December, 2018

Pseudoscorpion

The pseudoscorpion is perhaps one of the best kept secrets in the beneficial arthropod camp. These tiny (about 3 mm long) predators are often very common in gardens, where they crawl about looking for insect eggs, larvae, aphids, and anything else small enough for them to subdue and eat. Some species enter houses and feast upon dust mites, clothes moth caterpillars, and booklice. Although fearsome to their prey, pseudoscorpions are so small that they are no threat to humans and, in fact, aren't even usually seen by them.

Like scorpions, pseudoscorpions are arachnids. They have eight legs and a pair of conspicuous palps, part of their mouth appendages, that form large grasping claws. They use these to catch their quarry but can also grab a leg of a fly or beetle and hitch a ride to a new location (this relationship is called phoresy). The only thing missing from the little guys is a long tail with a stinger. These tiny animals also mate just like their bigger cousins, with the male placing a sperm pack on the ground and nudging the female until she picks it up. Pseudoscorpions are very difficult to identify, even to family, as the characteristics that separate the different kinds are mostly microscopic.