Lethal and sub-lethal effects of spirotetramat, thiamethoxam-lambda cyhalothrin and acetamiprid insecticides, on the biological parameters of Oenopia conglobata contaminata Menetries (Col.: Coccinellidae)

Introduction: Oenopia conglobata contaminata Menetries is regarded as one of the most important natural enemies of pistachio psylla in the pistachio-growing regions of Iran. Given the usage of three insecticides i.e. spirotetramat, thiamethoxam-lambda cyhalothrin, and acetamiprid in pistachio orchards, the present study attempts to investigate the side effects of some insecticides on the biological parameters of O. conglobata contaminata in the laboratory conditions. Materials and Methods: In this study, the effects of 500 and 250 mg/l concentrations of Spirotetramat, 300 and 5 mg/l concentrations of thiamethoxam-lambda cyhalothrin, and 250 and 30 mg/l concentrations of acetamiprid, and distilled water as control, on life table and reproductive parameters of the ladybird was assayed. The experiments were performed by immersing of the ladybird eggs in the various treatments. Results: The maximum of egg development time was 3 days in related to the concentration of 5 mg/l thiamethoxam-lambda cyhalothrin. The highest larval period was observed in 250 mg/l concentration of acetamiprid. The adult longevity was the highest in the control and the lowest in the 30 mg/l concentration of acetamiprid. In concentration of 250 mg/l of acetamiprid, the longevity of the adult was significantly reduced compared to the control treatment. The lowest values of population parameters inculding rm, R0, GRR and λ were observed in acetamiprid treatment with a concentration of 250 mg/l. The results showed that the sides of effects in spirotetramat were less and safer than the other two insecticides.