Long-whisked Blue Linen Flea

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

The blue flax flea is ubiquitous and, in addition to flax, often affects beets. The main harm is caused by larvae and adults. The larvae actively damage the roots, which contributes to the growth retardation of crops and their diseases. In the spring, adults gnaw small pits on the cotyledon leaves and actively eat the edges of these leaves. Sometimes they can damage the cotyledons with growth points, thereby provoking the death of seedlings. Such damage contributes to a decrease in the number of bolls and seeds, as well as a decrease in the length of the stalks. And the activity of the new generation of adults provokes a deterioration in the quality of the fiber, since they scrape off part of the parenchyma of the stems and the delicate skin

Meet the pest

The blue flax flea is a small bug measuring 1.5 to 2 mm. From above, it is painted in black and green tones, a little less often in bronze or blue. The elytra and pronotum of the dangerous pest are densely covered with barely noticeable small dots. His legs are yellowish, and the thighs of the hind legs are characterized by a yellowish color.

Oval eggs of blue linseed flea beetles reach 0.5-0.6 mm in size. They are usually painted bright yellow. The worm-like slender larvae, growing up to 4 - 5 mm in length, have a milky white color and are distinguished by a bright yellow head. And their abdominal segments do not have a clear separation.

Wintering of adults takes place under the remains of plants. They begin to get out approximately in April and immediately start feeding on various plants - on cabbage crops, on cereals, on beets, etc. And as soon as tiny flax seedlings hatch, harmful parasites will get over them in the shortest possible time. They are most active on sunny warm days. And a little later after the settling of flax, the pests mate and lay eggs.

As a rule, females place eggs one at a time or in small groups (two or three each) on the main and lateral roots of growing crops in the surface layer of the soil. The total fertility of females on average reaches three hundred eggs. After about 11 - 25 days, larvae will begin to appear, feeding on tiny flax roots for 26 - 29 days, which in turn contributes to the penetration of various fungal parasites through the roots and noticeably retards the growth of crops. And after completing their development, the voracious larvae move to the surface soil layer and pupate there. Seventeen to twenty days later, somewhere at the end of June, the emergence of the imago starts. Until the onset of August, they actively feed, and then, leaving the forage vegetation, they move to wintering places.

During the year, only one generation of blue flax flea bears has time to develop. Most often, these long-wattled pests can be found in Western Siberia and in the European part of Russia, as well as in the Caucasus.

How to fight

In order to prevent attacks by blue flax flea beetles, it is recommended to observe early and optimally short sowing dates - they will avoid the concentration of pests at later shoots. You should also systematically get rid of weeds, which are an excellent source of early nutrition for blue flax fleas. And early autumn plowing of flax contributes to a noticeable violation of the autumn feeding of long-wattled parasites and provokes their death even before they go to winter.

Pre-sowing treatment of flax seeds with Gamma-thiuram or Tigam also gives a good effect.

Insecticide treatments are started if, at the stage of mass migration of adults to flax stairs, their number is ten individuals per ten plants. Hexachlorane dust (12%) copes well with the task of getting rid of blue flax fleas. Treatments with this drug will be especially effective if they are carried out on the marginal stripes at the initial stage of parasite concentration.

As for the seedlings of fiber flax, if for every square meter of such crops there are eight to ten bugs, they begin to spray them with preparations "Karate" and "Decis extra".