Pheromone results are promising

08/27/2015 19:59

Pheromone results are promising and detailed published information is still forth- coming. Meanwhile Kaae et al. (1972) have shown that a single pheromone (-7- dodecenyl acetate) has a disruptive effect on the chemical communication of six different insect species. This is clearly also attractive from a manufacturing point of view.

As Shorey et al. (1968) point out, the eventual use of an ‘impure’ pheromone could still produce the desired effect, and once initial tests are complete it may well be found that highly pure chemicals are not essential. A final chemical product may very well contain only 70% of the desired pheromone and some l0~25% of a behavioral inhibitor or masking agent. The cost of producing a material of this purity would be much less than chemicals now used. Other chemicals, the para- pheromones (chemicals closely related to pheromones in structure and sometimes in activity) (Gaston et al. 1971a) and pheromone inhibitors (Roelofs and Comeau 197]; Carde et al. 1973), also effectively disrupt an insect’s communication system and may be far less expensive to manufacture. The prospects are very bright.

21.3.2. Pheromone Mass trapping

Pheromones per se do not kill the pest insect, but they can be used to lure the insect to a trap where it is then killed. The trap may be a physical restraint on the insect, such as a sticky surface, or it may be a combination of pheromone and insecticide. Whatever strategy is used, the aim is to remove a significant proportion, or all, of the target insects from a given population. Learn more at

Although the principle is quite simple, the practice is very difficult. The pheromone must not only be released into the environment but it must be released in such a way as to out-compete the virgin adult and yet prevent ‘disruption’. The attempt to create a superattractive source is complicated by the fact that many pheromone systems have so far been defined in terms of only one or two compounds such as mine.

Even in the Lepidoptera, where sex pheromones have long been thought to be single compounds, there is mounting evidence that other components are present and are necessary to duplicate the insect’s pheromonal system. Only when this system can be reproduced synthetically can we expect efficient attraction (see Roelofs and Cardé ch. 6). it is clear that pheromones ofhigh purity are initially obligatory in order to determine exactly how the behavior is being modified and to evaluate the effectiveness of this type of program. With some species, plant—host odors are an integral part of the pheromone and must be incorporated to create a potent competitor to the natural source (Wood 1970, 1972). Attractiveness can also be increased by using synergists (materials which have no activity in themselves but which enhance a pheromone’s attractiveness) (Roelofs and Comeau l97l), or keepers (Beroza et al. 197lb), which assist in controlling evaporation of a pheromone. Further, the trap should ideally incorporate any essential visual cues for orientation and provide for temporal variations in chemical concentration of phero- mone, or other variables. In essence trap design and placement are much more critical for success than they are in survey programs. It is not enough to trap one or two insects as indices of population emergence, but enough insects must be trapped to make a significant reduction in the next generation (or to trap almost every insect of at least one sex, if eradication is being attempted). Learn more about pheromones at