Cold Cricket Case Could Defrost Mysteries of Changing Climate

Article excerpt

Biologists from Western University have discovered that insects recover from chill-coma by getting water and salt back where it belongs. These findings not only identify the very mechanisms that drive insect movement at low temperatures but will lead to a better understanding of agriculture management, biodiversity, and climate change.

Wildlife photographers often pose insects by cooling them down in a refrigerator, where they enter a paralyzed state called chill-coma. Insects in chill-coma appear dead, but are still very much alive. If the shutterbug is patient, he or she will witness the bug as it awakens. Chill-coma was first noted more than a century ago and photographers are not the only ones who have found use for it.

Many alpine spiders prey on in-sects that have inadvertently landed on snowfields and have gone into a chill-coma while biologists, like Western professor Brent Sinclair and his PhD student Heath MacMillan, use chill-coma recovery as a way to measure insect cold tolerance. A research team, led by MacMillan, studied recovery from chill-coma in fall field crickets and found that recovery depends on fixing the water and salt imbalances that materialize when the insect is cold.

"Insects lose the ability to maintain proper water balance in the cold, so when they are chilled, water and sodium move from the insect blood, called hemolymph, into their gut," says MacMillan. …