Toxicity of the insect growth regulator diflubenzuron to the rove beetle Aleochara bilineata, a parasitoid and predator of the cabbage maggot Delia radicum

Diflubenzuron 25% w.p. applied at concentrations (0.001, 0.01, 0.1% w/v), which were effective against laboratory populations of the anthomyiid Delia radicum, did not affect the hatching of the eggs of its predator and parasitoid, the staphylinid Aleochara bilineata. Applied externally in distilled water, diflubenzuron was non-toxic to the 1st-instar larvae, to larvae developing within host puparia and to the adults of A. bilineata. When the growth regulator was dissolved in dimethylsulfoxide and applied topically to the exoskeleton of parasitized host puparia, the emergence of adult A. bilineata was suppressed by 50%. Carbofuran 48% e.c. at 0.001% w/v in distilled water was toxic to both the eggs and larvae of the staphylinid, with about 20.8% of treated eggs hatching..