The mass production cost of parasitoids is an important limiting factor in the development of successful biological control program. Parasitoids cannot be stored for a long time, thus should be produced shortly before use. Storage of host in low temperatures is an alternative technique to increase time flexibility of parasitoids production, thus contribute to reduction of production expenses. In this study, the influence of cold storage time (1 to 16 days) of host (Ephestia kuehniella Zeller) eggs on some qualitative characteristics of the egg parasitoid, Trichogramma brassicae Bezdenko (Hym.: Trichogrammatidae), was studied under laboratory conditions. The stored eggs were exposed to two different strains of T. brassicae, which were infected or uninfected with the endosymbiotic bacteria, Wolbachia, and the interactions between the host storage time and Wolbachia infection was studied. Increased host storage time negatively affected some qualitative characteristics of T. brassicae, such as fecundity, longevity, wing deformity and sex ratio. Some of these effects (e.g. fecundity, longevity and sex ratio) were different among Wolbachia-infected and uninfected strains. Given that the Wolbachia-infected strain produces higher proportion of females, they may compensate for other negative effects of Wolbachia as well as prolonged storage time of the host from biological control point of view.

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