Two-Spotted Spider Mite

Tetranychus urticae

Two-spotted spider mites on a leaf
Two-spotted spider mites on the underside of a leaf. Photo courtesy of Tracy Wootten, University of Delaware. Licensed under CC BY 3.0.
Two-spotted spider mites are tiny late-season pests of corn. They are most numerous in hot, dry weather.
Two-spotted spider mites are extremely small (1/50" in length). Females have two spots on either side of their body.
Two-spotted spider mites
Two-spotted spider mites. Photo courtesy of Frank Peairs, Colorado State University. Licensed under CC BY 3.0.
Two-spotted spider mites feed on the underside of leaves, giving it a burnt appearance and eventually kililing the leaf. In large numbers they can have a significant impact on yield
Some miticides are available to controlling spider mites, although they tend to develop resistance quickly. Control is difficult since the entire leaf area must be covered. Always read and follow all label instructions.
Spider mites have many natural predators which usually keep the population in check. Avoiding the use of broad-spectrum insecticides will protect these natural predators.