The most popular bee tunnels range from about 3/32” to 3/8” wide. The narrower ones are usually shorter (about 3-5 inches) and the wider ones are longer (up to 6 inches). These numbers are not exact, so approximations work fine. The tunnels are easily made with a long drill bit in blocks of dimensional lumber or in the ends of bucked logs. Three important points:

• Use untreated wood
• The tunnels should be as smooth as possible
• The holes should not go completely through the wood (one end remains closed)

Although most native bees are solitary in the sense that one female raises a family by herself, the members of a species like to live near to one another. For that reason, you should group tunnel sizes together. In other words, one block may have lots of ¼-inch holes, while the next block has lots of 3/8-inch holes. Space the holes at least ½- to ¾-inch apart—the larger the holes the bigger the spacing.

If at all possible, line the holes with paper straws or rolled wax paper. A paper liner does two important things:

• It keeps the inside of the nest smooth and snag-free
• It can be replaced every year, thereby reducing the accumulation of diseases and parasites.

The paper tubes can be gently withdrawn at the end of the season and stored in a cool dry place. Alternatively, the cocoons themselves can be taken from the paper and stored separately. In the spring, the paper tubes can be hung near the nests or the cocoons can be put in an open-ended container—like a pvc pipe or a small flower pot—from which the bees will emerge.

Hang your bee boxes at least three to four feet off the ground so they don’t disappear among the weeds and to keep them away from splashing water and small animals. Early morning sun is okay, but the boxes should be protected from direct afternoon rays. Additionally:

• Add a small overhanging roof to keep out the rain
• Mount the boxes on a steady structure rather than one that sways in the wind
• A loose covering of wire mesh (like chicken wire) can help deter hungry birds in winter

That’s really all there is to it. For maximum protection against disease build-up, boxes can be sanitized with bleach at the end of the season or replaced altogether after two or three seasons. In any case, always use liners for best results.

Rusty
HoneyBeeSuite

Nest box with ready-to-hatch straws nearby.

In truth bumble bees rarely smile, they are more hairy than fat, and they come in a variety of colors. Some are all black, while others have stripes that are lemon yellow, orange, dark rust, red, or white. Stripes may be wide or narrow and vary in number. Bumble bees are easy to recognize because they seldom wear costumes resembling dogs, cats, or kids.

Bumble bees belong to the genus Bombus. They are in the same order (Hymenoptera) and same family (Apidae) as honey bees and, indeed, they have a lot in common. The known bumble bees are divided into 250 species, most of which are found in temperate regions of the northern hemisphere. About 50 species live in North America.

Like honey bees, bumble bees are eusocial, meaning they live in colonies with a reproductive queen and cadre of sterile female workers. The nest of bumble bees is usually found underground and consists of perhaps fifty workers.

At the onset of winter both the female workers and the male drones die. The mated queens overwinter by finding a protected spot and holing up for the duration. Then, in early spring, those queens find a suitable nest, provision it with pollen and nectar, and begin a new colony. The solitary queen does all the work by herself until she has enough female offspring to take over raising the young. Once that happens, the queen stays in the nest and continues to lay eggs.

Within the confines of their nest—often a recycled rodent burrow—the bees build wax comb in which to store food and raise brood. The wax nest is irregular in shape and is often tucked into a soft, warm berth of straw or animal fur.

Bumble bees collect nectar and pollen for the young, carrying home large pellets of pollen on their rear legs. Bumble bees visit many flower types and are efficient pollinators, often pollinating flowers that other bees can’t manage. A famous example is the tomato, which needs the powerful vibration of a bumble bee’s wings to free the pollen from the flower.

Although there are many species of bumble bee, most of the species do not have a wide distribution. As a result, habitat destruction, urbanization, and intensive agriculture have put many species in danger of extinction. Pesticide-free agriculture, urban plantings, hedgerows, and habitat strips can give a boost to declining bumble bee populations.

For the most part, bumble bees are docile as they forage from flower to flower, but they can become aggressive and territorial if their nests are disturbed. Enjoy them from a distance and leave their nests alone if at all possible.

Rusty
HoneyBeeSuite

Bumble Bee. Flickr photo by Stephen Jones.

But I always kind of liked the holes. They felt as smooth as the inside of a seashell and were large enough to swallow my small finger. I thought they were cool because I couldn’t understand how a little bee could do that.

It turns out that carpenter bees use their mandibles to dig out and smooth the tunnels in which they will lay eggs. They do not eat the wood but may use the saw dust to build partitions between each chamber that contains an egg and a provision of pollen mixed with nectar. The holes are about a half-inch (1.25 cm) across and run 6-7 inches (15-18 cm) long. Sometimes more than one bee uses the main hole and each builds a tunnel that branches off inside the boards where you can’t see them. From a human point of view, this is probably not the highest and best use of your picnic table—but it’s really kind of awesome.

Carpenter bees will drill in trees, shingles, soffits, fascia, porch rails, eaves, decks, siding, and lawn chairs. They have preference for unfinished wood, but in a pinch will use pretty much anything they can find. Although most of the carpenter bees are solitary, they tend to live in proximity to each other, so you may see groups of them munching on your real estate investments, consuming your equity.

After the holes are drilled, the female provisions the nest, lays her eggs, and seals it up. The young emerge 5 to 7 weeks later and spend the rest of the summer eating, pollinating, and preparing for winter. Both the male and female bees overwinter as adults. Rather than drilling again, they clean out a previously excavated hole and hibernate there until spring.

Unfortunately, bees that nest in pre-drilled holes—such as mason bees—often get blamed for the holes that carpenter bees or other creatures build. Sadly, I’ve seen folks kill mason bees thinking they were responsible for the damage.

Carpenter bees are larger than mason bees; some are the size of bumble bees, some a bit smaller. But carpenters have a smooth—rather than a hairy—abdomen. Then too, bumble bees are often seen coming out of underground nests, whereas carpenter bees are seen hanging around wooden objects—usually treasured and/or expensive wooden objects.

The genus name for the nearly 500 species of carpenter bees is Xylocopa. According to Wikipedia this word comes from the ancient Greek for woodcutter. In the United States five species are prevalent, two on the east coast and three on the west coast. Both carpenters and masons are excellent pollinators so don’t kill either kind. If you have carpenters, provide some unpainted wood and try to guide them in that direction.

Rusty
HoneyBeeSuite

Carpenter bee showing smooth abdomen. Flickr photo by Anita Rust.

Carpenter bees defecate before entering the nest. Flickr photo by Tobyotter.

The structures are as varied as the insects that inhabit them. They may be smaller than a birdhouse or may cover the side of two-story building. They may be designed to attract bees, potter wasps, other pollinating insects, or even vertebrate pollinators like hummingbirds and bats. Some offer housing to non-pollinating beneficial insects such as ladybugs and lacewings. The options are endless and the designs are original and creative.

Germany seems to be the leader in bug structures, followed closely by Great Britain. Because those countries are small compared to places like Canada, the United States, and Australia, they were quick to realize the importance of coexisting with the beneficial insects and the need to provide shelter for them in the built environment. The insects use the habitat for shelter, safety, nesting, raising young, and finding food.

A feature that distinguishes walls, towers, and hotels from structures like mason bee condos or bumble bee nests is the wide variety of nesting choices. Pollinator walls may contain hollow reeds, wood with pre-drilled tunnels, cracked or drilled masonry, straw bundles, rolled corrugated board, clustered stones, or dry leaves. The “invertebrate habitat” shown below was built by the Cheshire Wildlife Trust. It contains many types of habitat and was built completely from recycled materials.

Invertebrate Habitat by Cheshire Wildlife Trust

The next photo shows the winner of the 2010 Beyond the Hive Competition in London. This “bug hotel” was built by Arup Associates and is designed to encourage many types of invertebrate inhabitants.

Insect hotel by Arup Associates.

If you decide to build your own habitat, here are some important issues:

• The structure should be in an area sheltered from bright sun and high wind, such as close to a building or under a shady tree. If you hope to attract some native bees, at least past of the structure should be in the sun.

• Insects need water, so a reliable supply such as a pond or creek should be nearby. Alternatively, you can provide an artificial source–just don’t let it run dry.

• Many solitary bees and wasps need a source of mud.

• The fill material should be varied in type (stones, masonry, dead leaves, reeds, wood, twigs) and have many little cracks and crannies, nooks and crevices.

• The design must be structurally sound so it doesn’t topple from wind, rain, or snow. If you live in an earthquake zone, keep the structure low and wide instead of tall and narrow.

Structures don’t have to be large. The one shown below is small enough to become part of the garden. This was an entry in the Beyond the Hive competition by Helaba Landesbank Hessen-Thueringen.

Small but effective.

The possibilities for building insect habitat are endless and can satisfy the artist in you. So give it a try. If you like, send me a photo and I’ll post it here on my site.

Pollinator housing attached to a building. Photo by Wildbienen.

Rusty
HoneyBeeSuite

Cloudcroft is a town on the northern border of the Lincoln National Forest in south-central New Mexico. Cockerell’s bumble bee was originally discovered north of this area in 1913. Between 1913 and 1956 it was reported 16 more times in Cloudcroft as well as a few times in neighboring areas along the Rio Ruidoso and once in the town of Ruidoso. And then it disappeared.

Most of the bumble bee species in the United States are identified from hundreds, or even thousands, of specimens. But with so few specimens of the Cockerell’s bumble bee available for study, a number of entomologists dismissed it as merely a variant of a more common species, and so paid little attention over the years.

New genetic tools, however, have shown that the bee is a distinct species—one with an incredibly small range for a bumble bee. As far as the researchers can determine, the Cockerell’s bumble has been living in an area of less than 300 square miles—mostly in and around the Lincoln National Forest and nearby tribal lands. This protected and isolated habitat helped the bee survive down through the decades in spite of its extremely small natural range. Scientists say the bee is not endangered by habitat loss, at least not for now.

Rusty
HoneyBeeSuite.com

Cockerell's bumble bee. Photo by Greg Ballmer/UC Riverside