Bees Endure One-Two Punch

Extreme heat waves affect pollinators and the pathogens that live on them, creating a mutual imbalance that could have major economic and public health consequences, according to a study led by researchers in the College of Agricultural Sciences.

The global team was the first to examine how extreme heat waves affect the host-pathogen relationship between solitary bees and a protozoan pathogen. The scientists found the one-two punch of extreme heat exposure and prior infection led solitary bees, which account for over 90% of the bee species in North America, to be less likely to forage for food. If bees don't forage, they don't eat and pollinate crops vital to the global economy and food security.

"These asymmetrical relationships between organisms are often overlooked when studying climate impacts, but they are essential," said Mitzy Porras, a postdoctoral researcher in the college and lead author of the study.

The researchers found that a healthy bee could tolerate a heat wave of 109.4 degrees Fahrenheit, but after infection, its tolerance was reduced to 98.6 F.

"Our results shed light on the implications of extreme heat waves on host-pathogen dynamics under a warmer world," said co-author Ed Rajotte, professor emeritus of entomology.

—Adrienne Berard