Sublethal Effects of Three Insecticides on Life History Parameters of Oenopia conglobata contaminata, an Important Predatory Coccinellid of Agonoscena pistaciae

The predatory ladybeetle, Oenopia conglobata contaminata (L.) (Col. Coccinellidae), is an important coccinellid predator of the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hem.: Psyllidae). Given public concerns about reducing dependence on chemical pesticides in pistachio orchards, the use of biological control agents is attracting growing attention.

In this study, effects of spirotetramat, fenitrothion, and chlorpyrifos (350, 40, and 10 ml/L, respectively) on some biological and life history parameters of O. conglobata contaminata fed on the common pistachio psylla were examined under controlled conditions (25 ± 1°C, 60 ± 5% RH, and 16:8 h L: D photoperiod). Accordingly, eggs of O. conglobata contaminata were exposed to pesticides by a dipping method.

The results revealed that spirotetramat, fenitrothion, and chlorpyrifos decreased the development time and total longevity in O. conglobata contaminata adults. The highest and lowest fecundity rates were observed in spirotetramat and fenitrothion treatments, respectively. The treatments of insecticides exerted adverse effects on life history parameters of O. conglobate contaminata. The highest values of r, R0, 𝜆, and GRR were obtained in the spirotetramat treatment, whereas the lowest values of these population parameters were recorded in the fenitrothion treatment.

The results suggest that spirotetramat could be effective in O. conglobata contaminata in an IPM program.