Although about 200 species of insects feed upon the beet, most of them are unimportant. Flea beetles are the most destructive pests. Bordeaux mixture is the best-known deterrent for these insects. Paris green and arsenate of lead may also be used as poisons for flea beetles.

327. Fungous Diseases

Leaf Spot (Cercospora beticola) is a destructive disease to sugar beets, but it seldom does much damage to the garden type. Potato scab (Oospora scabies) also attacks the various types of beets, and is often a serious disease of garden varieties. To secure roots free of the scab, seeds must be planted in soil free from the fungus. Rotation is necessary to escape this disease.