Biology and predation efficacy of three Coccinellid beetles species (Stethorus spp.) on spider mite eggs

Abstract

The dominant predator of Tetranychus sp. were Stethorus siphonulus Kapur and Stethorus pauperculus(Weise) while Stethorus indira Kapur was dominant predator of Eutetranychus africanus Tucker. The Stethorus spp. 3 species had characteristic different inegg to pupa stages but similary at adult stages. S. siphonulus had the largest size, followed by S. indira and S. pauperculus. The development period from egg to adult stage of S. pauperculus, S. siphonulus and S. indira was 16.35 days, 12.60 days, and 14.75 days, respectively. Preference test of the predatory beetles on egg of three spider mite species showed that S. siphonulus destroy eggs of Mulberry red mite, Tetranychus truncatus Ehara, S. pauperculus destroy eggs of Two spot spider mite, Tetranychus urticae Koch and S. indiradestroy eggs of African red mite, E. africanus more than other species. Efficacy test on predation of S.siphonulusand S.pauperculus on eggs of T. truncatus and S.indira on egg E. africanus, showed that larvae of three predators were able to consume 85.89, 62.61 and 81.71 eggs per day. Adult of S.siphonulus and S.pauperculus were able to consume 149.80, 102.90 and 146.85 eggs per day, respectively.