Prey range of the predatory mite Cheyletus malaccensis (Acari: Cheyletidae) and its efficacy in the control of seven stored-product pests

The prey range of the predatory mite Cheyletus malaccensis was evaluated on the basis of its population growth on various prey species under laboratory conditions. The prey species were selected from pest species syntopically occurring in stored grain habitats in central Europe. The laboratory experiments were carried out in vials containing 100 g of wheat grain and either 100 individuals of a mite pest species (Acarus siro, Aleuroglyphus ovatus, Caloglyphus redickorzevi, Lepidoglyphus destructor or Tyrophagus putrescentiae) or 50 eggs of an insect pest species (Tribolium castaneum or Ephestia kuehniella). The predatory mites were introduced at four predator-to-prey ratios: 0, 0.02, 0.04, and 0.1. The vials were maintained under optimal conditions for the pest species’ development (15% m.c. and 25 °C), and the pest and predator densities were checked after 21 days. C. malaccensis consumed all five mite species and some eggs of T. castaneum, but not eggs of E. kuehniella, suggesting a strictly acarophagous predatory habit. At low initial predator/prey ratios, the population of C. malaccensis increased most on diets of C. redickorzevi, A. ovatus or L. destructor, and less on diets of A. siro or T. putrescentiae. The highest control efficacy was achieved on A. ovatus and L. destructor. Thus, we conclude that C. malaccensis is an oligophagous predator of Acari and should be used in the control of mite pest species, particularly A. ovatus and L. destructor.