Functions
Maintain Community – Cooperate – Within the Same Species
Make – Chemically Assemble – Organic Compounds
Dufour’s Gland is a small gland near the stinger of a bee. It’s an exocrine gland, secreting chemicals, but the purpose of the chemicals and their structure differs from family to family. The secretions can be used for anything from nest building, to reproduction, to pheromones, to the production of larval food.1 Dufour’s Gland is not unique to bees, being found in many different insects.
Dufour’s Gland can produce both saturated and unsaturated hydrocarbons, with long chain hydrocarbons being the most common secretion across bee taxa. More volatile and non-volatile compounds are produced by certain taxa, including alcohols, esters, aromatics and fatty acids.
The most common Dufour’s Gland secretion among bees is used to create a waterproof lining for their brood cells, protecting the stashes of food they leave for their larvae, as well as the larvae themselves, from microbes or environmental conditions. The polyester brood cell lining has qualities much like those of cellophane. In the bee genus Colletes, the lining is made up of 18-hydroxyoctadecanoic acid and 20-hydroxy-eicosanoic acid, both stored as lactones in the gland before they are secreted and undergo a polycondensation reaction to become the lining.2
The larvae may also ingest secretions from Dufour’s Gland with their food. In Anthophora abrupta, the secretions are made up of a mixture of liquid triglycerides, one long-chain fatty acid and two short-chain fatty acids before they’re added to the food and are converted to solid diglycerides for ingestion.3
Dufour’s Gland secretions are also often applied to the entrance of the nest, being unique enough to each individual that they serve as a marker for which nest is their own.
In the Andrena genus the compounds produced by the gland vary based on genetics, implying they may play a role in recognizing kin. In some bees, such as the stingless Meliponini bees, the secretions of a virgin female and a non-virgin female differed by the inclusion of an ester compound, implying they could be used for sexual signalling.1
In bumblebees (genus Bombus), such as the Bombus borealis pictured above from the University of Calgary Invertebrate Collection, Dufour’s Gland increases in size with age and reproductive activity of the Queen, while in workers Dufour’s Gland advertises their sterile status using esters. When an individual develops ovaries, the esters are no longer secreted.1
This page was created by Holly Kerstiens in collaboration with Dr. Mindi Summers, Dr. Marjan Eggermont, Dr. Jess Vickruck, Lincoln Best and Dr. Alex Ralevski as part of an independent studies project in winter 2019. This information is also available as a collection on AskNature.org.
Sources
1 Function of the Dufour’s gland in solitary and social Hymenoptera
Journal of Hymenoptera Research. 2013.
Mitra, A.
2 Natural Polyesters: Dufour’s Gland Macrocyclic Lactones Form Brood Cell Laminesters in Colletes Bees
Science. 1979.
Hefetz, A., Fales, H.M. & Batra, S.W.T.
3 Anthophora Bees: Unusual Glycerides from Maternal Dufour’s Glands Serve as Larval Food and Cell Lining
Science. 1980.
Norden, B., Batra, S.W.T., Fales, H.M., Hefetz, A. & Shaw, J.G.