Ablabesmyia Midge

2024 January 14

There are many kinds of tiny midges that we get coming to our porch light, sometimes in quantity. This particular one from June 30, 2023 is pretty small, only about a third the length of the average mosquito. It also is distinct from the normal run of midges in that the wings are spotted, and the legs have many colored bands on them. And, judging from the relatively small and unobtrusive antennae, it is most likely a female, since male midges typically have big, bushy antennae.

The best match appears to be the midges in the genus Ablabesmyia, and the pictures on BugGuide that look closest are the ones in the subgenus Karelia. These are non-biting midges that breed in small ponds, swamps, and other standing water. While this is the same environment that breeds mosquitos, these midges manage to fulfill their protein and salt needs without having to go after animal blood, and so they are not a problem for us. In fact, if anything they probably compete with mosquito larvae for food, and may very well reduce the number of mosquito wigglers that a given body of water can support. So yay?

It looks like her hindmost right leg is significantly shorter than the corresponding left leg, so she probably lost part of it somehow. In fact, it looks rather like all of her legs on the right side have been shortened. They might have been lost to a predator, or they could have broken off while she was trying to get out of her pupal case, or they could have gotten stuck on something. Anyway, this does suggest that the legs are extremely fragile. It also looks like she can lose legs piecewise instead of shedding the whole thing. Those dark bands on the legs may correspond to break-off points, since the short legs all look like they terminate right at one of those bands. I can see that being useful if, say, she lands on a spiderweb or gets stuck on some plant sap. She could just shed the bit of the leg that was actually stuck, and fly off largely unharmed otherwise.

2 Responses
  1. Alex permalink
    January 16, 2024

    So interesting! Amazing observations.. I hope legs can grow back

  2. January 19, 2024

    Unfortunately for the midge, they can’t grow back legs. Once insects become adults, any damage to wings or legs just accumulates. But since insects generally spend most of their lives in the immature forms, and only spend a few days to weeks as mature adults, they wouldn’t have time to regenerate limbs anyway.

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