Pest Type: Sugar Beet Pest
It is found everywhere. It is especially numerous in the western regions of Russia, in areas with high humidity. Damages beets.
The beetle is 1.2-1.8 mm in size, with a flat elongated body and an almost square pronotum, covered with a light thin fluff; color from black-brown to black; antennae are red or yellow, with a 3-member club. The egg is 0.4 mm in size, oval, white, shiny. Larva 2.5-3 mm, mother-of-pearl white, translucent, with a yellowish flat head, legs short with long claws, on the last segment of the abdomen there are two hook-shaped processes bent upwards, a criticized ejector below. Pupa 1.6–2 mm in size, white, translucent, on the anterior segment of the abdomen a pair of long, sharp processes.
Half-matured beetles hibernate under plant debris and in the soil at a depth of 10-15 cm in birch hills, in fields from under plantings, in roadside ditches, forest belts, and slopes of ravines. Early in the spring at a temperature of 3-5 ° C, beetles come to the surface. There have been cases of the awakening of beetles with access to the soil surface during the winter thaws. Sudden changes in temperature at this time lead to the mass death of beetles.
Left beetles feed on beetroots and weeds. Resettlement takes place in the evening and at night at an air temperature of 9-12 ° C, mass years at a temperature of 17-22 ° C. Beetles populate sugar beets during the emergence of seedlings. Early in spring, beetles stay on the surface, later hide in the soil, appearing only in cloudy weather and in the evening. Egg-laying lasts from the first half of May to August. The female lays eggs in the soil to a depth of 20-30 cm. Fertility is up to 50 eggs. Embryonic development lasts 5-7 days. The birth of larvae begins in May and lasts until the first decade of August. Larvae are concentrated in the upper layers of the soil at a depth of 5-7 cm, where the bulk of beetroots of the first year and testes are located.
As they develop, the larvae, eating small roots, go deep into the soil to 40-60 cm, and in dry weather even up to 80-90 cm. After 35-42 days they pupate. Pupa develops 11-13 days. Once again, beetles remain in the soil until autumn. In the second half of September and early October, beetles massively go to the surface of the soil, additionally feed and, with the onset of cold weather, go to wintering places. One generation per year is developing.
Beetroot beetles gnaw oval and round pits in the underground parts of beet seedlings, from shallow, shallow to deep. Sometimes they damage the leaves by gnawing small holes in them. This pest is especially dangerous in years with a cool and wet spring. In case of significant damage, the plants die, which leads to a thinning of crops. Even minor injuries to the pidsimyadol knee contribute to the development of a corned.
Beetroot is destroyed by some ground beetles, parasitic nematodes that develop in the abdomen of beetles, as well as bacterial and fungal diseases of larvae and pupae, especially in wet years.
Protective measures. Full digging of root crops and planting of sugar beets during harvesting; removal of residues after harvesting; deep autumnal plowing; spatial isolation of the new sowing of sugar beets from last year’s birch forests; fertilizer application;
Well-developed sugar beet ladders are less affected by beetroot damage. With a dangerous number of pests – 1.5-2.5 beetles per 1 dm3 of soil (in autumn) or 20 beetles per 1 meter of row or 300 beetles / m2, pre-sowing treatment of seeds with systemic insecticides is necessary.