Molecular gut content analysis indicates the inter‐ and intra‐guild predation patterns of spiders in conventionally managed vegetable fields

• Published in: Ecology and evolution Vol. 11; no. 14; pp. 9543 - 9552
• Main Authors: Saqib, Hafiz Sohaib Ahmed, Liang, Pingping, You, Minsheng, Gurr, Geoff M.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.07.2021; John Wiley and Sons Inc; Wiley
• Subjects: Agricultural ecosystems; Arachnids; Araneae; Biological control; Brassica; Coexistence; community assembly; Community structure; Content analysis; Cropping systems; ecosystem services; Food resources; Foraging behavior; Genetic testing; Hunting; Insects; metabarcoding; Networks; niche partitioning; Original Research; Pests; Predation; Predator-prey interactions; Predators; Prey; Spiders; Structural analysis; Thermal cycling; trophic interactions; Trophic relationships; Vegetables; Visual observation; niche partitioning; metabarcoding; trophic interactions; community assembly; ecosystem services
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.7772

Inter‐ and intra‐guild interactions are important in the coexistence of predators and their prey, especially in highly disturbed vegetable cropping systems with sporadic food resources. Assessing the dietary range of a predator taxon characterized by diverse foraging behavior using conventional approaches, such as visual observation and conventional molecular approaches for prey detection, has serious logistical problems. In this study, we assessed the prey compositions and compare the dietary spectrum of a functionally diverge group of predators—spiders—to characterize their trophic interactions and assess biological control potential in Brassica vegetable fields. We used high‐throughput sequencing (HTS) and biotic interaction networks to precisely annotate the predation spectrum and highlight the predator–predator and predator–prey interactions. The prey taxa in the gut of all spider families were mainly enriched with insects (including dipterans, coleopterans, orthopterans, hemipterans, and lepidopterans) with lower proportions of arachnids (such as Araneae) along with a wide range of other prey factions. Despite the generalist foraging behavior of spiders, the community structure analysis and interaction networks highlighted the overrepresentation of particular prey taxa in the gut of each spider family, as well as showing the extent of interfamily predation by spiders. Identifying the diverse trophic niche proportions underpins the importance of spiders as predators of pests in highly disturbed agroecosystems. More specifically, combining HTS with advanced ecological community analysis reveals the preferences and biological control potential of particular spider taxa (such as Salticidae against lepidopterans and Pisauridae against dipterans), and so provides a valuable evidence base for targeted conservation biological control efforts in complex trophic networks. Inter‐ and intra‐guild interactions are important in the coexistence of predators and their prey, especially in highly disturbed vegetable cropping systems with sporadic food resources. In this study, we investigated the trophic interactions of a functionally diverge group of predators—spiders—to accomplish the ultimate goal, that is, the predation of spiders on major crop pests. Despite the generalist foraging behavior of spiders, the community structure analysis and interaction networks highlighted the overrepresentation of particular prey taxa in the gut of each spider family, as well as showed the intrafamily predation between different spiders. Identifying the diverse trophic niche proportions underpins the importance of spiders as predators of pests in highly disturbed agroecosystems.