There are a number of different arthropods which are considered to be pests.
Several species of arthropods employ a system of two or more pheromones to induce mating behavior; a long range attractant pheromone and a mounting/contact pheromone and in some species a genital sex pheromone. The present invention relates specifically to controlling harmful populations of arthropods which use a long-range attractant pheromone and a short-range mounting/contact pheromone for inducing mating behavior. Accordingly, "arthropod" hereinafter shall mean only those species of the phylum arthropoda which employ a two-pheromone system for inducing mating behavior.
It should be noted that both the long-range attractant pheromone and the short-range mounting/contact pheromone, hereinafter called the mounting pheromone, may be one chemical or a blend of several chemicals.
The primary method for controlling parasitic arthropod populations is by applying pesticides to host animals or plants via either spraying or dipping or a combination of both in order to eliminate the arthropods. This method has several drawbacks. The application of pesticide directly to the host animal or plant may cause contamination of the host with toxic materials. This is particularly undesirable if, for example, the host is used either directly or indirectly as a food source. This is because the pesticide is not directed specifically at the parasite but rather the parasite is affected because of the large amount of pesticide directed at the host generally.
Several methods for controlling insect populations exist which employ elements in addition to pesticides to achieve a more effective result from the application of pesticides. For example, a trap in use with beetles employs a plastic which has a pesticide and an attractive pheromone in association therewith. The pheromone attracts the beetles to the trap and causes the beetles to come into physical contact with the trap where they are contaminated with a pesticide. The male is attracted to the trap by a sexual device.
U.S. Pat. No. 4,493,161 discloses an insect trap which is formed to resemble an animal that attracts the targeted insect. This use of a visual lure in combination with a pesticide is an improvement over the use of pheromone-pesticide combination alone because the visual lure attracts the pest to the pesticide and in so doing reduces significantly dispersion of the pesticide over a wide area without loss of effectiveness. The arthropod is attracted to the trap by a visual device which represents the arthropod host, an animal.
Another variation of this theme is found in U.S. Pat. No. 229,222 which discloses an insect trap which is shaped like a plant that attracts the target insects. Again, the arthropod is attracted to the trap by a visual device which represents the arthropod host, a plant.
The use of a single pheromone may not provide the entire sequence of stimuli needed to induce prolonged mating contact between a trap and the target arthropod in all species. The target arthropod is attracted to the vicinity of the pheromone source and is expected to become entangled in an adhesive or caught in a container. Such traps may not be effective for all arthropod pest species, especially in those cases where additional chemical or physical stimuli are necessary to induce mating. Physical contact between the target arthropod and the source of pesticide is important because it increases the dose of pesticide received by the arthropod. The effectiveness of the trap improves accordingly.
Another problem with the prior art methods is that visual lures representing plants or host in combination with pheromones will not be effective in the reduction of populations of many arthropods. This is because they must be constructed to the same size as the real target and must be intermixed with the real population of hosts. However, they cannot replace the real hosts (in terms of numbers) and, therefore, they can only affect a percentage of the target arthropod population. The percentage of the target population affected is determined by the percentage of hosts replaced by the lures.
In Sonenshine, D. E., Taylor, D., and Corrigan, G. (1985). Studies to Evaluate the Effectiveness of Sex Pheromone Impregnated Formulations for Control of Populations of the American Dog Tick Dermacenter Variablis. Experimental and Applied Acarology 1, 23-34, it was demonstrated that a mixture of gelatin encapsulated long-range sex attractant pheromone and a pesticide would kill more males than standard application of pesticides to a host animal.
It is an object of the present invention to provide a method and apparatus for improving long-term control of arthropod populations.
It is a further object of the present invention to employ arthropod pheromones in combination with pesticides and a visual lure to improve upon the effectiveness of the use of pesticides to control arthropod populations.
It is a still further object of the present invention to provide a long-term means for controlling parasitic arthropods which may be attached to the host animal.
It is a further object of the present invention to improve arthropod population control by utilizing the multiple pheromone mating system of the arthropod to attract the arthropod to a source of pesticide.
It is a further object of the present invention that the decoys should bear resemblance to the potential arthropod by a combination of the integration of visual, olfactory, gustatory and in some instances tactile cues.
These and other objects of the invention will be apparent to one of ordinary skill from the summary and detailed description which follows.