Great green bush-cricket

Systematic position. The Great green bush-cricket (Tettigonia caudata) belongs to the order Orthoptera and the family Tettigoniidae. As a member of the Tettigonia genus, this insect is known for its size and vocal signals, but in agricultural landscapes, it can behave as a significant secondary pest depending on local population dynamics and environmental factors.

Biology and lifecycle. The species undergoes incomplete metamorphosis. It overwinters in the egg stage, which are laid in the upper layers of the soil. In spring, the nymphs emerge and undergo several molting stages, expanding their diet as they grow larger. By early summer, they reach the adult stage, becoming highly mobile and capable of flight, which facilitates their movement between wild grasslands and adjacent arable lands.

Crops and damage profile. These bush-crickets are polyphagous, meaning they feed on a variety of vegetation. While they are often predators of other insects, in the absence of prey, they turn to cultivated plants. The primary damage involves the chewing of leaf margins, stems, and reproductive parts of cereal crops, sunflowers, and maize. In severe infestations, the loss of foliage can retard plant development significantly.

Economic impact. The damage becomes economically significant during outbreak years, especially when drought forces them to leave desiccated pastures for irrigated fields. The direct consumption of plant material reduces biomass and yield. Furthermore, the physical damage created by their mandibles provides entry points for various phytopathogens, potentially leading to increased secondary disease pressure within the field.

Control measures. Integrated Pest Management (IPM) strategies for managing Tettigonia caudata include:

• Mechanical soil cultivation, especially deep autumn plowing to destroy egg clusters.
• Weed management in field margins and surroundings to eliminate refuge areas.
• Monitoring populations during the early nymph stages to determine the necessity of targeted insecticide application.
• Preserving natural habitat corridors to support populations of birds and spiders that predate on bush-crickets.