Red-Headed Gray Apple Aphid (Dysaphis Devecta)

Pest Type: Fruit Pest

Row: Equine – Homoptera

Family: aphids – Aphididae

It is found everywhere. Damages the apple tree.

Female 2 mm in size, broadly oval, almost spherical, from dark gray to dark green with a thick white powder; the head, antennae, legs, tubes, and tail are black; transverse dark stripes on the dorsal side of the abdomen.

A wingless parthenogenetic female up to 2 mm in size, olive pale yellow, rarely reddish-gray. Amphigone female – 1.6 mm, spindle-shaped, wingless, brown-green with black transverse stripes on the prothorax; coated with white powdery coating; antennae with 5 segments. Male – 1.5 mm, winged, dark brown with gray powder, with black transverse stripes on all segments of the abdomen. The egg is first light yellow, after 2-3 days – pale yellow.

Fertilized eggs hibernate under the backward scales of the bark of the trunks and skeletal branches. During budding, the larvae regenerate and colonize young leaves on the underside. Due to the nutrition of aphids, the edges of the leaves thicken, coarsen and twist, forming a hilly gal of red, pink or yellow. Before flowering, females appear that regenerate 50-70 larvae. The fertility of subsequent generations is reduced to 12-15 larvae. 3-4 generations develop during the season. In June, statenoscopes appear in aphid colonies, giving wingless females and winged males. After fertilization, the amphibole female lays 2-3 eggs, which remain until spring. During mass reproduction, aphids damage fruits, on the surface of which red spots form at the injection sites, which reduce the commercial quality of the fruits.

Measures to protect fruit trees from aphids. Cutting of root shoots and fatty shoots, especially intensively populated by aphids. With a population of more than 10-20 eggs per 10 cm of shoots, it is necessary for the pest breeding centers in early spring, before buds open, at a temperature not lower than +4 ° С, spraying – washing of ovicidal trees. If the aphid population density exceeds 5 colonies per 100 sheets, insecticide treatment is required. The regulated ratio of aphids and aphidophagous has one aphidophagous per 30 pest larvae. With this ratio, the use of affidavits is impractical.

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