Name: Petrobia latens

Alias: The brown wheat mite is a tiny, spider-like insect that is about the size of the period at the end of this sentence. They usually feed on small grains, grasses and onions. Young wheat mites are a bright red or orange that slowly becomes dark brown as they mature. They overwinter in the soil and produce multiple generations throughout the year, especially in the fall and spring. They remain active all year, even through cold temperatures.

Crimes: Wheat mites punch and suck the leaf surface, causing little dots of dried, dead cells on the plant. They most often start to feed on the tip of the plant leaf. Fields with a serious wheat mite problem will have a stunted, scorched look.

Redeeming qualities: None.

Sentence: Proper irrigation can have an effect on populations. They seem to favor dry spells, and irrigation and rainfall have shown to reduce numbers of wheat mites. If controlling in wheat, you have a wide variety of options labeled to control wheat mites, such as Lorsban or Cobalt. Grandevo is a pesticide that is labeled for organic use. Most other options for other crops are suppressants, which can be a useful tool. Whenever you add a strong survival pressure to mites, they have a tendency to come back with a vengeance, because they can reproduce faster than their natural predators. This causes a need for a second spray, and thus the pesticide treadmill picks up speed. Spray only when you absolutely need to, and always read and follow the pesticide label.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-270-4031 or email jsagers@uidaho.edu.