Scoop-gamma: multi-eating parasitic insects

Scoop-gamma belongs to the widespread subspecies of the scoop and differs from the others in the characteristic golden pattern on the wings, the outlines of which resemble the letter “γ” (gamma). This insect is widespread throughout almost the entire territory of Russia, with the exception of only the coldest regions. What do representatives of this species look like and how harmful are they?

Description

Scoop-gamma, or metallovidka-gamma, belongs to the order Lepidoptera. This insect is characterized by a complete transformation cycle, the duration of which will depend on environmental conditions.
An adult is a medium-sized butterfly, the front wings of which are painted in gray, brown, violet-brown or brown, the hind wings have a gray-yellow color and a wide fringing at the edges. The wingspan is 40-47 mm. In the photo you can see that the adult gamma scoop on the front wings has a bright spot, the outlines of which are similar to the letter of the Greek alphabet - “γ”.

Egg

The eggs of the scoop-gamut are oval and small in size - about 0.6 mm. On their surface, radial ribs are visible, which can be from 36 to 38 pieces. The color of the egg is watery white with a greenish yellow tint.

Caterpillar

The caterpillar of the scoop-gamut has an oblong body of green or yellow-green color. In this case, small dark brown spots, yellow side lines and white stripes on the back can be observed on the body. In the area along which the yellow lines pass, there are spiracles; they have a yellow color and a black rim. The head on the sides is painted black.

The size of the caterpillar of the first age is not more than 24 mm. By the last age, her body size increases and can reach 40 mm.

Doll

The body of the scoop doll gamma has a dark brown color. Its size is from 15 to 20 mm. A flask-shaped cremaster with a large forked hook at the end and 4-6 smaller hooks located on the sides and on the dorsal side.

Life cycle

Scoop-gamma refers to heat-loving insects, and it is able to winter both at the adult stage and in the phase of a caterpillar or pupa. Years of butterflies occur throughout the entire warm season - it can begin in April and lasts until November. The optimal conditions for this process are the air temperature, which is in the range +20 ... 25 ° C. When the thermometer drops to + 17 ° C and below, the activity of the butterflies sharply decreases and underdevelopment of the sexual products is observed.
For one year, the female scoop-gamma is able to give 1-4 generations, which will depend on the climatic conditions of the region in which she lives. Fertility is also variable and depends on the climate and weather conditions in a particular year, and in one clutch there can be from 500 to 1500 eggs.

On a note! If the summer was especially arid, then the second generation butterflies become barren!

The female lays its eggs, as a rule, on the lower side of the leaves, two or 3-6 pieces.The host plant can be either weed grass or cultivated species such as sunflower, cabbage, beets, peas, turnips, potatoes, etc.

Development takes place as follows:

• In an egg, the embryo spends 3-7 days. Its normal development occurs when the relative humidity is at least 80%, and the temperature is in the range from +20 to 30 ° C. If it gets colder, then the process of embryonic development may be delayed.
• From the eggs go the tracks of the scoop-gamut, which are initially inactive. However, at the same time, they already have the ability to release silk thread, which allows them to go down without much effort. The caterpillar phase lasts from 16 to 24 days, is characterized by four-fold molting and is divided into five ages. Caterpillars of the second and third ages can tolerate a significant decrease in temperature, up to -12 ° C. At an older age, for their normal development and transition to the pupal phase, they need a much warmer climate - from +22 to 30 ° C.
• Pupation of caterpillars occurs in the summertime or in the fall, usually on the leaves or between the shoots of plants on which they previously fed and developed. On a warm summer day, the caterpillar of the scoop-gamma is located on the top of the plant or under the bent edge of the leaf and envelops itself in a cocoon of thin web. In autumn, when it is already cold, for pupation, insects descend into the surface soil layer, where they hide under plant debris. The pupal phase can take anywhere from six days to two weeks.
  

  On a note! At this stage of development, the gamma scoop is able to withstand very low winter air temperatures - around -18 ° C.

• Imagoes emerge from the pupae, and since their years have been going on for a rather long period of time, the output of generations may somewhat overlap each other.

On a note! The rapid increase in the population of this species of scoop is influenced not only by the warm climate and high humidity, but also by the conditions in which the wintering occurred - mild winters with stable snow cover are considered very favorable!

Nutrition and harmfulness

Scoop-gamma is a polyphagous pest, a wide polyphage that can feed on a huge number of different plants.

As a result, this insect damages crops such as:

• cereal cereals;
• berry;
• vegetable;
• fruit;
• technical;
• legumes;
• decorative;
• oilseeds;
• cruciferous;
• the vine

On a note! In total, about 177 species of plants damaged by the scoop-gamut are registered, which belong to 38 different families!

The caterpillars of the scoop gamma are harmful. They begin their nutrition on weed grass, but subsequently migrate to cultivated plants. Caterpillars roughly eat young shoots, succulent leaves, sometimes buds and even unripe fruits can be damaged.

After the invasion of young caterpillars by scoops, the leaf plates remain skeletonized. Older caterpillars leave holes in leaf blades and gnaw them around the edges. As a result, only the largest veins manage to survive, and the fleshy part of the leaf disappears.

Methods of struggle

In order to protect the planting from the scoop-gamut, it is recommended to carry out the following agricultural activities:

• after harvesting, it is mandatory to remove and destroy weed grass, in which the parasite usually hibernates;
• every year on the site to carry out deep autumn plowing;
• it is desirable to observe the early dates of sowing;
• do not forget about the treatment of seed and seedlings with insecticides.

Some gardeners use sticky traps to catch flying adults. You can also do this in the evening using an ordinary lamp - butterflies will fly into the light, after which they will remain to collect their hands.