Brown wheat mites are metallic brown to black, and about the size of a period in ordinary newspaper print. Their legs are pale yellow, and their forelegs are distinctively longer than the other three pairs of legs. Female brown wheat mites lay two kinds of eggs on soil particles near infested plants which have very different biology. During the winter, females lay nearly spherical, cherry red eggs that hatch after a week or so of favorable, warm weather. As spring progresses, females begin to lay white eggs with a waxy coating and a ruffled cap that do not hatch until fall. The type of egg laid is determined by the environmental conditions experienced during female development, and no one female can lay both types of eggs.

Brown wheat mites pass the summer as diapausing (resting) white eggs in the soil. These eggs hatch in the fall as temperatures and moisture conditions become more favorable. The life cycle is short, and brown wheat mites can produce multiple generations over the winter, as environmental conditions permit. One or two generations can develop in the fall and another two or three generations in the spring. Brown wheat mite activity is highest in late fall and early spring, with populations usually peaking around mid-April. Outbreak potential is high because all adults are female, and each can produce 70 to 90 winter eggs in a three-week period, before later generation females begin laying the small, white, oversummering eggs. The mites feed mostly during the daytime, with activity on the plants reaching a peak about mid-afternoon. Unlike many other mites, they do not produce webbing. When disturbed, they run rapidly over leaf surfaces and drop to the ground. At night they crawl down into the soil. They can easily survive cold temperatures in the soil, but their populations can be dramatically reduced by a beating rain. The brown wheat mite has been most problematic during drought cycles in western Kansas. Even irrigated fields can be affected, although problems are typically more serious in dryland production. Although it is a perennial presence in wheat, damaging populations tend to occur where wheat is grown continuously, or where volunteer wheat was allowed to grow on summer fallow ground, as these conditions provide an uninterrupted food supply from year to year, facilitating population increase.

Brown wheat mite populations can be difficult to assess as mites quickly drop off plants if leaves are disturbed. The economic threshold is not well defined, but is estimated to be at least several hundred mites per foot of row in early spring. Concern is greater if plants are stressed or poorly tillered, or drought conditions impede the growth of wheat plants and allow damage to accumulate. Even when treatment is justified, plant recovery typically depends on subsequent rainfall. By late April, adults begin to lay the white, diapausing eggs and, once the white eggs outnumber the red, winter eggs, the population is in decline and chemical controls are usually not justified.