Field evaluation of Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae) in controlling Tetranychus urticae Koch on parthenocarpic cucumber under protected environments

The two-spotted spider mite, Tetranychus urticae Koch (Trombidiformes: Tetranychidae) is a major pest of greenhouses and field crops worldwide. Many attempts to control T. urticae by using chemical insecticides have failed because of the development of pesticide resistance. The use of natural enemies may represent both a more effective alternative and an environmentally-safer method to that of chemical products. Here, we investigated the predation efficacy of the anthocorid bug, Blaptostethus pallescens Poppius, on eggs and active stages of T. urticae on parthenocarpic cucumber grown under a polyhouse. The use of B. pallescens at 50 nymphs per plant led to a significantly higher level of predation on the two-spotted spider mite population (76.4% in egg and 81.7% in active stage of mites) than with 40 or 30 nymphs per plant (68.9% in egg and 69.4% in active stage of mites; 66.4% in egg and 68.2% in active stage of mites), respectively. Significantly higher yields of cucumber were recorded from the plot where B. pallescens at 50 nymphs per plant (2554.8 g/ plant) were released. Results suggest that two-spotted spider mite can be effectively managed by the release of this anthocorid bug. B. pallescens as part of an IPM system for the management of T. urticae on parthenocarpic cucumber grown under polyhouse.