Toxicity of insecticides to Coccinella repanda Thunberg and Harmonia octomaculata (Fabricius) (Coleoptera: Coccinellidae)

Abstract

Laboratory tests of the contact toxicity of eight insecticides to Coccinella repanda adults and six insecticides to Harmonia octomaculata adults were conducted at Toowoomba, Qld. Insecticides in ascending order of toxicity to C. repanda were endosulfan, chlorpyrifos, profenofos, methidathion, methomyl, monocrotophos, cypermethrin and deltamethrin; and similarly for H. octomacu/ata were permethrin, sulprofos, methidathion, chlorpyrifos, cypermethrin and deltamethrin. H. octomaculata was less susceptible to methidathion, cypermethrin and deltamethrin than C. repanda. Results are discussed in relation to choice of insecticides for control of Queensland sunflower pests.