Toxicity of botanic and synthetic pesticide residues to citrus psyllid Diaphorina citri kuwayama and Chrysoperla carnea (Stephens)

Abstract.- bioassays were conducted to investigate the toxicity and residual activity of botanic and synthetic pesticides against adult female citrus psyllids,diaphorina citri kuwayama and second instar larvae of chrysoperla carnea (stephens). a dose of 1% neem seed oil inflicted 80% mortality on d. citri and 100% to c. carnea within 48 hours. neem seed extract at a high dose of 3% resulted in 68.0 and 80% mortality to d. citri and c. carnea,respectively. addition of 5% sugar to neem oil or neem water extract as feeding stimulant improved toxicity of the product to about 30 and 50%,respectively. bioassays with synthetic pesticide such as methomyl and imadicloprid inflicted 97-100% mortality to d. citri on day 4,70% and 34% on day 9 post application. decline in mortality was gradual in case of methomyl but very quick in imidacloprid and lambda cyhalothrin from 100% on day 1 to 60% and 35% on day 9,respectively. neem oil and its extract also degraded very quickly and showed decline in mortality from 80 to 20% within 5 days post application period. © 2012 zoological society of pakistan.