Comparative Bioefficacy of Different Citrus Peel Extracts as Grain Protectant Against Callosobruchus chinensis, Trogoderma granarium and Tribolium castaneum
2 Abstract: Efficacy of essential oils extracted from peel of various citrus species; Citrus reticulata, Citrus sinensis, Citrus paradisi and Citrus grandis were determined against the adults of Callosobruchus chinensis and Tribolium castaneum as well as against the larvae of Trogoderma granarium in order to find out safe alternatives of high toxics. Four concentrations of each oil; 2%, 4%, 6% and 8% were assayed for their insecticidal activity after exposure durations of 24, 48, 120 and 168 h. The results revealed that the essential oil vapors showed variable toxicity to insects depending on concentration and exposure duration. Efficacy increased as the exposure time and concentration were increased for all insects. All the oils were found to be very successful against adults of C. chinensis. Out of which, the oil of C. sinensis was the best against C. chinensis even at lower concentrations; LD , LD and LD values were 3.49%, 4.70% and 5.91% after 72-h 50 70 90
Potentiality of essential oil from Citrus grandis (Sapindales: Rutaceae) against Culex quinquefasciatus Say (Diptera: Culicidae)
The present investigation was made for assessing the larvicidal, ovicidal, adulticidal and repellent effect of essential oil from the peel and leaves of Citrus grandis against Culex quinquefasciatus. The results revealed that the oil was the most effective as ovicides having LC50 value14.02 ppm in case of essential oil of leaves and 17.06ppm in case of that of peel at 72 hour followed by larvicidal activity with LC50 value 18.53ppm and 40.59ppm at 72 hour respectively. But there was not much adulticidal affect recorded though it gave good protection time against C. quinquefasciatus. Thus, it is a potential repellent, ovicidal as well as larvicidal agent for the control of C. quinquefasciatus. One of the most important detoxifying enzyme i.e. glutathione-s-transferase level was found to decrease after applying the LC50 dose treated larvae and adults than the non-treated control groups
Toxicity of citrus oils to several stored-product insects: laboratory evaluation.
Oils were extracted from the peels of 8 different fruits and tested for toxicity to serveral species of stored-product insects. Topical applications showed that lyophilized oils from lemon, grapefruit, lime, kumquat, and tangerine were highly toxic to the cowpea weevil, Callosobruchus maculatus (F.), and that all 8 oils were moderately toxic to the rice weevil, Sitophilus oryzae (L.). TLC analyses and topical applications to the insects showed that the active component of the lemon peel was not a residue of the insecticides and acaricides generally used as prehavest treatments, or of the fungicides used as postharvest treatments.