A method for host range testing of a biological control agent for <i>Uraba lugens</i>

Abstract

Uraba lugens (gum leaf skeletoniser) is a serious pest of Eucalyptus spp in Australia It is now well established in the greater Auckland region and is spreading Two parasitoid species are under consideration as potential biological control agents of U lugens This paper describes host range testing methods developed using one of these species (Cotesia urabae) against two nontarget species Helicoverpa armigera and Spodoptera litura Using sequential nochoice tests to test the response of mated C urabae females clear preferences were observed for U lugens over both nontarget test species Some females did attempt to attack the nontarget species but no evidence of parasitism was observed when nontarget hosts were reared or dissected This method elucidated both behavioural responses and physiological development of C urabae and it is proposed to be a suitable host range testing method for full evaluation of this species