Dear AntAsk Team,
Honey bee queens mate something like twenty times over a few days. That sperm then lasts for say 3 or 4 years. In the long lived queen ants how many times do the queens mate? And does that mating period last for their twenty odd year lifespan?
Figure 1. Copulating pair of Dorymyrmex bureni. The male is the small individual attached at the end of the large queen. Note that both individuals have wings. The queen of this species will probably only mate once.
Figure 2. Queen of Dorylus nigricans molestus. The highly specialized queens of Dorylus are wingless and must mate with multiple males before founding a colony, which they do by taking a proportion of the standing worker population with them.
Figure 3. Male Dorylus nigricans molestus. Males of Dorylus are massive and distinctive animals which probably only mate once in their life, unlike the queens, and which have bizarrely modified genitalia.
This is a great question which has several facets to it. In general, queen ants mate only during a very short period of time, such as a few hours during a nuptial (mating) flight (Fig 1.) or for a few seconds to several hours by calling males to her with chemical pheromones or with other signals (Figs. 2, 3). Regardless of how the queen is able to obtain sperm, she is stuck with this for the duration of her life. To the best of our knowledge, queen ants never re-mate, even in lineages which have extraordinarily long life-spans. There are several intriguing aspects to the reproductive biology of ants, but one which relates to your question is the number of males a queen mates with. In that single short period of time in which a queen will mate, she may mate with one or up to a dozen males. Usually queens will mate with one or a few males, but in some cases queens seem to never mate more than once, such as in the Carpenter ants (Camponotus) which have been studied and in ponerine army ants (Simopelta). In other lineages queens will always mate with several males. These lineages usually have massive colonies with complex social organization. Examples are the leaf cutter ants in the genus Atta, and in the New and Old World army ants Eciton and Dorylus (Figs. 2, 3), respectively. Because matings occur only once in a queen's and male's lifetime males only produce enough sperm for that single event. A remarkable exception to this is the genus Cardiocondyla (Fig. 4), where some males fly from the nest to mate and die, and other, wingless males remain in the nest and copulate with their sisters after killing their brothers. These wingless and incestuous males are able to continuously produce sperm so that they may monopolize the virgin queens eclosing from their pupal cocoons. Despite the detail I've provided in this email, much remains to be learned about the reproductive biology of ants---from both the queen's and the male's perspective.
All the best,
-Brendon Boudinot & the AntAsk Team