Two Robber Flies

Here are a couple predators, one of whom I've talked about before. The first is clearly a Red-footed Cannibalfly; I believe (but haven't gotten iNaturalist confirmation) that the second is another species of robber fly.

The robber flies are the fly order's answer to the odonates (dragonflies and damselflies). They're fast, sometimes (relatively) large predatory insects willing to attack any arthropod of an appropriate size. There are even reports of the Red-footed Cannibalfly attacking hummingbirds though they're probably a little undersized for that. And as you might guess with a name like "cannibalfly", they will eat other robber flies.

Here's the Red-footed Cannibalfly, perhaps our most visible robber fly. They're fairly large by insect standards and while not common, I'll run across at least a couple of them each year.

August 19, 2021 at Duke Farms
Photo 152593356, (c) jpviolette, some rights reserved (CC BY-NC)

My impression is that the following is another species of robber fly, perhaps an Efferia aestuans, who lack a common name. I read these are the most common robber fly in the northeast, and they're a bit smaller and darker than the RFCF above.

August 19, 2021 at Duke Farms
Photo 152593398, (c) jpviolette, some rights reserved (CC BY-NC)


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