Male Mosquito

2013 January 12

This little midge-like fly came to a light on the night before May 26, 2012, along with a bunch of moths. This was a bit unusual, as I normally don’t see midges being particularly drawn to lights.

There’s a lot of stuff sticking out of the head. There are a pair of feathery antennae sticking off to the side, but most of it is the hugely elongated maxillae (some of the mouthparts) that are sticking way out in front.

I had never actually seen anything like this, and thought it might be something exotic. Based on the feathery antennae, I figured it was a male, so I started by searching for male midges and gnats with elongated mouthparts (without much success) But there was something about the way it stood, with its long hind legs kind of ready to cock up in the air, that looked familiar . . .

. . . so I decided to search on “male mosquito”.


It turns out that male mosquitoes (family Culicidae) look rather a lot different from the females, and most (if not all) appear to have those long maxillae. Up until now, I had no idea that the males looked so different, I had figured that they were just another of those fluffy-antennaed “mufflemouths” like a lot of the midges.

We normally don’t see male mosquitoes, because they have no interest in humans and probably avoid us. Male mosquitoes have no need for the salt and protein in our blood (since they aren’t the ones laying eggs), so they get all their food from plant juices (and maybe nectar). Unlike the females, the males appear to be at least slightly drawn to light[1]

So, what does he use those long maxillae for? Beats me. I’ve been looking around the literature, and so far am not seeing anybody showing even a glimmer of interest in why certain male mosquitoes are like that. Maybe they have sensory cells on them, and act as supplementary antennae. Maybe he uses them to grip the female. Heck, maybe the males use them to joust with each other, kind of like rhinocerous beetles do. As far as I can tell, mosquito researchers are mostly so focused on the females, that they have little or no attention to spare for studying the males.

[1] This still is no excuse for using one of those UV light “bug zappers”. The male mosquitoes are obviously not strongly drawn to lights, or I would have seen bunches of them instead of just this one. Bug zappers are mainly effective for killing a lot of harmless moths, and for murdering beneficial predators like lacewings. They are practically useless for attracting the things we are actually concerned about like mosquitoes, black flies, and other biting insects.

10 Responses
  1. January 12, 2013

    This is why I see life as more of a kludge than a computer program of inexorable evolutionary advancement. The thing looks like it was designed by a kindergarten class. Sticking enormous, fragile mouth parts on the face of a tiny, flying insect? Seriously? You can’t tell me there wasn’t a more efficient design that would do the same thing.

    I’m fine with evolutionary biology, but I think there’s a lot of random artistry in the stuff and less logic and reason than the biology books would have us believe.

  2. jrr permalink
    January 12, 2013

    Randomness is what drives evolution. Selection is what steers it. Selection is only able to choose among the designs that randomly occur.

  3. katbird permalink
    January 12, 2013

    Beautiful photo. I have tried to find others for comparison on line. There really are no good ones easily accessible. Thank you.

  4. Carole permalink
    January 12, 2013

    I, too, had assumed the male would resemble the female. Reminds me a bit of a fan dancer.

  5. January 13, 2013

    Great macro, and otherwise interesting post, too. The randomness of evolutionary biology is why it is so interesting. What advantage do the maxillae give? Maybe none. Could be completely random, and if it turns out to be completely worthless or supplies a benefit inefficiently, it will disappear. Interesting to try and think about what it might do, though.

  6. January 20, 2013

    Regarding whether the long maxillae have an evolutionary benefit, or are just random things sticking out of his head, I think we need to remember that this is not something we find in just one mosquito species. It occurs in a whole bunch of species, maybe even all of them.

    While it is possible that it’s just a neutral mutation that neither helps nor hurts the mosquito’s ability to survive and breed, it doesn’t seem like such a thing would have been conserved through all the descendant species of the original long-maxillae parent. And from an aerodynamic point of view, it is something that would have to have an effect (and probably not a good one) on his flight characteristics. And, if nothing else it would be a metabolic burden on the growing mosquito to grow such a large structure. If it truly has no function, then the males with smaller maxillae should be able to fly faster, more easily evade predators, and produce more sperm, and so out-compete and replace their long-maxillae brothers.

    I just don’t buy the “purposeless appendage” theory in this case. Something that big and awkward has to provide *some* benefit in exchange for him hauling it around, or be a side effect of something that *does* provide a benefit. There are a lot of options as to what that benefit might be, like sexual display, or unsuspected aerodynamic benefits, or access to some specialized food, or better sensory abilities. Or maybe even it’s just what the female proboscis becomes when exposed to male hormones, so he’s got his version of a long proboscis because the female has to have hers. In which case, there might not be any way for males to evolve shorter, less-awkward mouthparts without also hurting the ability of the females to have the long ones they need to drink our blood. But there has to be *something* keeping the long-maxillae males in circulation.

  7. Kurt permalink
    January 25, 2013

    I’ve read that male mosquitoes eat the juices from plants. It’s possible that the long maxillae are used in a similar way to the proboscis in females. However, I’m not sure why they are fluffy.

  8. March 1, 2013

    Photo borrowed, entry linked.

  9. May 20, 2016

    Aren’t those feathery mouthparts palps,not maxillary? Just wondering.

  10. May 23, 2016

    RD: I think that “palps” (normally short for “pedipalps”) are specific to chelicerates like spiders and mites. The similar structures in insects are the maxillae. They get different names because they were evidently derived from different ancestral limbs – pedipalps were derived from the appendages on the ancestral 2nd body segment, while the maxillae were derived from appendages on the 4th and 5th body segments.

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