<i>Nysius huttoni</i> on exported kiwifruit the role of olfactory cues

Abstract

Nysius huttoni (Hemiptera Orsillidae; wheat bug) is endemic to New Zealand It is occasionally intercepted in overseas markets on exported kiwifruit jeopardising market access and leading to costly remedial processes (eg fumigation reexport) Studies have shown that N huttoni aggregate on weeds in orchard loadout areas and may gain access to kiwifruit whilst these are in wooden bins used for transport to the packhouse This behaviour may be moderated by olfactory cues The effect of olfactory cues released by kiwifruit and wooden bins (pallet wood) on the walking response of N huttoni was tested in a Ytube olfactometer over 4 months using fieldcollected adults Nysius huttoni collected in December showed no response to either of the odour cues tested Those collected during January/ February showed no response to pallet wood but they exhibited avoidance behaviour when exposed to kiwifruit odour Nysius huttoni collected during March emulated the January/February trends These results suggest that aggregations of N huttoni on wooden bins and kiwifruit during picking and transport may not be caused by olfactory cues rather from the texture of kiwifruit or bins which afford N huttoni an overwintering habitat particularly if the response of individuals in flight is similar to those walking