Native to East Asia, elm zigzag sawfly (EZS) has invaded 34 countries across Asia, Europe, and North America. First detected in North America in 2020, EZS has since been found in 17 states and 4 Canadian provinces as of 2025. Rapid range expansion has been facilitated by parthenogenetic reproduction, strong flight ability, and a multivoltine lifecycle, coupled with potential human-mediated movement via plant trade and transport of cocoons on vehicles. EZS feeds nearly exclusively on elm foliage (Ulmus spp.), although feeding on a Zelkova sp. has now been observed in North America. Fourteen elm species are known to be susceptible to EZS, including 4 North American elms already decimated by Dutch elm disease and elm yellows. Basic ecology of EZS in North America is poorly known and the relationship between it and its hosts is not well understood, highlighting a need to collate the disparate information on its life history, population dynamics, and potential impacts of this species as it expands spatially across the continent.
Durinzi et al. (Thu,) studied this question.