Pseudoscorpion, Vol. 5, No. 32
“My firewood is infested with baby scorpions! What should I do?” On rare occasions homeowners will become alarmed when they find what appear to be tiny scorpions in the house. Often these are in firewood that has been moved in preparation for the first cold snap, but pseudoscorpions also occur in other situations.
Pseudoscorpions are tiny arachnids that resemble scorpions except they do not have a tail or stinger, and they are completely harmless to humans. These little arachnids are common but go largely unnoticed because of their small size. Mature pseudoscorpions are only about ¼ inch long.
There are more than 3000 species of pseudoscorpions worldwide, with about 400 species living in the US. They live in a variety of habitats, including leaf litter, under rocks, under tree bark and in similar situations where they prey on small insects and mites. There is even one species, known as the book scorpion, that is found in and around old books, where it preys on the book lice and dust mites that live there. A stack of firewood with loose bark is good habitat for a variety of small insects and mites and makes a great hunting ground for pseudoscorpions.
Even though they do not have a stinger, many species of pseudoscorpions do produce venom, and this venom is deadly to the tiny insects and mites on which they prey. The venom glands are in the pinchers and there is a hollow venom tooth on the tip of the pincher(s) that is used to inject venom into prey. But fear not; this tooth is far too tiny to penetrate human skin.
One of the more interesting habits of pseudoscorpions is the way some species disperse to other habitats. They fly! These creatures do not have wings, so if they are going to fly, they must do so much like you would, by hitching a ride on something that can fly. You would use an airplane, but pseudoscorpions rely on flying insects for aerial transportation. They use their claws to grab an insect by the leg or antenna and hang on. Sometimes the arthropod they have chosen is something that can’t fly, like a daddy long legs, and then the pseudoscorpion is limited to ground transportation. Entomologists sometimes find pseudoscorpions hanging onto insects they capture when making collections.
Because of their small size and inconspicuous nature, pseudoscorpions are seldom featured in works of art, but there is at least one exception. Dr. Blair Sampson is a USDA Entomologist who spends some of his spare time drawing fanciful animal portraits that often include an insect or other arthropod. View some of his work. Look for the pseudoscorpions in Image #2.
Last Issue of the Year: This is the final issue of 2019, but Bug’s Eye View will emerge again next spring, sometime in March.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service. The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.
Mississippi State University is an equal opportunity institution.