关键词: 异色瓢虫, 成虫, 限域搜索行为, 摄食, 滨岸生态系统, 土壤有机碳, C3/C4草本植物, 碳稳定同位素

Abstract: The area-restricted searching behavior of both male and female imagoes of Harmonia axyridis is studied with methods developed by Nakamuta (1982).The total curved angle of searching trait of imagoes in 15 seconds after feeding is significantly larger than that in 15 secconds before feeding.Their food-searching efficiency is improved by frequent modification on search direction.The total distance between stops in 0～15, 15～30 and 30～45 seconds before feeding is significantly longer than that in 0～15, 15～30 and 30～45 seconds after feeding,respectively. The food-searching speed of imagoes in 0～15,15～30 and 30～45 seconds before feeding is 4～12 times quicker than that in 0～15, 15～30 and 30～45 seconds after feeding, which varies very little before feeding, but The longer the ime before the imagoes find the food,the quicker the searching speed is.The total rectilinear distance from food to stops is significantly longer and the searching area covered by the imagoes is 11～65 times larger before feeding than after feeding. It is believed that both male and female imagoes of Harmonia acyridis have area-restricted searching behavior.

Key words: Imagoes, Area-restricted searching behavior, Harmonia aryidis, Feeding, riparian ecosystem, soil organic carbon (SOC), C3/C4 herbaceous plants, stable carbon isotope