By Blake Jackson
Winter grain mites, small black mites with orange legs, have emerged as a potential concern for Pennsylvania farmers growing small grains like rye, wheat, and triticale annually. These mites, typically found in Great Plains states, were rarely reported in Pennsylvania until recently.
John Tooker, an Extension entomologist, encountered winter grain mites for the first time four years ago in Chester County and again recently in Franklin County. Both instances involved dairy farms growing small grains for silage.
These cool-season pests become active in fall and suck the contents out of plant cells, causing leaves to turn silver and then brown. They are most active at night and hide during the day at the base of plants or in the soil. When summer arrives, they enter a dormant state underground until fall.
While mites lack wings and spread slowly, continuous small grain production can lead to population growth. Their winter activity allows them to escape most natural enemies.
While economic thresholds for winter grain mite damage haven't been established, some infestations in Franklin County appear severe. Due to wet conditions, spraying isn't currently an option. Tooker recommends scouting nearby fields to identify existing infestations for targeted control.
Scouting is crucial to control these pests effectively and avoid unnecessary spraying. Thankfully, some miticides are labeled for small grains, but label instructions must be followed carefully.
In the long run, crop rotation with soybeans, sorghum, or alfalfa can eliminate winter grain mites if populations and damage become persistent.
Photo Credit: gettyimages-brian-brown
Categories: Pennsylvania, Crops, Wheat