Laboratory Studies of the Activity of Spinosad against Leptinotarsa decemlineata (Say) Depending on Different Temperature

Summary

Mortality of the Colorado potato beetle larvae (Say) and adults caused by commercial formulation of spinosad at 15, 20 and 250C was determined under laboratory conditions. The insects and the leaves of potatoes were sprayed with the insecticide. Thus, the insecticide was toxic by exposure to treated surfaces and ingestion. Three concentrations of insecticide were used: 0.2%, 0.1% and 0.05%. The effect was assessed the 6th day after treatment. All concentrations caused mortality both adults and larvae; however mortality of tested insect stages increased as concentration of spinosad increased. For adults was observed the highest mortality in combination with 0.2% at 150C, whereas at this same temperature in combination with 0.1% was reached the lowest mortality. In tests with the larvae was observed that 0.2% of spinosad caused the lowest mortality at 250C, whereas concentration 0.1% of spinosad reached the best results at this same temperature. For adults and larvae concentrations 0.05% of spinosad reached the lowest mortality and differences between results in this combination depend on temperature were not observed.