The butterflies of the meadow membranous-winged creature are small insects, with a wingspan ranging from 18 to 26 mm and a body length from 10 to 22 mm. The forewings are painted in shades of gray with brown speckles of yellow and dark brown. The hind wings are colored in a dirty yellow shade with dark smooth stripes and spots. A yellow stripe runs along the outer edge of both the forewings and hind wings, additionally there is a fringe. When at rest, the butterflies fold their wings forming a triangular shape.
Weather conditions favorable for the development of butterflies include warm weather and sufficient summer rainfall. The optimal temperature for the flight of insects is 16-17°C. This creature is actively engaged in its activities during the night and evening.
The following classification is used to assess the activity level of butterfly flight:
- single level - less than 1 butterfly per 50 steps;
- low level - from 2 to 5 butterflies per 50 steps;
- medium level - from 6 to 50 butterflies per 50 steps;
- high level - 51 or more butterflies per 50 steps;
- massive level - the number of butterflies visually cannot be counted.
After mating, butterflies lay 2 to 20 eggs on plant residues and leaves of various crops.
Eggs can appear 6-9 days after emergence, usually on the underside of leaves, especially on immature weeds. They have a yellowish-white hue, a length of 0.8 to 1.0 mm, and a width of 0.4 to 0.5 mm. At a temperature of about 34.5 °C, the development process will take 2 days, while at 14 °C - up to 12 days. The ideal temperature for development is 24-30 °C.
At a temperature of +24 to +30°C, caterpillars will appear in 5-7 days. They prefer mixed food, including beets, legumes, cereals, corn, and rapeseed.
It is recommended to regularly monitor the development of the harmful organism and begin protective measures before reaching threshold planting densities of 15 individuals/m² for peas and perennial grasses, as well as 10-20 individuals/m² for cereals, corn, sunflower, and rapeseed.
Treatment of insects with insecticides is advisable at the early stages of caterpillar development. The sooner action is taken, the better the result. The effectiveness of combating fourth and fifth instar caterpillars, as well as butterflies and egg laying, significantly decreases.
