Written collaboratively by Adam J. Varenhorst, Patrick Wagner, and Philip Rozeboom.
The straw itch mite, also referred to as the hay itch mite or grain itch mite, Pyemotes tritici (Lagrèze-Fossot and Montané) (Trombidiformes: Pyemotidae), is found worldwide (Bowles et al. 2018). Straw itch mites are most commonly encountered when working with contaminated hay, straw, brome seed, or other stored small grains. After exposure to contaminated materials, it is common to develop multiple skin lesions that itch intensely (Mullen and Durden 2019). Nearly all cases reported to South Dakota State University Extension Entomologists are the result of working with contaminated hay. It’s important to note that there is no way to predict the presence of straw itch mite prior to purchasing hay.
