Striped Deer Fly

2023 July 23

Sam spotted this deer fly on the milkweeds beside our back door on July 8, 2023

She was oddly calm about being photographed. I don’t know if was because it was still a bit cool in the morning, or if her distended abdomen indicates that she was so full of eggs that she could barely fly. Or, maybe that she had parasites

I got a few pictures of her on the milkweed leaf, but then she jumped onto my left finger and decided to hang out there for a while.

We can see the intricate interference patterns on her eyes.

Normally I get pictures of deer flies after they have been killed, and the eye colors start to fade as soon as they die. This one was still alive, though, and so the eye pattern remained pretty vibrant.

I am fairly confident that this is Chrysops vittatus[1], which is probably the most common deer fly species in this area. That eye pattern is pretty distinctive, as is the pattern of lines on the thorax and abdomen. Their larvae live in semi-aquatic environments, but the adults will fly a considerable distance looking for a source of blood. That enormous proboscis is quite painful when they use it to slash a hole in your skin so they can drink your blood.


[1] So I was looking at this, and I thought, “Hey, that species name, “vittatus”, sound familiar. Where have I seen it before? Well, it turns out that a lot of other creatures have “vittatus” as their species name:

. . . and that’s just among the arthropods. There are more if we look at other animal orders, and even a number of them among plants.

So what does “vittatus” mean, that it gets applied to so many different organisms, many of which are completely unlike one another?

It turns out it means . . .

[drumroll . . .]

“Having longitudinal stripes or bands”.

So, in each of these cases, the species are basically named “Striped [x]”

One Response leave one →
  1. Ben permalink
    August 11, 2023

    An apt subject considering the url! I’ve slapped my head so many times because of these little guys!

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