Wednesday, May 22, 2013

Polistes metricus

Paper wasps tend to be quite variable in color and pattern, even within one species, so identifying them is not easy, even for experts. Case in point is differentiating the common Northern Paper Wasp, Polistes fuscatus, from the very similar Polistes metricus.

Dark specimens of the Northern Paper Wasp are nearly identical to Polistes metricus, a consistently dark species that I have found to be less abundant than P. fuscatus in areas where their geographic ranges overlap. One fairly reliable, if subtle, clue is the shape of the abdomen. Note that the abdomen of P. metricus is highly convex on the underside, creating a nearly acute angle with the underside of the petiole (stalk-like segment connecting abdomen with thorax). This is usually much less pronounced in P. fuscatus.

Another difference is in the face of the female wasps. Females of P. metricus have an almost completely red face, the black markings confined to the ocellar triangle. Ok, so what is an “ocellar triangle?” Most wasps have a trio of tiny, “simple” eyes at the top of the head, between the large compound eyes. These simple eyes are usually arranged in a triangular pattern. Females of the Northern Paper Wasp have the black marking extended from the ocelli to the base of the antennae. Males of both species have square, yellow faces.


Female P. fuscatus. Note black face; gently curved venter of abdomen

Female P. metricus. Note convex venter of abdomen.

Female P. metricus. Note all-red face.

Polistes metricus ranges from extreme southwestern Ontario and Maine south to Florida, and west to southern Ohio, Nebraska, Kansas, Oklahoma, and eastern Texas. The Northern Paper Wasp has a much larger geographic distribution.

I was fortunate enough to find three embryonic nests of P. metricus on a recent trip to Missouri. Two nests were under the exterior of a recessed door frame in Excelsior Springs. The other was under the roof of a sign and kiosk at Little Dixie Lake Conservation Area west of Kingdom City. These are typical nesting sites, though they can also be built among shrubbery and other more exposed locations.

Both the Northern Paper Wasp and P. metricus prey mostly on caterpillars, chewing up the larvae and feeding them to their own grubs back at the nest. Look for the adult wasps on flowers as they fuel themselves on nectar. They can also be seen around aphid colonies, lapping up the “honeydew” secreted by the aphids as a waste product.

Source: Buck, M., Marshall, S.A. and Cheung D.K.B. 2008. Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region. Canadian Journal of Arthropod Identification No. 5: 492 pp. (PDF version).

17 comments:

  1. I have recently encountered 2 different nests of these dark wasps while clearing brush from my property here in east Texas. Might I mention that these wasps become very aggressive when bothered by someone shaking bushes near their nest! Furthermore; they have a nasty, painful sting! A word to the wise,,,,have Benadryl handy before cutting brush in east Texas!!

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    1. I dont think you have these wasps, these wasps arent very agressive, i occasionally feed the one in my backyard honey or jelly, when u create a mutual bond with them they are nice, and their sting isnt that painfull its more like getting a paper cut.

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    2. Sorry, but I disagree- the ones in Texas are aggressive. I think all wasps are here- at least at our house. If you simply walk 8-10 feet away from the guard wasps, they chase you. They are always building nests in the eaves and use the spaces in our metal roof to enter to the attic. Extremely aggressive. They are a battle every year and we all have strong reactions - pain, swelling, lymph nodes in head swell and stay swollen for months - they always catch us running away, in the neck or head. I was just stung again yesterday, that's why I'm on here looking for solutions.

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    3. Sorry, but I disagree- the ones in Texas are aggressive. I think all wasps are here- at least at our house. If you simply walk 8-10 feet away from the guard wasps, they chase you. They are always building nests in the eaves and use the spaces in our metal roof to enter to the attic. Extremely aggressive. They are a battle every year and we all have strong reactions - pain, swelling, lymph nodes in head swell and stay swollen for months - they always catch us running away, in the neck or head. I was just stung again yesterday, that's why I'm on here looking for solutions.

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    4. You have my empathy; but, I will never give information on insect control here. The entire goal of this blog is to change public attitudes towards insects. Thank you for sharing your experience.

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    5. All wasps in Texas are not aggressive! This particular one is most docile. This morning I belt sanded the whole top of a little table then flipped it to get the bottom side only to find a large nest with three wasps starting at me. Not once did they try to sting! I moved the table to the driveway and spent the next hour laying on the ground observing them. So fascinating. I got several minutes of video with my phone literally inches away while they groomed themselves and each other. Two flew away and were gone awhile, returning later with sonething in their mouth. One was a bit cautious of me and buzzed all around my head before landing again. I just remained still and all was good. Love these little guys and was so appreciative of the opportunity to get an up close observation of their behaviors. Thank you for your blog. I almost had then confused with a similar ringed species until I found your page.

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    1. This comment has been removed by the author.

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    2. The comment above was probably an attempt at spam.

      But I have a question which I hope you can answer. I recently ID'd a Polistes metricus for someone in Texas who was very afraid (I am not in Texas). Someone else came in and claimed it was a "Mahogany Wasp" which she further claimed are super aggressive (like if you breathe in the same town as them they will chase you down).

      I decided to do some research and could find no scientific name for "Mahogany Wasp" but did find one forum with 80+ responses about how mean the "Red Wasp" (which is apparently more orange than red) is.

      So wondering if you have any experience or knowledge of any of this.

      Thank you for your time. :)

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    3. Sabine: I have heard the same rumors about Polistes carolina/perplexus, but I have spent very little time in the southeast U.S. and have never come across a nest of them. So, I cannot speak to that. I strongly suspect such assessments of their temperament are greatly exaggerated.

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  3. I live up in Old Town Maine and have now im sorry to say this but,killed five females in my house. My cats been stung twice.
    How do I get rid of them!
    Thank you. Dcw

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    1. You don't have to apologize, they are certainly not an endangered (or even protected) species. I do not give pest control advice for a variety of reasons. I even wrote a blog post explaining why (several months ago now).

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  4. I've never met a non aggressive wasp, but I was pulling weeds around my house with my 4-yr old, and 4" from our face the earth opened up with hundreds of these wasps appearing in a quarter second. I hit two off her arm as I ran, and never got stung. Any other wasp would have nailed our ass. They were so docile in fact, I chose to keep the nest. Neighbors have never been stung either. This huge nest is right below my deck underground near a retaining wall and I never knew it!

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    1. You are definitely describing a yellowjacket nest (Vespula sp.) rather than this paper wasp species. Not that it is not possible, but I have never seen a paper wasp nest in an underground situation....and certainly no colony with "hundreds" of wasps. That said, thank you for your tolerance and appreciation of wasps!

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  5. I believe I identified one of these guys just a couple minutes ago after it crawled in my ankle for a minute on A&M campus. It didn’t seem bothered when I flinched and brushed it off in reflex. Very docile and very cool looking!

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  6. Neat encounter! Sorry it took so long to "approve" your comment. I was away on vacation....We've been watching a nest of these at our new home, I'll have to do another blog post on that alone. Enjoy the upcoming holidays!

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  7. These wasps are very docile in my experience. My girls (as i call them) live by my plants in my storage shed. Last year one of them did not develop her wings completely & i would help her get around if she got lost, pick her up to put her in the flowers for nectar or help her to her area in the shed. The colony never minded my movements & got to know me. They absolutely watch to see who is around & who presents a danger or not. I find them to be very intelligent. The ones that are intensely aggressive in my experience are the full bodied red ones. Barely walking past those will incite a chase with a nasty sting.

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