Relationships between Pentatomoidea insects and natural enemies spiders in ‘Baihaozao’ tea garden

Objective  To clarify the relationships of Stephanitis chinensis and Lygus lucorum with natural enemies in ‘Baihaozao’ tea garden.

Method  The population numbers of pests and natural enemies were investigated. The numerical, temporal and spatial relationships of natural enemies with S. chinensisand L. lucorum were studied using grey relational analysis and niche analysis.

Result  The major natural enemies of pests in ‘Baihaozao’ tea garden includedTetragnatha squamata, Tetragnatha maxillosa, Theridion octomaculatum, Clubiona japonicola, Neoscona theisi, Misumenops tricuspidatus, Erigonidium graminicolum and Oxyopes sertatus. The top four enemies showing close relationships with S. chinensis wereC. japonicola, O. sertatus, T. maxillosa and N. theisi in 2015, while C. japonicola, O. sertatus, E. graminicolum and N. theisi in 2016. The natural enemies ranking the first, second and fourth were the same in two years. The differential degree between the ranks of natural enemies in two years was 62.5%. The top four enemies showing close relationships with L. lucorum were T. maxillosa, M. tricuspidatus, T. squamata and T. octomaculatum in 2015, while M. tricuspidatus, N. theisi, T. maxillosa and E. graminicolum in 2016. Two of the four major enemies were the same in two years, but the order was different. The differential degree between the ranks of natural enemies in two years was 87.5%.

Conclusion  The changes in ranks of natural enemies possibly depend on the ratio of the number of pests to their natural enemies.