Wood wasps?

[pdqdl]

I was asked by one of my best commercial customers to please respond promptly; their trees were under invasion by wood wasps, and the pest had clearly been identified by one of their staff who "looked it up". They were extremely concerned about this invasion (their words, not mine) because the business tenant had an employee that was acutely allergic to stings.

They did not even tell me where to find the tree in question, nor could they tell me what kind of tree it was. Sadly, they also never gave me a captured sample nor even a picture of the offending insect. For the purpose of identifying the pest in question, please keep in mind that I am in Kansas City, Mo.

When they told me where the tree was, I knew that the observed invasion was almost certainly related to a green ash tree that I have previously identified as dying from borers. So...I went and looked at it again. No invasion of any kind of insect was present. I did see this:


Given these facts and the carefully observed photograph, can you name genus & species of the observed insect invasion? Luck won't count here, you must also tell us why you came to that conclusion and why it is definitely the problem pest.

Note: this won't really be that easy, unless you are really good at knowing your bugs. All the critical details are present for you to be assured of the right answer.

 

[pdqdl]

Nobody?

 

[ChoppyChoppy]

We have wood wasps here. Been stung a few times by the bastards!

 

[pdqdl]

True wood wasps don't sting! https://en.wikipedia.org/wiki/Horntail It is quite likely that you were stung by a real wasp.

This is exactly where I started my research: from what the customer prompted me. Nope, not our bug at all.
Reasons:

1. They don't seem to be present in this area, according to all my searches. I have not been able to find any reports of horntails in Mo or Kansas.
2. They prefer pines or other gymnosperms. Not hardwoods (at least I can't find any that do).
3. Although my knowledge is rather weak on this topic, I don't think the pupae resemble too much the abandoned shells of the larvae I posted a picture of in the original post.

 

[ATH]

banded ash clearwing borer (a moth)

Had to look up latin name: Podoseia Aureocincta

But those left-behind pupal casings are distinctive.

Also of note: if you assumed the tree was being attacked by EAB and treated with imidacloprid, you probably didn't do a good job controlling these because imidacloprid doesn't do well against lepidoptera.

 

[pdqdl]

Excellent choice, but how would you distinguish it from the myriad of other ash borers, using the facts that I offered? You may recall that my challenge is to identify WHY your choice is correct. Quite frankly, I couldn't find any sort of guide to the pupal casings, so I cannot really say that they are distinctive to the species you mentioned. Some entomologist somewhere probably can, but I was unable to find any guide with pics that help the ID of the species: they all seem to go off pics of the adult.

Other Ash boring insects: (some of these are obviously not our pest, but you may not have considered them)

Banded ash borer, Neoclytus caprea (very common nation-wide)

From a Virginia tech guide: "Banded ash borer should not be confused with the similarly named banded ash clearwing moth Podosesia aureocincta" Also: "Overall, the shape, size, and coloration of the adult redheaded ash borer mimic that of a wasp" ​

Red Headed Ash Borer - Neoclytus acuminatus (common as dirt in Kansas City, very similar to the banded ash borer)
Lilac/Ash borer- Podosesia syringae (very common in our area, and is a clear-wing borer like the one you mentioned)
Shothole borers Scolytus rugulosus (not a common borer of ash trees, but it does happen)​

Of course, you are right, it certainly isn't the EAB. No, this customer won't pony up the money for borer treatments of any kind; they realize that it is cheaper in the long run to just cut them down when the time comes, and they have hundreds of ash trees. I have been telling them for about 5 years that all their ash trees are infested, and that it would only get worse. At this point...it has gotten worse. Sadly, they have an entire office park that is mostly planted in ash trees. I am slowly chipping all of them as the branches die.

 

[ATH]

I guess it could be one of the other clearwing borers...but frankly who cares ! It is not Red Headed Ash Borer or Emerald Ash Borer.

Here is the site that I verified I was right before posting my answer... Picture looks pretty much identical to yours.

 

[pdqdl]

Yep, I looked at that page also.

The two Neoclytus borers are very similar, and they are both long antennae beetles that don't (in my opinion) look a whole lot like wasps. You are right, the clear wing borers leave pupae like the pic I showed, but which Podosesia species is it?

I was kind of hoping to get a few more folks involved with this ID, but I sure appreciate your participation. I'll give a hint: think about their life cycle. There is a significant difference between the two similar bugs that tips you off to the correct id.

Knowledge of this tiny detail is actually important to the treatment of the tree; some otherwise useful treatments might fail if you don't know for sure which bug you are preventing. This is why I thought this little problem was such a good candidate for Arb 101.

 

[PJM]

I'm with ATH; identifying as a clear wing borer is detail enough. Surely, the adult emergence times of the the banded and the lilac borer are different but knowing that doesn't change that treatment for this native, secondary pest is hardly warranted, especially in light of the presence or even threat of EAB infestation.

 

[ChoppyChoppy]

True wood wasps don't sting! https://en.wikipedia.org/wiki/Horntail It is quite likely that you were stung by a real wasp.

This is exactly where I started my research: from what the customer prompted me. Nope, not our bug at all.
Reasons:

1. They don't seem to be present in this area, according to all my searches. I have not been able to find any reports of horntails in Mo or Kansas.
2. They prefer pines or other gymnosperms. Not hardwoods (at least I can't find any that do).
3. Although my knowledge is rather weak on this topic, I don't think the pupae resemble too much the abandoned shells of the larvae I posted a picture of in the original post.

Huh, didnt know that. Do real wasps live in trees and in the ground? We had lots of real wasps this year too, I found a few nests the size of basketballs!

 

[pdqdl]

I'm with ATH; identifying as a clear wing borer is detail enough. Surely, the adult emergence times of the the banded and the lilac borer are different but knowing that doesn't change that treatment for this native, secondary pest is hardly warranted, especially in light of the presence or even threat of EAB infestation.

When it comes to effective treatments with any pesticide, timing is everything. I could wipe out next years infestation with an insecticidal drench of the tree trunk. That will only work well if timed correctly to kill the larvae as they hatch and begin burrowing into the tree. This is an older style of borer treatment is quite effective if timed correctly. In other words, a spring treatment will work for lilac borer, and have no effect on the Banded Clearwing. That would require a fall treatment after the pupae have hatched.

So YES, knowing which clearwing is the problem is definitely important to know, unless of course you are just going to put a chainsaw to it and take it out.

 

[pdqdl]

Huh, didnt know that. Do real wasps live in trees and in the ground? We had lots of real wasps this year too, I found a few nests the size of basketballs!

Further south, wasps are everywhere, in many sizes. Huge thumb sized wasps (hornets), down to tiny little braconid wasps that parasitize caterpillars. Nesting in the ground, in the trees & bushes, in your garage or barn. Paper nests to mud nests to underground tunnels, wasps are everywhere.

Up in Alaska? Probably not quite so many.

 

[pdqdl]

There are even wingless wasps that crawl around on the ground looking like giant predatory ants: Velvet ants


Actual sting at 9:40, good info at 2:35

I used to see these all the time in Kansas City; haven't seen one for many years.

 

[Zale]

That is not a smart man.

 

[Jason Douglas]

Lilac ash borer is a spring emerger, at about 330 GDD.
Banded as clearwing emerges much later, about 2200 GDD.
Treatments include strong borer rates of pyrethroids to trunk at scaffolds during adult flight and egg laying or perhaps emmamectin injection if its particularly damaging.