Technical notes. Toxicities of insecticides to pasture white grubs in Queensland

Abstract

Larvae of Rhopaea magnicornis Blkb. and Lepidiota caudata Blkb. (see Saunders 1958) were bred or collected in the field and first-stage Dermolipeda albohirtum Waterh. (bred) were used in one series as this species is controlled in sugarcane fields by applications of BHC (Mungomery 1949, Wilson 1956). The insecticides were thoroughly mixed with air-dry soil from relevant habitats, but p.p.m. (active) were calculated on oven-dry weights. Either one third-stage, two second-stage, or five first-stage larvae were placed in each pot containing about 1 lb. of soil (and insecticide) kept suitably moist. No fewer than 100 larvae per treatment were used. When examining larvae the pot contents were placed in a scoop, and after adding water, if required, were returned to the pot.