Beekeeper checking the top feeder frame Honeycomb with Bees

Do You Have to Harvest Mason Bee Cocoons?

Mason bees are a solitary species that create their nests from mud-rich clay, lay their eggs there, and then a new population emerges from those cocoons. 

So, do you have to harvest mason bee cocoons?

The short answer is yes. We know the prospect of harvesting cocoons might seem scary to first-timers, but this step helps protect your bee population and ensure they stay healthy.  

Beekeepers harvest, clean, and store mason bee cocoons every season to prevent the larva from falling prey to species-specific parasites and diseases.

Mason Bees Life Cycle

Let’s first look at mason bees’ life cycle to fully understand why we harvest their cocoons.

In the wild, adult mason bees naturally create nests in gaps, holes, and cavities of stems, wood, and other crevices. They use mud-rich clay to make their homes, filling it with pollen and nectar for their eggs after mating.

When each nest cell has enough pollen and nectar, they lay their eggs on each one, separating compartments by creating mud partitions. Male eggs are laid towards the front of the nest since they emerge earlier.

After a female is done laying her eggs, she seals the nest’s entrance with mud and continues looking for another nesting place. When the male eggs emerge, they push through the mud partitions, look for females to mate with, and the cycle continues.

Why Harvest Mason Bee Cocoons?

So, why do we need to harvest mason bee cocoons if they survive without us in the wild? 

The primary reason is to protect them from opportunistic parasites, increase their chances of surviving, and create a healthier bee population.

Unfortunately, mason bees can fall prey to parasitic wasps, Houdini flies, Chalkbrood, and pollen mites. These can come from anywhere, including the female mason bee when she collects pollen outside.

Pollen mites can attach to the female and fall off while she’s building her nest. Even if the female mason bee seals the nest cells, the pollen mites can easily latch onto the larva when it emerges and pushes through the mud partition.

Close-up of a Mason Bee Head

Yes, mason bees have a chance of surviving without harvesting, but it’s risky because they can fall prey to parasites. If nests are left unattended, it could easily wipe out an entire bee population.

To protect these pollinators and give them the best chance at surviving, we need to take the time to harvest the cocoons. 

How to Harvest Mason Bee Cocoons

Here’s a quick five-step guide on harvesting mason bee cocoons:

1. Prep the Area

Before anything, you have to prepare a few things.

This process tends to get messy, so it’s best to do it in a place where you can easily clean up any mess, like on a table outside. Alternatively, you can lay out old newspapers on whichever surface you use.

In addition, you want to stay in a cool, dry place to do the harvesting. Warm temperatures can cause premature hatching. 

Next, keep the following materials close by: 

  • Tissue or old towels for cleanup and drying
  • Clean Bee solution or bleach with a gallon of water in a 1:10 ratio
  • Clean trays or storage containers
  • Strainer
  • Cold, clean water
  • Chopsticks

You’ll also need reed splitters or a knife if your cocoons are in natural reeds or bamboo nests. Other nesting materials will be relatively easier to pry open.

2. Open the Nesting Material

Now it’s time to open the nest. There are several nesting materials that beekeepers use for mason bee populations, and here are the ways you can open and take them apart: 

Paper Tubes

Paper tubes can easily be opened by unraveling the tips using your fingers. However, if they’re glued on tightly, soak them in warm water first and then try again.

Nesting Trays

There are rubber bands that usually hold together nesting trays. Simply remove the bands and set them aside for when you want to assemble the trays again.

Natural Reeds

You need to use a reed splitter for natural reeds and other similar nesting materials like bamboo. This saves your fingers from any accidental cuts.

3. Scrape Off the Cocoons 

Once the nesting material is open, carefully scrape the cocoons off using chopsticks or any other material that isn’t too sharp. This is where it can get a bit messy. 

Close-up of Beekeepers Harvesting Mason Bee Cocoons

Don’t worry; finding various things inside the nest cells is natural. You can find anything from mite droppings to dried mud.

Sometimes, you may also find dead cocoons. Discard these and other cocoons with visible parasite infestations.

4. Rinse, Scoop, and Dry the Cocoons

After scraping, rinse the healthy cocoons in the bleach solution to wash off the mites. This won’t kill the cocoons because they have tough shells and are hydrophobic.

Use the strainer to scoop off clean cocoons from the bleach solution and dry them using clean paper towels.

At this point, you may also opt to keep a record of the cocoons, how many in total, and how many males and females. You’ll notice that there are cocoons that are bigger than the others; these are male mason bees.

Keeping a record will help you visualize how your bee population is doing in terms of numbers.

5. Store the Cocoons Until Spring

All that’s left now is to store the clean cocoons. Place all of the healthy cocoons in a clean storage tray or container, and then poke holes in the cover to make it breathable.

Put them inside the refrigerator, preferably in the crisper drawer. 

To prevent dehydration, you can place a damp paper towel near the cocoons—not on them—to maintain humidity and moisture inside the tray. 

Check every now and then for signs of mold. If you see any, remove the damp paper towel, as there might be too much moisture inside the tray.

Final Thoughts

To sum up, do you have to harvest mason bee cocoons? 

Yes! The process of harvesting, cleaning, and storing mason bee cocoons protects them from parasites and helps them survive through their dormant period.

Mason bees are important pollinators, and it’s a bee keeper’s best interest to give them the best chance of surviving and creating healthier populations. Healthy bees can help pollinate more fruits and flowers.

By harvesting cocoons, you’re contributing to the conservation efforts surrounding mason bees and, ultimately, helping their populations thrive.