Xue-Qin Wang1, Guang-Hua Wang1, Zeng-Rong Zhu1, Qi-Yi Tang1, Yang Hu2, Fei Qiao1,3, Kong Luen Heong1,4, Jia-An Cheng1. 1. State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, 310058, Hangzhou, China. 2. Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, 550006, Guiyang, China. 3. Institute of Biology, Guizhou Academy of Sciences, 550009, Guiyang, China. 4. Centre for Agricultural Biosciences International (CABI), South East Asia, Regional Centre, University Putra Malaysia, Serdang, Malaysia.
Abstract
BACKGROUND: Spiders are effective biological control agents in rice ecosystems, but the comparative study of predations among main spider species under field conditions has not been fully explored owing to a lack of practical methodology. In this study, more than 6000 spiders of dominant species were collected from subtropical rice ecosystems to compare their predations on Sogatella furcifera (Horváth) (white-backed planthopper, WBPH) using DNA-based gut content analysis. RESULTS: The positive rates for all spider taxa were closely related to prey densities, as well as their behaviors and niches. The relationships of positive rates to prey planthopper densities for Pardosa pseudoannulata (Böes. et Str.), Coleosoma octomaculata (Böes. et Str.), Tetragnatha maxillosa Thorell and Ummeliata insecticeps (Böes. et Str.) under field conditions could be described using saturated response curves. Quantitative comparisons of predations among the four spider species confirmed that P. pseudoannulata and C. octomaculata were more rapacious than U. insecticeps and T. maxillosa under field conditions. A comparison of ratio of spiders to WBPH and positive rates between fields revealed that biological control by spiders could be effectively integrated with variety resistance. CONCLUSION: Generalist spiders could follow up WBPH population timely, and assemblages of spiders coupled with variety resistance could effectively suppress WBPH population.
BACKGROUND: Spiders are effective biological control agents in rice ecosystems, but the comparative study of predations among main spider species under field conditions has not been fully explored owing to a lack of practical methodology. In this study, more than 6000 spiders of dominant species were collected from subtropical rice ecosystems to compare their predations on Sogatella furcifera (Horváth) (white-backed planthopper, WBPH) using DNA-based gut content analysis. RESULTS: The positive rates for all spider taxa were closely related to prey densities, as well as their behaviors and niches. The relationships of positive rates to prey planthopper densities for Pardosa pseudoannulata (Böes. et Str.), Coleosoma octomaculata (Böes. et Str.), Tetragnatha maxillosa Thorell and Ummeliata insecticeps (Böes. et Str.) under field conditions could be described using saturated response curves. Quantitative comparisons of predations among the four spider species confirmed that P. pseudoannulata and C. octomaculata were more rapacious than U. insecticeps and T. maxillosa under field conditions. A comparison of ratio of spiders to WBPH and positive rates between fields revealed that biological control by spiders could be effectively integrated with variety resistance. CONCLUSION: Generalist spiders could follow up WBPH population timely, and assemblages of spiders coupled with variety resistance could effectively suppress WBPH population.