Dozens of students at Claremont School in Oklahoma developed bite induced rashes after attending a September football game. The culprit is thought to be a mite, Pyemotes herfsi, that has been introduced to North America from Europe. The mite is a predator of multiple species of insects including midges in the Genus Contarinia. Contarinia forms “leaf roll galls” on the margins of oak leaves. An earlier outbreak of mites in Kansas was associated with these oak galls.
The mite is small and its bite is unremarkable. It’s saliva is more remarkable, containing a toxin capable of paralyzing an insect 4 orders of magnitude larger than the mite. The saliva can elicit a strong immune reaction in humans.
The mites can be carried in the air. A sticky trap under an infested tree can capture hundreds of mites. Under favorable wind conditions a football field downwind from infested trees can become a mite bite site.
*ALBERTO B. BROCE, LUDEK ZUREK, JAMES A. KALISCH, ROBERT BROWN, DAVID L. KEITH, DAVID GORDON, JANIS GOEDEKE, CAL WELBOURN, JOHN MOSER, RONALD OCHOA, EDUARDO AZZIZ-BAUMGARTNER, FUYUEN YIP, and JACOB WEBER. Pyemotes herfsi (Acari: Pyemotidae), a Mite New to North America as the Cause of Bite Outbreaks. Journal of Medical Entomology 2006 43 (3), 610-613