Mason Bees

Mason bees are one of nature’s best pollinators. Thirty five female mason bees can pollinate a one acre apple orchard. It would take two honey bee hives to pollinate the same orchard. Mason bees can be easily managed by almost anyone. They are nearly stingless, but if you were to be stung, it is compared to a mosquito bite. There have been no reported cases of anaphylactic shock from the sting of a mason bee. Mason bees are very docile even around the hive as they will not defend their hive. A mason bee house can be kept on the back porch and are enjoyable to watch by young and old. 

There are 130 species of mason bees in North America. One of the most commonly known is the Blue Orchard Bee, Osmia Lignaria, and also referred to as BOBs. 


We started to fly our mason bee cocoons as they were hatching out within 24 hours of placing the cocoons in the hives. Some of the bees are returning. 

I will keep watching them, as I am releasing bees every other day now. Today, a student noticed two mason bees mating and we took photos, which is shown below.

Blue Orchard or

Osmia lignaria    Mason Bee Cocoons    Mason Bee House

Mason Bees emerging and mating from our hives in Lakewood.


Photo below has a bee wall habitat incorporated in a fence. The pond will supply water for the mason bees and honey bees. The pond also provides mud for the mason bees. The need of mud is to seal off the egg chambers. 

This is another link to learn about mason bees from British Columbia ministry of Agriculture.

Dave Hunter with Crown Bees has a page that talks about what to do during the taking care of your mason bees. Here is the link.

Gardening with Mason bees from the Washington State University Extension.

Bumble Bees

Dakota Bees

Bumblebees are one of nature’s best pollinators and can be found throughout North America. They are used for pollination services in green houses for the pollination of tomato, cucumbers, peppers and other crops. Bumblebees, like honey bees, are in decline/danger. Help these bees by providing simple habitat and limiting the use of pesticides.

Dakota Bees

There are 23 species of bumblebees found in Colorado. The most common is Bobus Hunti, known for its orange band. These bees can be found at mountain elevations as well as the plains. Unlike honey bees, bumblebees are native to North America.

Here is an easy way to make bumblebee habitat using a cardboard, nuc box or a scrap piece of card board as a divider and burlap bag scraps. Place old mouse nesting materials under the burlap. I have kept rescued bumblebee nests in this set up with good results. Join us in the bumblebee study.

Dakota Bees

After four years of no bumblebee queens occupying any of the habitats, I have placed in the Denver Metro area. I think I found the reason. Bumblebees use old mouse nests for their habitat and they are attracted to the urine orders in the mouse nest. As bad as a mouse nest smells, the bumblebees do not seem to mind. In fact the last removal I did, I notice the only way the bumblebee queen could have found this old mouse nest was through order. I plan on collecting used mouse nesting materials from a local pet shop. Then, using it to line the bottom of all of my habitats. I am confident that this will bring the queens to the habitats.

Leafcutter Bees

Dakota Bees

Most common leafcutter bees (Megachile spp.) are approximately the size of the common honeybee, although they are somewhat darker with light bands on the abdomen. They also have different habits. Leafcutter bees are not aggressive and sting only when handled. Their sting is very mild, less painful than that of honeybees or yellowjacket wasps.

Leafcutter bees are solitary bees, meaning that they don't produce colonies unlike social insects (honeybees, yellowjackets, ants, etc.). Instead, individual female leafcutter bees do all the work of rearing. This includes digging out nesting areas, creating nest cells and providing their young with food. Adult females may live up to two months and lay some 35 to 40 eggs during this time.

Dakota Bees

Leafcutter bees nest in soft, rotted wood; thick-stemmed, pithy plants (e.g., rose); and in similar materials that the bees can easily cut through and excavate. Nest tunnels may extend several inches deep and coarse sawdust may be deposited at the entrance. This sometimes causes confusion with other wood nesting insects, such as carpenter ants. 

However, leafcutter bees restrict their tunneling to soft, rotted wood and do not cause damage to homes or other wooden structures.

There are also concerns about leafcutter bee nesting in rose canes, excavating the pith of pruned canes. Leafcutter bees sometimes nest in the largest diameter rose canes but cause little damage because they restrict tunneling to the pith and rarely girdle cambium. Furthermore, other insects, including various hunting wasps (Pemphredon species) and small carpenter bees more commonly tunnel and nest in rose canes.

Dakota Bees

After the nest is made, the bees collect fragments of leaves to construct individual nest cells. The bees cut leaves in a distinctive manner, making a smooth semicircular cut about 3/4 inch in diameter from the edge of leaves. Although, they cut many types of leaves, leafcutter bees prefer certain types, notably rose, green ash, lilac and Virginia creeper. This injury often is only a minor curiosity. However, where leafcutter bees are abundant and concentrate on cultivated plantings, the removal of leaf tissues can be damaging. Serious damage most often occurs in isolated rural plantings.