Big black basswood-bark burrowing beetles (False Mealworm)
Our friend Seri was chainsawing some logs in our driveway yesterday[1], and she turned up these two beetles under the bark of a basswood log[2]. They were each about an inch long, and were initially stunned by the cold, although they got over it quickly enough.
Normally, when you find a beetle under tree bark, it is some variety of bark-borer and a pest species. But, this one looks to be a “False Mealworm” beetle, probably Alobates pennsylvanica. I come to this conclusion based on the size, shape, where it was found, and the rows of small punctures running the length of the wing covers.
The False Mealworm beetles are not a pest species[4]. Far from it. They are actually predatory, the adults and larvae eat the other beetles and grubs that are burrowing under the bark[5]. They obviously overwinter as adults under the bark of dead or dying trees, and can be found under the bark year-round, merrily chowing down on the many other things that live under the bark, too. The probably aren’t actually beneficial, as such, because they don’t appear in a tree until the other bark pests have most likely already killed it, but they certainly aren’t doing any harm, either.
At any rate, there probably wasn’t any significance to the fact that they were under basswood[3] bark, they could just as easily have been in any of the other logs. It does make for a nice alliterative post title, though.
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[1] She had some logs that needed to be cut up into chunks so she could turn them into bowls, coasters, eggs, and similar art items with her lathe, and had a new electric chainsaw to use to do it. She lives in an apartment in town, where it would be a bit awkward to do much chainsawing (wielding a chainsaw on a public sidewalk is usually frowned upon, especially since the police station is only a couple of blocks down the road). Our driveway was a much less attention-grabbing place.
[2] She’d been storing the logs along with several other types of wood in her apartment, and had recently started noticing beetles like these crawling around the place. “Now I know where they were coming from”, she said.
[3] Basswood, also known as Linden, is a very common tree around here. They have very nice-smelling blossoms around June, that honeybees really like. The seeds are attached to specialized leaves by a short stalk, that fly away when they get ripe and the wind blows.
[4] Unlike their relative Tenebrio molitor, whose larvae are the true mealworms.
[5] So, Seri, you can relax. The ones in your apartment aren’t going to start chowing down on the structure or damage any other logs you may have handy. Just so you know.
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Hi Tim,
This is quite a comprehensive site you’ve got here – obviously you’ve been at it for quite a while. I’ve added you to my “Insects & Invertebrates” blogroll. I hope you’ll consider linking my blog, Beetles In The Bush.
regards–ted
My rabbit isn’t too fond of them either, but as far as damage goes, I wasn’t too concerned. And they appear to have only been in that log. The others had ants! Maybe that was the food they were after?
Thanks for linking to my site!
I think they eat the log itself.
Thanks also for the link to my site – it works, but it’s “Bush” rather than “Brush” (although that actually sounds good, too).
regards–ted
Ted: fixed the link title(although, even now, my brain keeps reading your title as “brush” instead)
I suppose experiments are in order to see whether or not they eat the log, fungus in the log, or just other small insects burrowing in the log. Hm, how to set that up . . .
do these live in canada because i found a big black bug in my house and i was wondering if this was it
Maddi: I practically live in Canada, and they live around here, so I’d have to say yes, it is a definite possibility. Especially if you bring firewood into your house in the winter. BugGuide shows them living in Ontario, and I expect they live as far north as there are hardwood trees.
I sell dog face shirts at farmers markets. Just last week I was setting up for a day at the market and found two of these beetles in between the shirts. They had both eaten several holes in the 100% cotton shirts making them worthless. They had landed on black shirts so they were not easy to spot but the holes made it easy to notice. Would putting mouth balls in with the shirts prevent this. I am just glad they did not chew through the whole stack.
Could you just find these beetles away from things such as logs? I recently found one flying around in my bedroom and it scared the living crap out of me and i was wondering if it was this type or not since the one i killed sort of looked like this. Obviously many beetles look alike but are there other species that look very similar like this and fly?
Steve: Moth balls help on stored clothing in containers, but it sounds like you had shirts out in the open where beetles could just drop into them. In a well-ventilated area, the beetles probably wouldn’t even notice mothballs. Since moth balls reek pretty bad, I expect you’d end up losing more customers due to the smell than you would save by preventing beetle damage. It might work better to just give the shirts a once-over and maybe shake them out before packing them away.
Nick: There are lots of kinds of black beetles that look generally similar to this, and they are all over the place. It sounds like you might have had one of the darker May Beetles, which are pretty intimidating when they fly around, bumbling into walls and smacking into windows. They often get into houses in the spring. They are completely harmless to you, though.
I found one of theses beetles crawling on the side walk so I picked it up poked some holes on a jars lid and put the beetle inside the jar. My question is how long do they live how many years
Mathew: The adult beetles might live for up to a couple of months. Their complete lifespan starting from an egg might be a year or two, but they spend most of that time as grubs.
I found one at school and now junior is our new class pet
okay so we have noticed over the last few month we dad moths in our house which we was getting concerned about. They seem to have gone and these little fellows have come all over the house, I was wondering if there may be a link, or if there is anything I can do to keep them outside. Lol
If anyone has any information please reply to this, kind regards Lisa
Lisa:
Since there are a number of species of predatory beetles that look a lot like these, then yes, there could be a connection. If they moved in and ate the moths, then you are probably all to the good. They are then likely to eat any other pests around, and once the food is gone they will move on.
Although, I might have misunderstood you. If by “moths” you meant something caterpillar-like, then it is possible that they were actually beetle larvae. In which case, they have all grown up now. As long as you keep them from getting into your stored food or wool products, they should eventually be on their way.
How do you get rid of one in your room
Ana:
If there is only one, pick it up and toss it outside. If you grab it by the sides, it won’t bite you. Or just put a jar over it, and then slide a card under the jar to trap it inside.
If you have more than one, there is probably someplace in your room where they are hanging out, probably someplace where there is moisture. Check around and correct the problem.
I found one of these beetles on my window. Very large. Do they bite? I only saw 1
I don’t think they bite, no. They certainly don’t seek people out to bite them. They might possibly nip a person if they are roughly handled, but in my experience most beetles aren’t too inclined to bite. They just try to get away.
Hello everyone, I live in Central Europe, I live in a house made of some wood, although not the dominating part of the house is wooden, and I noticed that this kind of bug is going into my room constantly. I don’t like bugs, that’s why I’d like to ask how to get rid of this bug, or make sure they don’t come into my room as often, or at all? I had to deal with 3 today, which wasn’t difficult, but they are somewhat annoying if they get into your room and all you can hear is something making sounds behind you, either on your desk or on your floor.
So, how do I get rid of this kind of bug?
Also, there is no bark at all inside or outside the house I live in.