The trophic ecology of Bulimulus bonariensis (Rafinesque, 1833) snails in Florida citrus

Bulimulus bonariensis (Rafinesque) is an invasive terrestrial snail that has become a nuisance in Florida citrus production by clogging irrigation equipment, negatively impacting tree health. Few anecdotal reports from growers suggest that B. bonariensis is not consumed by many organisms, and B. bonariensis may feed on citrus bark and leaves, but the ecology of B. bonariensis in Florida citrus is unknown. Camera traps and Molecular Gut Content Analysis (MGCA) have become indispensable tools for elucidating trophic relationships, as they allow for thorough identification of predators and consumed species in field settings. In the presented studies, snails were monitored in camera traps within a commercial citrus grove in Indian River County, Florida and observed for predation events. Snails were also hand-collected, and had DNA fragments of isolated gut contents identified to species using nanopores, gel electrophoresis, PCR, and NCBI BLAST. No organisms were observed consuming snails but four earwigs were observed attacking snails on separate occasions, with no discernable cause. Collected snails primarily consumed weedy forbs and grasses such as Phyla nodiflora and Scoparia dulcis. Citrus made up less than 1% of the DNA found in the snails. Our data found a range of plants consumed and suggest that in commercial Florida citrus groves, B. bonariensis primarily consumes weeds, with very little feeding on citrus plant matter. Results are discussed in the context of ongoing integrated pest management efforts.