Effect of Host Egg Storage Time and Wolbachia Infection on Qualitative Characteristics of Trichogramma brassicae Bezdenko (Hym.: Trichogrammatidae)

Document Type : Research Article

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Abstract

Factors hindering the development of inundative biological control are insect rearing costs and provide an adequate amount of natural enemies at the appropriate time. Storage of natural enemies is a useful technique to increase time flexibility of parasitoids production, and coincide the natural enemies release with pest outbreaks period, and also could reduce costs of mass production. Another way for parasitoids, is to keep host of natural enemies instead of biocontrol agent in cold. In this way because of lack of necessity to survive insect hosts after storage, temperature range and storage periods can be much more than that for predators and parasitoids. In this work, the effects of storage time of host eggs Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) on the qualitative characteristics of Trichogramma brassicae Bezdenko (Hym.: Trichogrammatidae) were studied. Regarding to identification of Wolbachia-infected strain of T. brassicae and relative advantages of thelytokous strain, these treatments were applied on thelytokous and arrhenotokous strains of Trichogramma. Qualitative characteristics of parasitoids consisted parasitism rate, adult emergence proportion, longevity, fecundity and number of deformed adults. The results indicated negative effects of host storage time on some qualitative characteristics of T. brassicae. Developmental time, emergence proportion, longevity, fecundity and wing deformity, were under negative influence of host storage time. However, because of different effect of storage on two strains, by selecting suitable strain, there is a possibility to reduce some negative effects.

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