Sugar-beet weevil

Scientific Name: Bothynoderes punctiventris
Type of pest:  Pests of sugarbeet
Order: — Coleoptera
Family: — Curculionidae
 
Beetle is widespread in the central and eastern forest-steppe, as well as the northern part of the Steppe. Damaged beets, as well as seeds from the family of Chenopodiaceae.
The beetle has a size of 11 - 15 mm, black, densely covered with short scales of gray color; Overlapping at the top is rounded, in the middle of the overshall passes a black intermittent strip - lace.
Near the top of the top is a white hollow with a black border; crutches are austere.
In males, the two-legged segment of the anterior legs reaches the middle of the last segment, the female reaches the third; In the middle of the first and second abdominal rings there is a large fossa.
Egg oval, 1,2-1,4 mm, light yellow. The larva is light yellow, fleshy, arched curved, wrinkled, without legs, consists of 12 segments; brown head, the length of the adult larva is 27-30 mm.
Pupae has size 11 - 15 mm, elongated, neck, yellowish-white, with pronounced proboscis.
Pupae wintered in the soil, at a depth of 5 - 10 to 50 - 60 cm.
The output of beetles on the surface begins when the soil is warmed at a depth of 7 to 10 ° C in the first and second decades of April and lasts no less than 20 days.
Within a day they can go up to 200 meters. In cool weather, move to the east, south-east and south, in warm, sunny weather - to the west, north-west and north.
Beetles feed on weeds, from the family of loboda. Beetles begin to fly in 10 - 20 days after they reach the surface.
They are especially active in warm and sunny weather, at wind speeds of less than 5 m / s. Bulky summer takes place from 10 to 16 hours at an altitude of 5 - 10 meters. For a day they can fly up to 8-10 km.
In May, beetles become mature, paired and lay eggs in the surface layer of the soil at a depth of 0.3 to 1 cm, very close to the plants.
A hole with a lay egg causes the female to fall asleep and rams up. The laying of eggs lasts more than a month.
The fertility is 100 - 200 eggs. Embryonic development ends 6-10 days.

The first larvae appear in the second half of May, they are very mobile, move quickly in the ground and, finding the roots of beets, begin to eat them.
The development of larvae lasts an average of over 65 days (from 45 to 90), passing through this time of five centuries.
The full cycle of development from egg to the imago lasts from 65 to 148 days (an average of 85).
Sugar-beet weevil develops in one generation in all areas of residence. Damage is caused
beetles and larvae. Damage is especially dangerous in the early period of development of plants  The beetles eat cotyledons and genuine leaves, sprouting shoots, sometimes even before they leave the soil.
The feeding of beetles depends on the temperature of the air, rising sharply in dry and hot weather. Strongly damaged young plants die. During one's life, one beetle eats 13-14 g of green mass (one hundred times more than its own weight).
The larvae swallow at the root ulcers, which leads to a decrease in the weight and a decrease in the sugar content of the root crops.
Sugar-beet weevil outside beet crop rotations occurs in single copies.
Favorable for the development of the pest are Light, drained chernozems, air-permeable and quickly warmed spring soils than heavy clay, in which larvae and pupae massively die from illness.
In the cold and rainy years, the development of the pest is delayed, and before the winter, more larvae and pupae die from illness.
Sugar-beet weevil destroys their natural enemies: Poecilus, Bembidion, Pterostichus, Amaro, Agonum, Broscus, Ophonus, Platiderus, Calathus, Asaphidion; Tetramorium caespitum L., predatory mites.
Beetles feed on magpies, crows, rooks, jowls.
Protecting the seeds by insecticidal insecticides is used for protection.