A simple in vivo estimation of hypopharyngeal gland activity in honeybees (Apis mellifera L., Apidae, Hymenoptera)
The hypopharyngeal glands (HGs) are important protein-producing food glands in worker honeybees (Apis mellifera L.). A simple in vivo method is described for estimating HG activity. Radioactive 14C-L-Ieucine (0'1 /-lei in 1 /-If) is injected directly into the haemocoele of honeybees, and is subsequently incorporated into the HGs during protein synthesis. After 2 h incubation, the amount of radioactive leucine incorporated by the gland is measured and serves as an indicator of synthetic activity in the glands. The technique has been used successfully to reveal gland activity differences in bees from hives with and without brood. This technique is simple, fast, and reliable. Its advantages and disadvantages compared with the in vitro assay method of Brouwers (1982) are also discussed.