Leafcutter Bees

Colonies and nests created by bees are fascinating examples of reusing materials that surround a habitat. The bee family Megachilidae is known as the architect of the bee world, creating long chambers for their little baby bees to hatch in. Not all bees live in giant colonies, like the honey bee. Most bees are solitary; each family of bees creating individual nests depending on their needs.

The nickname, Leafcutter Bee, explains exactly what they do — they cut leaves! The female Leafcutting Bee is responsible for building a “nursery” for her little larvae. She finds a suitable space in preexisting tubular cavities (basically holes). These cavities could be in hollow stems, rotting wood, empty tunnels left by beetles, snail shells and even man made holes in buildings! This is a totally tubular example of reusing material.

Read more: Natve Bee Parasites: Wasps

  Leafcutter Nests

Leafcutter Bees are cavity dwelling bees that lay their eggs in existing holes. They do not create holes or damage structures to make holes. Leafcutter Bees stay close to home, foraging for pollen and nectar within 300 feet of the nest. This proximity makes them an attractive pollinator for summer yards and gardens. There are more than 130 species of spring and summer solitary bees in North America alone.

When the female Leafcutter Bee finds a cavity that is long and wide enough, she begins to carefully line the hole with leaves and petals to create a nice and comfortable brood chamber (this is the nursery). When she finishes one chamber she will lay her egg and provide pollen for the larva to eat.

Each chamber is home to one egg which means the female Leafcutting Bee is constantly adding chambers until the hole is filled. Each chamber is separated by a wall made up of chewed leaves and mixed with resin. When the baby bees mature they are thankful for the home their mother has created and they stay the winter in their cozy chambers. When the spring arrives the adult bees chew their way through the chambers and exit the nest.

  Productive Pollinator

The Leafcutter Bee is a productive pollinator for summer gardens and flowers. The female carries pollen on the underside of her hairy abdomen, and then scrapes the pollen off within her nesting hole. Because the pollen is carried dry on her hair, it falls off easily as she moves among blossoms. This results in significantly more pollinated flowers than her cousin, the honey bee, who wets the pollen so it sticks to the legs during transport to the hive.

  They Like To Live Alone

All leafcutter bees are solitary, meaning each female is a queen who does all of the chores. Each performs all of the duties that an entire honey bee hive might undertake: gathering pollen and nectar, laying eggs, and ensuring her eggs are protected when she’s not there by sealing them with cut leaf bits. Leafcutter Bees appear to like company because they build their nests near one another. There is no sharing of nests, however.

  Leafcutter Description

How do you identify these bees? Leafcutter Bees are similar in size to honeybees. The females are larger than the males and have a triangular shaped abdomen that ends in a point. The males can be identified by their smaller, blunt pointed abdomens and their long antennae. The leafcutter has a larger head than most bees due to extra muscles they have developed to help them chew through leaves. The females even have teeth! An interesting difference between leafcutters and honeybees is that leafcutters carry pollen on the underside of their abdomen rather than on their legs like honeybees. This creates bright yellow/gold colored bee butts that are easy to spot.

  Leafcutter Bee Facts

 They live 5 to 6 weeks
 They do NOT produce honey
 Imported to North America about 60 years ago
 Extremely gentle
 The female does everything
 Solitary
 Dry pollen fall off everywhere - extremely effective pollinator

  Gentle Natured

The leafcutter bee is extremely gentle and allows you to confidently get inches from her nesting hole without fear of being stung. Since each female performs all the duties, she doesn’t have time to also defend her nesting hole. Therefore, there’s no need for aggression. Although Leafcutter Bees have stingers, they will only sting if their life is threatened. More times than not, stings are caused by being caught in clothing and bee feels it is being squished. Even if you are unfortunate enough to be stung, the effects are generally no worse than a mosquito bite. In fact, you are more likely to be bit by their mandibles before you will be stung.

She does have a couple of built-in defenses for her hole. She seals each egg chamber with cut leaf bits to protect her eggs from predators while she is away. Also, once she claims a hole, other Leafcutter Bees will honor it. She might visit someone else’s hole by accident while looking for hers, but she won’t lay eggs anywhere but in her own home.

  Help Homeless Leafcutter Bees!

It doesn’t take much money or time to raise leafcutter bees. Nesting holes, housing and bees are quite affordable, and come in a variety of price ranges. Also, there is no need for protective gear, since they rarely sting, nor expensive equipment to buy.

In terms of time, plan about 15 minutes to select a location and set up your house. Warning! When your bees emerge and start pollinating, you’ll have to set aside time to observe them. Time flies as you watch them laying eggs for next season’s bees!

In late August, after bee activity stops, store filled nesting holes (open ends up) in an unheated garage or shed that is dry and secure. This will protect them from pests. Overwinter bee larvae in the nesting holes until next summer. That takes about 10 minutes. In just 1 to 2 hours a year of your time, you’ll get a healthy garden yield and amazing garden companions.

A bonus is that you’ll typically increase your bee cocoons from when you started.

  Keys to Successfully Raising Leafcutter Bees

 Place your house with nesting material facing the early morning sun. The warmth wakes your bees earlier to start pollinating. Follow the setup instructions.
 The leafcutter bee seals each egg with cut leaf bits. If she can’t find the right type of leaf (like the non-fibrous rose or lilac leaf) to cut and carry in her legs to the nest, she’ll leave your yard and set up her home elsewhere. This is the number one problem people face. Compare what rose leaves look like in comparison to other leaves in your yard. Not too thick, nor too thin, and with few veins.
 Store filled nesting holes (open ends up) in an unheated garage or shed that is dry and secure, after bee activity stops. Overwinter bee larvae in the nesting holes until next summer. Leaving them outdoors exposes them to pests and weather elements.