There are over 200 species of pseudoscorpions in North America. Although very common, they are only occasionally found indoors and then only a few at any given time. Pseudoscorpions may be found in any room in a home, although they are usually more common in relatively damp areas, such as laundry rooms, basements, and bathrooms. Despite their appearance, pseudoscorpions are harmless to people.

Identification
Pseudoscorpions, literally 'false scorpions', are small (most are about 1/5 inch long) and reddish or brown. They have oval, flattened bodies with two conspicuous pedipalps (pincer-like appendages). When they walk, they often appear crab-like. They can move as quickly backward as they move forward. Pseudoscorpions are a type of arachnid and are related to spiders, ticks, scorpions, and mites. Without their large pedipalps, pseudoscorpions look very much like ticks. Pseudoscorpions are also similar to scorpions but lack the long tail and stinger that is common to scorpions.

Life Cycle and Habits
Pseudoscorpions live in many different types of habitats, including forests, grasslands, sand dunes, and sea shores. They prefer to live in crevices and similar spaces and can be found in leaf litter, moss, under tree bark and stones, in bird and mammal nests, and in buildings. Many pseudoscorpions favor sites with high humidity, although some species can tolerate dry conditions. Although they are not commonly seen, pseudoscorpions can be quite abundant. Under favorable conditions, hundreds can be found within just one square yard.

These 'false scorpions' are predaceous, feeding on many types of small insects and other arthropods, including springtails, psocids (bark and book lice), thrips, beetles, flies, ants, and mites. Many aggressively stalk their prey while others prefer to ambush insects.

They generally have poor vision, usually possessing four eyes (some may have two eyes while others have none). They use sensory hairs on their pedipalps to sense when prey is nearby. When a small insect brushes against these sensory hairs, it triggers a reaction to seize the insect. Most pseudoscorpions have poison glands in their pincerlike claws which they use to paralyze prey. They inject a saliva into the victim; the pseudoscorpion feeds on the liquified contents.

Pseudoscorpions produce silk from glands on their chelicerae (mouthparts). They use silk to spin cocoons in which they overwinter and deposit molted exoskeletons. They also use silk to make sacs that protect their eggs.

When psuedoscorpions mate, they usually first engage in a complex courtship dance. After the female is fertilized, she carries her eggs in a sac attached to her abdomen. Once the young hatch, they remain on their mother obtaining nourishment for a short time before moving away on their own. There are usually no more than two dozen immature pseudoscorpions. They molt three times, taking one year or more to develop into adults. Pseudoscorpions usually live two to three years. There may be one or two generations in a year

Control
In nearly all cases, just a few pseudoscorpions are found indoors. Physical removal (i.e. remove by hand) is the only necessary control. If pseudoscorpions are relatively numerous, that indicates that an insect, such as springtails or psocids are also abundant. Control pseudoscorpions by drying out damp areas with fans or dehumidifiers to make the area less inviting for pseudoscorpions and their prey. Because pseudoscorpions are uncommon indoors and do not harm people, insecticides are not necessary or suggested.

E610P
Revised 12/99