What's That Beetle?: Unknown Metallic Green and Orange Beetle from Pacific Northwest is Pseudogaurotina cressoni

Beautiful metallic green and orange beetle
Location:  Southern Central Washington State, 2000 ft. elevation.
August 3, 2010 8:17 pm
Dear bugman,
My boys and I found this lovely beetle crawling across our deck this June. It’s a beautiful metallic, almost iridesent dark green with bright orange on it’s legs and abdomen. I placed a ruler next to it for an idea of it’s size.
I did some research and found that it might be a ”Ground Beetle” known as a Caterpillar Hunter, but none of the examples I found displays the bright orange this one does.
Just wondering if you know.
Thanks so much!
Curious Mom

Is it a Longhorned Borer Beetle? Yes, it is Pseudogaurotina cressoni

Dear Curious Mom,
This is one of the greatest challenges we have faced in a long long time.  First, this beetle is positively gorgeous and we are not certain where to begin to try to identify it, but we do not believe it is a Caterpillar Hunter.  Challenges like this make us lament that we do not have a strong science background.  We have to approach this from the eyes of artists who are generally not as structured as scientists.  Our gut instinct is that is must be a Longhorned Borer Beetle in the family Cerambycidae based on the antennae, including their position on the head, but we question that taxonomy.  We are going to post your letter as unidentified and it will be prominently featured on our homepage until we get an identification.  We will also elicit the assistance of Eric Eaton who we suspect will be able to nail a proper identification lickety split.

What is this Beetle?: Pseudogaurotina cressoni

We want to compliment you on the excellent photographs that should assist in the identification process.  The ruler for scale indicates that this is a large beetle, which makes it all the more confusing that we cannot recall ever seeing anything remotely similar in appearance.

Mystery Beetle from Washington is Pseudogaurotina cressoni

Eric Eaton responds
Your family ID is totally correct:  Cerambycidae.  Looks to me like a species of Gaurotes, but I don’t know which ones occur there in the Pacific Northwest.  I sold my reference to the beetles of that region, and my books on U.S. beetles in general are on loan to a friend.
Oooh, have the person send the images over to Bugguide.  That way one of our longhorned beetle experts can address it.  Might well be a new species for the guide.  Thanks.

One of our readers who frequently assists with difficult beetle identifications, mardikavana, has confirmed our original suspicion that this beauty is a Longhorned Borer Beetle in the family Cerambycidae, more specifically
Pseudogaurotina cressoni.  BugGuide does have a page on this species, but there is not much information on it.  The Insects of Alberta website indicates that it is found in June and it feeds on pollen.

Thank you so much! My boys were thrilled to find out that it is a pollen eater, they weren’t too fond of the idea of it out there eating caterpillars. They loved seeing the pics posted on the site too and I am happy to know what it is. We have a variety of the longhorn beetles around here, but I have never seen one as beautiful as this one.
Thanks again for the wonderful educational service you provide! Your information on house centipedes kept me from having a small heart attack when I found several of them on my deck 🙂
Curious Mom

Hi Again Curious Mom,
We heard back from Eric Eaton who has requested that you also submit your photo to BugGuide.

I would be glad to.

Another Update from Eric Eaton
August 5, 2010
I’m really not sure, but the main way I usually tell the two apart is that Gaurotes has smooth, shiny elytra (wing covers), whereas Pseudogaurotina has textured elytra that are consequently slightly duller in color.  Bugguide experts on Cerambycidae should know more.

14 thoughts on “What's That Beetle?: Unknown Metallic Green and Orange Beetle from Pacific Northwest is Pseudogaurotina cressoni”

    • Thanks voltron7. We have gotten a second opinion and we have posted the correct identity. Thanks so much for your assistance.

  1. I’m glad to read that you see that it is a longhorn despite this creature’s unusual appearance. Those kind of antennae are unique to cerambycidae. This is Gaurotes cyanipennis. Imagos are found mainly on flowers.

    • Thanks so much mardikavana. Getting a compliment from you just made our day. We will now link to additional information on this gorgeous specimen.

  2. Dear Bugman,

    Sorry, but I must disagree mardikavana.
    I still think Curious Mom’s images look different than the Gaurotes cyanipennis and still think it looks more like Pseudogaurotina cressoni. The legs are 2 toned black and orange and the antennae are black. The Pseudogaurotina cressoni images show all orange legs and orange antennae, too. Actually, I can’t find an image of Gaurotes that matches the submitted images.

  3. I’m now rather curios. What is the main difference between genus gaurotes and Pseudogaurotina? As I see they were in the same genus some time ago. Could you please ask Eric Eaton.

  4. Beautiful metallic green and orange
    Location: Bilston, West midlands, UK
    20th May 2012
    Dear bugman,
    I was in my in-laws garden yesterday afternoon and sw this bug on a nettle. Have never seen anything like this before and it was the same size as a ladybird. I was wondering if you knew what this bug is and what you know about it.
    Thank you

  5. I’m in Moundsville WV, clear across the US and I found this exact beetle just now. It is quite pretty and this one played opossum when I picked it up. It finally woke up and I switched hands and it did it again. Is this a trait of this beetle or did I just get a scardy cat beetle.

    • The beetle in question is a West Coast species, however, a similar looking relative in the same genus, Pseudogaurotina abdominalis, is reported on BugGuide from Ontario and Quebec.

  6. 313D9FAB-CE6A-4ABB-BE66-CC25A79A615F.JPG
    My cousin and I were at the bird banding/mist netting site run by Pt Blue, formerly PRBO, on May 31, 2017 and one of our seven year old grandchildren spotted the same insect. The site is near Bolinas California. We were delighted to read all the notes on it. We are wondering if it has been spotted this far south before. It is soooo beautiful.


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