FERTILIZATION BY MICROINJECTION OF CRYOPRESERVED SPERM IN THE SAWFLY,ATHALIA-ROSAE (HYMENOPTERA)

Sperm of the turnip sawfly Athalia rosae (Hymenoptera) were frozen in liquid nitrogen without cryoprotectant, and were stored for weeks at - 80 degrees C. The sperm, upon thawing, were non-motile and had abnorma l morphology. They were, nevertheless, able to fertilize micro-injecte d mature oocytes which developed to fertile adults. The fertilization rate was sufficiently high for the practical preservation of the mutan t stocks, but was lower than obtained using fresh sperm. These results indicate that simple frozen sperm can be regarded as a fully capable genetic reserve in systems in which the micro-injection of oocytes is possible.