Wednesday, December 19, 2012

Wasp Wednesday: Not Wasp IX

I have recently begun participating in “Project Noah,” and as a result find yet another demand for identification of mystery bugs, like this one posted just yesterday. The subject of the image is a Red-necked Ash Borer, Neoclytus acuminatus, a type of longhorned beetle in the family Cerambycidae.

The person who posted the image says he calls them “crickabees” because they have “legs like a cricket….and stripes like a bee.” Most folks mistake these beetles for wasps, though. They can be fast-moving insects, a trait not always associated with beetles. Couple that with their bold markings, and it would be easy to assume they are a stinging insect.

Despite its name, this beetle bores in virtually any hardwood tree during its larval stage, though it does seem to favor ash. It has also been recorded from woody vines and shrubs. I have noticed the adults on freshly-cut trees, but also on older logs. While dead, dying, or weakened trees are most commonly exploited by the Red-headed Ash Borer, it is also a serious pest of healthy black locust trees planted as windbreaks or on farm woodlots. It may also attack recently-planted trees. So, trees stressed in some way are going to be vulnerable to this beetle.

References indicate that the normal flight period for Neoclytus acuminatus is between May and August in the northeast U.S., and from February to November in the southeast. There may be up to three generations each year in the south, usually only one in the north. Firewood brought indoors in late winter or early spring may yield adult beetles emerging inside your home.

This species is widespread, found almost everywhere east of the Rocky Mountains (and into Idaho). It is not one of the larger longhorned beetles, adults measuring only 4-18 millimeters in length.

Sources: Shour, Mark. 2008. “Red-headed Ash Borer Also a Threat to Ash Trees,” Extension News.
Solomon, J.D. 1995. Guide to Insect Borers of North American Broadleaf Trees and Shrubs. Agric. Handbk. 706. Washington, DC: U.S. Department of Agriculture, Forest Service. 735 pp.
Yanega, Douglas. 1996. Field Guide to Northeastern Longhorned Beetles (Coleoptera: Cerambycidae). Illinois Natural History Survey Manual 6. 184 pp.


  1. Thank you! I was concerned that it may be a baby yellow jacket as we had an issue with them outside a year ago. It doesn't look like he has wings, but he was able to fly. Still not sure how this beetle got into the house in the middle of the winter, but glad it's just a beetle.

    1. Hi, Dani! There are several kinds of lonhorned beetles that are wasp mimics, and many of them will emerge indoors from stored firewood, or, more rarely, structural timbers in the home itself. The larvae sometimes get trapped in the milled lumber and this, for reasons still mysterious, usually extends their life cycle by years, even decades. So, a house build in, say, the 1970s, could still have a beetle pop out of the floorboards.

  2. I found one today as I was cutting down a tree. Looks identical as the picture you have. But I noticed the one I have had a stinger coming out of its backside as it was digging into he tree. So I know what I have is similar to the one shown here..... Just curious if it can sting and what the outcome would be if it did sting.

    1. Beetles do not sting, but females of some species have an ovipositor (egg-laying organ) that *resembles* a stinger.

  3. Replies
    1. There is no need to kill them. They are "infesting" dead wood; and they will not re-infest furniture or baseboards.

  4. Today, I found three of these flying about in my backyard here in Tri-Cities, WA. Commenting because your post suggests these are primarily in and east of the Rockies. Two of them were apparently copulating as well. I agree they look like crickets crossed with a bee or other assassin. Whenever I got close they would invariably dart away. The body of the one I caught is approximately 13mm, but when it is upright (legs positioned like a grasshopper or cricket) it’s length is approximately 1”. They were also seemingly aggressive towards one another, as in when two of them met, they fought and one flew away.


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