study on the mortality and repellency effects of three insecticides on aphelinus mali (haldeman) (hym.: aphelinidae)

abstract in a laboratory study the effect of three insecticides (pirimicarb, pymetrozine and spinosad) was evaluated on aphelinus mali a parasitoid of woolly apple aphid. to investigate the contact effect, adults were caged for 16 hours in petri-dishes containing apple leaves sprayed with each insecticide. to determine the oral toxicity in the same period of time, other petri-dishes containing filter paper soaked in poisoned solution of 10% sugar were used. to determine the repellency effect of the insecticides in question, we used busvine y shape tube and host choice experiment between treated and untreated leaf disks was carried out. the results revealed that the rate of mortality was 89.43 and 89.01% spinosad in contact and oral testes respectively. in the case of pymetrozine and in similar tests 78.85 and 62.72% mortality was observed. moreover, spinosad and pirimicarb showed marked repellency effect on the adult stage of a.mali while pymetrozine didn’t show similar effect.