any beetle of the family Curculionidae that is harmful to beets. Such weevils are found primarily in the steppe and forest-steppe zones of Europe and in some regions of Asia. Four species constitute the most harmful beet pests.
Bothynoderes punctiventris has a gray body 10–16 mm long. It produces one generation per year. The beetles hibernate in the soil. Before the beets sprout, the weevils feed on wild plants of the family Chenopodiaceae; they then attack the beet fields. The adult beetles eat the cotyledons, chew through small stalks, and sometimes damage parts of the plant that have not pushed through the soil surface. The sprouts are thinned out, and entire fields are sometimes completely destroyed. The beetles are especially voracious in hot and dry weather. The larvae damage the beet’s root system. Young plants usually die; more developed plants lag behind in growth and wither, the tubers take on deformed shapes, and the weight and sugar content are reduced.
Bothynoderes foveicollis is 8–10 mm long and has a yellowish white body with indistinct black spots at the base, in the middle, and at the apexes of the elytra.
Tanymecus palliatus is 8–12 mm long and does not have developed wings. In addition to beets, it harms sunflowers, vegetables (including gourds), melons, legumes, tobacco, cotton, and many weed plants. One generation develops in two (more rarely, three) years. The beetles damage cultivated and wild plants, but the larvae do not damage cultivated plants.
Psalidium maxillosum is 6–10 mm long. The body is black or black-grayish brown and shiny; the wings are not developed. One generation develops in two years. The weevil damages up to 130 species of plants, in particular, beets. The beetles cause the primary damage; the larvae feed on the roots of various plants, mostly weeds.
Control measures include the use of cropping techniques to destroy weeds and promote good growth and development of the crop, trap ditches around old and new beet fields, preplanting treatment of seeds by combination seed treaters, and the spraying of fields with insecticides.
REFERENCEOsmolovskii, G. E., and N. V. Bondarenko. Entomologiia. Leningrad, 1973.
O. I. PETRUKHA