Dolichothrombium sp.

Description: This is a large (1-3 mm) soft bodied, red mite. Their distended ovoid bodies are completely covered with a coat of fine red hairs, making them appear velvety. The front pair of eight legs is held forward much like antennae. Hidden between a pair of stout palps are the sharp mouth parts.

Habits: Although they appear to be sluggish, fluffy creatures, adult red velvet mites are actually voracious predators capable of attacking and consuming prey many times their size. Young red velvet mites are parasites on Orthoptera (grasshoppers, locusts and crickets), perhaps focussing on Pristoceuthophilus spp locally. Relatives of these mites are utilized as a biocontrol agent against locusts. Dolichothrombium probably spends most of its time in the litter of the forest floor.

Range and Habitat: Little is known of the range and habitat of this genus. Dolichothrombium spp. were captured at 22 of 29 sites on the Mt. Hood National Forest. All of the sites were forested, however stand age, plant community, elevation, and moisture levels varied significantly at these sites. The greatest number of specimens were collected in west side mature and naturally regenerating second growth stands.

Abundance: Common within appropriate habitat.

Ecological Role: Adults are voracious generalist predators on arthropods. Young are parasites on Orthoptera.

Indicator Value: Questionable. Presence may indicate the presence of Orthopteran prey base.

References: 3, 8