Relationships between two species of insect pests and their natural enemies in tea gardens of three different altitudes
3种海拔高度茶园中2种害虫与其天敌间的数量和空间关系

To conserve and utilize natural enemies for comprehensive control of insect pests in tea gardens, the quantity and space framework of the green leafhopper (Empoasca vitis Gothe), citrus whitefly (Dialeurodes citri Ashmead) and their natural enemies in three different altitudes in Qianshan area, Anhui province were systematically studied using grey system analysis and ecological niche analysis. The results showed that the greatest values of the correlation degree, spatial niche overlaps index and spatial niche proportional similarity of natural enemies for Empoasca vitis (Gothe), respectively, were Tetragnatha maxillosa (Thorell) (0.9144), Tetragnatha maxillosa (Thorell) (0.5985) and Xysticus ephippiatus (Simon) (1.5290) in low-altitude tea garden; Theridion octomaculatum (Boes.et Str.) (0.8644), Xysticus ephippiatus (Simon) (0.5143) and Neoscona theisi (Walckenaer) (0.1990) in mid-altitude tea garden; Tetragnatha maxillosa (Thorell) (0.9693), Tetragnatha maxillosa (Thorell) (0.6564) and Neoscona theisi (Walckenaer) (2.2027) in high-altitude tea garden; whilst for Dialeurodes citri (Ashmead), they were, respectively, Theridion octomaculatum (Boes.et Str.) (0.8809), Theridion octomaculatum (Boes.et Str.) (0.5143) and Neoscona theisi (Walckenaer) (0.6316) in low-altitude tea garden; Xysticus ephippiatus (Simon) (0.8832), Xysticus ephippiatus (Simon) (0.4222) and Xysticus ephippiatus (Simon) (0.6929) in mid-altitude tea garden; Tetragnatha maxillosa (Thorell) (0.9518), Tetragnatha maxillosa (Thorell) (0.4807) and Clubiona reichini (Schenker) (1.6661) in high-altitude tea garden. In addition, our results also indicated that Empoasca vitis (Gothe), Dialeurodes citri (Ashmead) and Erigonidium graminicolum (Sundrall) were aggregated distribution, while Tetragnatha maxillosa (Thorell) was random distribution in three altitudes tea gardens. The synthetic ranking results indicated that the orders of main natural enemies of Empoasca vitis (Gothe) in tea gardens of three different altitudes were, respectively, Tetragnatha maxillosa (Thorell), Neoscona theisi (Walckenaer), Xysticus ephippiatus (Simon) in low-altitude tea garden; Theridion octomaculatum (Boes. et Str.), Tetragnatha maxillosa (Thorell), Xysticus ephippiatus (Simon) in mid-altitude tea garden; Tetragnatha maxillosa (Thorell), Neoscona theisi (Walckenaer), Erigonidium graminicolum (Sundrall) in high-altitude tea garden. Whilst the orders of main natural enemies of Dialeurodes citri (Ashmead), respectively, were Theridion octomaculatum (Boes. et Str.), Neoscona theisi (Walckenaer), Harmonia anyridis (Pallas) in low-altitude tea garden; Xysticus ephippiatus (Simon), Theridion octomaculatum (Boes. et Str.), Neoscona theisi (Walckenaer) in mid-altitude tea garden; Tetragnatha maxillosa (Thorell), Theridion octomaculatum (Boes. et Str.), Clubiona reichini (Schenker) in high-altitude tea garden. The quantity and space framework of the natural enemies above, were closely related to those of the main inse