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Spider Wasp: Entypus unifasciatus
Location:  North Middle Tennessee
August 3, 2010 8:32 pm
Hi Daniel,
I think I have an ID on this very busy wasp. I believe it is an ”Entypus unifasciatus” (no common name) It was in the grass and a brush pile. It would go beneath the grass and emerge several inches away, never still. A bit diffult to photograph, this is the best shot of three or four attempts. My very best wishes to you.
Richard

Spider Wasp

Hi Richard,
You have done a nice job of identifying your Spider Wasp,
Entypus unifasciatus.  BugGuide has a very informative page on this species which is reported to have a transcontinental range but for the Pacific Northwest.  The active behavior is a characteristic of the Spider Wasps in the family Pompilidae.  The females often rapidly dart about on the ground waving their antennae in search of spiders to feed to their progeny.  BugGuide describes the habitat as:  “Always in semi-open or open situations (“waste areas”, meadows, pastures, open woods and edges, desert, semi-arid grassland, etc.). Never found in deep woods.”  Of the life cycle, BugGuide explains:  “Parasitoid of spiders, including wolf spiders (Lycosidae). Prey records only exist for E. unifasciatus unifasciatus. They are known to prey on Pardosa riparia and Rabidosa rabida and “Females dig a burrow that ends in a terminal chamber off of the side of a mammal burrow or large crack in the ground. The serrations on the hind tibiae are used to aid the movement of soil out of the burrow entrance. The position in which the egg is laid is unknown. Larvae feed on one large spider and, as in all Pompilids that have one generation per year, overwinter as pupae.”  Though this is reported to be a common species with a transcontinental range, your letter is only the second posting we have of this species on our site.

What's That Bug? does not endorse extermination

2 Responses to Spider Wasp

  1. E. C. Dean says:

    I live in Grafton, WV and was doing laundry today when I looked outside and saw a blue wasp following a brown spider. Just before it got off the concrete the wasp jumped on him. After some back and forth struggle the wasp flipped the spider over and stung it. The wasp jumped off and the spider righted itself. At first there was a little motion but soon went still. I watched the wasp come back once but then flew away. As we speak the still paralyzed spider is out on the walk way. I’ve only seen this on animal shows and in some other part of the world. Is this normal in WV? I was completely facinating and showed my wife and kids. I just want to know if this is common for the area.

    • bugman says:

      Common is relative. We are curious why the Spider Wasp took the trouble to sting and paralyze a Spider and then not take it to the nest. We did a bit of research and we learned that the Blue-Black Spider Wasps in the genus Anoplius have a wide range in North America, and according to BugGuide, the female constructs a nest and then “Larvae are provisioned with wolf spiders, funnel web spiders. Many are generalists and will provision with nearly every common family of spider found in North America. … Most are fossorial ground nesters, although some will use borings in wood and other crevices.” We also learned that one species, Anoplius aethiops is only reported from Ohio and West Virginia, and according to BugGuide: “A. aethiops visits flowers while A. cleora RARELY does. Soil type is also significant. A. cleora is almost completely restricted to very sandy soil and A. aethiops is not. Note by Nick Fensler”

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