Distribution host range and flight pattern of the lettuce aphid in New Zealand

Abstract

The lettuce aphid (Nasonovia ribisnigri) was first reported in New Zealand on lettuce (Lactuca sativa) in Canterbury in March 2002 During autumn 2002 the lettuce aphid was collected in three suction traps (75 m high) around Canterbury Within one year it had spread to all of the main lettuce growing regions of the country mostly as a result of transporting aphidinfested fresh lettuce or lettuce seedling transplants to these regions It was found on its primary host Ribes spp (eg currants and gooseberries) and moved to its secondary hosts (eg lettuce and weeds) in late spring having survived the winter in sexual and asexual forms Up to 73 lettuce aphids per flower head were found on flower buds and flowers of some widely distributed weeds in New Zealand including Crepis spp Hieracium spp Cichorium intybus and Lactuca virosa during summer and autumn 2003 This infestation resulted in a number of crops being deemed unfit for marketing