Plotnikov's Cross-grasshopper

Plotnikov's Cross-grasshopper (Dociostaurus plotnikovi) belongs to the order Orthoptera, family Acrididae. This insect is of medium size and displays significant color variability, ranging from grayish-brown to yellowish-green, which serves as camouflage in arid environments.

The adult insect features a distinct pattern on the pronotum resembling a light-colored cross, which provides the common name. Its body is slender, and well-developed wings enable high mobility for migration across large territories.

Nymphs undergo five instars, gradually increasing in size and developing adult characteristics. Early identification can be challenging due to physical similarities to other non-swarming or swarming locust species.

The primary habitat includes dry steppes and semi-desert regions. The insect prefers areas with sparse vegetation and well-heated soil, which are optimal conditions for egg development within the egg pods.

For accurate identification in the field, agronomists utilize sweep netting and visual inspection. Sexually mature females are larger than males and possess a robust ovipositor designed for laying eggs into dense soil.

This species is a typical phytophage with a broad diet. The pest causes significant damage to cereal crops such as wheat, barley, and oats, consuming both foliage and generative parts of the plants.

Besides cereals, it feeds on various grass species in pastures and hayfields. Large-scale outbreaks can lead to total defoliation of forage areas, significantly reducing their value for livestock production.

The pest is most dangerous during the crop vegetation period when young shoots are particularly vulnerable. High densities of grasshoppers can devastate significant portions of fields during early development stages.

The insect can also attack technical crops if they are adjacent to breeding hotspots. Damage to ears leads to thin grain and substantial yield losses, potentially causing the complete failure of the crop.

The damage typically manifests as uneven gnawing of leaf edges and total destruction of stems. With high population density, only coarse veins or bare stalks remain of the plants.

The life cycle of Plotnikov's Cross-grasshopper is univoltine (one generation per year). The insect overwinters exclusively in the egg stage, laid by the female in the soil during autumn within protective capsules known as pods.

In spring, once the soil warms up to optimal temperatures (usually in April-May), massive hatching of nymphs occurs. The timing of the new generation depends strictly on the local climatic conditions.

Nymph development lasts from 30 to 45 days, depending on temperature. During this period, the insects are highly voracious and move across the field in groups.

Fledging occurs in mid-summer, typically June or July. Adults become highly mobile, capable of long-distance flights, and feed actively in preparation for the reproductive phase.

Mating and egg-laying take place by late summer or early autumn. After reproduction, the adults die, and the eggs remain in the soil until the next season to restart the cycle.

The control strategy is based on population monitoring. Spring field surveys are essential to detect nymph hotspots and prevent their spread into neighboring agricultural crops.

Agrotechnical measures include deep autumn plowing. This destroys the egg pods by exposing them to the surface, where they succumb to freezing temperatures, solar radiation, or predation by birds.

Chemical control is the primary method once the economic injury level is reached. The application of broad-spectrum insecticides, such as pyrethroids or organophosphates, is most effective during early nymph stages.

• Strict crop rotation implementation.
• Elimination of weeds along field borders.
• Use of biological preparations based on entomopathogenic fungi.
• Timely treatment of pastures adjacent to cropping areas.

Monitoring efforts should include not only arable land but also abandoned fields, ravines, and dry pastures, where primary breeding sites for Plotnikov's Cross-grasshopper frequently form.