A 50-year love affair with hairy caterpillars reveals their squirmy secrets

Western tent caterpillars might not be on your mind every year, but during their peak outbreaks, they’re impossible to ignore—hairy larvae wriggling across roads and swarms of caterpillars climbing houses to form yellow silken cocoons.

They’re certainly on the mind of Dr. Judith Myers, UBC professor, who has spent five decades studying this native moth species and their boom-and-bust population cycles.

In this Q&A, she discusses her journey and findings from  a recently published study, including the caterpillars’ surprising resistance to climate change.

Summary:

- In early May, extreme wildfires in Manitoba ravaged some 8,667 square kilometers of land, claiming lives and forcing the evacuation of nearly 1,000 residents.

- A new study explains that conditions such as a combination of unseasonably warm temperatures, prolonged drought, and stressed vegetation led to the wildfires.

This study reveals that female Helicoverpa armigera moths utilize plant-emitted CO₂ as a key cue for egg-laying, preferring young leaves with higher CO₂ emissions to enhance offspring survival. However, the increase of CO₂ concentration in the atmosphere disrupts this oviposition strategy. Three gustatory receptors (HarmGR1, HarmGR2, and HarmGR3) were essential for CO₂ detection in H. armigera. Disrupting any of these receptors impaired CO₂ sensing and oviposition behavior. These findings highlight how climate change may alter insect reproduction and crop pest dynamics.

Natural weathering processes are removing CO₂ from the air in a wide range of environments across continents and ocean. Until recently these ‘CO₂ vacuum cleaners’ were often studied separately, without properly examining their complex interactions. Now, an international team of Earth scientists is proposing an integrated vision of the many factors that influence the removal of atmospheric CO₂ from the highest mountain peaks to the deep ocean floor, including their various interactions. The so-called weathering continuum provides a much more complete picture on what controls and regulates the natural removal of CO₂, which could help in the development of enhancing weathering techniques.