Early steps of cryopreservation of day one honeybee (Apis mellifera) embryos treated with low-frequency sonophoresis.

Honeybees, major providers of pollination, are endangered in many areas. Embryo cryopreservation may be a very useful tool to maintain their genetic diversity. However, it is complex in insects, because embryos are chill sensitive and are surrounded by two protectant membranes, the chorion and vitelline.