Comparative toxicities of some insecticides to Cacopsylla pyri L. (Hom., Psyllidae) and one of its important biological control agents, Anthocoris nemoralis F. (Het., Anthocoridae).

This study determined toxicities of three insecticides/acaricides representing three classes (formamidines, avermectins, and norpyrethrates) to a prey-predator complex consisting of anthocorid bug ( Anthocoris nemoralis F.) and its phytophagous prey, pear psylla ( Cacopsylla pyri L.). The anthocorid bug LD₅₀s were generally lower than those of the pear psylla indicating greater susceptibility in the predator than the prey. Determination of residual activities of the test insecticides indicates different selectivities to the beneficial insect. From this study, abamectin alone may be sprayed to control the pear psylla when the anthocorid bug populations are active. Reasons for the susceptibility variations to insecticides in phytophagous-entomophagous systems are suggested and discussed. [ABSTRACT FROM AUTHOR]