Drones – an indispensable luxury …
To rear drones or not to rear drones – that is the question posed to our bees with the return of the favourable season. Within a colony, males are indeed a luxury: they are far more costly to rear than workers. And the expense does not end at emergence: as adults, drones largely remain dependent on their sisters. In addition, they contribute nothing to foraging activities and very little to hive maintenance. Yet this luxury is necessary: the sole function of males, the transmission of genes, lies at the very heart of the biological meaning of life. Maximising the chances of reproduction while preserving those of survival – it is this subtle balance, to which both the queen and her workers contribute, that we propose to explore today.
Drones – an indispensable but costly luxury of honey bee colonies
This two-part article explores the role of drones in honey bee colonies, highlighting the paradox between their high energetic cost and their essential biological function. Drones do not forage, build comb or maintain the hive and are entirely dependent on workers for feeding. Yet they are indispensable, as their sole role is the transmission of genes during queen mating.
Mating competition is extreme. At drone congregation areas, a single virgin queen may encounter tens of thousands of drones, of which only a few succeed in copulating—a process that is always fatal to the male. Strong selection therefore favors high-performance drones, characterized by large UV- and blue-sensitive eyes, elongated antennae, powerful flight muscles and highly developed reproductive organs. Body size is directly linked to sperm production and thus to genetic contribution.
This performance comes at a high cost. Drone larvae consume nearly twice as much sugar and more than twice as much pollen as worker larvae and reach a much higher body mass. Adult drones have a limited digestive capacity: they poorly digest pollen and rely almost entirely on worker feeding. The colony effectively functions as a collective digestive system for its males.
Experimental studies demonstrate the economic consequences. Colonies producing many drones yield significantly less honey. The production and maintenance of 5,000 to 15,000 drones can cost a colony 15–20 kg of honey per year, due to direct consumption, reduced worker numbers and the energetic cost of mating flights.
As a result, colonies tightly regulate drone production. It depends on colony strength, season and resource availability. During food shortages, drone brood is preferentially reduced or cannibalized. Workers can recognize male larvae early and selectively eliminate them when they are in excess. Adult drones are expelled once their cost outweighs their potential reproductive benefit.
Regulation is decentralized. The presence of existing drone comb strongly influences whether new drone cells are built, provided workers have direct contact with them. The queen plays only a limited role; most decisions arise from worker behavior and local cues.
Drone-laying (queenless) colonies represent a special case. They tolerate drones much longer and may produce small drones from worker-laid eggs. Despite their smaller size, these males are fertile and can contribute genetically late in the season, offering a potential opportunity for bee breeding.
In conclusion, drones are not merely a burden but a carefully regulated, costly yet indispensable component of the colony. For beekeepers, this implies managing drone production deliberately rather than suppressing it entirely, especially in the context of breeding, Varroa control and seasonal resource management.
See also:
- Drone rearing – biology, genetics and beekeeping practices
- Everything about the drone
- Introduction to bee genetics
- The drone-laying colony