Nasonov Gland
Margaret Thomas NDB
Scientific Beekeeping
Scientific Beekeeping
The Nasonov Gland the scent gland is an exocrine gland.

This gland is commonly known as the 'come hither' gland. Bees at the entrance of the colony entrance will expose the gland and fan to distribute the pheromone to call bees back to the colony after disturbance.

Bees will further use the pheromone to gather bees to the swarm cluster, entice bees into the new swarm home and to scent a food source that has a poor natural scent.

The Nasonov gland is located on the upper side of the abdomen between tergite 6 and 7. The individual glands lie in a cluster under the intercostal membrane. The outlets are shown on the diagram. What the scenting bee does is expose the membrane by tipping the posterior part of the abdomen down clearly exposing the whitish membrane. The bee fans to blow currents of air backwards so releasing the scent to the general atmosphere.

The human nose can detect this scent in particular the geraniol part of the makeup as it is similar to that when bruising geranium leaves. The composition is:
(Z)- citral
(E)- citral
necrolic acid

Please note that the spelling of Nasonov (Free, Davis, Hooper, Wikipedia) can be Nasnov (Snodgrass). The gland was named after the Russian who in 1883 first described it (I could not find the correct spelling of his name). At that time the true function was unknown and thought to secrete surplus water possibly from nectar the bees had collected (Zoubareff 1883).
Ref: Snodgrass Anatomy of the Honey Bee
Free Pheronones of Social Bees
Davis The Honey Bee Inside out
Morse and Hooper The Illustrated Encyclopedia of Beekeeping

This information is based on an article that appeared in the Scottish Beekeeper Magazine in 2017
The Nasonov Gland Pheromone is Involved
in Recruiting Honeybee Workers for Individual Larvae to be Reared as Queens. AL-Kahtani et al, 2011