Reduction in responsiveness of male apple moths, Epiphyas postvittana, to sex pheromone following pulsed pheromonal exposure

Abstract

The degree of reduction in sex pheromone-mediated responsiveness of male light-brown apple moth, whch results from previous exposure to the pheromone, is increased by presenting the pre-exposure dose as a sequence of short pulses, rather than as a single pre-exposure. This effect is interpreted in terms of adaptation and disadaptation of the pheromone receptors, and of central habituation and dishabituation. When the interval between pulses is of sufficient length for receptor disadaptation, the total amount of excitatory input generated by the pulsed pheromone would be greater than if the same dose were to be applied continuously. It is concluded that the greater resultant reduction in responsiveness following pulsing is directly related to the greater degree of habituation resulting from this presumed increased amount of excitatory input.

Development of single‐dispenser pheromone suppression of Epiphyas postvittana, Planotortrix octo and Ctenopseustis obliquana in New Zealand stone fruit orchards

“…Pre‐exposure of moths to sex pheromone reduced male moth sexual responsiveness in E. postvittana ,28–31 and the present wind tunnel trials after pre‐exposure corroborated this effect with a new method. This physiological and behavioural response contrasts with P. octo , where results confirm that a more rapid recovery of response took place after pre‐exposure, compared with the other two species.…”

Wind Tunnels in Pheromone Research

“…Because electroantennogram responses of males preexposed to both pulsed and continual pheromone recovered within minutes after the exposure, habituation rather than sensory adaptation was proposed as the mechanism for reducing flights in the tunnel. This corresponded well to bioassay studies and predictions by Bartell and Lawrence (1977), but contradicted the results of Farkas et al (1975), who thought pulsed exposure did not affect subsequent responses. Farkas et al's responses were measured in small bioassay chambers, and in this respect, their lack of reduced wing-fanning responses was similar to that found by Kuenen and Baker.…”

Concentration of air‐borne pheromone required for long‐lasting peripheral adaptation in the obliquebanded leafroller, Choristoneura rosaceana

“…For example, perhaps moths experiencing long‐lasting adaptation might sufficiently suppress overt sexual responses so as to allow them to depart extraordinarily high‐dosage pheromone sites where the likelihood of finding and mating with a female is nil. If they then happen to arrive in a location of low pheromone, disadaptation would occur within 10 min and their ability to discriminate and orientate to a natural pheromone plume would be restored, provided the possible effects of central nervous system habituation were shielded (Bartell & Lawrence, 1977; Kuenen & Baker, 1981). Alternatively, long‐lasting adaptation might preclude normal orientation and act to arrest flight so that the responder is not attracted to an abnormally high pheromone dosage.…”