Molecular analysis of three material types to reveal biodiversity of Joro spider (Trichonephila clavata) trophic interactions and web contents

Authors: Grabarczyk, Erin; QUEREJETA, MARINA - Universite De Tours; Tillman, Patricia - Glynn; WALLACE, REBEKAH - University Of Georgia; BARNES, BRITTANY - University Of Georgia; MEINECKE, COLTON - University Of Georgia; VILLARI, CATERINA - University Of Georgia; GANDHI, KAMAL - University Of Georgia; LAFOREST, JOSEPH - University Of Georgia; ELLIOTT, MATT - Department Of Natural Resources; SCHMIDT, JASON - University Of Georgia

Submitted to: Frontiers in Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2023
Publication Date: 7/18/2023
Citation: Grabarczyk, E.E., Querejeta, M., Tillman, P.G., Wallace, R.D., Barnes, B., Meinecke, C., Villari, C., Gandhi, K., Laforest, J., Elliott, M., Schmidt, J.M. 2023. Molecular analysis of three material types to reveal biodiversity of Joro spider (Trichonephila clavata) trophic interactions and web contents. Frontiers in Ecology and Evolution. 1:1177446.
DOI: https://doi.org/10.3389/fevo.2023.1177446

Interpretive Summary: Joro spiders (Trichonephila clavata) are native Japan, China, Korea, and Taiwan and were first detected in Georgia, USA during 2014. Scientists at USDA - ARS, University of Georgia, Georgia Department of Natural Resources, and Université de Tours are working together to determine if Joro spiders will have a negative impact on the environment. In this study, scientists used molecular tools to ask what insects the Joro spider eats by collecting materials from spider webs, fecal samples, and female guts. They found a variety of insects trapped in spider webs and in fecal samples. However, gut contents had lower amounts of insects.

Technical Abstract: Introduced species alter established trophic interactions and molecular analysis can resolve changes in community structure and associated foraging links. Joro spiders (Trichonephila clavata) were recently introduced to the United States and their range is rapidly increasing across the southeast. Here, we used molecular gut content analysis via DNA metabarcoding of fecal samples, prey remains from webs (eDNA), and dissected guts to compare diet composition and prey diversity of female Joro spiders (Trichonephila clavata) in the southeastern United States. Arthropod DNA was amplified from three material types using universal COI primers and sequenced with IIlumina MiSeq. Prey remains from webs had the highest diversity, richness, as well as the highest proportion of prey reads relative to Joro predator reads. Recovery of prey reads from fecal samples and dissected gut content was low and both were overwhelmed by Joro spider DNA. Although fecal samples and female guts had a similar high proportion of Joro spider reads, fecal samples had higher prey diversity and richness. Moreover, prey DNA was detected from fecal samples several days after capture from the field, which provides some of the first data to reveal gut retention time estimates using fecal samples for arthropods. Combined our results reveal a first glimpse at the complexity of trophic associations for an introduced web-building spider and viable novel material, prey remains from webs, as a valuable eDNA source for minimally disruptive estimates of biodiversity associated with web-building spiders.