Bees can't handle the heat

Miles was recently on the PBS NewsHour, talking about two subjects: bee health and climate change. You can watch the video below:

Another study caught our attention, but we didn’t have time to dive into it on the air. This study, performed by scientists at NC State, combined the two subjects we covered, trying to determine how different species of bees react to warming climates.

The team found that almost all of the 15 most common bee species in the southeastern U.S. could not handle rising temperatures.

In a lab, the team stuck these bees in tubes and turned up the heat until, as the press release state, “each bee became incapacitated”. Don’t try this in your local sauna! The researchers found that even the most hardy bees became totally incapacitated when temperatures hit 122°F.

Now, 122°F is hot. Real hot. The hottest recorded temperature ever in the state of North Carolina was 110°F, so 122°F may seem like overkill, but they needed to actually make the bees pass out--that’s an extreme case that the team could quantitatively observe. They predict that bees are affected negatively even before they pass out.

A carpenter bee, one of the more heat-resilient species tested. Credit: Elsa Youngsteadt.

A carpenter bee, one of the more heat-resilient species tested. Credit: Elsa Youngsteadt.

Along this line of thinking, the scientists also wanted to see how these bees fare in the rising temperatures of urban heat islands. They surveyed 18 urban sites in North Carolina’s Wake County for two years and found that the relative populations of the bee species was correlated with how resilient they each were to warmer temperatures.

In other words, they found that the worse a bee species was able to handle the heat, the fewer bees of that species there were when areas start to heat up.

Considering honey bees alone pollinate $15 billion worth of crops a year in the U.S., a declining population due to a warming climate will have a direct economic impact. How’s that for buzzkill?


Banner image credit: Elsa Youngsteadt