Smelly male bumblebees!
By Cathy Horsley, Conservation Officer West Country Buzz
This summer, I learnt that different species of male bumblebees have different scents. I use a marking cage to examine bumblebees on my surveys to get a good close up look to identify them, and the male bees sooner or later released a puff of perfume.
Red-tailed bumblebees and Early bumblebees have a pleasant citrus smell, whereas the Buff-tailed bumblebees are more like smelly feet!
The odour comes from the release of pheromones, which are chemicals used to attract queens. By having their own distinctive aroma, males can be sure of attracting females from the same species.
Ever since Darwin’s day, and even earlier, male bumblebees have been observed following a set flight path. They tend to follow a linear circuit and pause at various places along the route to deposit a drop of pheromone. It has been noticed that males will temporarily leave their flight path, often in the early afternoon, to refuel on flowers. Different species will fly at different heights, or at different times of day, which also helps males to find the right species of female. By attracting queens to a particular place, males also avoid trying to mate with workers. Patrolling males on the lookout for queens is a fascinating subject, not least because although this is often observed, mating is rarely seen.
