Temperature Impacts on Mating and Oviposition of the Emerald Ash Borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)

Local temperatures can shape the ability of introduced species to flourish and disrupt novel environments. The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive beetle that threatens ash trees in North America and Europe. To assess the role of temperature on EAB reproduction, we reared groups of adult beetles at one of four temperatures (12°C, 15°C, 18°C, and 21°C) and measured reproductive success (laying fertilized eggs and egg hatching). There was no effect of rearing temperature on EAB female lifespans, but no eggs laid at 15°C or 18°C hatched, suggesting these temperatures disrupt the reproductive process of EAB. Females reared at 21°C, however, consistently laid eggs that hatched. We then used these results to assess the likelihood of reproductive success over a recent 10‐year period in eight cities in Canada that host EAB. All locations experienced temperatures of ≥ 21°C, but the number of hours and the number of days above this critical temperature were highly variable. There were ample opportunities in all locations for EAB to reproduce, but EAB in cooler cities would experience thermal limitations, thus slowing the spread of EAB populations.