title: Intraguild Predation Among Three Common Coccinellids (Coleoptera: Coccinellidae) in China: Detection Using DNA-Based Gut-Content Analysis.
abstract: The ubiquity of intraguild predation (IGP) has been widely recognized for predatory coccinellids (Coleoptera: Coccinellidae). In Chinese agroecosystems, three species (Coccinella septempunctata L., Harmonia axyridis (Pallas), and Propylea japonica (Thunberg)) are particularly common, but there is little information of interactions occurring between them. In no-choice laboratory feeding trials, differential directional predation was observed between species: C. septempunctata preyed on eggs of P. japonica more than H. axyridis and H. axyridis consumed eggs of C. septempunctata and P. japonica equally, whereas P. japonica had a very low predation rate on eggs of the other two species. In choice trials, C. septempunctata and P. japonica larvae preyed less on H. axyridis eggs than those of P. japonica and C. septempunctata, respectively, contrasting with H. axyridis larvae, which showed similar preference for both species. Species-specific primers were developed for each coccinellid and used to determine the relative frequency of prey consumption in the field. Prior to field-based analysis, primer specificity was confirmed and consumption of prey elicited a positive reaction success, and detection time varied between different predator-prey combinations. Predators were then collected from cotton agroecosystems and, interestingly, no DNA of C. septempunctata was found in P. japonica, but all other predator-prey combinations yielded positive documentation of IGP in the field, with the greatest rate of 9% of C. septempunctata testing positive for H. axyridis DNA. This study confirmed the frequency of IGP among three common coccinellids in Chinese agroecosystems and the likelihood for interference to the biological control services provided by these important natural enemies.
authors.affiliation: College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China (15652780936@163.com; 852003959@qq.com; 939289372@qq.com; jxxu@yzu.edu.cn).|State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China (yhlu@ippcaas.cn).
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China (15652780936@163.com; 852003959@qq.com; 939289372@qq.com; jxxu@yzu.edu.cn).|State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China (yhlu@ippcaas.cn).
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China (wdm872@sina.com).
authors.forename: Dongmei
authors.initials: D
authors.lastname: Wang
authors.affiliation: College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China (15652780936@163.com; 852003959@qq.com; 939289372@qq.com; jxxu@yzu.edu.cn).|State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China (yhlu@ippcaas.cn).
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China (15652780936@163.com; 852003959@qq.com; 939289372@qq.com; jxxu@yzu.edu.cn).
authors.forename: Jianxiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China (yhlu@ippcaas.cn).
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Entomology, University of Kentucky, Lexington, KY 40546-0091 (jharw2@uky.edu).
authors.forename: James D
authors.initials: JD
authors.lastname: Harwood
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D020387:Food Chain; D005766:Gastrointestinal Contents; D058865:Introduced Species; D007814:Larva / Q000502:physiology; D010063:Ovum / Q000502:physiology; D011235:Predatory Behavior; D017422:Sequence Analysis, DNA; D013045:Species Specificity
keywords: Gut-content analysis; biological control; generalist predator; intraguild predation; predation rate