Abstract
An outbreak of Locusta migratoria L. occurred in September 1986 on Mageshima Island (820ha) which is located 11km west of Tanegashima Island, Kagoshima Prefecture. Since then we have continued to observe the behavior of nymphs and adults on the island at least once a month. Marching, basking and hopper band of nymphs were observed from September to mid-Octorber. A large number of adults swarmed over the island, moving from one place to another and repeating feeding and resting repeatedly, until the end of November. Because we anticipated that the locusts might invade to Tanegashima Island where sugar cane has been extensively cultivated, 3 % fenitrothion dust was sprayed against the nymphs twice in Octorber and against the adults four times from December 1986 to January 1987.
