Tuesday, July 28, 2009

Mydas Fly- Wasp Mimic






These large flies are mimics of Spider Wasps. Their common name is Mydas Fly (Mydas clavatus). They can reach lengths up to 1 1/2 inches and wingspans of 2 1/2 inches. With jet black bodies and wings, and an orange band on the second segment of their abdomen they are easily identified. Although they so closely resemble wasps that many people are fooled by the pretence. They are common and widespread throughout the United States and parts of Canada. They are often found in open fields, and shrubby borders near deciduous woodlands. Adults feed on nectar. Some individuals claim they feed on caterpillars, flies, bees and true bugs. With no documented proof of this, it is only theory. I have only ever seen them on flowers in my yard, or perched on the ground or other vantage points sunning themselves. Females lay their eggs in rotting stumps or logs, and the resulting larvae will feed on beetle grubs. The adults are most generally seen in the summer months and very little is known about their mating rituals. It can be intimidating to have these large insects buzzing around you, especially if you make the assumption they are wasps. These are gorgeous flies and I get excited each time I spot one, and I consider myself lucky when I can get a decent picture of one of these fast fliers.

9 comments:

  1. Nor have I ever seen a Midas Fly feeding in any way other than nectaring. Nice shots of these insect that don't tend to hang around in one spot long.

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  2. These flies are amazing, their mimicry is so complete that they fool me on a regular basis and I am familiar with them. Thanks for the compliment, and you are right they sure don't hang around long, very recalcitrant subjects.

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  3. I saw my first one today and thank you for identifying this odd critter. - Jim, Arkansas

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  4. I don't know if the one I saw attached to my door-bell button one night was actually a mydas fly or not but it definitely looked rather unusual. It had black wings with a large body and a wing-span that was almost proportionally bigger than its body. I saw it at night as I was entering my home. It was right on the glowing button of my door-bell. I also noticed something peculiar about its color because it seemed to match that of the black metal plate which surrounded my doorbell. These plates are usually artistically shaped to accentuate the doorbell...Anyway I wasn't sure if thats what drew this bug or the warm glow of my doorbell button, but either way it was an unusual species I never seen before. It was night time when I spotted this creature. Wish I got a photo but it was gone before I could do that... -T.C., Massachusetts

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  5. Do they bite? My dad got bit by something that looks just like this and he got bit twice by it.

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    1. As far as I know they do not bite, but they are a wasp mimic. It could be that a wasp that looks like this fly stung your dad.

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  6. Observed these mating joined on a sunflower leaf. Then the female buzzed around laying eggs on the mulch. The male followed the female "encouraging" her. Sometimes looked like he was attacking her.

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  7. I watched these guys mating joined on a sunflower leaf. The female buzzed around the garden, appeared to laying eggs on the wood mulch. The male followed her around diving at her repeatedly for 15 minutes or more. Looked like he was attacking her but I'm guessing it was some sort of enouragement. They kept me occupied for half an hour lol.

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  8. I mulched my entire front yard and they have become regulars in my garden, it must be the mulch for egg laying that has drawn them. Spotted them mating today. Glad to know that they aren't bad for my plants, they are now welcome garden buddies! :)

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