Mike's Rancid Thoughts On Life and Health

Combining Pheromones

Pheromones have great value in a number of survey, detection, monitoring and research programs (Hardee 1972). From the standpoint of future usage in control, suppression, and pest management, pheromones has tremendous potential in programs other than traps and trap crops. For example, field observations show clearly that boll weevils aggregate in the late fruiting plants which continue to grow in moist places within fields after the crop is mature. Boll weevils also respond to pheromones in the fall after the crop reaches maturity. Learn more about pheromones at

These observations suggest that the pheromone control procedures could be streamlined and insecticide usage reduced by restricting treatment to the late fruiting cotton baited with grand- lure rather than applying the insecticide treatment to the entire field. The confusion or inhibition technique for behavioral control of Lepidoptera (Shorey and Gaston 1964; Gaston et al. 1967; Shorey et al. 1967) has not been investigated satisfactorily in the boll weevil.

Combining pheromones in a bait containing a feeding stimulant and small quantities of chemosterilant, insecticide, or pathogens is also planned. Using pheromones alone or in traps to manipulate diapausing boll weevils into a natural or artificial hibernation site to be destroyed during the winter has shown promise in west Texas where hibernation sites are somewhat limited (Bottrell, Texas A & M University, personal communication). Finally, we hope eventually to correlate numbers of boll weevils captured in traps with potential damage to cotton, so that when a given number of boll weevils are captured per trap per hectare, farmers are alerted to initiate control measures for boll weevils. This would reduce the farmer’s need for early season scouting of his crop for boll weevils at a time when he is so busy.

Admittedly, these systems (and undoubtedly others not discussed here) will require a great deal of research before they can be used on a grower basis, but they do have potential. In the meantime grandlure in traps and trap crops is one of the most promising of the known pheromones as a tool for detection, suppression and possible elimination of any insect species. Check out pheromones at

22.6. The gypsy moth ‘by E. Alan Cameron‘

The gypsy moth, Porthetria dispar (L.) (Lepidoptera: Lymantriidae), a native of Eurasia and North Africa, was carried to North" America in 1869 in an attempt to establish a silk industry. A few larvae accidentally escaped from the laboratory in Medford Massachusetts, became established, and, within 20 years, had caused se- Vere tree defoliation in the local area.

It has been estimated that in excess of $100 million have been spent combating the insect since it was introduced (Beroza 1971) and expenditures continue at a multi-million dollar annual rate. Forest defoliation in the northeastern United States over the past ten years has averaged 198,801 hectares annually, with a high of 582,433 hectares in 1971 (Anon 1973).

It has long been known that the normally flightless female moth emits a pheromone chemical signal to which males respond. Beroza and Knipling (1972) briefly reviewed the history of attempts to isolate, identify and synthesize the responsible chemical(s), which work culminated with the determination of cis-7,8-epoxy-2-methyloctade- cane, called ‘disparlure’, as the sex attractant (Bierl et al. 1970). Since then, this material has undergone field testing for use in survey and detection, and as a tool with which to manipulate populations both by physical capture of male moths in traps and by otherwise disrupting chemical communication between the sexes.

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