The mites are barely visible, measuring about 0.2–0.8 millimeters; their great reproductive potential, small size, and high capacity for dispersal by wind make them difficult to control or avoid.

[1] The mites' reported hosts have included Anobium punctatum, the pink bollworm, Grapholita molesta, Tineola bisselliella, Apis cerana (Asiatic honey bee), periodical cicadas, and various pests of stored grain, as well as humans and their pets.

Outbreaks of attacks on humans in the United States have been attributed to fluctuations in the supply of both oak midge larvae and periodical cicada eggs.

Based on this information, a search was initiated and resulted in the discovery of Pyemotes herfsi preying on midge larvae in leaf galls on pin oak trees.

The United States Centers for Disease Control estimated that during an outbreak in August 2004, 54% of the population of Crawford County, Kansas, or about 19,000 people, suffered from its bites.

[14] Many reports of itch mite bites on people's necks, shoulders and chests appeared in the Washington metropolitan area in July 2021 after an emergence of Brood X of the periodical cicada had ended.

The rash that results from the bites is usually described as a red patch with a small blister in the center, most often found on the neck, face, arms, or upper torso.