During an interview about bee stings earlier this week, I happened to mention that drones don’t sting, which lead to a discussion of male bees in general. The fact is, none of them sting.
As it turns out, the stinger is a modified ovipositor. An ovipositor is an egg-laying organ that transmits an egg from the female to it’s final resting place, which may be a cell, a pollen ball, or in the case of wasps, inside another animal or plant. Injecting eggs to the inside of an organism required a long, slender, needle-like appendage.
In the distant past, wasps that needed to subdue the host into which they laid their eggs were aided by chemicals they injected along with the eggs. Later, these chemicals evolved into venom that could also be used for defense.
In an interesting twist of evolution, a queen honey bee has a usable stinger but her eggs are no longer laid through the ovipositor. Instead, her eggs are placed into the brood cell directly from the vagina.
No eggs means no stinger
Since males don’t have any eggs to lay, they don’t have an ovipositor, and without an ovipositor, they don’t have a stinger. To make up for this lack of armor, some bees have a barbed abdomen which they can use to fight off other bees. A common example is the European wool carder which has three dagger-like points that it uses to defend its territory from other bees. The males circle their favorite plants and aggressively chase away any unwanted visitors.
What it means to be male
Because they are all so different, it’s hard to make general statements about male bees. However, a few rules hold up most of the time:
- Like all male hymenoptera, male bees are haploid, meaning they have only one set of chromosomes. Normally, fertilized eggs become female and unfertilized eggs become male. However, if an egg is homozygous at the sex locus, meaning there are two identical alleles at the sex locus, the bee becomes a diploid male and usually does not survive.
- After emergence most male bees do not re-enter the nest where they developed. Instead, they stay outside and sleep on a flower in a protected place. Exceptions include the honey bee drone, which is allowed back in until the approach of fall.
- Males have more body segments than females.
- Males have more antenna segments than females.
- Most males bees can mate many times, except for bees in the tribes Meliponini and Apini, which lose all or part of their genitalia during mating.
- Many males have colorful patches on their faces. If the female of the same species also has color on her face, the male face will be more striking in appearance. In many ways male bees are like male birds, showy and ostentatious.
More differences than similarities
On the other hand, the differences in male bees from species to species is amazing, and encompasses behavior, morphology, and appearance.
Honey bee drones are known for congregating in mating areas known as drone congregation areas. These areas are high in the air and often reform in the same place year after year. Some bee species gather in similar groups, except the gathering occurs not in the air but in flowers. These groups are called leks and are very similar to sports bars.
But not all male bees gather in groups. Some just peruse the nesting areas near to where they were born and wait for females to appear from their nests. Some males even dig down into the ground, intercepting females on their way out.
The size of males differs as well. In some species the males are larger than their female counterparts and in others they are smaller. The size of males can vary within the species as well. In his book, The Bees of the World, Michener writes that within a species the larger males are more apt to cruise the nesting area looking for females, while the smaller males are more likely to look for females on flowers.
So which is it?
On the wing, it is hard to tell one sex from another. But if you watch bees frequently, you may be able to see them mating (an excellent clue as to who is who), or you may see the the bright colors on the face of a male.
The males drink nectar from flowers, but their visits are usually very short. They do not collect pollen deliberately, and have no corbiculae nor any scopae on their legs, abdomen or thorax. The males may nevertheless be dusted with pollen, and for that reason, some of them make good pollinators.
Honey Bee Suite