Mason bee harvest

I have begun the work of my mason and leaf cutter bee harvest, which can start anytime after mid-October, when the bees have finished developing in their cocoons.

I took a great workshop last Saturday, and found out a few things I have done wrong: I should have brought my tubes inside in June, and since I didn't, I've got lots of parasites. Also, my one house got drenched and left wet too long- they all molded and died... I need to do better next year!

1. Mason bee harvest:

In the wild, mason bees rarely reuse the same nesting cavity, and so in order to be a careful steward for my bee hotels, I will have a yearly “house cleaning”. 

This year I found chalkbrood fungus and also some beetle larvae (yuck). Mason bees can also bring the hairy-footed mite, also known as a pollen mite, into their cocoons. The mites will feed on the pollen stores, bee eggs, and larvae. When mites infest a nest and adult bees emerge from the infected nest the following spring, the mites can climb onto bees and hitch a ride to a new location.

Mason bee cocoons

I got some harvested on Saturday, and the rest I will do today.

1. First, use a thin stick to check for cocoons. Save empty reeds for next year.

2. Pinch the mud-capped end with your fingers or a pair of clippers, splitting the reed open. This won't harm the bees. Pry the reed apart and gently remove the cocoons with my nifty new scooper tool.

Then rub off the mud walls and frass (poop).

Leaf-cutter bee cocoons

3. Next, prepare a 1-quart bowl of cold water with 1 drop of dish soap and 1 Tbsp. bleach (to kill the chalkbrood). Add cocoons and set a timer for 2-5 minutes, swirl them around for at least 2 minutes to dislodge any mites, then pour through a sieve, and run a gentle stream of cool water over them. 

4. Dry the cocoons on a towel for an hour.

2. Storage:

Once the bees are dry, it's time to store them away in the refrigerator until March 1 (Mid-May for leaf cutter bees). Use a firm plastic container with holes around each side, and a paper towel in the bottom. Stick in a small container holding a crumpled damp towel to provide moisture, then add the cocoons all around. (I made a small envelope to hold the leaf cutter bees separately.)

Store in the fridge and check monthly to make sure it doesn't dry out for get moldy.

3. House Cleaning:

Clean the house and the empty reeds by submerging them in a bleach bath for 10 minutes, then scrub off any accumulated debris and let dry thoroughly. 

I've also got an old drilled block mason bee house, and next spring I will discard it.