Currently viewing the category: "Powder Post Beetles"
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Subject: Tale of two beetles
Location: Southern California, USA
May 20, 2015 2:45 pm
Hello Bugman!
I recently pulled the included two beetles from my Lindgren beetle trap. In our area here in southern California we’ve had large numbers of Pine trees in the area killed off by some type of pest. My trap is about 40 feet from several pines of various types. The trap has a generic methanol lure and one specific to western pine beetle.
I’d like to find out if the two beetles (image attached) are pests or just native harmless beetles. The one brown beetle is about 2/3 the size of a June bug (may be a small one) though their season is still about 4 weeks away normally.
The black beetle I’ve never seen before and it’s about 0.5 inches in length.
About 20 miles from my location the polyphagous shot hole borer has also been located.
Any help in Identifying these beetles would be greatly appreciated.
Thanks,
Signature: Eric

Engraver Beetle, we believe

Horned Powder-Post Beetle

Dear Eric,
We believe, but we are not certain, that this is an Engraver Beetle in the genus
Ips, based on an image of a False Five Spined Ips in “Insects of the Los Angeles Basin” by Charles Hogue, where it states:  “The adults of this species are very small (1/4 in., or 3 mm, long) and dark brown.  The prothorax is large and partly conceals the back of the head; the wing covers are finely haired and have linear series of punctures’ the antennae are clubbed.  The species develops under the bark of pines — in our area, primarily Monterey Pine.  Usually only unhealthy or cut trees are attacked, but healthy trees are sometimes infested.  The larvae make fine tunnels through the growth layer beneath the bark, and these tunnels may connect, girdling and killing the tree.”  BugGuide has a single dorsal shot of this species, but other members of the genus pictured on BugGuide have a similar profile.  The University of California Integrated Pest Management page includes the genus Ips in the table of Bark Beetles common in Southern California landscapes.  We will try to seek opinions from Eric Eaton and Arthur Evans.  Your other beetle looks like a May Beetle, commonly called a June Bug.

Hello Daniel,
Thank you very much for the quick reply.  Time to do some more research on the little beetle.
Thanks again.  I measured the beetle in question and he is 11mm long.  So almost 3 times the length of the Ips Engraver beetle.
http://cru.cahe.wsu.edu/CEPublications/FS085E/FS085E.pdf
So perhaps he is something a little different.  Or a giant 😛
Eric

Arthur Evans provides a correction
This is a bostrichid beetle, not a bark beetle. Where is it from? Size? Any other details might help to narrow down its identity.

Ed. Note:  Our response to Arthur Evans was:  “It is from Southern California and it is about .5 inch long” and we are now awaiting further information on this Horned Powder-Post Beetle in the family Bostrichidae where, according to BugGuide:  “Most species attack wood, either living, or in some cases, dead, including seasoned lumber. A few are associated with woody fungi or stored grain.”

Sue Dougherty, Alfonso Moreno, John Giangrosso, Alisha Bragg liked this post
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Subject: beetle
Location: Hesperia, California
August 13, 2014 1:03 pm
what kinda of beetle is this.
i have alot of mealworm beatles
running wild from my own breeding.
could it have bred with a wild beetle
Signature: Brian

Stout's Hardwood Borer

Stout’s Hardwood Borer

Dear Brian,
Your image is not terribly clear, but this sure looks like a Stout’s Hardwood Borer,
Polycaon stoutii, to us.  We got that common name from Charles Hogue’s Insects of the Los Angeles Basin, but BugGuide refers to it as the Black Polycaon and has very little information about it.  Hogue on the other hand writes extensively about the Stout’s Hardwood Borer.  Hogue writes that they “appear in the fall (September) in unlikely places, such as in the hallways and rooms of new buildings, in warehouses, and in homes.  Their occurrence is explained by their breeding habits.  The larvae are wood borers that feed within various hardwoods such as oak, California Laurel, alder, maple, and eucalyptus — construction woods that are often used in building boxes, shipping crates, storage racks, and the slats used behind scoustic ceiling tiles;  the larvae will also infest finished wood products such as cupboards, cabinets, and furniture.  The adult Stout’s beetles may emerge from these products after the construction is completed and even after the product has been finished. … There is no evidence that the species reinfests lumber or manufactured wood products once the adults have emerged from them.”

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Subject: Tiny black bugs under bed
Location: Sydney, Australia
February 22, 2014 11:59 pm
We have found lots of tiny black bugs under our bed, they crawl around the floor and sometimes crawl into the crack between the floor and skirting board. They are about as big as ants. They sometimes crawl into the chipboard at the back of our bedside tables. They do not jump or bite us, only crawl. They look black but when you look closer they are dark brown.
Signature: Sarah

Powder Post Beetles

Powder Post Beetles

Dear Sarah,
We believe you have Powder Post Beetles in the subfamily Lyctinae.  According to BugGuide:  “powder-post beetles refer to the propensity of the larvae to reduce sapwood into a powdery frass.”
  BugGuide also notes several other items of interest, including the range of Powder Post Beetles being “worldwide (easily spread with commerce), more diverse in the tropics” and regarding food, that the “larva feeds mainly on the sapwood of hardwoods; species are polyphagous.”  Perhaps the most significant bit of information for you is that “The destructiveness of lyctid beetles to wood and wood products is second only to that of termites.”  If this is a new bed, it is possible that the wood was infested with Powder Post Beetle larvae which emerged in the new location.  Catseye Pest Control provides this information:  “Adult Powder Post Beetles range from a 1/8th of an inch to 1/4th of an inch in size and larvae are usually less than a 1/4th of an inch long. When fully matured, Powder Post Beetles slender and flattened in shape with short antennae and are reddish brown to black in color. The larvae, which are left behind in the cracks of the wood by the adults, are cream colored and slightly C-shaped.  The long, narrow, flat bodies of the mature adults allow them to easily bore into wood surfaces, the first place to look during powder post beetle control procedures. They prefer the sapwood of hardwoods, especially oak, hickory and ash and creates small, round holes. Common household places to find these holes are in hardwood floors, furniture, molding and fixtures. These pinhole openings are a tell tale sign of an infestation. Powder Post Beetles lay their eggs in cracks of wood and the larvae tunnel into the surface filling it with a very fine powder-like dust, hence the name Powder Post Beetles.”

Powder Post Beetles

Powder Post Beetles

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Pin Prick of a Hole
location:  Great Smoky Mountains
July 14, 2013
Hi Daniel,
It’s been a while, I know.  I hope you and Lisa have been happy, healthy, and busy.
For years now, I’ve noticed itsy-bitsy, extremely tiny holes in the pine boards from which we built our home surrounded by a relatively huge pile of sawdust.  You wouldn’t have any clue as to what tiny,”bug” is up to this task, would you?  ‘Preciate your time.
Thank you.
R.G. Marion
Great Smoky Mountains

Powderpost Beetle Damage, we believe

Powderpost Beetle Damage, we believe

Dear R.G.,
Our best guess on this is Powderpost Beetle Damage.  These are often small beetles with larvae that bore in the wood.  The holes are produced when the adult bores to the surface and emerges.  You can read about Powderpost Beetles on BugGuide.  There are also many fact sheets online, like the University of Kentucky Entomology site and the Penn State Entomology site.

What's That Bug? does not endorse extermination

Subject: Stout’s Hardwood Borer
Location: Central Hollywood
May 22, 2013 7:56 pm
This is an insect I understand is under represented on your site. I have seen tow of them in and around my apartment. I think it is kinda cute, but it’s jaws scare me a little. I put him outside by the big OLD tree. I hope he is happy there.
Signature: Jessica Brecker

Stout's Hardwood Borer

Stout’s Hardwood Borer

Dear Jessica,
We felt obligated to lighten and crop your image.  We are very impressed with your graphic composition.  You have good sense to be cautious about the mandibles of the Stout’s Hardwood Borer.  It chews its way out of dead wood including, we suspect, telephone poles when it ecloses into an adult.

What's That Bug? does not endorse extermination

Subject: Stout’s Hardwood Borer
Location: Redwood City, CA
September 28, 2012 6:23 pm
We seem to have had an ’infestation’ of sorts for the past month. I don’t know how they are entering the office, but we are on the 2nd floor and there are quite a few trees outside. These guys fly around, are up on the carpeted walls, or in boxes. They bite each other’s legs off if kept in the same container.
Signature: -D

Stout’s Hardwood Borer

Hi D,
Perhaps you have some new construction or new furniture at your office and wood that was infested with Stout’s Hardwood Borer larvae was used as a raw material.  Your observation that they bite each others’ legs off might explain why this Stout’s Hardwood Borer from our archive and this individual that our editorial staff photographed are also missing legs.  It is possible that males battle with one another for dominance.

Stout’s Hardwood Borers

What's That Bug? does not endorse extermination