Pest Type: Multi-Pest
Row: Lepidoptera – Lepidoptera
Family: Scoops – Noctuidae
It is widespread in Russia everywhere. From field crops, it damages flax, hemp, beets, sunflowers, potatoes, legumes and legumes, corn, etc.
Butterfly size 40 – 48 mm; the front wings are gray to violet-brown in color, with a silver spot in the form of the Greek letter “gamma”.
Egg 0.6 mm, with 36 – 38 radial ribs, watery white with a greenish tint. The caterpillar of the last stage is up to 40 mm, the color is greenish-yellow or green, also brownish-green with dark brown small spots and dark sides, on the upper side along the whole body there are eight longitudinal narrow strips.
Pupa 15–20 mm, dark brown, strongly elongated body with a large forked hook at the end with four smaller hooks. The pupa is located inside a translucent spider web cocoon. A pupa hibernates in the soil. In the Russian beet-growing zone, the years of butterflies of the first generation begin in mid-May.
Unlike other scoops, butterflies of the gamut scoops fly in the afternoon. Butterflies need nectar-fed flowers. Their fertility is quite variable. On average, the female lays 500 eggs, a maximum of up to 1400 eggs. Summer drought causes infertility of second-generation butterflies. The gamma scoop lays 1 to 6 eggs in one clutch on the underside of the leaves of weeds, as well as on the leaves of beets, flax, clover, sunflower, vetch, lupine, peas, potatoes, and vegetable cabbage crops.
Embryonic development at a relative humidity of at least 80% and a temperature of 20 – 30 ° C is completed in 3 to 7 days.
The caterpillars of the first and second stages are inactive but are able to release a silky thread and move down. When moving, the caterpillar of the gamma scoop bends loop-like. The development of caterpillars lasts 16-24 days, during which time they fade four times. Caterpillars of the last stage pupate on leaves or between shoots on plants, where they complete nutrition and development. The pupal stage lasts, depending on meteorological conditions, 7–13 days. The development cycle of one caterpillar in the summer is 26 – 44 days. In the steppe and forest-steppe zones of Russia, the gamma scoop develops in two generations per year.