Rv. Gunning, BIOASSAY FOR DETECTING PYRETHROID NERVE INSENSITIVITY IN AUSTRALIAN HELICOVERPA-ARMIGERA (LEPIDOPTERA, NOCTUIDAE), Journal of economic entomology, 89(4), 1996, pp. 816-819
A simple locomotory knockdown bioassay was used to detect Kdr-like ner
ve insensitivity to pyrethroids in pyrethroid resistant Australian cot
ton bollworms, Helicoverpa armigera (Hubner), larvae. Resistant popula
tions with high-level nerve insensitivity had >250-fold resistance to
knockdown compared with susceptible populations. Pyrethroid resistant
populations without nerve insensitivity were only 2.5 times more resis
tant to knockdown than susceptible individuals. Use of a discriminatin
g dose, slightly in excess of the KD100 of the resistant strains lacki
ng nerve insensitivity, is suggested as an easy, rapid method to monit
or for nerve insensitivity to pyrethroids in H. armigera larvae.