The alteration of calling behaviour by female Choristoneura fumiferana when exposed to synthetic sex pheromone

Abstract

The calling behaviour of 0‐day‐old and 2‐day‐old virgin female eastern spruce budworm moths, Choristoneura fumiferana (Clem.) was observed during exposure to different concentrations of the synthetic female sex pheromone. Regardless of whether the females were exposed to pheromone or not, there were two daily peak periods of calling activity, one in the afternoon and the other after dusk. Those moths exposed to pheromone commenced calling at least 2 h earlier during their first peak of calling activity. Also, a greater number of moths engaged in calling when exposed to pheromone than those under control conditions. RÉSUMÉ Modification du comportement d'appel des femelles de Choristoneura fumiferana exposées à la phëromone sexuelle synthétique de leur propre espèce. Des expériences ont été menées au laboratoire pour examiner si la phéromone sexuelle synthétique de C. fumiferana pouvait altérer le comportement d'appel de femelles vierges de la même espèce. Un appareil a été conçu pour libérer alternativement ‐ à des intervalles déterminés ‐ un courant d'air portant de la phéromone sexuelle ou un courant d'air pur, dans plusieurs flacons contenant des femelles vierges. Le comportement sexuel de mouches de 0 et 2 jours a ainsi été observé. Indépendamment de l'exposition des femelles à la phéromone, il y avait deux pics quotidiens d'activité d'appel, l'un dans l'après‐midi et l'autre après le crépuscule. Des papillons exposés au 1 × 10−6 mg ou 1 × 10−3 mg de phéromone avaient un premier pic d'appel au moins antérieur de 2 heures par rapport aux témoins. Ainsi il y avait un plus grand nombre de papillons engagés dans une activité d'appel en présence de la phéromone que chez les témoins.

Behavioral Ecology of Pheromone-Mediated Communication in Moths and Its Importance in the Use of Pheromone Traps

“…When exposed to a pheromone source, spruce budworm virgin females initiated calling several hours earlier than the con trols, and at any time during the calling window the proportion of females calling was higher in permeated than clean air (99). The inverse situation has been reported for the small tea tortrix and the oriental tea tortrix in which, under both laboratory and field conditions, the presence of conspecific pher omone resulted in a delay of up to 40 min in the onset of calling in virgins (95).…”

Ordinary glomeruli in the antennal lobe of male and female tortricid moth Grapholita molesta (Busck) (Lepidoptera: Tortricidae) process sex pheromone and host-plant volatiles

“…In contrast to the numerous studies dealing with male moth pheromone detection and processing, female autodetection of sex pheromone has been demonstrated in only a few moth species, and little is known about central pheromone processing in female moths (e.g. Barnes et al, 1992;DeLury et al, 2005;Palaniswamy and Seabrook, 1985;Schneider et al, 1998;Stelinski et al, 2003;Stelinski et al, 2006;Weissling and Knight, 1996).…”

Autodetection in <i>Helicoverpa armigera</i> (Hubner)

“…The functions of autodetection may vary such as establishment of societal contacts 38 , jointly calling or spacing of food plants, control of timing of pheromone release 34 and spacing to avoid interference of pheromone plumes.…”

“…Autodetection was also considered as a mechanism to reduce competition between conspecific females 34 . Unmated males always showed greater response to pheromone blends in several species of moths in olfactometer experiments 22 , confirming our studies of greater response of unmated males towards pheromone.…”