Cryopreservation of embryos of Culicoides sonorensis (Diptera : Ceratopogonidae)

The successful long-term storage of insects that are used for research purp oses can eliminate the need for ongoing colony maintenance on a large scale . In addition, rare and valuable genotypes of insects can be preserved. Thi s study was conducted to determine whether cryopreservation is a suitable m eans of storing embryos of Culicoides sonorensis Wirth & Jones, an importan t vector of animal pathogens. We determined that eggs of C. sonorensis can withstand vigorous treatments of dechorionation, permeabilization, and load ing with the cryoprotectant, elthylene glycol. Although their viability was reduced, an average of 80.3% of the embryos developed into larvae. Dehydra tion in vitrification solution caused a much greater reduction in egg viabi lity (42.7% survival), and freezing in liquid propane further reduced the n umber of eggs that developed into larvae (40.1%), pupae (22.9%) and adults (18.8%). This work demonstrated that this procedure may prove useful for th e cryopreservation of standard laboratory colonies and genetic lines of C. sonorensis.