关键词: 步甲, 桃园, 桃李间作, 群落组成, 营养级, 捕食能力

Abstract: 【Objective】 There are many plum-peach intercropping or neighboring orchards in many regions in China due to their similar ecological environments. The experiment was carried out to clarify the effect of plum-peach intercropping on trophic structure of ground beetles, and to assess whether plum-peach intercropping is beneficial to pest control. 【Methods】 Ground beetles were investigated with pitfall trapping method in three mono-peach orchards and three plum-peach intercropping orchards in Linfen, Shanxi from April to October in 2006 and 2007, of which each experimental orchard is about 0.3 hm². The Carabidae species richness was compared between the two kinds of orchards. For the six dominant Carabidae species determined, two different species in combination were placed in one glass bottle with 10 beet webworms as food, and the bottles were placed under peach trees. The results of beetle attacking recorded from these bottles were used to determine the trophic level of Carabidae species. The relative abundances of carabids from each trophic level were compared between the two kinds of orchards. 【Results】 The 24 species of ground beetles were found, and the number of species showed no significant difference between in mono-peach orchard and in plum-peach intercropping orchard (P≥0.38). In addition, the six dominant species could be classified into four trophic levels: Lesticus magnus (Motschulsky) belongs to the senior predator, Scarites acutides Chaudoir the intermediate predator, Chlaenius bioculatus Chaudoir and Calathus halensis (Schaller) junior predators, and Harpalus tschiliensis Schauberger and Harpalus griseus (Panzer) herbivores. The relative abundance of carabids at different trophic levels was higher in plumpeach intercropping orchard than in mono-peach orchard. The results of T test showed that extremely significant difference (P≤0.002) and significant difference (P=0.013) in relative abundances of herbivores and junior predators existed between the two kinds of peach orchards in 2006, respectively, but no significant difference (P≥0.085) in relative abundance existed in carabids of other trophic levels in the surveyed two years. 【Conclusion】 It is concluded that plum-peach intercropping has no effect on the species component and richness of the ground beetles in the plum-peach intercropping orchard, but has some effects on population relative abundance of different trophic levels in the ground beetles. In general, plum-peach intercropping has significant effects on carabid abundance at different trophic levels of herbivores, but has no significant effect on carabid abundance at most trophic levels of predators.

Key words: Carabids, peach orchard, plum-peach intercropping, community composition, trophic level, preying ability