What's That Bug? does not endorse extermination

Very large flying insect in compost pile
May 16, 2010
I first saw this bug when I was emptying yard trimmings onto the compost pile. Unfortunately I saw it too late that day and it got covered by the trimmings. It is very large 1 3/4 -2 inches with very bright orange bands on its abdomen? One thing I do remember was when I first saw it’s abdomen had bands of black hair/fur around the orange bands. With this siting It was crawling around on the ground about 10 feet from my compost pile. It now seems to be relatively smooth and if anything not as large as the previous time I saw it. Sorry for the photos all I had was my iphone… I have the good camera at the ready if I see it again.
Darin Davis
Austin, Central Texas, USA

Scarab Hunter Wasp

Moth or Fly?
May 16, 2010
I recently posted a request for ID with some rather poor photos. Got another chance at photography with better results. Previous post… first saw this bug when I was emptying yard trimmings onto the compost pile. Unfortunately I saw it too late that day and it got covered by the trimmings. It is very large 1 3/4 -2 inches with very bright orange bands on its abdomen? One thing I do remember was when I first saw it’s abdomen had bands of black hair/fur around the orange bands. With this siting It was crawling around on the ground about 10 feet from my compost pile. It now seems to be relatively smooth and if anything not as large as the previous time I saw it. Sorry for the photos all I had was my iphone… I have the good camera at the ready if I see it ag ain.
Darin Davis
Austin, Central Texas, USA

Scarab Hunter Wasp

Hi Darin,
We really want to thank you for going through the trouble to provide better images. Your first set would have made identification quite difficult if not impossible, though we knew by your written description that you probably had a Scarab Hunter Wasp in the genus Campsomeris, but we would not have ruled out a Digger Wasp in the genus Scolia. Your new photos will allow us to correctly identify it as the former, a Scarab Hunter Wasp in the genus Campsomeris, which takes nectar, according to BugGuide, and “Females provision nests with beetle larvae, esp. scarabs.
” If your compost pile is like ours, there are probably numerous Scarab Beetle Grubs in it so that is is a rich hunting ground for the female Scarab Hunter Wasp. BugGuide also indicates: “Eric Eaton has pointed out in comments under various photos of Scoliids that there is considerable taxonomic confusion in this family, so that has to be a caveat in any photo identified as to genus here. According to Nick Fensler: The females Campsomeris as well as other members of the subfamily Campsomerinae are predators on white grubs (Scarabaeidae), using these larvae as food for their young. Unlike sphecids, eumenines, and pompilids these wasps do not appear to have any type of prey transportation and dig to the ground-dwelling beetle larvae, sting it to paralyze it, and then lay an egg. They may dig around the grub to form a small cell. Since they use this nesting strategy they are often seen flying low to the ground (searching) in a figure eight pattern (but the flight pattern gets more erratic when they “smell” something). The adults use nectar as a food source and are common on flowers.” Unless there are future taxonomic changes, we would identify your wasp as Campsomeris ephippium based on BugGuide’s images, and all reports on BugGuide’s data page were from Texas.

A friend of mine already identified it as Campsomeris ephippium see below.  It sure is a big wasp!
Thanks,
Darin Davis

May 16, 2010
Dear Darin,
Your bug is what I thought it was from Margaret’s description. Campsomeris ephippium, a wasp in the family Scoliidae. This is a really cool insect and not at all common. I’ve only photographed one and it was so heavy that it made the flowers bend down when it was feeding. What you’re seeing is a female looking to lay her eggs on scarab beetle larvae. That’s what the babies eat. Your compost probably has some of those huge grubs of the Ox beetle and that’s what she’s after.
You probably don’t have to worry about the wasp stinging you, but don’t go playing with it or anything 😉 This is a solitary wasp and they are not nearly as territorial as the social ones. Here are some other pics/comments on the web:
http://bugguide.net/node/view/328454/bgimage
Thanks for getting some pics and sending them. It’s fun to see some unusual insects like this.
Val

Thanks Daniel for the information.  Yeah there has been more than one occasion that I have inadvertently squashed a Scarab Grub in the compost screen.  This is a rather impressive/large wasp.  I would say for me that its rather large size makes me less primordially fearful than of a smaller more fluidly moving wasp.  I don’t know why I typed that other than I thought it to be an interesting observation.  From what I see it is not all that common and from the lack of any Central Texas (Austin)  chatter on the internet it seems to be moving further north.
Thanks Again,
Darin Davis

What's That Bug? does not endorse extermination

4 Responses to Scarab Hunter Wasp

  1. dscintilla says:

    I just came across several holes in my yard and what appear to be the wasps above coming out of them. They look like wasps on steroids. My question is should I get rid of them or would they be helpful in ridding the yard of grubs? I live in southeastern VA. Thanks o much!

  2. mort says:

    why do some always think to destroy things they dont understand?
    they have a right to live. i hate spiders but thy dont harm and i dont harm them.

  3. Dan says:

    I think iv got one of these wasp. I live in New Zealand, Kaitaia. is this ment to be here??

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