Flour Mite

Flour Mite 

(Tyroglyphus farinae), an arthropod of the superfamily Tyroglyphoidea, or Acaroidea; a dangerous pest of grain and grain products. The oval body is 0.3–0.67 mm long and whitish; the head section and the legs are pinkish or reddish brown. The flour mite is found throughout the world on threshing floors and in haystacks, granaries, and food-storage places. It damages grain, flour, groats, oil cakes, all types of seeds, dried vegetables, fruits, mushrooms, dried and smoked meat, hay, and straw.

The female lays 20 to 30 eggs (when fed with wheat germ, up to 200 eggs). The developmental cycle includes a six-legged larva, an eight-legged nymph, a second nymph, and a sexually mature mite. If conditions are unfavorable, the first nymph may molt into a hypopus, which has an armor and is resistant to unfavorable external effects. The optimum temperature for the development of flour mites is 18°-22°C. It takes 26–52 days for one generation to develop. The flour mite cannot live in grain with a moisture content less than 13 percent or in flour with a moisture content of less than 12 percent. Products that are severely infested with flour mites become sticky, acquire a honey-like odor, and lose nutritional value. The flour mite is particularly harmful to seed grains, because it first eats the embryo.

KH. A. BRUDNAIA