True velvet mites

Overview

Trombidium is a genus of small parasitic arachnids. It was formerly known as red velvet mites, but that name could easily have been allpied to several other genera in the family Trombidiidae. The name red velvet mites has been retired and the genus now has no officially recognized common name.

Trombidium is very widespread, occurring on every continent except Antarctica. It is most common in northern Europe and in North America. In the United States it is common east of the Great Plains and west of the Rocky Mountains, scattered and uncommon between. It is common in Minnesota. There are at least 35 living and 1 fossilized Trombidium species worldwide, at least three species in North America north of Mexico, and at least 1 species in Minnesota.

Adults are found in moist woods on vegetation, in forest litter, and on soil. They feed on other mites, primitive wingless insects, and eggs of insects and snails. Larvae are parasitic on insects, spiders, harvestmen, and scorpions. Some species live for several years, while other species live for just one year. The female scatters eggs on the surface of the soil. When the eggs hatch, the larvae search for a host to feed on.

Description

Trombidium are small arachnids but large mites. Adults are ⅛″ (3 mm to 4 mm) in length and oval to more or less rounded rectangular in shape. They are bright red and and densely covered with short, velvety hairs. This is the feature that gives the superfamily Trombidioidea its common name. Adults have four pairs of legs. Juveniles have just three pairs.

Distribution

Sources

24, 30, 82, 83.

Trombidium Fabricius, 1775 in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org. Accessed 4/18/2026.