Exposure of cold-adapted Diamesa mendotae Muttkowski, 1915 (Diptera: Chironomidae) to short-term high temperature reduces longevity and reproduction

Abstract

Climate change is increasing mean winter temperatures and the frequency of short-term high temperatures. Winter-emerging aquatic insects require an extended cold period to develop and may be negatively impacted by high winter air temperatures. Diamesa mendotae Muttkowski, 1915 is a cold-adapted, winter-emerging chironomid common in groundwater-dominated streams in Minnesota. Previous studies have found constant exposure to high air temperatures reduced adult D. mendotae survivorship, but not how short-term high temperature exposure may affect D. mendotae survivorship and reproduction. We found short-term exposure (24 or 48h) to 22 °C decreased adult D. mendotae longevity and reduced egg laying and larval hatch success, which may reduce future D. mendotae population sizes. Disruptions in D. mendotae and other cold-adapted insect populations may have broad ramifications for groundwater-fed stream ecosystems. Our study highlights the need for further research on cold-adapted insect survivorship after short-term winter temperature spikes to understand impacts of climate change beyond mean annual temperature increases.

Keywords:

• Climate change
• winter
• Chironomidae
• stream ecology
• Diamesa mendotae

Acknowledgements

We are grateful for the late Len Ferrington’s guidance and mentorship during this project. We thank the many members of the Chironomidae Research Group for their support, especially Tessa Durnin and Rebecca Swenson. We also thank Jim Cotner, Jacques Finlay, and two anonymous reviewers for their constructive comments on this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This project was supported by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR) under grant M.L. 2018, Chp. 214, Art. 4, Sec. 02, Subd. 03i awarded to Len Ferrington.