Behavioral and Electrophysiological Responses of the Diamondback moth, Plutella xylostella, to Polyamines (Lepidoptera: Yponomeutidae)

Abstract

The most common polyamines, putrescine [put], spermidine [spd], and spermine [spm], were tested against adult diamondback moth, Plutella zylostella Linnaeus 1753. A Y-tube olfactometer was used to assay the behavioural response of moths to the polyamines and cabbage [Brassica oleracea var capitata L] juice [cj]. Both naive males and the virgin females responded significantly to the three kinds of polyamines tested. In addition, the mated females were only significantly attracted to the 0.5% put. While compared to the cj, the naive males and the virgin females were only significantly attracted to 0.5% put and 0.5% spd separately and the response to three polyamines had no significant difference. Moths exhibited varying electroantennogram [EAG] responses from 6.80 to 14.18 mV to three polyamines, and showed higher responses to polyamines compared with the control. The EAG responses of the naive males were significantly higher than the virgin females, while in most situations, there were no significant differences between virgin and mated females response to any other odors tested. Taken together, our results demonstrated that polyamines could be important general olfactory stimuli of diamondback moth.