Abstract – Predicting Lysathia cilliersae establishment and survival in cooler climates

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Abstract

Tropical and sub-tropical plants are invading temperate regions, a phenomenon driven partly by climate change. Myriophyllum aquaticum, originally from South America, has invaded aquatic ecosystems worldwide, and is considered invasive in temperate regions, such as North America and Europe. Biocontrol in these cooler areas is challenging due to climate limits on agents, including more extreme weather and colder winters than where the species originated. Lysathia cilliersae is native to South America and is a potential biocontrol agent to control M. aquaticum. Although other abiotic factors are important, temperature is a key driver of insect physiology, as they are ectotherms. Laboratory data on insect thermal physiology, such as long exposure to cold, CTmin, Chill coma, lower lethal limits and temperature-dependent development, allows us to explore the impact of thermal limits to control M. aquaticum. Using Generalized Additive Models, we mapped these thermal tolerances to visualize the limits of winter establishment and to identify release locations. In this presentation, we will show how these thermal metrics collected in the laboratory can be used to understand the thermal tolerance of an insect and predict its establishment and survival in a new thermal niche. This allows us to identify which agents are likely to establish and ultimately have an impact on the target plant, and thus which to invest the time and resources into the full risk assessment for release.

keywords 

Lysathia cilliersae 

Myriophyllum aquaticum 

Biological control 

Thermal tolerance 

Establishment and survival 

Highlights 

Laboratory data reveal the thermal limits of Lysathia cilliersae in cooler climates. 

Thermal tolerance metrics help predict establishment and survival in temperate regions. 

Results support risk assessment and biocontrol planning against Myriophyllum aquaticum.