Cutworm

The cutworm (Feltia experta) belongs to the order Lepidoptera, family Noctuidae. It is a nocturnal pest, with adult moths having a wingspan of 40–45 mm and protective coloration in grayish-brown tones, allowing them to effectively camouflage against soil and vegetation.

Older larvae reach a length of 40–50 mm and have an earthy gray or brownish color with a lighter stripe along the back. The body of the caterpillar is dense, and when touched, it often curls into a tight ring, which is an important diagnostic feature of this species.

Larvae overwinter in the soil at a depth of up to 15–20 cm, where they pupate in the spring. The pupae are brown and have a shiny surface, located in special earthen cells constructed by the larvae before pupation.

Moth activity occurs primarily in the evening and at night, as they are nocturnal insects. A single female is highly fertile, laying several hundred eggs, predominantly on the underside of weed leaves or directly onto the soil surface.

The insect's development is directly dependent on temperature and soil moisture levels, with excessive soil moisture during the egg-laying period potentially reducing the survival rate of the clutches.

This pest is a polyphage and affects a wide range of agricultural crops. Vegetables, cereals, and many technical crops grown on an industrial scale are at significant risk of infestation.

The greatest damage is caused by early-stage larvae, which feed on leaves by skeletonizing them before moving on to the root part of the plants. Damage to the root collar is a critical threat to young seedlings.

Older larvae are capable of completely severing stems at the soil surface, leading to the death of entire plants. Seedling crops are particularly vulnerable during the first weeks after transplanting into open ground.

The pest is non-selective and can destroy sugar beet, sunflower, potato, and various cabbage varieties. Mass reproduction of the cutworm leads to thinning of crops and the need for costly replanting.

Root crops, such as carrots or beets, often rot at the points of injury when attacked by cutworms, rendering them unsuitable for long-term storage or commercial sale.

The cutworm life cycle typically includes one or two generations per year, depending on the region's climatic conditions. The emergence of larvae from hibernation coincides with soil temperatures rising above 8–10 degrees Celsius.

The active flight of first-generation moths is observed in late spring or early summer. Monitoring crops during this period using pheromone traps is essential to determine the pest population size.

The larvae pose the greatest danger in June and July, during the period of intensive crop growth. It is during this time that the pest feeds most actively to accumulate energy for further development.

A second generation of moths appears in late summer, laying eggs that produce the overwintering larvae. Late-season vegetable crops can be particularly affected by this generation.

Weather characterized by moderate temperatures and sufficient moisture is most favorable for the pest's development, whereas severe drought can somewhat suppress their activity.

The primary sign of crop infestation is the sudden wilting of individual plants against a background of otherwise healthy crops. Upon inspection of the stem base, characteristic damage such as gnawed sections or complete severance is visible.

The presence of abundant weeds in the field significantly increases the risk of cutworm appearance, as females prefer weedy areas for egg-laying. Initial infection hotspots are often field edges or uncultivated strips.

When excavating the soil around a dead plant, one can often find the larva hiding in the top layer of the ground during the day, emerging at night to feed. This is a primary indicator of the pest's presence.

• Presence of skeletonized leaves at the plant base.
• Wilting of young shoots in the morning hours.
• Damage and holes in the root collar.
• Soil disturbances where larvae create tunnels leading to the stem.

If "bald spots" of dried-up plants are observed in the field, it is necessary to immediately inspect the root zone to confirm cutworm activity.

Effective protection begins with quality agrotechnical practices, including deep autumn plowing. This disrupts the earthen cells and brings pupae to the surface, where they succumb to low temperatures and predators.

The eradication of weeds is a mandatory condition, as they serve as a food source for young larvae and sites for moth egg-laying. A field free of weeds is less attractive to the pest.

During periods of mass outbreaks, chemical treatments with systemic and contact-stomach insecticides are effective. It is important to spray in the evening when the larvae are most active on the soil surface.

Biological control methods include the use of entomophages, such as Trichogramma, which parasitizes cutworm eggs. This is an environmentally safe method that requires strict adherence to release schedules.

Constant monitoring using light traps allows for the timely detection of the beginning of moth flight and helps plan protection measures before mass larval hatching occurs.