Scorpion or not?
June 24, 2010
This bug was found at our campsite in the Davis Mountain State Park near Ft Davis, Texas. Pinchers and hard body suggest scorpion but the stinger and fore legs do not match any species I have searched, the bug was very aggressive as well. What is it?
West Texas Camper
Davis Mountain State Park. Ft Davis,Tx.

Giant Vinegaroon

Hi West Texas Camper,
This is a Giant Vinegaroon, Mastigoproctus giganteus, one of the Whipscorpions which are not true scorpions.  Unlike their stinging relatives, Giant Vinegaroons do not sting and have no venom.  They do secrete a concentrated acetic acid that smells like vinegar, hence the common name.  According to BugGuide:  “
The vinegaroon is nocturnal and has poor vision. The whiplike tail is used as a sensory organ, as is the first pair of legs, which is not used for walking. Although its tail in unable to sting, this creature can spray an acidic mist from a scent gland at the base of the tail when disturbed. The spray is 85% concentrated acetic acid/vinegar, hence the common name ‘Vinegaroon.’ The heavy pinching mouthparts (modified pedipalps) can also inflict a painful bite. Although very unlikely to attack humans, it can certainly defend itself if provoked.”  We have also seen the name Grampus used in literature regarding the Giant Vinegaroon.

Thank you Daniel. Your response is greatly appreciated. The Giant Vinegroon was quite a site for my 11 year old daughter, she was horrified when she saw it while roasting marshmallows around our camp fire. We did notice a vinegar smell in the air and just couldn’t place its origin. Thanks again!

2 Responses to Giant Vinegaroon

  1. Annie Miller says:

    I live in Artesia, New Mexico, southern part of NM, I found this bug in my house by the bathroom door, hallway. Do I need to be concerned that there will be more or this was just a fluke and it just happen to come in. I did have my sliding doors open that day.


    • bugman says:

      If you leave the doors open, things will come into the house, though we haven’t the prescient powers to determine how many or how often. In many parts of the world, Whipscorpions are tolerated indoors since they eat Cockroaches.

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