Field work with human pheromones has been confined to two small trials conducted by Hathaway et al." In the first trial EEAc was liberated from a large number of rubber septa“ distributed throughout pear trees in several small plots, and captures of males were monitored with traps baited with virgin females. The compound was released at the very high rate of 130 mg/ha/hr initially, declining to 60 mg/ha/hr after 7 weeks, and male captures were reduced by about 98% throughout this period. in the second trial, EEAc was released at the lower rate of 25 mg/ha/hr, and the reduction in male pheromonescaptures was maintained at 90% over 7 weeks. a level similar to that achieved in adjacent plots where EEOH was liberated at 15 mg/ha/hr. Check out http://pheromones-work.weebly.com/
These pheromones trials were undertaken on a very small scale. using five-tree plots, and further work is necessary to establish whether there are significant practical advantages in using EEAc for mating disruption. Such studies should include observations on the influence of EEAc on the behavior of male and female moths in the field and the ineffective. At the very high release rate of 600 mg/ha/hr, pheromone mating of tethered virgin females in apple trees was reduced by only 40%. and the number of males captured at EEOH-baited traps was 50% lower than those taken in control plots. Find out more at https://botw.org/
SOME FACTORS AFFECTING SUCCESS OF Pheromone Mating
Earlier discussion (Section Il.B) indicated that the codling moth was a likely candi- date for control by mating disruption because of certain biological and ecological characteristics. However, the results of trials reviewed in this chapter show that the degree of control achieved is very variable, particularly where success is measured in terms of fruit infestation, rather than only male captures at traps or mating of “decoy” females. Reasons for this variability could include (1) inadequate release and uneven aerial distribution of EEOH; (2) the existence in the female pheromone secretion of compounds additional to EEOH that enable a limited, but significant, number of males to locate calling females (the contribution of both (1) and (2) could become greater as adult density increased); (3) mated females immigrating into EEOH-treated areas; (4) a reduction in the number of fertile eggs laid not necessarily influencing population trends where numbers are normally regulated by density-dependent mortality processes of human pheromones.
Inadequate Release and Uneven Aerial Distribution of Pheromones
The data of Cardé et al.,“ Charmillot,” and others suggest that disruption with EEOH is largely the result of “confusion” — that is, an inability of the sexually aroused flying males to perceive and locate the olfactory signal from the calling female in the presence of a “background” of synthetic EEOH. The EEOH treatment may, through adaptation, raise the response threshold of the male to a level where the female signal can no longer elicit a response; alternatively or additionally, the males may constantly encounter stimuli (“false trails”) from the EEOH evaporators that are comparable to those produced by the calling females but are perceived at many points within and between trees. There is no pheromones evidence that relatively high release rates of EEOH cause long-term habituation and suppression of the sexual response of males under field pheromones conditions.