An enormous egg

Ergatoid queen of Leptogenys josephi, in the process of laying an egg (image by J. Pillow)

Ant guru Jack Longino sends in a myrmecological wonder:

Hey Alex,

You and/or the antblog might find this interesting. I thought it was pretty cool. Ergatoid queen of Leptogenys josephi, in the process of laying an egg. That’s a big egg! Bet they don’t lay those too fast.

Various species of small Leptogenys have these weird ergatoid queens with inflated, ivory-colored mandibles. Lattke writes about them in his new revision. I’ve found a couple of colonies now of L. josephi/pusilla, both polygyne and subterranean.

Gotta be a fun story there.

Jeremy Pillow, a recent grad working in my lab, made the image.


Indeed. Passing an egg that large has to hurt.

John Lattke’s revision of the new world species- including discussion of these odd queens- is here: (pdf).

11 thoughts on “An enormous egg”

  1. As Jack hints, perhaps a number of interesting stories about egg size among ants, but it ‘s hard to imagine the what adaptive significance of such a large egg as this could be? I’m reminded of the gigantic eggs of kiwis.

    On the other hand, I observed once in Costa Rica that Odonotomachus erythrocephalus seems to lay eggs that are about 1/8 the volume of eggs of other species of the genus. Their queens are typical, barely different from workers queens of the genus, but their colonies are rather populous. I wonder if the egg size allows a smallish queen in this latter case to produce more brood?

    PS @ Warren – This is about ants!

  2. I’m wondering if she was dead by the time the photo was taken. It seems so, because of her position and the cotton, but the egg don’t look like something that had been drowned in alcohol…

  3. The kiwi analogy is great. A lot of questions can be raised about such a huge egg. A lot of resources are put into that one egg. How does it compare with other Leptos or Ponerines? How many can she produce in a day? Would it be enough to maintain a colony? Do only polygynous colony queens produce such a monster egg? Or do only the enlarged mandible queens? Would it be worthwhile to invest so much into a worker, if the egg is indeed a worker? Presumably the larva should be huge also so is it somehow getting a head start, perhaps passing less time as a larva before weaving its cocoon? Like Jack mentioned … a fun story to be unravelled!

  4. Interesting article but the jargon is stiffling. Try googling ‘gamergate’ and you get swamped with ‘gamersgate’ and them ergatoids make me paranoid.

    But pretty cool still, I mean the only known ‘molluscan myrmecophile’, isopod specialists, and ‘ground nesting species may be recognized by the scattered exoskeletons of isopod prey’ – sounds like something out of H. Rider Haggard or a scifi film. Big eggs, interesting, but lots of mites produce eggs that are 30-40% of their body mass and can lay a dozen a day.

  5. I was wondering if adaptation to nomadic behavior. If you are always on the move, transporting small eggs could be a challenge. Another idea could be that their isopod prey are tough, and larvae need to be fairly large to get their first bite. Making “enough” eggs may not be a problem for polygynous colonies. All a matter of resource dynamics and classic problems of allocation: many small or few big.

    To answer a comment, specimen was found in a Winkler sample, so presumably fell into alcohol during process of extruding egg.

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