An integrated framework to identify and characterize regional-scale insect dispersal

Area of Science:

• Ecology
• Biogeography
• Environmental Science

Background:

• Forest pest insects cause significant socio-economic and ecological damage globally.
• Accurate tracing of insect dispersal is crucial for effective pest management and understanding outbreak dynamics.

Purpose of the Study:

• To develop and apply an integrated framework for tracing the regional origins of pest insect dispersal events.
• To investigate the dispersal patterns of the eastern spruce budworm moth (Choristoneura fumiferana) in North America.

Main Methods:

• Developed a North American sulfur isotope (δ34S) isoscape model.
• Calibrated the isoscape model using spruce budworm tissues of known origin.
• Utilized an automated trap network to collect samples and identify immigrant insects.
• Integrated isotopic data, ecological information, and atmospheric transport models to trace natal origins.

Main Results:

• Successfully narrowed down the potential origins of immigrant spruce budworm moths.
• Demonstrated long-distance dispersal of spruce budworm moths (~400 km) across the Gulf of St. Lawrence.
• Validated the effectiveness of the integrated tracing framework for identifying insect origins.

Conclusions:

• The integrated framework combining isotope geolocation, ecological data, and atmospheric modeling enhances the resolution of insect dispersal ecology.
• This approach is transferable for tracing other migratory insect species, aiding conservation, agriculture, and bio-surveillance efforts.
• Improved understanding of insect dispersal is vital in the context of global environmental change.