First ant mating flight of the year

It’s a balmy 75º here in Champaign-Urbana, the warmest day this year. The winged Prenolepis reproductives that have been waiting patiently for spring have decided today is the day, and all over town the little ants are erupting from their underground empires to mingle and mate. Our front yard has become an ant orgy! Here are a few pics:

Prenolepis imparis
Prenolepis imparis
Prenolepis imparis

26 thoughts on “First ant mating flight of the year”

  1. Hey Alex or anyone who knows..a question:

    why are the male and femal different colors? Is this common for most ant species?

      1. Secondary sexual characters (like the color dimorphism here) in insects often result from mate / mating selection bias.

        Perhaps the queens like a sleek black male. Perhaps this species always mates in early season and the darker colored males warm up in the sun faster and thus become more active and quicker to find the females. Winter stoneflies definitely (imo) have bias black body color across all taxa for solar heat capture.

        You could always schedule an interview with successful males !!
        Film at eleven.

        1. This species does in fact mate early in the season – the first to fly in most places where it occurs, but only when the first short-sleeve day occurs. On the other hand, nearly all of the males of the tribe to which this ant belongs, and indeed of most ants, are black or nearly so, regardless of the time of year when they fly, and no matter what color the females are. Male ants retain a suite of characters that hark back to their wasp-like ancestors, and one wonders if this might be a conserved, ancestral character. It seems most of the more derived character states of ants are expressed only in the diploid castes.

        2. Thanks, knowing more is always better than shooting in the dark.

          Conserved sexual characters is a fairly strong suite in the evolution of life – funny thing that. I think I will go with that one despite the sexy black outfit theory, lol.

  2. Jonathan Nixon

    I had a woman bring in a jar of these a few weeks ago or more that she found in her yard around her house.

  3. Hard to believe that only a few skinny males like that could provide enough sperm to found colonies that could last for years.

      1. do these queens mate with multiple males ? sperm is pretty small and the males could be like mayflies with all energy invested into proportionally huge gonads and none into other internal organs.

  4. How typical is the fairly extreme size dimorphism here? It’s impressive. I have to confess that I have almost never seen ants mating, and when one sees the alates emerge it’s not clear whether one is seeing both sexes or not.

    1. It is very common in ants to be so sexually dimorphic. Even in those species whose males and females are closer in body length, the males have much less mass, I believe without exception. This may ring a bell for you regarding this topic:
      Trivers, R. L.; Hare, H. (1976). “Haploidploidy and the evolution of the social insect”. Science 191 (4224): 249–63. doi:10.1126/science.1108197. PMID

  5. In California, San Francisco Bay Area, I observed the frenzied mating aggregation of Prenolepis imparis on February 23 (76 F temperature, sunny), while most other ants were still scarce (apart from the abominable Argentines). For the hundreds of males I saw flying and running about I only spotted a single female. Many males were swarming over her at any one time, but few appeared to be successful in their endeavors. She was fairly placid considering the fervor of her suitors, constantly walking at a steady pace and occasionally climbing grass stalks without ever directly shaking off a male. It was difficult to tell if the males were actively competing with one another or if their large numbers and frantic behavior gave the impression of combat. Also interesting to me was that the mating was within a meter or so of a large nest of the same species; consequently ‘cleanup’ teams of workers were roaming the area, antennating the less active males and pulling the disabled and deceased (and potentially already mated males?) away from the hole entrances; transport was jaw-to-jaw. I didn’t see any conflict between workers or males/workers, which suggested to me that they were all of a single colony, despite multiple hole-in-the-ground entrances as well as a larger entrance under a flat stone (more nest access than I’ve seen in other P. imparis in the area). I observed the behavior for around 25 minutes and they were still at it when I gave them their privacy.

    1. Interesting – up here in Olympia, Washington, the weather is shifting week-to-week from warm to snowy. We don’t have Prenolepis imparis, but I did observe Myrmica specioides gynes (a European import) on March 8th, a particularly nice day in our early spring. I was observing Formica obscuripes actively foraging and nest-building, when I found two gynes of Myrmica specioides. One was an alate wandering in the grass, while the other was dealate and walking about on the surface of a F. obscuripes mound. I do not know if the dealate queen was looking to nest in the thatch mound.

  6. I have a completely different interpretation of the female-male pics:

    It clearly demonstrates the well known fact that virgin (alate!) ant gynes give birth to males only. Here it is a little, sweet baby male 😉

  7. Pingback: – The Midwestern Ant Season Begins With the Prenolepis Mating Flight

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