On facebook, in the Beediverse bee group I was asked why only 50% of their cocoons hatched. This looks like a complicated puzzle, but I have seen it once and think I know why this happened.
I think the problem is that the bees that did not emerge did not have any fat body reserves left by the time spring came around.
It is truly amazing that the female lays the egg with enough pollen and nectar reserves to grow a bee that has enough fat stores for the bee to eat her way through to the outside world, and never mind the overwintering metabolism. It is all about whether the bee uses all her fat bodies while she is going through the autumn and overwintering period. If temperatures are unusually high in the fall, the bees’ metabolism is also unusually high, and the worse case scenario is that the bees run out of fat stores and perhaps die. What I have seen is when bees are kept in a warm basement over part of the fall and winter, there is the little energy or fat stores left to eat through the cocoon to the outside world. Sometimes bees are still moving, but after manually removing the bee from the cocoon, she ends up dead. More usually, you find a perfectly normal dead bee inside a cocoon. I don’t expect that bees can look ‘wasted’ because their exoskeleton keeps them in one shape only, no matter how wasted they are on the inside. Hope this helps.
During the summer months, remove nests from hot sites that for example, face the hot afternoon sun. Store them under cover, away from direct sun.
Tim started harvesting his mason bee cocoons from his wooden trays last week using our fabulous SCOOP. He emailed me this photo showing a very good harvest. 60 cocoons in just one layer.
See what your harvest looks like per female cocoon. And see what your mite infestation is to tell you how well you removed mites from cocoons before setting them out in the spring.
In spring before setting cocoons out, count the number of total cocoons. This will help in calculating if your harvest is a good one.
Total at site in spring = 600 or 300 females ( about half of total)
Tot cocoons harvested = 1540
Lets look at the numbers:
Each female produced 1540/300 or 5 offspring. Nothing wrong with this production.
Before removing all the cocoons, count the total number of cells with or without cocoons
TOTAL CELLS with cocoons and CELLS WITH MITES
8 and 0 (First tunnel at the top)
9 and 0
9 and 1
9 and 2
9 and 0
7 and 0
10 and 0
2 and 0
63 and 3
Number of cells with mites/ total cells x 100 = Percent of mite infested cells
or 3/63 = 4.76%
If the percentage of mite infested cells is less than about 5%. You have done a good job of cleaning mites of cocoons and nests.
In this case mite infested cells is 4.76%
Good job Tim!
Things you might see while harvesting and cleaning cocoons
Cleaning cocoons and freeing them from pests is like any gardening adventure. Keep pests low and you will have a great harvest.
Pollen lump amongst cocoons.
These are cocoons harvested from nesting tunnels and placed in water just prior to washing.. Cocoons are still covered with various debris. At the top left hand corner of this picture is the tip of a Beediverse scoop. It is pointing to a pollen lump. A pollen lump found in a nesting tunnel means that the bee larvae died and did not consume the complete pollen lump. This most often happens when a period of cold weather makes it impossible for the bee larvae to live and feed on the pollen. Various debris still adhere to cocoons.
These larvae are in the nest because earlier in the spring a fruit fly laid her eggs on top of a mason bee pollen lump. These fruit fly larvae eat the pollen and leave nothing for the developing bee larva. This new species of fruit fly has been on the west coast of NA for more than 5 years now. Removing these pests will remove potential pests from next year’s nest.
Here are two rows of healthy looking cocoons. But look closely, they are lightly covered by tiny pollen eating mites (white specs). Pollen eating mites feed on pollen lumps left behind for the bee larva. These pollen mites feed on the pollen and leave nothing for the bee. In the lower right hand corner is a cell fully loaded with mites. Mites are always present and can be a real problem for bees if these are not removed every year. Mites can easily be washed off under running water while rolling cocoons in a sieve.
Keys to success
Storing harvested and cleaned mason bee cocoons is easy when 2 facts are taken into consideration:
1. Storing cocoons outside works well when outside humidity is at least 60% and winter temperatures dip around or below freezing for about 2 months. The key to success is protection from other animals. Our Beediverse Hatching box is made from solid wood and keeps animals out. This method works well until temperatures go over 2-4C. Before temperatures go above this range, rotate lid of hatching box and bees can emerge as temperatures rise
- Keep other animals from eating cocoons
- Store in a cold place with approx. 70% humidity for two months to ensure proper overwintering.
2. Storing bees in a fridge at 2-4 C keeps bees hibernating until you want bees to start pollinating. Keeping humidity above 70% is the key to success. Our Beediverse Humidity cooler has a compartment for water and this makes it easy to keep humidity at the right level when storage is inside a fridge.
3. For temporary storage after candling, our candling dish is the tool to use. Dishes can be stacked until setting cocoons into a storage system.
These photos below clearly show what is a ‘good’ cocoon and a cocoon that needs to be discarded. In one cocoon a bee is clearly outlined showing its feet and mouth parts. The next photo is empty with the remains of a dead larvae. These are discarded. (You may want to have a closer look at what is inside these cocoons). The most common parasitic wasp species have about 10 little wasps per cocoon.
OVERVIEW OF HARVESTING COCOONS
- Harvesting cocoons begins by opening nests and carefully removing cocoons with a scoop.
- Cocoons are placed in water to remove sand and mud and some mites.
- Then cocoons are rinsed under running water while in a metal sieve to remove remaning mites,
- The final rinse is in a weak bleach solution (0.05%)
- Cocoons are dried for about 1 hr on a paper towel.
- Dry cocoons can then be candled. Candling is done over a flashlight (6V with an irridescent bulb) in a candling dish in a dark room to remove any parasitized cocoons.
- The final stage is cleaning the nesting trays .
If you are planning on ordering mason bee cocoons and or nesting supplies- do it before spring. Mason bees emerge when it gets warm, and having things prepared for them is the way to proceed. What is this insect?
To Dr Margriet Dogterom,
My Grandson’s monetary Scout Project is to make money for the Scout Jamboree in NS. This project started me with Mason Bees for New Brunswick area along with a retired bee keeper/neighbor. Picture #3045 is my first prototype after reviewing video’s on the internet about mason and leaf cutter bees. These worked well in trees near to flower and vegetable gardens (interesting for talkative neighbors). In picture #3071, the 10 houses on top, were built for a blueberry farmer to place in his fields. The next 5 houses were built to place in Kingsbra Gardens- similar to Buchard Gardens in BC, but smaller. In the town of St. Andrews (named as the best tourist town in 2017) Mason bees are not known here at all, it is hard to promote….. to get houses set up in public places.THIS WAS MY FINDINGS in YR. ONE to all involved with thisI assume I started setting up the Mason Bees houses a little to late this year (June 10th). I am quite disappointed in the results though……. my investigation was Nov. 7th. I found no Mason Bee cocoons. All I got was leaf cutter bee cells instead of Mason Bee cocoons. I also found some pupae that have no covering. (as shown in picture# P1030581). The houses were very easy to take apart and the paper tubes just pulled out for investigation. For some reason the mud was solid on the front of a few …… but bees were dead inside.Needless to say I went on the internet looking for suppliers of “Mason bees Cocoons” this week for in the spring. Your site was the most informative and interesting as you have the tools for teaching and demonstrating properly which I seen today for the very first time. I was just fascinated by your viewing units, your books, your houses and wall literature. May I have permission to foreword your site “product information” to Kingsbra Gardens Management..?? I have made lots of mistakes and wish I had have gone to “Beediverse” prior to getting started I read from someone that the mason bees west of the mountains are a different species than what may survive in the Maritimes? ……..so I may have to get my cocoons from Ontario? ……Is this true?THANK YOU…….. for taking the time to read this infoYours truly …..Ralph S.Hello Ralph,Thank you for your story, questions and kind words. I find it exciting that you are starting with mason bees in New Brunswick. Mason bees are native to North America. The same species Osmia lignaria occurs across North America and these have been named the Eastern and Western subspecies. You should first see if anyone is producing them locally. If not, you will have to look elsewhere. I am not familiar with others who produce mason bees in the East.To start with mason bees, without some additional mason bee cocoons, is difficult. Since you may have set your bee homes in spots with no mason bees. A trap line is one way to do it. Set up a bee home every km or so. This will most likely find you some mason bees that you can start off with at home. Small homes like your prototype is a great way to do it. Image 1593 is not ideal since you cannot harvest bees from these nests nor can one clean these nest types out free of pests. Although pretty- not recommended.It is best to set these bee homes out BEFORE SPRING in order for emerging females to find your bee home. You will have a better chance of finding mason bee offspring.Your bee home design is good- routered wood, stacked inside a wooden home. The paper tubes are not necessary but are useful to keep debris off the wood.Good luck for next year and let me know if you have additional questions- Dr Margriet Dogterom
We were at the wholesale Green Industry conference this week. Met up with lots of retailers and people interested in getting mason bees and leafcutter bees into their stores and making this line of products available to their customers. The viewing home was a highlight. An innovative bee home for sure. And it is beautifully crafted. If was a very exciting 2-day show. We showcased our Beediverse line of products and they liked what they saw.
“Beediverse is the One supplier for all things Mason Bees and Leafcutter bees that are needed in the Home and small orchard markets.” Garden shows are fun events where we can meet up with our customers.