Toxicity of spinosad on common green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) larvae via ingestion technique under laboratory conditions

摘要

The use of selective insecticides could improve conservation of natural enemies and therefore contribute to the success of integrated pest management programmes. In this study, the toxicity of one selective insecticide, spinosad to common green lace-wing Chrysoperla carnea (Stephens) was evaluated. Several stages of C. carnea larvae were exposed to spinosad via ingestion technique under laboratory conditions. The used quantities of spinosad were less than the maximum recommended rate given on the product label. In ingestion bioassay tests, a direct relationship was detected between the concentration of spinosad and mortality rate of first instar larvae. So that, the applied of 250 and 2500 ppm of spinosad caused 35 and 90% mortality, respectively. Mortality rate was recorded 1-3 days of post treatment. An implementation of 250 ppm of spinosad on second and third instar larvae showed negligible mortality rate after 3 days, whereas the first instars larvae suffered 35% mortality. On the basis of collected data we could conclude that spinosad is not merited to be considered to have an environmental safety profile on C. carnea similar to well-established conventional biological insecticides.