Nondescript Leafy Alfalfa Elephant

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

The leafy alfalfa elephant is especially widespread in the forest-steppe zone, and in the steppe it is slightly less common. This pest is extremely polyphagous: it eats over eighty plant species from as many as nineteen families. Leafy alfalfa elephants give particular preference to alfalfa, clover, sainfoin, melilot and other legumes. To a large extent, they harm gooseberries with currants, as well as grapevines, hops, sugar beets, etc

Meet the pest

The leafy alfalfa elephant is a tiny beetle ranging in size from 10 to 12 mm, endowed with a rather thick, short and widened rostrum closer to the end. The convex elytra of gluttonous parasites are distinguished by their ovoid shape - closer to the tips they are narrowed and slightly pointed. On the sides of the breasts and along the seams, the elytra are partially fused, and their shoulders are slightly rounded. The color of both the elytra and the prothorax of the pests is quite variable and is characterized by the predominance of small specks, on which numerous scales are rather densely located. And the wings of harmful parasites are absent. By the way, the males of this species, oddly enough, are unknown.

Eggs of pests reach 1 mm in size and are characterized by a small pebbled structure and an oval shape. Initially, they are painted in milky white tones, and a little later they become dark yellow. Yellowish-white legless and curved larvae grow in length up to 16 - 20 mm, and their bodies are equipped with spiny hairs partially forming transverse rows on segments. The size of the pupae is about 8 - 12 mm; all of them are painted in yellowish tones and have four spine-like outgrowths on their heads.

Both bugs and larvae overwinter at a depth of twenty to sixty centimeters in the soil. When, with the onset of spring, the soil warms up to four to five degrees, harmful bugs wake up, but for some time they hide under the remains of plants or in the upper soil layer. The parasites begin active movement only after the thermometer rises to eight degrees. As a rule, in the forest-steppe, this occurs closer to the second half of April. Beetles feed mainly in the evenings and at night, and their food is all kinds of plants, particles of leaves and young stems.

Approximately at the end of April and at the beginning of May, when the average daily air temperature reaches twelve to thirteen degrees or more, the egg-laying process starts in beetles. Mass egg-laying usually occurs from mid-May to June. Eggs are laid by females in the soil near melilot, alfalfa and other legumes. If the soil is dense enough, then the depth of the eggs is about two to five centimeters, and with loose soil, it increases to ten centimeters. The total fertility of females reaches three hundred to four hundred, and sometimes even nine hundred eggs.

The embryonic development of pests is within ten to thirty days. The larvae hatching from eggs first feed on various plants, causing serious damage to them, and then pupate (approximately in May-June). Pupae develop within 21 to 28 days. And the bugs that hatched in June-July do not come to the surface, but continue to stay in the soil until next spring. The full life cycle of leafy alfalfa elephants is completed within two years, although in extremely rare cases this period can increase to three years.

How to fight

The most important protective measure against leafy alfalfa elephants is following crop rotation rules. Legumes are returned to their former sites no earlier than after four to five years. Between crops of various perennials, a distance of half a kilometer should be observed. And in fodder crop rotations, it is recommended to grow a variety of legumes no longer than three years.

Insecticides are used if, at the stage of alfalfa regrowth, from three to six bugs begin to fall on each square meter of crops. Such preparations as Aktellik, Votekst and Agria have proven themselves well in the fight against leafy alfalfa elephants.