Pseudoscorpions on fly legs

Title Info
Common name Pseudoscorpion; Fly
Scientific name Pseudoscorpiones; Diptera
Taxonomic group Arachnida; Insecta
Level OrderOrder
Source Dan L. Perlman
Ecological interactions Commensalism
Organisms Animals
Animals Arachnids
Date July 12, 1999
Location Monteverde,Costa Rica,North America

Pseudoscorpions hitching ride on a fly's leg, Costa Rica. Pseudoscorpions, tiny relatives of true scorpions, often engage in the practice of phoresy, or hitchhiking. Ecologists still debate whether pseudoscorpions sometimes harm the organisms that carry them around, but many believe that the pseudoscorpions gain a ride without any real cost to their carriers. If so, this is a good example of a commensalism, a relationship in which one partner benefits and the other neither benefits nor is hurt. Pseudoscorpions are quite small (typically about 1/10 of an inch or 3 mm long) but are impressive predators. Although they do not have the stinger of a true scorpion, they have poison glands in their pincers and feed heavily on tiny arthropods such as mites and springtails.