Sunday, July 24, 2016

Leafcutter and mason bees: Home gardener helpers

When talking about pollinators, often times the honey bee is the first we think of. While there is no doubt of their importance to pollination, their lesser known cousins—the leafcutter and mason bee—are much more effective pollinators. In fact, they are of more use to a home gardener than a honey bee.

Honey bee vs. leafcutter and mason bees

Honey bees are indeed great pollen gatherers, but leafcutter and mason bees are great pollinators. They carry pollen on their hairy abdomen and scrape the pollen off within their nest. Because the pollen is carried dry on their hair, it falls off easily as they move among blossoms. As a result, they pollinate more flowers than the honey bee, who wets the pollen so it sticks to its legs during transport.

While honey bees may visit your yard as they pass through, leafcutter and mason bees are permanent residents. The honey bee travels up to five miles from its hive to forage, but leafcutter and mason bees stay within 300 feet of their home. For this reason, housing these species in your yard will increase your flower and fruit productivity.


Leafcutter Bees

Leafcutters have the ability to handle extreme temperatures, and are most active in late summer, thriving in 80 to 110 degree weather. They are ideal for pollinating melons, blueberries, peas, and other late summer vegetables.

The leafcutter gets its name because it cuts leaves and uses them in their nest. They are particular about the kind of leaf they use; it can’t be too tough to cut with their mandibles, it can’t be too thick to roll for transport, and it can’t be too veiny to cut easily. In the Northwest, prefered leaves come from hostas, lilacs, roses, or bougainvillea. Having leaves they like within 100 feet of their home is essential or they will move on.


Mason Bees

The mason bee is a productive pollinator for early spring flowers, fruits, and nuts. They emerge when daytime temperatures reach a consistent 55 degrees. Generally, this is about the same time as cherry trees blossom.

What is unique about the mason bee is they gather nectar with their tongue at the same time they collect pollen on their underside. Because they gather pollen and nectar on the same visit, they are excellent cross-pollinators as they move between trees and flowers.

The mason bee gets its name because of its craftsmanship when building its home. An essential element to keep mason bees in your yard is to have available mud within 150 feet of their home. The mason bee packs its nesting hole with the mud, separating each egg chamber from the other, just as the leafcutter uses leaves. If they cannot find mud in your yard, they will vacate.

Mud for mason bees

You will need to keep a small amount of mud, about 9 inches wide and deep. Ideally, the mud should be in a hole in the ground and not exposed dirt or in a container. When in the ground, the moisture is higher and less dried from the sun.

When you dig your hole in a shady place, ensure there is clay-like mud on a sidewall. Mason bees prefer more compact mud because it is easy to carry in their mandibles. If it is too dry it will be difficult to carry and harder to pack into their “hole.”


Placing a bee home

Both leafcutter and mason bees are cavity dwellers and do not create holes or damage structures to make holes. They are opportunists that like a hole slightly larger than their bodies, about the width of a pencil, with a depth of about 6 inches. The same home can be used for both species because they are active during opposite seasons.

Homes often have the appearance of a bird house, with an open face and straw-like tubes piled on top of each other. The tubes are the “holes” the female will pack with her eggs. Each hole will have up to 15 egg chambers, each packed with pollen, one egg, and a leaf cutting or mud, depending on the species, to close the chamber.

Homes should face a southern or southeastern wall so morning sun will wake your bees to begin pollinating. If your climate has hot summer weather, consider a location with sun in the morning and shade in the afternoon. Prolonged direct sunlight will overheat the home and kill cocoons.

Do not place the home near a bird watering station. Your bees may become a tasty treat to visiting birds. If birds take interest in the bee home as a potential nesting site for themselves, placing chicken wire on the front will keep them out.

It’s important to not move the nest once bees have arrived. They know exactly which hole is theirs and may get confused and leave if the hole they remember is moved.

Getting started

Shonnard’s Nursery has a full-service bee department if you are in the Willamette Valley. There you can find everything from the bees to homes to accessories. Crown Bees is a good place for online orders. They too offer all you need to get started and maintain bee homes.

Crown Bees offers a program to trade excess bees for nesting material to use in the next season, as each year your bee population should double. Shonnard’s offers services to help maintain homes. Both companies offer items to help harvest and incubate cocoons if you should choose to winter them under protection of a garage or shed for maximum survival of the brood.

No comments:

Post a Comment