It feels weird calling this a harvest, cause I am not consuming them. But I am indeed "processing" the cocoons and giving them a better chance of survival. And at the same time reducing the predator population of pollen mites and wasps. Without my help, they may only have a 50% success rate or possibly an entire collapse of their local population. So I am happy helping them out cleaning up the cocoons and then storing them until its time for them to be released. Out in nature no one is caring for them, so the predators can really put a dent in their numbers.
Many of my followers ask about the honey, do they make it? The answer is no, but they do collect pollen. But in a different way than honey bees do. Solitary bees tend to cover their bottom part of their abdomen with pollen and then shake it off while in their home. We can see in the above image how much pollen they stockpile. Taking dozens if not hundreds of trips to get this much stored up for their larva to eat.
The bee boards I constructed give them a place to form their mud homes, when the weather is good they will fly back and forth to their favorite flowers and collect pollen. And also they collect mud which they use to seal off the chambers. When the weather is bad, from too much wind, rain or cold the bees will take shelter in the channels. Its cute to see their little bee faces peering out checking to see if the weather has warmed up yet. If its under 55F they are not active.
It would seem the larva do not always eat all of it, so the bees must place more than they need. Though other times they will indeed eat it all and then form cocoons. I have thought about harvesting some of their pollen but just seems like alot of work and the larva need it to survive.
Last year I had some troubles keeping the boards together while removing them from the cubbies. The bees formed mud holding them in place, so by removing them some of the larva may have not made it. So we can see some of these channels filled with pollen where the larva did not make it. This year I have binded the bee boards together using wire hoping that will keep them together and allow me to collect without disturbing the homes.
Not all the channels were filled, and some it appears a be started to mud them over but then stopped. Maybe that bee got eaten by a bird or got lost and did not find its way back. Its hard to say why they did not finish the homes.
Once I clean out the boards, we can still see some mud stains from where they once were. I use a brush to clean them out the best I can.
I eventually got to a cluster of bee boards that had alot of pollen mites inside. These little critters will cling to the bees when they visit flowers and then brought back to the Mason bees homes where they multiply. If left untreated, as the bees emerge from their homes the mites will cling to them and spread to other bees during their breeding cycle. That is one of the reasons I do this "harvest"
The pollen mites are no threat to me, they do not bite but still gross to see 10s of thousands of them crawling all over my cocoons.
The boxes I stored them in have those mites crawling all over the bottom. I dumped them outside in the cold where the mites would die. I will need to wash the trays covered in mites as they will probably die on them and leave a mess behind. I have a big stack of them that needs to be dunked in some water with more spearmint oil.
Many of the channels where I found the mites I noticed the larva were missing, it would seem the mites consumed the larva. Not sure if that is what happened but weird to find missing larva in those channels.
Where I live our dirt has alot of red clay mixed in, this is due to a high iron content giving it a orange color. We can see where the bees used the clay, and then collected some other dirt that was the more common brown color.
The engineering of these solitary bees is quite amazing, building all these homes in just a matter of months. I guess its all possible with the hundreds of female Mason bees that I have. Just always amazed by their handy work.
The wasps were less of a problem this year, as I removed the bee boards before they showed up. Though it would seem they found the boxes I stored them in and since they are not air tight some of the wasps found their way in. After they penetrate the cocoons and lay their own competing wasp larva the adults die.
We can see the dead wasps, though I did not find many so it would seem it helped to protect them somewhat.
A cluster of dead wasps, glad to not see them wide spread as in previous years they probably destroyed 1/4-1/2 of all the cocoons.
The cocoons that were indeed penetrated will not float as they have a hole in them. And that is how I know which are still good cocoons and which ones are bad. I skim the top of the cocoons to remove the good ones. They are all soaked in spearmint oil to kill any of the pollen mites that are clinging to the cocoons. The wasps die by drowning and left at the bottom of this container.
It looks like bee cocoon soup, though I will rinse them off. Dry them and then bag them up. I store them in my refrigerator until the frosts are mostly over. Probably in a few weeks to a month I will take them out and start letting them warm up and give them time to eat their way out of the cocoons. Which they then start the next cycle of adult Mason bees.