Bee Hospitality

I have two new bee houses, one I bought from Crown Bees, and a fantastic homemade one I got from my sister and brother-in-law for Christmas.

I also have a tube of Mason Bees in the refrigerator and no idea what to do with them, so a little research is in order. 

The purpose of a bee house is to attract solitary bees, who are  extremely docile and up to three times more effective as pollinators. Some of the most common solitary bees are mason bees, leafcutter bees, and miner bees. Many of these native bees are already a part of the local ecosystem, but providing them with a perfect place to nest in your backyard can improve their lives and yours.

Agenda:

1. Put my bee houses up

2. Release the Mason Bees!

3. Bee House Maintenance

1. Put my bee houses up:

Hole-nesting bees need a place that’s dry and safe. Tips:

• 
  Put bee houses on a sturdy wall, fence, or post (bees do not like swinging in the breeze) in a place with an overhang to protect nesting materials from bad weather. 
• Orient it to face the morning sun, as hole-nesting bees need the sun’s warmth to give them energy to fly. Placing two bee houses—each facing a slightly different direction—can produce even better results. 
• Most native bees prefer some afternoon shade, but too much shade could attract hole-nesting wasps. (Solitary wasps are generally considered beneficial predators in a garden, as they attack pests like caterpillars, grubs, and aphids. However, they may also prey on the bee pupae in your bee house.)
• Hang a bee house at eye level, about 5 feet off the ground to protect the bees from small predators, like mice or ants. Plus, these bees are fun to watch!
• Place the house near open blooms (black-eyed Susan, bee balm, or purple coneflower) because Mason bees only fly about 300 feet searching for nectar and pollen.
• Mud is vital for mason bee reproduction, and females will not nest if they do not have a reliable source mud with a high clay content nearby (within 25 - 50 feet).
• Stay away from bird feeders or ponds.

2. Release the Mason Bees!

I bought some Mason bees from Crown Bees, and they are currently in residence in my refrigerator.

I know that Mason bees emerge in early spring when temperatures rise to the 50s and early flowers start to bloom. Mason bees are among the earliest bee species to emerge in the spring, making them essential for spring crops. They forage in low light levels and cool and wet weather, whereas honey bees and leaf-cutter bees tend to show up at the beginning of summer. On average, mason bees forage 2x longer per day than honey bees.

I can release my mason bee cocoons once daily temps are consistently 55°F or warmer (usually late February to mid-March in western Oregon). Freezing temperatures at night do not affect the bees. They will find a safe place to shelter in the evenings.

The other factor is food, in the form of nectar and pollen. A single female mason bee can visit 10,000 - 20,000 flowers in her short lifetime, collecting pollen and nectar to feed her offspring. Research has found that solitary bees have more offspring when lots of floral resources are available, so I need to provide plenty of open blooms nearby for the bees to forage.  
If the bees emerge before the flowers are open, they will either fly elsewhere in search of food or be unable to survive.

My neighbor's plum tree is in full bloom now, so maybe it's time to release the bees! Some nesting houses have a protected, predator-proof emergence area (an “attic”) above the nesting tubes where you can place the cocoons. The old cocoons produce a scent that encourages the newly emerged females to choose that nesting house to lay their eggs.

3. Bee House Maintenance:

Bees mate during late spring through early summer and they will move into bee houses during early summer.

If birds are attacking the nesting holes, use a 1”-wide wire cloth and bubble it around the bee house. Do not install wire cloth flush against the nesting holes, as this will obstruct the bees from entering. Bees need some space for landing and taking off!

Bee houses can be left out year-round, especially if you have tubes plugged with fully developed cocoons inside. 

If you’re worried about extremely cold temperatures, you can slide the full tubes out of the house and put them in an unheated barn or shed where temperatures stay between 36-39 degrees. Keeping the tubes in something like a fine mesh bag helps to keep small parasitic wasps from attacking larvae. Keep an eye on the filled nesting materials, as your bees may be a species (such as leafcutter bees) that produce multiple generations per season.

In the spring, put the tubes in a cardboard box with an exit hole for the new bees. If you can, organize and separate cocoons based on appearance and when their nesting holes were capped. With proper care, these cocoons will develop into a new generation of native bee pollinators and residents of your bee house!

Once all of them have emerged, wash and brush the tubes with warm soapy water and a mild bleach solution. You may also choose to replace the tubes rather than wash them.