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The potential impact of an invasive pentastome parasite (Raillietiella orientalis) on North American pitvipers

Palmisano, Jenna N.

Farrell, Terence M.

Department of Biology

Stetson University

DeLand, Florida USA

Lind, Craig M.

Department of Natural Sciences and Mathematics

Stockton University

Galloway, New Jersey USA

Agugliaro, Joe

Department of Biological & Allied Health Sciences

Fairleigh Dickinson University

Madison, New Jersey USA

An emerging parasite from Southeast Asia, Raillietiella orientalis, has exploited at least 14 snake species native to Florida as hosts. All three pitviper genera (Agkistrodon, Crotalus, and Sistrurus) in Florida have been infected with this invasive pentastome parasite. Mature R. orientalis are hematophagous and reside in the lungs of snakes. Native snake species have higher infection intensities and larger adult pentastomes compared to snake species that share a native range with R. orientalis. Snakes with a co-evolutionary history with pentastomes may experience reduced pathogenic effects compared to naïve species. Sistrurus miliarius appears highly susceptible to infection and lacks a history with any pentastomid, including New World species. Approximately 70% of the Crotalus, Sistrurus, and Agkistrodon species in the USA also appear naïve to pentastome infection. The known intermediate hosts of R. orientalis in Florida include members of several genera of geographically widespread lizards and anurans, which help indicate the pitvipers at high risk of pentastome infection. We document several sites in Florida where pygmy rattlesnakes have undergone severe population declines after the arrival of R. orientalis. We will present the results of a simulation model designed to predict the effects of pentastome infection on female reproduction. As this pathogen spreads beyond peninsular Florida, it could present a threat to many pitviper species in the USA. Highly abundant synanthropic intermediate hosts, including cockroaches, treefrogs, and anoles, could assist the rapid range expansion of R. orientalis. Further efforts should be made to better characterize the threats posed by R. orientalis spread and infection in pitvipers.