Robber Fly

Bug from the End Times
Location:  Bend, Central Oregon
July 23, 2010 5:07 pm
Good afternoon Bugman! I have enjoyed your site thoroughly for some time and thought of you when I began being plagued by these bugs. I live in Bend, OR and we have had tons of these creepy looking flies around lately (July-ish). They are about 1/2”, maybe a bit longer, and seem to especially be prevalent on hot, dry days. They look like something from the end times, and my first inclination is to kill them. Especially when they land on myself or my infant. (They give me the evil eye- I’m assuming they’re doing the same to the bubs.) However, before declaring war, I want to know what they are. (After scouring your site, I’m guessing maybe a Robber fly???) Whenever I look up flies in Central Oregon I get a lot of pictures of fly fishing. Not helpful. What are these evil looking bugs, and are they harmful? Should I interrupt the bug-lovemaking in the future to decrease their population?
Thanks for your time and help!

Mating Robber Flies

Dear Bugged,
You are correct that these are Robber Flies in the family Asilidae, and it appears the pair in one of your photos is mating.  We would recommend that you learn to tolerate them.  Whatever small annoyance they bring you is probably greatly outweighed by the advantage of having them prey upon undesirable flying insects, like mosquitoes and disease carrying flies.  We don’t believe we will be able to provide you with a species name, or even a genus name, because there is not enough detail in your images, and Robber Flies can be somewhat difficult for us to properly identify even under the best of conditions.

Robber Fly

Thanks for your help! I will leave them be in the future, and perhaps not be so freaked out by them now that I know what they are! You will be happy to know I rescued one just earlier today from the bub’s wading pool where I’m assuming it stopped by for a drink. Or perhaps a refreshing swim.
Next time one lands on me, I will be sure to thank them for controlling the fly and mosquito population in my area.
And thanks for the time and effort you put into the website. Over the years I’ve developed an unhealthy interest in studying spiders, and your site has helped me learn to appreciate even more bugs. They really are pretty cool when it comes down to it.

Thanks for the update.  We would like to add a precaution to our earlier response.  You most likely have nothing to fear should a Robber Fly land on you, but swatting them may cause them to bite.  You should exercise caution when trying to handle any predatory species.  Should you be bitten, though, there is no cause for alarm as Robber Flies do not have venom.

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