The first sign of an attack is usually a smell, an aroma that can be quite pleasant, like a freshly cut Christmas tree. It emanates from some of the deepest swamps and most hidden recesses of Minnesota’s forests. But along with that aroma, there is something else in the air, something sweet to a destructive type of bark beetle. It’s a trail of pheromones signaling that it is time to feast.

Scientists at the University of Minnesota have identified the chemicals and compounds that eastern larch beetles produce to communicate with one other.

— Read more in Pheromones from tiny beetles could help save Minnesota’s tamarack trees at The Minnesota Star Tribune.

The heat waves reduced the strength of the neurons’ electrical signal by up to 80 percent; workers, which are all female and forage for the hive, were more affected than males. Even worse, the antennae of the bees that had 24 hours to cool off still hadn’t recovered their sense of smell after that time. “That was surprising,” Nooten says. The team had expected those antennae to recover. The fact that they didn’t, she says, suggests the bees don’t recover swiftly, which spells trouble for getting food for the colony.

— Read more in Bumblebees lose most of their sense of smell after heat waves at Science News.