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Quality Control and Captive Rearing Genetics of the Biological Control Agent Trichogramma pretiosum


In these studies, we determined the quality of Trichogramma parasitoids reared in several Mexican insectaries, evaluated the clonal variability found in Trichogramma pretiosum populations where the infection has gone to fixation, and determined the potential for genetic changes taking place during mass rearing of Trichogramma spp. The results showed that there is substantial potential for adaptation to mass rearing conditions when mass reared populations are initiated with genetically variable populations. In addition, we determined that inbreeding depression is possible even in species such as Trichogramma pretiosum where their sex determination and normal sibmating mating system would predict a minimal effect of inbreeding. With respect to the quality of mass reared Trichogramma, we found discrepancy between the reported and the reared specie, presence of unnoticed species replacement, and we found that the reared species barely met the minimum standards suggested by the international organization for biological control/ European community. From the PI-Wolbachia infected population, we found a surprisingly large amount of variability among the different clonal lines when life history measurements were made. In this dissertation, we also outlined several guidelines for insectaries regarding how to maintain high "field quality" of the natural enemies they produce. Finally, our findings of the high diversity of clones in entirely asexual populations may result in a more rational future use of asexual wasps in biological control.

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