Horizontal Transmission of Wolbachia in Trichogramma Wasps (Hym., Trichogrammatidae)

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Abstract

Wolbachia is an intracellular endosymbiont, which can induce thelytokous parthenogenesis in Trichogramma egg parasitoids with the infected females producing daughters without any mating. With regard to the usual transfer of Wolbachia which is vertical from the mother to her offspring through the cytoplasm of eggs, this manipulation of host’s reproduction can enhance its transmission to future generations. In this study, the intra- and interspecific transfer of this bacterium among Trichogramma wasps were investigated using one Iranian infected line of Trichogramma brassicae Bezd. (B 11W+) as donor and two Dutch uninfected lines of T. brassicae and Trichogramma evanescens West. (Y 175 and GD 011) as recipients. In both cases, horizontal transfer was observed when infected and uninfected parasitoid’s larvae shared the same host egg, Mamestra brassicae (L.). The F1 females from recipient lines were tested for the presence of Wolbachia and to determine their origin through PCR using wsp primers, specific primer of the ITS-2 region as well as TTG 49 microsatellite primer, respectively. On the whole, intraspecific horizontal and subsequent vertical transmissions (%78.8 and %38.5) occurred with significantly more success than interspecific transfer. Because of the advantages of unisexual wasps in biological control programs, the results obtained may be found as very useful in practival applications.

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