Rice grasshopper

The rice grasshopper (Oxya yezoensis) belongs to the order Orthoptera and the family Acrididae. It is a significant agricultural pest primarily found in East Asia, including regions of Russia, Japan, and China. This insect is well-adapted to the humid environments characteristic of rice paddy cultivation, which allows it to thrive in large numbers.

The primary host for Oxya yezoensis is cultivated rice (Oryza sativa). However, the pest is known to feed on various aquatic grasses, reeds, and occasionally nearby soy crops if the ecological conditions allow. Its ability to utilize various grasses as food sources ensures the persistence of the population throughout the growing season.

The life cycle of the rice grasshopper is typically univoltine, meaning there is one generation per year. The species overwinters in the egg stage, with eggs deposited in the soil along embankments, levees, or fields with dense vegetation. Larvae emerge in the spring, undergoing five nymphal instars before reaching the adult stage, when feeding intensity peaks.

The damage caused by these insects is characterized by significant defoliation. Both nymphs and adults consume leaf tissues, leaving behind ragged margins and reducing the leaf area available for photosynthesis. In cases of severe infestations, the cumulative damage can drastically reduce grain yield and weaken the structural integrity of the rice stalks.

Integrated Pest Management (IPM) is the most effective approach to control this pest. Key strategies include:

• Maintaining field hygiene by removing weeds on levees.
• Deep plowing of field edges to destroy overwintering eggs.
• Strategic application of approved insecticides during the early nymphal stages.