1. Field of the Invention
This invention relates generally to the production of stable cockroach aggregation pheromone products, active extracts thereof, and insect traps utilizing them. These products are useful in the control of cockroach infestation.
2. Description of the Background
Because of their exposure to unsanitary areas, such as sewers, cockroaches are generally associated with the arousal of many health related problems. Over one hundred different species of disease-causing pathogenic bacteria have been found to be carried by cockroaches. Cockroaches have also been found to carry, in addition, other microorganisms such as viruses, protozoa, and parasitic worms (Cornwell, The Cockroach, vol. 1, (1968)).
The use of certain chemical and food attractants for cockroaches is known. Among them are starch, sugar, and fatty acids, such as myristic acid, and palmitic acid and esters of these fatty acids (Japanese Patent Publication No. 44-320). Other chemicals, such as derivatives of naphthalene (Japanese Patent Publication No. 61-69701 and 61-72702); alkylphenol or alkylphenylamine (U.S. Pat. No. 4,911,907), which are specific for male cockroaches, and furanose derivatives (U.S. Pat. No. 4,945,107) have been suggested. Most of the substances, however, have been shown to have low activity and had to be used in extremely high concentrations. In addition, a method for controlling cockroach infestation has also been proposed, which relies on exposing the cockroaches to irradiation with ultraviolet rays. For example, ultraviolet light of longer wavelengths and below 291 nm were utilized in an on and off manner for 15 min. each, for a total time of 9 to 96 hours. This method is said to also inhibit the formation of ootheca. However, this method of controlling cockroaches is expensive and difficult to implement except in specific instances.
Several cockroach traps are now commercially available. Most of these traps, however, are rather ineffective because they do not contain effective cockroach attractants. Such is the case of sticky traps and traps containing boric acid bait.
Aggregation pheromones are produced by many cockroaches, such as the American cockroach or Periplaneta americana, the oriental cockroach or Blattela orientalis, and the German cockroach or Blattela germanica, among others. The production of these pheromones induces the cockroaches to aggregate locally (Bell et al, J. Kans. Entomol. Soc. 45: 414 (1972). The aggregation pheromone composition produced by the German cockroach has been reported to contain over 150 different chemical compounds (Fuchs et al, Z. Angew. Entomol. 99: 499 (1985)). Several components of the aggregation pheromone composition produced by the American cockroach have also been identified (Koehler, et al, Handbook of Pest Control, Franzak and Foster Co., Cleveland, Ohio (1990)). However, they were found to be very volatile and extremely expensive to produce. Thus, no method for producing large quantities of stable aggregation pheromones is currently unavailable.
Aggregation pheromones had previously been extracted from the feces of German cockroaches (Blattella germanica) using Freon 11 as a solvent (Fuchs et al., Z. Angew. Entomol. 99: 499 (1985)). The use of fecal materials from cockroaches not only poses logistical problems, but is also uneconomical. The Freon 11 extracts of cockroach feces have been characterized. They contain chemicals which can be roughly classified in two groups. The first group comprises volatile substances that attract cockroaches while the other group comprises non-volatile substances having arresting activity, e.g., act to aggregate the cockroaches.
An ideal attractant should not only attract cockroaches in low concentrations but, once cockroaches are attracted to the site, should have a prolonged stationary effect on the insects. However, up to the present time, even though aggregation pheromones were known to be present in the feces of cockroaches, the extraction of these pheromones has been impractical and uneconomical because it requires large amounts of fecal material and poses sanitary problems.
U.S. Pat. No. 4,337,592 to Hasegawa discloses the extermination of cockroaches with ultraviolet radiation. In addition, the prior patent describes the elimination of aggregation pheromone activity by ultraviolet irradiation of insect feces and pheromones extracts from P. americana, P. fuliginosa, P. austrasiae, B. germanica, and N. cinerea. In the prior art patent, pheromones were obtained by extraction from cockroach excrement with methanol, and then irradiated with a holder type ultraviolet germicidal lamp.
U.S. Pat. No. 4,608,774 to Sherman discloses a gravity operated cockroach trap having a rectangular funnel-like interior chute, with walls arranged at an angle greater than 10.degree. and preferably 44.degree. to 45.degree. so that the insect on the incline will be drawn by gravity into the receptacle. In one of the embodiments, the prior patent contemplates coating the chute's surfaces with silicone or vaseline. These are solid lubricants which are rendered less and less useful as the angle of the receptacle walls increases. When the inclination of the walls is much greater than 45.degree., the insects are able to scratch the surface of the solid coating and grip onto the solid wall material.
The complex nature of cockroach aggregation pheromone compositions, their instability, and an inability to mass-produce them in large quantities have precluded the manufacture and availability of effective cockroach lure or trap products containing them.
Thus, there exists a need for a low cost, reliable method of manufacturing formulations containing cockroach aggregation pheromones which preserve their ability to attract and arrest cockroaches.