Worker Pheromones
Scientific Beekeeping
info@scientificbeekeeping.co.uk
Chemical Communication in the Honey Bee Society.
Queen
Pheromone
Worker
Pheromone
Drone
Pheromone
Brood
Pheromone
Queen
Retinue
Pheromones
MANDIBULAR GLAND (MG)
These glands are situated anteriorly in the "cheeks" of the face. They consist of a number of collections of cells with a large lumen which acts as a reservoir.

Younger workers' mandibular gland pheromones are dominated by the two fatty acids 10-hydroxydecanoic acid (10-HDAA) and 10-hydroxy-2(E)-decenoic acid (10-HDA) (Plettner et al. 1993). The former is the principle lipid (fatty) component of larval food and represents the main food of queen larvae. It contains no phenolic acids. It is opaque.
Older workers produce 2-Heptanone from their mandibular glands, a secondary alarm pheromone, when they have ceased nurse duties.



ARNHART OR TARSAL GLANDS
This pheromone is also known as the footprint horomone. It confirms to workers that they are in the correct place should it be foraging or at the correct hive entrance.

The cells of the tarsal gland do not have ducts to transport the pheromones to the exterior surface of the foot. The gland cells are bounded by cuticle and to enter the reservoir the secretion must cross this barrier .

The secretion of worker tarsal glands is thought to have a role in marking the hive entrance and nectar and pollen sources. It is deposited on the hive entrance by returning workers and on visited flowers, adding to the attractiveness of the Nasonov pheromone. The footprint pheromone is only active over short distances.

If bees are allowed to walk on glass the oily nature of these tarsal secretions can be seen. At least 120 elements (alkanes, alkenes, alcohols, organic acids, esters, aldehydes) and 27 compounds have been identified in footprint pheromones. . Eleven elements are specific to queens, 10 to workers and 2 to drones. Some compounds are also detected in the secretions of other exocrine glands of the honey bee .


Postcerebral
Salivary Gland
Hypopharyngeal
Gland
Mandibular
Gland
Thoracic
Salivary Gland
Wax Glands
4 pairs
Venom
Gland
Dufour's
Glands
Nasanov
Gland
Koschevnikov's
Gland
Gland
Wax Glands
4 pairs
The diagram above is adapted from an excellent website www.honeybee.drawwing.org. It contains a lot of valuable information. Please do visit it. The venom, wax and salivary glands are not known to secrete pheromones.

HYPOPHARYNGEAL GLAND (HG)
The Hypopharyngeal glands consist of a pair of long glands coiled in the sides of the head. Each gland consists about 550 oval acini attached to an axial collecting duct. It is lined with cuticle. The ducts open on the suboral plate of hypopharynx.

These are a pair of glands with no reservoir and are subject to and age polyethism. In nurse worker bees they produce brood food. This food is translucent and contains proteins and vitamins and is fed to workers and drones along with a small amount of mandibular gland food (royal jelly).

As the worker bee ages it becomes a forager and the HGs produce the enzymes Sucrase (Invertase) and glucose oxidase.

The pheromones of the worker honey bee alter during their lives, according to the tasks performed. This changes from "housekeeping", tending brood to foraging and hive defence. The bees are influenced by the pheromones that come from the brood and queen.
VENOM GLAND
The venom gland it attached to the sting mechanism as found on the linked page to the left.

The constituents of honey bee venom can be found following the link venom ( to the left).
DUFOUR'S GLAND
The dufour glands were identifed in 1841 and used to be called the "alkaline gland".

The positional anatomy of the Dufour glands was finally established in 2004 by Martin et al (see link to left). It is a small gland associated with the venom gland, sting sheath and Koshevnikov glands (see below). it opens onto the dorsal vaginal wall close to the setosa membrane, which surrounds the sting bulb and, being hairy is an excellent vehicle for pheromone release.

To quote from the Martin et al (link to the left) re the position of the dufour gland
"Both the exits of the venom sac and Dufour gland approach the base of the sting bulb. However, where the venom sac opens directly into the base of the sting bulb the Dufour gland narrows before exiting between the sting lancets. The exit is very narrow and indistinct, which explains the confusion in the literature and inability to observe the exit using a binocular microscope (×60). In A. mellifera ... the Dufour gland exit is in the same position in both workers and queens"

The secretions in workers consist of a series of long-chain hydrocarbons. It lacks the queen's waxlike esters.

KOSCHEVNIKOV'S GLAND
The position of the Koschevnokov Gland (KG) can be seen in the diagram at the top of the page. It is made of many smaller glandular units, each with a secretory cell and duct cell connected to the epidermis.

This gland produces the principle alarm pheromone . Isopentyl acetate (AKA IPA or isoamyl acetate) is the main constituent. There is a second important chemical (Z)-11-eicosen-1-ol. It is volatile and quickly disseminated from the hairs of the setosa membrane.

Bees showing defensive behaviour raise their abdomens and fan their wings thus circulating the pheromone.

List of some of the chemicals making up KG pheromones:
2-Nonanol
1-Hexanol
n-Hexyl acetate
Isopentyl acetate
(Z)-11-eicosen-1-ol
n-Butyl acetate
Benzyl acetate
2-Heptanol
Iso-pentyl alcohol
1-Acetoxy-2-nonene
1-Butanol (St)
2-Nonyl acetate
1-Octanol
n-Octyl acetate
2-Heptyl acetate
1-Acetoxy-2-octene
n-Decyl acetate
Benzyl alcohol
1-Decanol
Phenol

NASANOV GLAND
Please go to the Nasanov Gland page (left).


Arnhart (Tarsal)
Glands (on feet)
Nasanov
Gland
Sting
Anatomy
Venom
Morphology of the Dufour gland within the honey bee sting gland complex1. Martin et al 2004
The Scent of the Waggle Dance, Thom et al, 2007
CUTICULAR HYDROCARBONS
The cuticular hydrocarbons seem to have been overlooked in most texts. These aliphatic hydrocarbons are found in the wax layer covering the cuticle. Bees appear to be able to recognise their relatives, even their degree of kinship. These cuticular hydrocarbons also seem to act as a karimone to varroa and tracheal mites. They are found in all stages of development.

The cuticular hydrocarbon profile changes with reproductive status and has a genetic component.

Thom (see link left) found that waggle-dancing bees give additional information by produceing and releasing four cuticular hydrocarbons (two alkanes, tricosane and pentacosane, and two alkenes, Z-(9)-tricosene and Z-(9)-pentacosene) from their abdomens into the surrounding air. These compounds are produced subcutaneously and secreted on the surface of the cuticle. When artificially introduced into a hive, the number of foragers leaving the hive increases significantly, suggesting a pheromonal role in worker recruitment.