Tokyo cutworm

Taxonomic position and range. The Tokyo cutworm (Agrotis tokionis) belongs to the order Lepidoptera, family Noctuidae. It is a significant agricultural pest primarily found in East Asia, including Japan, Korea, and parts of China. Within the farming sector, it is recognized as a formidable member of the subterranean cutworm complex.

Host crops. This species is a polyphagous pest, meaning it feeds on a wide variety of plant hosts. It frequently attacks vegetable crops such as cabbage, potatoes, carrots, onions, and various root vegetables. Its ability to thrive on both wild weeds and cultivated plants allows it to sustain large populations in diverse agricultural environments.

Biology and life cycle. The life cycle involves four stages: egg, larva, pupa, and adult. The insect typically overwinters as a larva deep within the soil. As temperatures rise in spring, the larvae resume feeding and eventually pupate. Adult moths emerge later, mate, and lay eggs, leading to at least one or two generations per growing season depending on local climatic conditions.

Damage and severity. The larval stage is responsible for all crop damage. Being nocturnal, these larvae feed at night, cutting through the stems of young plants at the soil level or burrowing into the edible parts of roots and tubers. This activity often leads to total plant loss or significant decay of harvested vegetables, greatly reducing overall market quality.

Management strategies. Integrated Pest Management (IPM) is crucial for controlling Agrotis tokionis. Cultural practices, such as deep plowing in autumn, help expose larvae to predators and environmental stress. Weed management is also essential to reduce alternative food sources. Chemical control using soil-applied or systemic insecticides is recommended when population thresholds are exceeded.

• Deep soil cultivation in late autumn.
• Rigorous weed control throughout the season.
• Monitoring moth flights using pheromone traps.
• Strategic application of labeled chemical insecticides.