Ecological Studies on Formica yessensis Forel, with Special Reference to Its Effectiveness as a Biological Control Agent of the Pine Caterpillar Moth in Korea

Two experiments of artificial colonization of Formica yessensis were conducted in several red pine stands of Gyeongsang-Na m-Do, Korea in 1972 and 1977. The ant easily established in forests growing 10 to 20-year-old red pine trees at a relatively high density but admitting sunlight to the forest floor, harbouring much bare grounds and long graminaceous grasses. The ant favours soils with much organic material and rather high moisture content but not wet excessively.