Predation by Blattisocius tarsalis (Berlese) (Acari: Ascidae) on eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Abstract

The mean predation rate of female B. tarsalis on eggs of E. kuehniella was determined at 15°C, 21°C, and 27°C with prey densities of 3, 5, 10 and 15 eggs. Young eggs less than 24 h old were used as prey. Under all experimental conditions most eggs were only partially consumed, confirming the general theory that predatory mites leave most of the food content unutilized. A mean predation rate of 2.2–7.0 eggs destroyed in 24 h was found, reflecting that a large proportion of the available prey was destroyed. The result supports the view that the predatory mite B. tarsalis could be a relevant biological control agent against E. kuehniella in flour mills. It was further demonstrated that frozen moth eggs can be considered as an appropriate food source.