Beetroot Weevil

In the spring, beds and vegetable gardens are flooded with various insects, including beet weevil. The name fully reflects the gastronomic predilections of the insect. Beetles infect leaves, tops, and root system of beets. Homeowners are rarely interested in which order the pest belongs to. The most relevant questions are how to recognize beetroot weevil and how to deal with it.

What does a beet field pest look like?

Common beetroot weevil - beetle from a large family weevils. In some regions it is called a beetroot eater. Widely distributed throughout Europe and Central Asia. The sizes of adults reach 1.5 cm. A distinctive feature is an elongated thick rostrum. Elytra and sides densely covered with scales. Color is variable and depends on where the weevil lives. The vast majority of insects are gray with dark, almost black strokes.

Winter beet weevil in the soil at a depth of 20-25 cm at the sites of beet planting, in regions with more severe conditions can bury to a depth of 45 cm. With the onset of heat, when the ambient temperature reaches 8-10 ° C, the beetles come to the surface.

Interesting!

In 5-10% of the population, the wintering stage of development passes into diapause. Insects do not leave the lower layers of the soil and remain in them until the next year.

After wintering, the beetles are very mobile. Thanks to the developed paws, the gray beet weevil is able to overcome up to 300 m per day. Under favorable weather conditions, the years of weevils begin. They fly only on a hot day when the soil temperature exceeds 30 ° C. According to the observations of biologists, the peak of flight activity occurs at lunchtime. Beetles do not rise above 4 m above the surface; they overcome 500 m in one take-off, and several kilometers per day. Biology of the body structure and natural data help beet weevils migrate to beet fields and populate them in a short time.

The diet of beetles after wintering consists mainly of weeds. After the appearance of beet sprouts, insects begin to feed on young leaves. It is possible to determine that the beetle weevil is the culprit of the defeat, by specific notches at the edges of the leaves.

Interesting!

One adult beetle eats up to 15 g of green leaf mass, which is 100 times its own mass.

Pest propagation

The peak in flight activity coincides with the start of mating. In late May, early June, the female begins laying eggs on the soil. One female beet weevil lays from 20 to 200 embryos. Oviposition rate is determined by weather conditions and habitats.

Interesting!

Females lay the largest number of eggs on moderately warm days, which were preceded by small precipitation. The egg-laying period ends in July. After the female fulfilled her mission, she dies.

Embryos yellow oval 1.2 mm in length. In the soil are located no deeper than one centimeter. After 10-12 days, white legless larvae hatch from the embryos.The newborn individual has a small size - 1.5 mm. As they grow older, it increases to 13 mm.

What the larva eats depends on its age. Caterpillars are very mobile and quickly penetrate into the soil. Young individuals begin to eat the lateral processes of the roots at a depth of 15 cm. Older larvae deepen by 30-40 cm and are able to completely gnaw the central root. A group of several dozen larvae can be concentrated on one plant. The beet weevil in the photo and its larvae are presented below.

The larval stage lasts from 40 to 90 days, after which the larva burrows in the ground for pupation. After 12-28 days, a young beetle appears from the pupa. Most newly minted individuals remain living in the soil and come to the surface next spring.

What damage do insects do?

Beetroot weevil damages all types of beets, including fodder, table and sugar. The damage is noticeable even during the sprouting of crops, when the beetles starving after winter begin to gnaw on the leaf mass, gnaw on the stems. Larvae damage the root system, which leads to drying out of the testes and death of plants. The combination of actions of beetles and offspring leads to a decrease in beet yield.

Beet weevils also affect flowering plants from the family of purslane, amaranth, young shoots of oaks, maples.

How to deal with weevils

The fight against beet weevils in the infield begins even before the emergence of seedlings. Primary control measures come down to weed control in order to deprive beetles of an intermediate food base. To prevent the emergence and development of the population, it is necessary to carry out comprehensive measures:

1. Seed treatment before sowing.
2. Timely irrigation and loosening of the soil. Excess moisture is detrimental to weevil eggs.
3. Manual collection of beetles with a small number.
4. With severe infection, chemical soil treatment is allowed.
5. During egg laying, fertilize the soil with ammonia water.
6. Thorough cleaning of all plant debris and deep plowing.

Among folk methods, the organization of traps for beetles stands out. To do this, grooves with a depth of 25-30 cm and a width of 20-25 cm are dug in the soil around the beds with beets. Mini-wells with a depth of 30 cm are cultivated along the bottom of the grooves with an interval of several meters using a drill. Regularly, ditches and wells should be inspected manually to collect caught beet weevils.