Fall armyworms have been found in fields in Kagoshima Prefecture, the first discovery of the exotic invasive pest in the country, according to the agriculture ministry.
In order to prevent the spread of the insect, a type of moth that causes damage to corn and other crops, the ministry will spray agricultural chemicals and examine the situation nationwide.
Fall armyworm larvae were found on July 3 in a field in Minamikyushu, Kagoshima Prefecture. By Monday, larvae were found in a total of 53 fields growing field and sweet corn in the prefecture.
Eating corn and other crops containing the insect is not harmful to humans.
The moths can fly long distances, and the larvae can eat away crops such as corn, rice, tomatoes, eggplants and potatoes.
Damage to crops caused by fall armyworms has been confirmed in many parts of the world, including Africa, the Americas, India and China.
In June, damage was reported in South Korea and Taiwan.
The ministry has announced a list of effective pesticides and launched subsidies to support their purchase and other costs.