Subject: Big flying unknown insect
Location: SE WISCONSIN
July 11, 2017 7:53 pm
I just moved into a new home this month. Today, I have seen 4 (possibly 5, might have seen the same one more than once) of these bugs. I have never seen this kind before and have had no luck with Google. All the ones I’ve seen are rather large, about a quarter size or more. I’m worried there’s some kind of nest or something since I’ve seen so many in one day. Also worries if they sting or anything, as I have 4 small children in the home. I am located in southeast wisconsin, in a rural area with farm fields all around us. Please solve this mystery for me!
We identified your Hairy Rove Beetle, Creophilus maxillosus, thanks to Arthur V. Evans’ excellent book Beetles of Eastern North America where it states: “Adults appear in late spring, again in late summer; feed on maggots at carcasses in open, wooded, and coastal habitats; not uncommon in urban and suburban habitats.” Here is a BugGuide image for comparison. According to BugGuide: “food maggots and adult flies, also other arthropods” and the habitat is “grassy and open forested habitats, lake/ocean shorelines; on carrion (typically, larger carcasses), rarely on dung, compost, or at lights.” If you are finding them indoors, perhaps there is a dead animal in immediate vicinity of the house. From the descriptions, we would go on the record that this is a beneficial predator that helps to control populations of flies. Rove beetles are not venomous, but Evans’ book does state: “Produce an irritating defensive chemical at the tip of the abdomen.”