Impact of temperature on the acaricidal activity of spiromesifen on two-spotted spider mite Tetranychus urticae

The two-spotted spider mite (TSSM) Tetranychus urticae Koch is one of the most destructive mites in many plants due to its characteristics, such as high reproductive potential, short life cycle, and feeding method. Excessive use of chemical compounds without considering environmental factors has led to high residual toxins in food products and resistance to pesticides. Temperature is an essential non-living factor that affects various biological aspects of pests and pesticide toxicity levels. In this study, the interaction of different temperatures (15, 20, 25, and 30 °C) in the photoperiod (16L:8D h) was investigated on the toxicity of spiromesifen on the adult TSSM. Then the levels of α-esterase and glutathione S-transferase activity were measured. The highest LC50 was recorded at 15 °C after 24 h (LC50 = 21.269 mg ai/l), and the lowest value corresponds to 30 °C after 48 h (LC50 = 0.860 mg ai/l). The level of toxicity also increased with a temperature increase, so the toxicity was recorded 3.6 folds higher at 30 °C compared to 15 °C. The α-esterase and glutathione S-transferase activity also increased with an increase in the temperature, but this increase was significant only for esterase activity. The relationship between temperature and the power of pesticide toxicity in areas with different daily and controllable temperature changes can effectively provide a valuable proposal to reduce pesticide consumption and increase the efficiency of pest control.

Impact of temperature on the acaricidal activity of spiromesifen on two-spotted spider mite Tetranychus urticae Keywords:

Tetranychus urticae , spiromesifen , temperatures , α-esterase , glutathione s-transferase