Polyphagous Meadow Moth

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

The meadow moth lives everywhere, and most of all harm it causes in the north of the steppe zone and in the forest-steppe. Caterpillars of these dangerous parasites are incredibly polyphagous - they damage vegetation from 35 families. Corn, sunflowers, beets, as well as melons, legumes and a number of other crops are especially loved by meadow moths. On the territory of Russia, two generations develop per season, occasionally three, and in the southern regions, under favorable conditions, almost always three generations develop

Meet the pest

The size of the butterflies of this pest can range from 18 to 27 mm. Their light brown front wings are decorated with a light spot in the middle and a yellowish-brownish pattern of several stripes on the outer edges.

The eggs of meadow moths are flat-oval in shape and reach sizes from 0.8 to 1 mm. Their color is dull white, with a slight pearlescent tint.

Caterpillars of the first instar can initially be either colored in yellow-greenish shades or transparent, and subsequently their color can vary in the range from light grayish-greenish tones to dark ones, close to black. There are two yellow stripes on their backs, and shiny yellow lines can be seen on the sides. And the tiny body of harmful caterpillars is covered with bristle-like tubercles. By the end of their development, their length reaches 28 - 35 mm.

Pupae can be either light brown or straw yellow, and just before the butterflies emerge, they acquire a dark gray color. Their size is about 10 - 12 mm, and they are located in cylindrical cocoons located vertically in the upper soil layers, the width of which reaches 3 - 4 mm, and the length - from 20 to 70 mm. Outside, all the cocoons are carefully covered with soil lumps, and on their tops one can see silky holes intended for the exit of butterflies.

Caterpillars of the final stage of development overwinter in cocoons. When the soil warms up to twelve degrees in the spring at the depth of the cocoons of meadow moths, the pests immediately pupate. And the flight of butterflies starts most often in early May, when the temperature reaches fifteen to seventeen degrees. Depending on the meteorological conditions, the duration of their summer is from a month to two. Butterflies are most active before the sun rises, as well as when dusk falls. In the daytime, the parasites hide under the foliage of plants. On warm nights, they are very active in flying into the light. Their mobility also sharply increases with an increase in air temperature, and especially during a thunderstorm. Due to the increased activity, meadow moths are able to migrate over fairly substantial distances. Butterflies need additional nutrition in the form of drip-liquid moisture or sweet nectar.

When dry weather is established in females, the ovaries are often degraded, which in turn leads to their infertility. Their average fertility is about 120, and the maximum is about 800 eggs. The laying process lasts for females from five to fifteen days.

The duration of embryonic development of meadow moths takes from two to fifteen days. Voracious caterpillars eat the undersides of young leaves without damaging their upper skin and gnawing out juicy tissues. A little later, they begin to roughly nibble the leaves, braiding them with thick cobwebs. And at the stage of completion of nutrition, they can even damage fruits and juicy shoots with cuttings. Once fed, caterpillars immediately go deeper into the surface soil layer and weave cocoons there for subsequent pupation. Years of the second generation of butterflies are observed at the end of June and in July. When the weather is good, they lay eggs, and in July or August, wintering caterpillars already appear.

How to fight

In order to make the site unattractive for meadow moths, all weeds on it must be systematically destroyed. On areas densely populated with harmful caterpillars (in other words, if there are more than five individuals per square meter), deep fall plowing and soil disking are carried out.

If necessary, the use of approved insecticides is allowed. Spraying against meadow moths is carried out only if large clusters of gluttonous caterpillars are found.

Among biological products, Bitoxibacillin and Lepidocide have proven themselves best.

A lot of meadow moths and natural enemies. Tahini flies and horse parasites, as well as lacewing larvae, ladybugs and carnivorous ground beetles, contribute to the reduction of their numbers. Rooks and some other birds willingly eat butterflies.