MORTALITY OF 2-SPOTTED SPIDER-MITE (ACARI, TETRANYCHIDAE) AFTER EXPOSURE TO ETHANOL AT ELEVATED-TEMPERATURES

Mortality responses were determined for twospotted spider mite, Tetran ychus urticae Koch, on apples to immersion in ethanol solutions at 20 degrees C (nondiapausing and diapausing mites), and 30, 40, and 45 deg rees C (diapausing mites only). At 20 degrees C, nondiapausing T. urti cae were more susceptible to ethanol immersion than the diapausing for m. Increasing immersion times from 10 to 1,200 a significantly increas ed mite mortality for nondiapausing I: urticae but did not affect diap ausing T. urticae. Increasing immersion temperatures for diapausing T. urticae from 20 to 40 degrees C did not change the ethanol concentrat ion required to achieve 99% (LC99) mortality. Raising the immersion te mperature from 40 to 45 degrees C only increased diapausing mite morta lity at immersion times >800 s. Immersion of diapausing T. urticae for >600 s at 20 degrees C in 70% ethanol achieved 99% mortality and was more effective than immersion at 30-45 degrees C.