Journal of Chemical Ecology (2003) 29, 2131-2142

Jörg Romeis, Dirk Ebbinghaus and Jürgen Scherkenbeck (2003)
Factors accounting for the variability in the behavioral response of the onion fly (Delia antiqua) to n-dipropyl disulfide
Journal of Chemical Ecology 29 (9), 2131-2142
Abstract: The onion fly Delia antiqua is a specialist herbivore attacking only onions and closely related Allium species. n-Dipropyl disulfide (Pr₂S₂) has long been known to be attractive to onion flies in the laboratory and in the field. However, the insect's response is highly variable. Using behavioral bioassays we found that Pr₂S₂ was highly attractive to gravid, mated female onion flies, but did not stimulate oviposition. The response of female onion flies was concentration dependent. The physiological state of the flies (i.e., age, mating status, egg load/oviposition experience) also affected their responsiveness. The response of both sexes of onion flies varied with age, but females were always more strongly attracted than males. Responsiveness of females increased during the first 10 days after emergence. It stayed at a high level until 21 days after which the experiment was terminated. The responsiveness of males reached a maximum at 6-7 days after which it declined. Mated, gravid females responded more strongly to Pr₂S₂ than unmated, gravid females. Females deprived of the opportunity to oviposit were more attracted compared to females that had oviposited on cut onions prior to the experiment. Electroantennograms (EAG) of females revealed a higher response to stimulation compared to males. The EAG-response of females was not affected by mating status.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jörg Romeis

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
pheromones/attractants/traps

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Delia antiqua	Onion/garlic/leek (Allium)