Why Harvest Bee Cocoons?
People often ask why harvesting mason bee cocoons is important.
Here's a helpful analogy? You wouldn't get a new puppy, buy him a comfy pillow, and then put him in a dog house infested with fleas. If you did that your puppy would suffer, loose vitality, scratch endlessly, and can become very ill or worse. Instead, you would do whatever is needed to protect your puppy.
In the same way, mason bees have many natural enemy pests that claim countless numbers of bees each year.
The photo shows a cell filled with mites and mite poop. The orange is mostly droppings. The mites are numerous but they are somewhat clear to whitish colored. You will not find a bee larva in the cells with numerous mites. The mites either destroyed the bee egg or ate the bee larva food supply so the larva starved.
While the bees have few defenses against them, we can help save them from the agony of defeat.
How Nature Works
Here's how it happens. In nature, wild mason bees find holes left behind by wood boring insects or look for hollow stems to use as nesting tubes. Pollen mites collect on the bee when foraging for pollen. While the female is building the cells inside the holes some mites drop off in the pollen pile.
The mites multiply rapidly numbering hundreds or thousands in a short time. The bee egg within those infested cells are killed. The mites are usually locked into the single cell due to the mud walls separating the bee larva.
In the spring, the emerging bee must break through the mud wall and crawl through the wall of mites where they immediately cling to the bee's body. The blossoms and tree leaves get infested with mites that are scratched off by the bees. Other bees pick up the mites. When the bees enter a new nesting hole, the mite invasion starts over again.
What You Gain From Harvesting Cocoons
When you examine the cocoons you will immediately notice the male to female ratio (male cocoons are a third smaller as shown in the photo). The ratio should be about 50/50. Too many males means your tubes are too short.
(Photo courtesy of Dave Hunter)
Other Methods of Protecting Your Bees
prevent other pests from preying on the bee larva, gently remove the
nesting boxes shortly after the bees stop flying. This is sometime
around the first of May in most areas. Place the box in a net bag, i.e.
Bee Guardian Net Bag. You can use hose stockings of you prefer.
Place the net bag in a well-ventilated corner of the garage. This keeps the parasitic wasps, carpet beetles, and other insects from entering the nests.
In the fall you can harvest the cocoons and place them in a small humidity box (plastic container with vent holes and a damp paper towel). Make sure the wet towel is not touching the cocoons.
Do not harvest the bees too early or they will be underdeveloped and die. November is a prime month for harvesting mason bee cocoons.
Method One - Washing the Cocoons
This method involves washing the mason bee cocoons in a bleach and water solution. Don't worry, the cocoons are tough and will not be hurt. This does not kill the mites, but washes them off. The mites are extremely hard to kill, even with bleach.
Method Two - Using sand to Clean Cocoons
This method was developed by Hutchings Bee Service, British Columbia.
After Cleaning Cocoons
After cleaning the mason bee cocoons, put the clean cocoons in a breathable sealed container and place them in the crisper drawer of the refrigerator. Place a damp paper towel in the container near the cocoons to provide humidity. Do not place the cocoons directly on top of the wet towel. Storing them in the refrigerator is the best method because you can keep them in hibernation until you are ready for them in the spring.
An important caution if storing cocoons in a non-heated garage during the winter:
A second option is to place the mason bee cocoons in a non-heated garage or shop building. If you experience several days of unseasonably warm weather, the heat may warm the cocoons enough to trigger an emergence. If that happens, but is followed by freezing weather, or if you have no blossoms yet, you will lose your bees. For this reason, it is better to keep them in a controlled environment.
Mason Bee Pollination vs Honeybee Pollination
Both mason bees and honeybees are incredibly beneficial to life on earth. Both bees pollinate, but their methods are different. Find out why researchers say the mason bees are the better pollinator.
The Orchard Mason Bee's Life Cycle and Behavior
Learn about our native Orchard Mason Bee life cycle. You will also see why this bee is so gentle and great for home gardens and backyard orchards.
Protecting Your Bees From Pollen Mites
Pollen mites can harm your bees. If you harvest your mason bee cocoons (and you should), learn how to remove mites from bee cocoons to ensure a good spring emergence.
Nature can only go so far in protecting bees. Harvesting your mason bee cocoons benefits your bees in more ways than you know. Don't skip this Step! Read this page to find out how.