Variation in Time of Egg Hatch by the Honey Bee, <I>Apis mellifera</I> (Hymenoptera: Apidae)

Abstract

More detailed information on the age at which a honey bee, Apis mellifera L., egg hatches and the natural variation of this trait was needed to guide development of cryopreservation technology for honey bee embryos. Therefore, honey bee queens were caged on a clean, empty comb for 4 h to obtain groups of eggs of known age. These eggs were collected from the comb using a special forceps and placed on beeswax-coated petri dishes. Individual eggs were observed from 65 h after oviposition until they hatched (48.6% hatched). A tracheal network became visible ≈2 h before hatching. Then, slow flexing of upright embryos and abdominal peristalsis were seen. Release of a fluid along the dorsal midline of the embryo was observed rarely in normal hatching. In contrast, fluid was frequently observed seeping from bulges on embryos that hatched poorly (30.6%). In a normal sequence, the eggshell was gradually digested away, and complete hatch accomplished. The age at which this occurred was significantly different between eggs from different queens, ranging from 66 to 93 h. Hatching age may be a useful marker for selection of faster development time overall, a possible mode of resistance to the varroa mite. Respiration was visible in the larvae for 1–9 h after hatch. In vitro rearing procedures for embryos preserved by cryopreservation will be designed around the parameters estimated in this study.