Mantid expansion into North American salt marshes

Abstract

Mantids are influential generalist predators in terrestrial systems. Therefore, large mantid species like the European mantid, Mantis religiosa (Linnaeus, 1758), are often used by humans and purposefully introduced as a form of biocontrol, greatly expanding their geographic ranges. However, mantids are rarely recorded in marine systems. In this study, we present an observation of European mantids living in a salt marsh and actively moulting in the vegetation in Elkhorn Slough, in Monterey Bay, California, United States of America. Not only are these European mantids a nonnative species, but every observed individual was a flightless juvenile, meaning they hatched nearby. Although mantids are not usually associated with intertidal ecosystems, there are multiple potential reasons that mantids would be drawn to salt marshes, including food, potential for camouflage, and lower predation pressure. The addition of a generalist predator could produce a complex mix of positive and negative impacts on the marsh itself and, given the importance of marsh systems, these possible effects warrant further study.