Gall Mites

four-legged mites (Tetrapodili) of superfamily Arachnida, order Acarina.

Gall mites are very small (0.1-0.6 mm). They have only two front pairs of legs, and the two hind pairs are reduced. The trunk is divided into a short forward section covered by a scutellum and an elongated rear with a finely annulated covering. Its mouth organs are of the sucking type. There are no respiratory organs or eyes. Gall mites lay eggs out of which the larva, pupa, and adult mite develop. They live on plants by sucking the contents of cells. The mites cause various plant disorders, such as deformation of the tissues, curling and changes in color of the leaves, and abnormal branching of the shoots.

Many gall mites, especially those of the genus Eriophyes (pear mites, apple gall mites, plum gall mites, and so on), form various galls, inside of which the mites live and reproduce. About 150 species of gall mites are known in the USSR. Many cause damage to fruit, vineyard, and field and garden crops and also to forest vegetation; some carry viral diseases of plants. Methods of fighting gall mites are complicated by their hidden mode of life; systemic poisons are used in conjunction with agrotechnical measures.