Sexing of newly hatched live larvae of the honey bee, Apis mellifera, allows the recognition of diploid drones

(Received 15 February 2001; revised 14 January 2002; accepted 15 January 2002)

Abstract
In the honey bee, it is difficult to recognise the sex in first instar larvae. As workers and haploid drones develop in differently sized brood cells, they can be discriminated without sex inspection. However, because diploid drone larvae originate from fertilised eggs like workers, they hatch in brood cells of the same type and cannot be sampled according to cell size. In search of a reliable method of sexing live first instar larvae, we found that the contour and size proportions of the epiproct can be used for discrimination. The sex diagnosis based on these characters is carried out rapidly under a stereo microscope and allows the collection of pure samples of newly hatched diploid drone larvae from brood combs of inbred colonies.