What do leafcutter bees do?

Originally found in Africa, the leafcutter bee was introduced to the United States sometime before 1940. It is well established here now and is the world’s primary pollinator of alfalfa (responsible for 2/3 of total production), which feeds pigs and dairy cows. It is able to avoid the spring-loaded pistil of the alfalfa flower, unlike larger honeybees that trip the spring mechanism. Once farmers replaced the honeybee by the leafcutter bee to pollinate their alfalfa crop, production increase fifteen-fold. They do not have a stinger and are a gentle generalist bee that will visit a majority of types of flowers in your backyard during their flying months of July and August.

Leafcutter bees are solitary, gregarious (like to live near each other) cavity-nesting bees. The leafcutter bee will sit on a leaf, hold it with her legs, and chew the leaf around herself. Once it is completely chewed, she and the leaf will free-fall until she is able to fly away with the leaf fragment. She will bring the piece of leaf back to her nesting hole, and chew it until it becomes pliable. Multiple pieces are then attached in long sheets, pushed up against the walls of the hole, and filled with pollen, nectar and an egg. She will then wrap the leaf pieces around the contents. It can take up to three hours to wrap a single offspring in the protective leaves! The offspring will remain wrapped up until the follow year until they chew their way out when temperatures rise above 80 degrees.

Great leafcutter bee picture by local photographer Ed Sullivan