Efficacy of Selected Acaricides against the Two-Spotted Spider Mite Tetranychusurticae on Strawberries in Greenhouse Production

The efficacy of seven acaricides with their distinctive modes of action against the two-spotted spider mite, Tetranychus urticae (Koch), on strawberries was evaluated in potting and ground soil experiments in greenhouses. In the potting trial from 1 to 3 weeks post-treatment, bifenazate suppressed the adult mite numbers by 91% to 99% and the immature numbers by 98% to 100%; etoxazole and spirodiclofen reduced the immatures by 72% to 91% and 61% to 91%, respectively; pyridaben decreased the adults by 41% to 64% and the immatures by up to 67%. At 1 week post-treatment, Abamectin reduced the immatures by 59%. Up to 2 weeks post-treatment, matrine decreased numbers of immatures by 50% to 74% and beta-cypermethrin depressed the adult numbers by 61%. In the ground soil experiment from 1 to 4 weeks post-treatment, bifenazate decreased the adult numbers by 92% to 100% and the immature numbers by 98% to 99%; etoxazole reduced the adults by 62% to 87% and immatures by 91% to 97%; spirodiclofen reduced adults by 60% to 90% and immatures by 60% to 81%; pyridaben decreased the adults by 48% to 93% and immatures by 35% to 85%; abamectin suppressed adults by 43% to 84% and immatures by 45% to 75%. At 1 week post-treatment, matrine reduced the adults by 84% and immatures by 73%, while beta-cypermethrin suppressed the adults by 48% and the immatures by 61%. The potential role of these acaricides in integrated management of the two-spotted spider mite on strawberries in greenhouse production was discussed.