Submitted to: National Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/7/1999
Publication Date: N/A
Technical Abstract: Cryopreserving embryos of insects propagated for use in pest control programs allows implementation of certain economic and management benefits such as countering genetic drift and preserving rare or numerous genotypes. Previous studies on 4 species of livestock insect pests, Musca domestica, Cochliomyia macellaria, Cochliomyia hominivorax and Lucilia sericata, established that the Drosophila embryo cryopreservation protocol was not directly suitable for use with these flies. This report describes our work on modifying the cryoprotectant and the vitrification and recovery steps of the Drosophila protocol. When one or a mixture of two or three of conventional cryoprotectants were used, < 5% of the embryos developed into larvae after recovering from liquid nitrogen. Significant progress was made when a vitrification solution containing ethylene glycol, polyethylene glycol and trehalose was developed and when the cooling and recovery steps were done in liquid nitrogen vapor. More than 70% of M. domestica and C. macellaria embryos withstand treatments of dechorionation, permeabilizaton, loading with cryoprotectant and dehydration in vitrification solution, but the cooling and warming steps still cause some reduction in embryo viability. Up to 57.1% of vitrified M. domestica embryos developed into larvae. Further development of these larvae into pupae and adults was observed. With the same procedure as many as 50.9% of C. macellaria and 63.9% of C. hominivorax larvae hatched from the embryos vitrified in liquid nitrogen vapor. Only a 20.2% hatching rate has been achieved with the vitrified L. sericata embryos. Further development of the C. hominivorax larvae to pupae and adults was also obtained.