New Zealand Plant Protection 68 (2015): 450
Epiphyas postvittana (lightbrown apple moth, LBAM) is a polyphagous pest of horticulture, native to Australia and introduced into New Zealand, New Caledonia, the British Isles, Hawaii and California. Olfactory responses of LBAM have been well studied, but this has mostly been confined to adult moths. In this study, olfactory responses of LBAM larvae to apple leaf extracts were measured using a new laboratory bioassay technique for choice tests. Apple leaf extracts were prepared using four different extraction methods: methanol soak, near boiling water dip, chloroform soak and 70% ethanol blended. The choice of larvae between an apple leaf extract and solvent control was examined, and the bioassays were video-recorded in time-lapse mode with an infrared-enabled camera. LBAM larvae were significantly attracted to some of the apple leaf extracts. The results indicate that the new bioassay method can be used as a reliable tool for evaluating the olfactory attraction of LBAM larvae and, most likely, also of many other species. Based on these findings, an attempt will be made to identify the active compounds present in the apple leaves that are responsible for the larval attraction.
Copyright © 2015 New Zealand Plant Protection Society (Inc.).