Synthetic pheromone exposure increases calling and reduces subsequent mating in female Contarinia nasturtii (Diptera: Cecidomyiidae).
BACKGROUND
Pheromone-mediated mating disruption, which uses large amounts of synthetic female pheromones to interrupt insect reproductive behavior, has been successful for managing important agricultural pests. While multiple mechanisms have been discovered explaining how synthetic pheromone treatments prevent males from finding females, it is less clear how unnaturally large doses of synthetic sex pheromone impact the behavior of female insects, particularly nonlepidopteran females. In some species, 'autodetecting' females possess pheromone receptors and respond to ambient pheromones by altering their mating behavior. Here, we test whether exposure to stereospecific and racemic synthetic pheromones influences calling and subsequent propensity to mate in female swede midge (Contarinia nasturtii Kieffer; Diptera: Cecidomyiidae), a pest of Brassica crops.


RESULTS
In both laboratory and field settings, females exposed to stereospecific and racemic three-component pheromone blends called significantly more frequently and for longer durations than midges in control treatments. In the field, midges were twice as likely to call in pheromone-treated plots versus nontreated plots. Additionally, pheromone pre-exposure reduced subsequent mating: while 68% of female midges mated following control conditions, only 42% and 35% of females pre-exposed to stereospecific and racemic three-component blends mated, respectively.


CONCLUSION
While more frequent calling within pheromone-treated backgrounds may increase the likelihood that females are detected by males, a reduction in female propensity to mate would increase the efficacy of a pheromone-mediated mating disruption system. Our work presents the first known investigation of autodetection behavior in Cecidomyiidae. Additional research is necessary to understand the implications of female autodetection for swede midge management.
['Hodgdon|Elisabeth A|EA|https://orcid.org/0000-0002-2432-9201', 'Hallett|Rebecca H|RH|', 'Heal|James D|JD|', 'Swan|Andrea Em|AE|', 'Chen|Yolanda H|YH|']
D000818:Animals D004175:Diptera D005260:Female D008297:Male D000074703:Nematocera D010675:Pheromones D012098:Reproduction D012724:Sex Attractants D012726:Sexual Behavior, Animal
mating pheromone-mediated mating disruption autodetection insect behavior invasive pest pest management