Evaluation of the Efficacy of the Acaricide spiromesifen SC 240 in Control of Vegetable Spider Mites

Introduction of new and alternate use of acaricides is an approach in mite management strategy to overcome further mite pests resistance to pesticides. Therefore in the present research the efficacy of the new insecticide/acaricide, spiromesifen (Oberon® 240 SC) in four doses 300, 400, 500 and 600 ml/ha) was tested against active stages of vegetable spider mite (cucumber, melon and water melons) in different parts of the country with the history of acaricide usage. The recommended doses of bromopropylate (Neoron® 25% EC), hexythiazox (Nissoron®10% EC), fenpyroximate (Ortus® 5% SC), and water as control plot were used to compare the efficacies. Experiments were conducted in a randomized complete blocks design with three replicates. Spraying was done when minimum of 5 active mite stages were observed under the 20 of the randomly collected leaves. To evaluate the effect of the treatments, 30 leaves were collected randomly from each treatment, 4, 7, 14 and 21 days after spraying and the number of live mites in an area of 4 squared centimeters in the middle of lower part of the host leaves were counted. The results show that mean mortality caused by various doses of spiromesifen in spider mites of cucumber fields of Isfahan after 4 days (75.39±2.36%) and 14 days (74.30±13.61%) were not significant, whereas after spraying after 21 days (99.15±0.85%) resulted in a complete control of the mites. Maximum mortality of the spider mites recorded on the water melon was with the dose of 500 ml/ha spiromesifen (91.09±3.16%) in Kerman. Maximum mortality 14 and 21 days after spraying were recorded with the dose of 600 ml/ha of spiromesifen which are 78.76±11.54% and 83.14±5.04% respectively. Based on the present findings it is concluded that doses of 500 and 600 ml/ha spiromesifen resulted in maximum mortality of the vegetable spider mites and could be used as the alternate doses with other acaricides.