Beet Leaf Miner

(Pegomyia hyosciami), also known in the USA as the spinach leaf miner, an insect of the family Muscidae and a dangerous beet pest. The ash-gray body is 6–8 mm long.

The beet leaf miner is widely distributed in Europe, North America, and Asia; it is found throughout the USSR except in the Far North. The insect causes great damage to sugar and garden beets and mangel-wurzels (feed beets), particularly in regions with damp climates. It is found on many wild plants of the families Chenopodiaceae, Solanaceae, and Compositae.

There are two to four generations per year. In the temperate zone first-generation flies appear in the second half of May, and second-generation flies in July. Between 40 and 100 eggs are deposited, usually on the underside of leaves. After hatching, the larvae enter the leaf parenchyma and form cavities as they feed. Bubble-like mines form around the larvae, and the leaves wither, yellow, and die. Plants damaged in early developmental stages—when the tops have furcated or one to two pairs of true leaves have formed—usually die. More developed plants produce small tubers with reduced sugar content.

Control measures include deep autumn plowing, destroying weeds and contaminated beet leaves when weeding, and treating fields with insecticides.