looking for food . as grotesque as this may sound , it is a key to pest control that helps achieve timely and effective cockroach elimination . professional baits are slow - acting by design . when the adults start feeding on baits , they are preparing a final meal for the young roaches . they live just long enough to digest the bait , get back to their aggregation hangout , and leave their final legacy for the up and coming young roaches .

habitat german roaches require moisture to thrive and so tend to dwell in moist places , such as kitchens and bathrooms . however , they may inhabit any room of a structure or home , particularly if the infestation is severe . german cockroaches spend about 75 % of their time hanging out in cracks and crevices near food and water sources . adult german cockroaches can hide inside cracks as small as 3 / 16 " wide , while the nymphs can fit into cracks as small as 1 / 32 " wide .

if you have a german roach problem , it could be that you are at your wits ' end wondering how to get rid of one of the most stubborn household pests in existence . german roaches get into everything , multiply rapidly , and can survive for several months without food and up to two weeks without water . these little guys definitely pose a challenge , but with the proper tools and products , you can win the battle over german roaches by following this strict integrated pest management ( ipm ) program .

eliminating food sources is a constant battle in german roach control . while this effort involves a great deal of work and vigilance , the results are well worth the effort .

nymphs molt several times as they become adults . the period between each molt is known as an instar . each instar is progressively more like an adult cockroach . in some species , this process takes only a few weeks . in others , like the oriental cockroach , it takes between one and two years . the overall life span of cockroaches differs as well - - some live only a few months while others live for more than two years .


the tennessee darter ( etheostoma tennesseense ) is a species of darter endemic to the eastern united states , where it occurs in the tennessee river drainage from western virginia to western tennessee .

it also occurs in the upper bluestone river drainage in western virginia .

it inhabits current-swept rocky pools and adjacent riffles of creeks and small to medium rivers .

this species can reach a length of 6 cm ( 2.4 in ) .

tennessee darter

tennessee darter <EOT> etnier d . 1993 " the fishes of tennessee " university of tennessee press .

in order to facilitate compute intensive research at the university of tennessee , knoxville and its collaborating institutions , nics has deployed a supercomputer named darter . darter is named after a freshwater indigenous fish native to east tennessee .

north america : found only in the upper tennessee river drainage in virginia , north carolina , tennessee and georgia , usa .

range includes the upper tennessee river drainage , western virginia , western north carolina , and eastern tennessee ( page and burr 2011 ) .

) in the upper tennessee river drainage . journal of the tennessee academy of science 83 ( 3 - 4 ) : 52 - 56 .

north america : found only in cumberland and tennessee river drainages in virginia , north carolina , kentucky , tennessee , georgia and alabama , usa .

as of june 30 , 2016 , darter is no longer an allocatable resource .

etnier , d . a . , and w . c . starnes . 1993 . the fishes of tennessee . university of tennessee press , knoxville , tn .

u . s . fish and wildlife service . 1982a . snail darter recovery plan .

reasons : discontinuous distribution in tributaries of upper tennessee river in georgia , north carolina , tennessee , and virginia ; distribution fragmented by many impoundments , but locally common and currently stable .

range includes the middle and lower cumberland river drainage , kentucky and tennessee ( mostly below caney fork but occurs in obey river system and barren fork collins river ) ; middle duck river system , including upper buffalo river , tennessee ; shoal creek system ( tennessee river drainage , tennessee and alabama ) ; and tributaries to the mississippi river in western tennessee ( reelfoot lake , bear creek ) and southern illinois ( cache river ) ( page and burr 2011 ) .

the tennessee aquarium offers a wide variety of special events each month . . . . learn more

numerous individuals and environmental groups filed suit to stop construction of the tellico dam , arguing that damming the little tennessee river would destroy the snail darter’s natural habitat . the court case , tennessee valley authority v . hill , went to the supreme court of the united states . the supreme court decided to uphold the mandate of the endangered species act to protect the snail darter and its habitat . after further political maneuvering , however , the tellico dam was completed , and the snail darter’s natural habitat was destroyed .

findlaw . “tennessee valley authority v . hill . ” urltoken ( accessed may 2 , 2008 ) .

global range : ( 5000 - 200 , 000 square km ( about 2000 - 80 , 000 square miles ) ) this darter is disjunctly distributed in tributaries of the upper tennessee river in georgia , north carolina ( menhinick 1991 ) , tennessee ( etnier and starnes 1993 ) , and virginia ( jenkins and burkhead 1994 ) . elevational range in tennessee is about 260 - 550 meters ( etnier and starnes 1993 ) .

in september 1979 , congress passed an amendment that exempted the tellico dam project from the endangered species act . the tva closed the gates of tellico dam in november 1979 , flooding the native habitat of the snail darter . in an effort to save the snail darter , the tva had relocated many snail darters to the nearby hiwassee river prior to damming the little tennessee river . scientists also discovered snail darters in other areas of the tennessee river valley watershed after the completion of tellico dam . in 1984 , the fish and wildlife service delisted the tellico dam area as a critical habitat for the snail darter because the species died off in that area . because of the newly discovered snail darter populations , the fws changed the classification of the snail darter from endangered to threatened in 1985 .

in the mid - 1970s , a well - publicized legal battle pitted environmental groups and an endangered species of fish against a $ 100 million federal construction project . the tennessee valley authority ( tva ) was constructing tellico dam on the little tennessee river when a new freshwater fish species , the snail darter , was discovered upstream . the u . s . fish and wildlife service listed the snail darter as an endangered species under the endangered species act of 1973 .

the snail darter is a small fish , about 2 in ( 10 cm ) in length that was discovered in the little tennessee river in 1973 . in 1975 , the fws listed the snail darter as an endangered species under the esa . when the snail darter was listed on the endangered species list , the secretary of the u . s . department of the interior , which oversees the fws , stated that the snail darter resided only in a small portion of the little tennessee river . furthermore , the secretary stated that the construction of the nearby tellico dam would destroy the critical habitat of the snail darter . the secretary then stated that “all federal agencies must take such action as is necessary to insure that actions authorized , funded , or carried out by them do not result in the destruction or modification of this critical habitat area . ”

range includes the upper holston river system ( tennessee river drainage ) , eastern tennessee and western virginia ; mcclure river and russell fork ( big sandy river drainage ) , western virginia and extreme southeastern kentucky ( page and burr 2011 ) .

additional surveys may be needed in tennessee : emory river , upper duck river , roaring river , obey river system .

darter is a cray xc30 system with an aries interconnect and a lustre storage system , that provide both high scalability and sustained performance . the darter supercomputer has a peak performance of 240 . 9 tflops ( 10 12 floating point operations per second ) .

plater , now a distinguished law professor at boston college , was the lead attorney in the fight to save the little tennessee river , the last undammed river in the tennessee river basin . the river was , at the time , the only known habitat of the endangered snail darter , a minnow - sized member of the perch family . in addition , the little tennessee was part of the sacred homeland of the cherokee and , later , numerous families farming the rich bottomlands along the river . moreover , the little tennessee river was , in plater ' s description , the best trout stream east of montana .

the tennessee aquarium is home to a richly diverse living collection of the world’s most fascinating animals . . . . learn more

forest history society . “1979 : snail darter exemption case . ” november 1 , 2004 . urltoken ( accessed may 2 , 2008 ) .

the wounded darters inhabits the upper tennessee river drainage , western virginia , western north carolina , and eastern tennessee . its instream habitat is among boulders or coarse rubble and cobble , often with overhanging ledges , in medium to large slow - moving rivers . like other members of the

upper tennessee drainage of eastern tennessee , northern georgia , and alabama , including little tennessee river , watts bar reservoir below fort loudon dam , south chickamauga creek , lower portion of big sewee creek in meigs county , lower sequatchie river in marion county , little river in blount county , lower french broad river in sevier county , and lower paint rock river in madison county , alabama ( page and burr 1991 ; etnier and starnes 1993 ) .

members of the perch family , redline darters are distinguished from other species of darters by their horizontal bars and orange and white spots , giving them an almost plaid appearance . redline darters bury their eggs in the substrate . rainbow darters and redline darters are the most abundant darter species in the tennessee river drainage in alabama .

the secretary’s findings troubled the tennessee valley authority , the agency responsible for the construction of tellico dam . the tva began the tellico dam project in 1967 . many homes and farms were relocated because tellico reservoir would flood 16 , 500 acres of land . the snail darter had not been discovered when the tellico dam project began . tellico dam was 70 % to 80 % complete ( a cost of tens of millions of dollars ) by the time the snail darter was listed as an endangered species .

the biggest threat to the tangerine darter is habitat degradation . this is due to point and nonpoint pollution , erosion and sedimentation . on the pigeon river in east tennessee , tangerine darter populations declined and recovered . in 1908 , champion international built a paper mill on the little pigeon river and decimated many of the native fish . in the 1980s the mill cleaned up its refuse and the river is steadily getting better . tangerine darters have been successfully reintroduced back into the pigeon river downstream of the paper mill .

in may 1976 , the u . s . district court for the eastern district of tennessee denied relief for the snail darter advocates and dismissed their complaint . the court determined that the completion of tellico dam would probably jeopardize the continued existence of the snail darter . the court concluded , however , that “at some point in time , a federal project becomes so near completion and so incapable of modification that a court of equity should not apply a statute enacted long after inception of the project to produce an unreasonable result . ”

they are a fairly common species ; however , their range is limited to clear , cool streams of the southern appalachian mountains . the tangerine darter is found throughout mountainous regions of the upper tennessee river drainage . it resides in smaller rivers and is most common in the emory , hiwassee , little , little pigeon , and tellico rivers . it is found in eastern tennessee , northern georgia , and western north carolina , and virginia . in georgia and north carolina , it is listed as a historic species in need of management .

despite this , the free - flowing little tennessee was marked for extinction by the construction of tellico dam . building the dam was the tennessee valley authority ( tva ) , the mammoth federal agency that , out of the depths of the depression in the 1930 ' s , literally brought light and power to the tennessee and cumberland basins . as plater eloquently describes in his book , tellico dam made neither environmental nor economic sense , but that did not deter either tva or congress from pouring millions of dollars into the project .

range includes the holston and nolichucky river systems , upper tennessee river drainage , eastern tennessee , western virginia ( extremely rare , south fork holston river above the head of south holston reservoir ) , and western north carolina ( rediscovered after reported extirpation ) ; the species occurs in the nolichucky river in tennessee and north carolina , two nolichucky tributaries in north carolina , and south fork holston river in tennessee and virginia ( jenkins and burkhead 1994 ) . the largest and most viable populations are in the nolichucky river , tennessee ( about 125 river km ) ; range extends both above and below davy crockett reservoir . in north carolina ( 1991 - 1993 ) , this darter was found at 11 of 57 sites sampled in the nolichucky river and upstream in the lowest 8 km of the cane river , the lowest 18 . 6 km of the north toe river , and in one tributary of the last ( rohde and arndt 1994 ) . this species occupies not more than 5 km of the south fork holston river in virginia . see etnier and starnes ( 1993 ) for a historical account of the known distribution .

remember the snail darter ? the little fish that brought the construction of a multimillion dollar federal hydroelectric project to a screeching halt in the 1970 ' s ? even if you ' re not old enough to remember the carter administration , you ' ve probably heard of the snail darter . but you probably don ' t know the whole story . for that , you will need to turn to a terrific book , the snail darter and the dam : how pork barrel politics endangered a little fish and killed a river , by zygmunt j . b plater ( yale university press 2013 ) .

wounded darter propagation protocols , as expected , were found to be essentially identical to those we have developed and refined since 1995 for a close relative , the boulder darter . a total of 494 wounded darter juveniles survived for release to the cheoah river in fall 2008 and spring 2009 ; and ultimately , 388 juveniles survived for a fall 2009 release to the cheoah river . 2010 and 2011 propagation efforts produced 284 and 308 juvenile wounded darters respectively for release . efforts to produce this fish have been put on hold as we evaluate the habitat suitability in cheoh . to date no wild reproducing populations have been found from our stocking efforts .

standing up to tva was a small but determined group of farmers , anglers , scientists , law students , and activists , represented by plater . over a few years , this group , with assistance from a few national conservation organizations including , i am proud to say , my organization , american rivers , learned to navigate the corridors of power in washington to press their fight to save the little tennessee river and the snail darter . eventually , the case went all the way to the u . s . supreme court which , in a landmark decision in tva v . hill , held that by enacting the endangered species act , congress intended endangered species to be given the highest priority , even above completion of a nearly - finished multimillion dollar dam . thus , it appeared that the snail darter had won and the little tennessee river was saved .

the tangerine darter is an insectivorous fish . juveniles feed primarily on mayflies and midges , and adults feed on mayflies and caddisflies . tangerine darters get their food by searching through the aquatic vegetation and eating the aquatic insects off of the plants . adults are also big enough to roll small gravel in search of prey . although the tangerine darter is not a game species , it is sometimes caught by fly fishermen using mayfly and caddisfly patterns .

the snail darter was intentionally introduced to create an additional population of this endangered fish when its only known habitat was threatened by construction of a dam . seven hundred and ten snail darters were introduced into the hiwassee river from june 1975 to february 1976 ( u . s . fish and wildlife service 1982a ; etnier and starnes 1993 ) . in october 1975 , 61 were introduced into the nolichucky river . introductions into the nolichucky river were halted when the sharphead darter etheostoma acuticeps was discovered there , for fear the introduction would jeopardize this rare species ( u . s . fish and wildlife service 1982a ; etnier and starnes 1993 ) . the holston river was stocked with 533 snail darters from the hiwassee and little tennessee rivers during the period 1978 to 1979 . the elk river was stocked in july 1980 with 425 snail darters from the little tennessee river ( u . s . fish and wildlife service 1982a ) .

section 11 of the esa contains a citizen suit clause that allows any citizen to sue “to enjoin any person , including the united states and any other governmental instrumentality or agency… who is alleged to be in violation of any provision of this act . ” in 1976 , hank hill , a student at the university of tennessee , and others filed suit in federal court seeking an injunction to stop the construction of a dam that would destroy the habitat of the snail darter .

the tangerine darter spawns in shallow sandy gravel riffles that have consistent flowing water . the tangerine is a late spring to summer spawner . the breeding season , which is triggered by water temperature , begins in may and runs through july . spawning occurs at about three to four years of age , although sexual maturity comes much earlier for tangerine darters , with males reaching sexual maturity at one year of age and females two years of age . the life span of the tangerine darter is about four years .

this species has a widespread but spotty distribution in the tennessee , cumberland , and duck river systems of kentucky and tennessee ( etnier and starnes 1993 ) ; it has been extirpated in georgia ( known from one specimen collected several decades ago ) and alabama ( known from a pre - 1845 collection ; boschung and mayden 2004 ) , and it is rare in virginia , where it is known from one specimen collected in 1964 ( jenkins and burkhead 1994 ) and confirmed as still present in the clinch river in 2004 ( pat rakes , conservation fisheries , inc . ) . in recent years , ashy darters have been found in big south fork and rockcastle river of the cumberland river system in kentucky and tennessee and buffalo , little , emory , elk , and clinch rivers of the tennessee river system . the most substantial populations exist in big south fork ( cumberland river system ) and buffalo river of the ( tennessee river system ) ( etnier and starnes 1993 ) . populations in the emory and elk rivers are represented by few recent specimens ; very small populations may exist there ( see powers et al . 2004 ) . various populations were probably extirpated before they could be discovered ( etnier and starnes 1993 ) .

range includes the tennessee river system from western virginia to hardin creek ( hardin county ) , western tennessee ( absent in upper holston river system [ north , south , and middle forks ] ; upper bluestone river system ( new - ohio river drainage ) , western virginia ( page and burr 2011 ) . menhinick ( 1991 ) mapped " questionable stream records " in north carolina and stated that this species ( as a member of the e . simoterum complex ) is " probably extirpated " from north carolina .

as global climate change continues , we will see more frequent and more severe droughts , reduced river flows , and greater conflict over leaving sufficient water in rivers to sustain fish and wildlife and the rivers themselves . whenever there is conflict over a river , and how its water should be used , the ghost of the snail darter looms again . it is convenient for those who favor damming and diverting water from our rivers to paint a picture in which the choice is for either people or fish , particularly if it is just a " stupid little fish " like the snail darter or the delta smelt . as these conflicts deepen , it will be increasingly important to remember that the fight over the snail darter was more than just a fight to save a tiny fish . it was a fight to save a river , one that was itself endangered and crucial to the lives , livelihoods , and heritage of the people who loved it . thus , the true lesson of the snail darter is that when we fight to save a river , we fight to save part of ourselves .

range includes the ohio river basin , from the tennessee and cumberland drainages , tennessee , western virginia , kentucky , and alabama , to the vermillion river , eastern illinois , and tippecanoe river , indiana , east to the kanawha and monongahela rivers , west virginia , and upper allegheny river , pennsylvania and western new york ( lee et al . 1980 , mettee et al . 1996 , page and burr 2011 ) . however , the species is absent from most rivers within this range ( page and burr 2011 ) .

the snail darter case changed the face of environmental law in the united states , especially in regard to the endangered species act . the decision of the supreme court demonstrated the importance of the esa and other environmental laws . the court rejected the view that environmental laws should be enforced only when convenient . the court sided with the esa over a $ 100 million federal project . despite this victory in court , however , the snail darter case illustrated the political nature of environmental law when congress voted to exempt the tellico dam project from the esa .

the snail darter was listed as a federally endangered species in 1975 ( u . s . fish and wildlife service 1982a ) . after several more populations were discovered in the early 1980s , the species ' status was changed to threatened in 1984 ( etnier and starnes 1993 ) .

the tangerine darter inhabits clear and cool creeks or small rivers . in these rivers it likes areas that have large boulders , bedrock and a gravel substrate . it also likes to swim in the deeper riffles of these rivers . in winter , the tangerine moves to deeper pools .

the decline of this species is due primarily to elimination and fragmentation of habitat by inundation ( reservoir construction ) and degradation of habitat by nonpoint - source siltation resulting from land clearing and agricultural development ( boschung and mayden 2004 , powers et al . 2004 ) . powers et al . ( 2004 ) cited genetic distinctness and recommended that each major unit of the distribution ( duck river , upper tennessee river , and cumberland river ) be considered imperiled . jelks et al . ( 2008 ) categorized four segments of this species separately : duck river populations = vulnerable , lower tennessee river populations = endangered , upper cumberland populations = vulnerable , and upper tennessee river populations = endangered . urbanization is a threat to habitat in the lower reaches of the little river ( powers et al . 2004 ) . potential threats include pollution , siltation , and inundation of habitat .

in the nearly four decades since the little tennessee river was lost , the real story of the river and its value to the farmers who lived along it , the cherokee who held it sacred , and the anglers who traveled for miles to cast a fly in its clear , trout - rich waters , has been largely forgotten . in its place , the fight to save the snail darter has been lampooned as the archetype of environmental extremism , putting the needs of a tiny fish over those of people . as plater ' s book reveals , that story is wrong but still resonates today .

in the lawsuit to enjoin the tellico dam project , now called tennessee valley authority v . hill , the tva argued that the esa’s protection of endangered species and their critical habitats did not extend to government projects that were authorized , funded , and underway at the time congress passed the esa . essentially , the tva argued that congress did not intend for the esa to interfere with projects that congress had approved . the tva also pointed to the fact that in 1975 congress appropriated an additional $ 29 million for the tellico dam project after the tva informed congress that the project could threaten the snail darter .

in january 1977 , the u . s . court of appeals for the sixth circuit reversed the lower courts decision . the court of appeals remanded , or sent back , the case to the lower court “with instructions that a permanent injunction issue halt [ ed ] all activities incident to the tellico project which may destroy or modify the critical habitat of the snail darter . ” the court of appeals directed that the injunction “remain in effect until congress , by appropriate legislation , exempts tellico from compliance with the act or the snail darter has been deleted from the list of endangered species or its critical habitat materially redefined . ” the court of appeals noted that the near completion of the tellico dam project and congressional appropriation of money to the project were irrelevant .

this species is represented by a large number of occurrences ( subpopulations ) . total adult population size is unknown but apparently quite large ( likely greater than 100 , 000 ) . this darter is common throughout much of its range ( page et al . 1992 ) ; locally abundant ( page and burr 2011 ) . trend over the past 10 years or three generations is uncertain but likely relatively stable .

comments : this species is represented by at least a few dozen distinct occurrences ( subpopulations ) , evidenced by more than 100 collection sites . on a state - wide scale , jenkins and burkhead ( 1994 ) mapped 27 collection sites in virginia , etnier and starnes ( 1993 ) mapped 52 collection sites in tennessee , and menhinick ( 1991 ) mapped 32 collection sites in north carolina .

habitat includes rocky pools and adjacent riffles of headwaters and creeks ( page and burr 2011 ) . this darter prefers small quiet streams with large flat rocks or bedrock bottoms ; small populations occur in small gravelly streams and in larger streams along quiet margins and beneath undercut banks ( braasch and mayden 1985 ) . spawning occurs in cavities under rocks ; females attach eggs to undersides of stones ( braasch and mayden 1985 ) .

this specuies would benefit from improvements in water quality , including reduction in siltation . populations apparently may respond quickly to improvements in water quality ( etnier and starnes 1993 ) . the south fork holston river population may benefit by transplanting fishes from the nolichucky river , though fish competitors ( redline darter , sculpins ) in the former stream may limit or prevent the success of such a transplant ( burkhead and jenkins 1991 ) . conservation status can change quickly , so regular monitoring of populations is needed .

of course , as yogi berra reportedly said , " it ain ' t over ' til it ' s over . " reacting to the supreme court ' s decision , congress created a cabinet - level body , the endangered species committee ( commonly referred to as the " god committee " ) to decide whether tellico dam and future projects should be granted an exemption from the endangered species act . when the committee met to consider an exemption for tellico dam , it quickly determined that the project was an economic loser , quite apart from its environmental cost , and denied the exemption . finally , tva ' s political patrons in congress , led by senator howard baker ( r - tn ) , slipped through a rider on an appropriations bill allowing tellico dam to be completed . the little tennessee river was lost and , although the snail darter was transplanted to other streams and found in a few others , the clean , free - flowing river in which it evolved was destroyed .

this species is sensitive to habitat alterations ( braswell 1991 ) . it has disappeared from much of its former range due to the prevalence of impoundments on most rivers in the upper tennessee river drainage ( etnier and starnes 1993 ) . it is moderately threatened by residential development in north carolina ( h . legrand pers . comm . 1997 ) . some populations have been lost in virginia due to pollution or impoundments ( jenkins and burkhead 1994 , s . roble pers . comm . 1997 ) .

this species is represented by a large number of occurrences ( subpopulations ) . stauffer ( 1978 ; in lee et al . 1980 ) ) mapped 80 + collection sites . total adult population size is unknown but presumably exceeds 10 , 000 . this species is " regionally abundant " in the allegheny system of north - western pennsylvania and the cumberland basin in tennessee and kentucky . overall , it is locally common ( page and burr 2011 ) . trend over the past three generations is unknown but probably relatively stable or slowly declining .

this species is represented by at least a few dozen distinct occurrences ( subpopulations ) , evidenced by more than 100 collection sites . on a state - wide scale , jenkins and burkhead ( 1994 ) mapped 27 collection sites in virginia , etnier and starnes ( 1993 ) mapped 52 collection sites in tennessee , and menhinick ( 1991 ) mapped 32 collection sites in north carolina . total adult population size is unknown but presumably exceeds 100 , 000 . populations have been characterized as " relatively small " ( thompson , in lee et al . 1980 ) and locally fairly common ( page and burr 1991 , etnier and starnes 1993 ) . in virginia , this darter is generally uncommon , and apparently rare in the south fork holston river ( jenkins and burkhead 1994 ) . this species formerly was thought to be rare , based on seining surveys , but snorkeling efforts have revealed it to be relatively common ( greenberg 1991 , etnier and starnes 1993 , jenkins and burkhead 1994 ) . some populations probably have been extirpated by impoundments , but the degree of long - term decline is not precisely known . warren et al . ( 2000 ) categorized this species as " currently stable . "

comments : total adult population size is unknown but presumably exceeds 100 , 000 . populations have been characterized as " relatively small " ( thompson , in lee et al . 1980 ) and locally fairly common ( page and burr 1991 , etnier and starnes 1993 ) . in virginia , this darter is generally uncommon , and apparently rare in the south fork holston river ( jenkins and burkhead 1994 ) . this species formerly was thought to be rare , based on seining surveys , but snorkeling efforts have revealed it to be relatively common ( greenberg 1991 , etnier and starnes 1993 , jenkins and burkhead 1994 ) .

this darter typically occurs in warm , typically clear or slightly turbid , creeks and small to medium rivers with moderate gradient ; adults generally are in moderately swift runs and riffles with substrate of coarse gravel , rubble , or boulders ; this species is much less commonly found in areas of large slab rock and in shallow runs over gravel ; it has low tolerance of silt ( kuehne and barbour 1983 , burkhead and jenkins 1991 , page and burr 2011 ) . eggs are laid in sand or fine gravel beside large rocks at heads of riffles , and in riffles ( lee et al . 1980 , page 1983 ) .

as california is enduring the worst drought in its history , some politicians are blaming it all on federal and state environmental laws that protect fish and wildlife and the rivers they depend on for survival . and , as predictably as water flows downstream , these politicians are looking for oddly - named and seemingly insignificant creatures to cast as villains . thus , in a february 5 , 2014 speech on the floor of the u . s . house of representatives , congressman devin nunes ( r - ca ) referred to the threatened delta smelt as " the stupid little fish " whose protection is causing central valley farms to dry up and wither away . call it snail darter politics .

tangerine darters spawn by first the male mounting the female ; the female then scatters her eggs over the gravel , while the male disperses milt and fertilizes the eggs . while doing this both the male and female make a quivering motion . females choose the most brightly colored males ( bright orange black line with some blue where orange meets the black ) . males also become territorial during mating season and will defend their spawning riffles . females lay between 120 and 1 , 100 eggs . the tangerine darter does not care for its eggs . juvenile tangerine darters are found in calmer water and grow to between 2 and 3 inches ( 5 . 1 and 7 . 6 cm ) in their first year of growth .

populations have been greatly reduced or eliminated through siltation and inundation and cold tailwaters resulting from impoundment ( burkhead and jenkins 1991 ) . one large toxic spill in the upper nolichucky river could severely damage the population there and affect the conservation status of the species ( burkhead and jenkins 1991 ) . this species is regarded as " secure " in north carolina ( rohde and arndt 1994 ) . this species apparently increased in abundance or recolonized the upper nolichucky river in tennessee after water quality improved there ( etnier and starnes 1993 ) . some previous pollution problems in the south fork holston river system " have been relieved , but other potential pollution problems exist " ( jenkins and burkhead 1994 ) .

the tva appealed the court of appeals ruling to the supreme court of the united states . the supreme court issued its opinion in june 1978 , affirming the ruling of the court of appeals . the supreme court found that the esa prohibited the construction of tellico dam , because the project would threaten the snail darter and its critical habitat . the court noted that the language of the esa is plain and does not make any exception for projects underway at the time congress passed the esa . if congress had intended to exempt such projects from the requirements of the esa , they could have simply added language to that effect to the esa . the court refused to read exemption into the esa in the absence of such language .

established in hiwassee river and range expanding ( u . s . fish and wildlife service 1982a ) . one darter observed in nolichucky river in 1980 . single individual possibly from small reproducing population or escapee from fish hatchery upstream ; none found since . elk river populations apparantly extirpated due to failed introduction ( etnier and starnes 1993 ) . snail darters found in lower french broad and lower holston rivers in 1988 and 1989 presumably represent progeny of holston river transplants ( etnier and starnes 1993 ) . in 2005 , ashton and layzer ( 2008 ) found robust populations in french broad and hiwassee rivers , and low abundances in holston , little , and sequatchie rivers and big sewee and south chichamauga creeks . ashton and layzer ( 2008 ) suggested that these low population sizes may be due to a lack of reproducing populations in these streams , with individuals migrating into these streams from larger , reproducing populations in french broad and hiwassee rivers .

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powers , s . l . and mayden , r . l . 2007 . systematics , evolution and biogeography of the etheostoma simoterum species complex ( percidae : subgenus ulocentra ) . bulletin of the alabama museum of natural history 25 : 1 - 23 .

justification : this species is listed as least concern in view of the fairly large extent of occurrence , large number of subpopulations , large population size , apparently stable trend , and lack of major threats .

this species is represented by a large number of occurrences ( subpopulations ) . total adult population size is unknown but presumably exceeds 10 , 000 . this fish is common ( page and burr 2011 ) .

habitat includes current - swept rocky pools and adjacent riffles of creeks and small to medium rivers ( page and burr 2011 ) .

currently , this species is of relatively low conservation concern and does not require significant additional protection or major management , monitoring , or research actions .

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all darters lack swim bladders , which give most fish the ability to control their buoyancy . darters rest on the bottoms of streams and will jump or dart upwards when they need to gain buoyancy for swimming or eating . they are very strong swimmers and maneuver with or against strong current with ease .

native fishes are affected by runoff from agriculture and roadways . to reduce the chances of contaminants entering their habitat , always recycle your oil and leave stream banks planted to reduce erosion .

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justification : listed as vulnerable because extent of occurrence is less than 20 , 000 sq km , area of occupancy is less than 200 sq km , and the species occurs in not more than 5 locations ; the small number of locations makes the species highly vulnerable to catastrophic events ( such as a large pollutant spill ) that could rapidly cause the species to become critically endangered .

justification : listed as least concern in view of the large extent of occurrence , large number of subpopulations and locations , and large population size , and because the species probably is not declining fast enough to qualify for any of the threatened categories .

no major threats are known . locally , threats include siltation , pollution , and impoundment ( burkhead and jenkins 1991 ) .

currently , this species is of relatively low conservation concern and does not require significant additional protection or major management , monitoring , or research action .

justification : small extent of occurrence , but listed as least concern inview of the fairly large number of subpopulations , apparently large population size , and relatively stable or slowly declining trend .

this species is represented by a fairly large number of occurrences ( subpopulations ) . total adult population size is unknown but presumably exceeds 10 , 000 . this species is regarded as common ( page and burr 2011 ) . trend over the past 10 years or three generations is uncertain but likely relatively stable or slowly declining .

no major threats are known in much of the range , but aquatic habitats in the big sandy drainage " have been much abused , " resulting in a localized distribution of this species in that area ( jenkins and burkhead 1994 ) .

justification : listed as least concern in view of the fairly large extent of occurrence , large number of subpopulations , large population size , apparently stable trend , and lack of major threats .

justification : this species is listed as least concern because its extent of occurrence , area of occupancy , number of subpopulations and locations , and population size are still relatively large , distribution is not severely fragmented , and the species probably is not declining fast enough to qualify for any of the threatened categories under criterion a .

habitat includes fast rocky riffles of small to medium rivers ( page and burr 2011 ) .

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the nonindigenous occurrences section of the nas species profiles has a new structure . the section is now dynamically updated from the nas database to ensure that it contains the most current and accurate information . occurrences are summarized in table 1 , alphabetically by state , with years of earliest and most recent observations , and the tally and names of drainages where the species was observed . the table contains hyperlinks to collections tables of specimens based on the states , years , and drainages selected . references to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the table 1 caption or through the individual specimens linked in the collections tables .

page ( 1983 ) ; page and burr ( 1991 ) ; etnier and starnes ( 1993 ) .

table 1 . states with nonindigenous occurrences , the earliest and latest observations in each state , and the tally and names of hucs with observations† . names and dates are hyperlinked to their relevant specimen records . the list of references for all nonindigenous occurrences of percina tanasi are found here .

inhabits clean gravel or sandy shoals in large creeks and rivers ( boschung and mayden 2004 ; ashton and layzer 2008 ) . prefers areas lacking aquatic macrophytes and with low degrees of turbidity or siltation ( ashton and layzer 2008 ) .

diet primarily consists of snails , but also consumes trichopteran , dipteran , and ephemeropteran larvae ( boschung and mayden 2004 ) .

boschung , h . t . , and r . l . mayden . 2004 . fishes of alabama . smithsonian books , washington , dc .

lee , d . s . , c . r . gilbert , c . h . hocutt , r . e . jenkins , d . e . mcallister , and j . r . stauffer , jr . 1980 et seq . atlas of north american freshwater fishes . north carolina state museum of natural history , raleigh , nc .

page , l . m . 1983 . handbook of darters . t . f . h . , inc . , neptune city , nj .

page , l . m . and b . m . burr . 1991 . a field guide to freshwater fishes of north america north of mexico . the peterson guide series , vol . 42 . houghton mifflin company , boston , ma .

pam fuller , and matt neilson , 2018 , percina tanasi etnier , 1976 : u . s . geological survey , nonindigenous aquatic species database , gainesville , fl , urltoken revision date : 8 / 16 / 2011 , peer review date : 4 / 1 / 2016 , access date : 7 / 9 / 2018

this information is preliminary or provisional and is subject to revision . it is being provided to meet the need for timely best science . the information has not received final approval by the u . s . geological survey ( usgs ) and is provided on the condition that neither the usgs nor the u . s . government shall be held liable for any damages resulting from the authorized or unauthorized use of the information .

the data represented on this site vary in accuracy , scale , completeness , extent of coverage and origin . it is the user ' s responsibility to use these data consistent with their intended purpose and within stated limitations . we highly recommend reviewing metadata files prior to interpreting these data .

citation information : u . s . geological survey . [ 2018 ] . nonindigenous aquatic species database . gainesville , florida . accessed [ 7 / 9 / 2018 ] .

contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co - authorship if warranted . for queries involving fish , please contact pam fuller . for queries involving invertebrates , contact amy benson .

inhabit clear , fairly deep , rocky pools ( usually below riffles ) of creeks and small rivers . large males often found in rocky riffles ( ref . 5723 ) . juveniles feed on mayfly and dipteran larvae , while the adults consume caddisfly larvae ( ref . 10294 ) . eggs are found buried in the substrate ( ref . 7043 ) .

18 . 0 cm tl ( male / unsexed ; ( ref . 5723 ) ) ; max . reported age : 4 years ( ref . 12193 )

non - migrant : yes . at least some populations of this species do not make significant seasonal migrations . juvenile dispersal is not considered a migration .

locally migrant : no . no populations of this species make local extended movements ( generally less than 200 km ) at particular times of the year ( e . g . , to breeding or wintering grounds , to hibernation sites ) .

locally migrant : no . no populations of this species make annual migrations of over 200 km .

comments : adults feed heavily on immature insects associated with riverweed and on insect larvae living among gravel and rubble . young and juveniles feed on small crustaceans , diptera larvae , and baetid mayflies at stream margin .

note : for many non - migratory species , occurrences are roughly equivalent to populations .

comments : most active 0600 - 2030 h , peak at 1300 h ( page 1983 ) .

spawns may to june or july ( page 1983 , page 1983 ) . very small young have been taken in early july ( lee et al . 1980 ) . age range of breeding females is 2 - 4 years ( bart and page 1992 ) . life span is a little more than 4 years ( howell 1971 ) .

the following is a representative barcode sequence , the centroid of all available sequences for this species . there are 11 barcode sequences available from bold and genbank .

below is a sequence of the barcode region cytochrome oxidase subunit 1 ( coi or cox1 ) from a member of the species .

listed as least concern in view of the large extent of occurrence , large number of subpopulations , large population size , and lack of major threats . trend over the past 10 years or three generations is uncertain but likely relatively stable , or the species may be declining but not fast enough to qualify for any of the threatened categories under criterion a ( reduction in population size ) .

comments : warren et al . ( 2000 ) categorized this species as " currently stable . "

comments : some populations probably have been extirpated by impoundments , but the degree of long - term decline is not precisely known .

distribution has been fragmented by many reservoirs , but the species " continues to be reasonably widespread and abundant " ( etnier and starnes 1993 ) .

comments : distribution has been fragmented by many reservoirs , but the species " continues to be reasonably widespread and abundant " ( etnier and starnes 1993 ) .

biological research needs : life history aspects have been investigated ( howell 1971 ) .

comments : some occurrences are in protected areas , such as the great smoky mountains national park . this species has been collected from copper creek in western virginia , which has been designated critical habitat for the yellowfin madtom .

needs : doesn ' t seem necessary to single out a particular population for vigorous protection at this time .

tangerine darters are typically 4 . 3 to 7 . 1 inches ( 11 to 18 cm ) in length ,

species . the males are usually a bright orangish - red color , more elaborately colored than the females , which are yellow .

chadwick d . 2010 . " silent stream . " national geographic vol 217 issue 4 116 - 128 .

greenberg l . 1993 . " a descriptive and experimental study of microhabitat use by young of the year benthic stream fishes " ecology of freshwater fish .