Hard year for our mason bees! But why?

[kincade]

We are having a tough year for our mason bees for some reason... I'd love any comments from the experts as to any causes or remedies for next year.

Last year we lost a lot of our cocoons to Mono wasps in early June (they even bored through the thick craft tubes). IIRC we ended up with about 60 or so cocoons after throwing most of them out (candled with a flash light to see the wasp larvae). This year I supplemented my remaining cocoons with an order of 20 and 30 cocoons from one of the well respected suppliers in order to build the population back up. We have 2 bee homes and my cocoons went in the top house and the 'replacement' cocoons went in the bottom.

Of my original cocoons most of them hatched but something is wiping them out in a hurry. All were placed out about 3-5 weeks ago and only 2 femalesremain. Last week there were 11. I found one dead on the ground, and another headless in the box. I haven't seen any birds around the boxes, and both our honeybee hives are thriving so far with no evidence of pesticide poisoning.

Even stranger, of the 'replacement cocoons' most never hatched. All were wintered together in my fridge in 2 separate boxes but the same environment.

I don't understand what happened this year and likely never will, but it's somewhat frustrating after doing everything by the book. Last year we had a fantastic year until the Mono hit. This year who knows? Maybe they had a poor pollen resource and ran out of fat reserves?

Here are a few photos. Note the queens that I cut out of the cocoons, one very dark and one very light.

mason01.jpg

mason02.jpg

mason03.jpg

[rwurster]

Aye rough year here too. Last year by this time I had probably 1000 mason cocoons, this year, i probably have 50 i would estimate. The mild winter with the intermittent hard freezes are what whacked ours I would believe. It's actually getting late for mason bees in their life cycle, I personally am not going to sell any this year and keep the cocoons for next year. SLC and where I live have really similiar climates so I would say that the weird winter might be the cause but you mention queens... do you mean females? anyway i summer/winter mine outside in a shed where predatory wasps are dealt with in a unique way but I don't understand why yours would not hatch unless there was excess moisture in your fridge or something weird happened to them in cold storage.

[kincade]

Rwurster, yes, I meant females. Post corrected.

Thanks for your input. Did you overwinter your cocoons outside? I left mine in a fridge, 36*, in a small humidity controlled drawer. No power losses and nothing out of the ordinary at all. Do you think excessive humidity could cause them to not emerge? I stored my cocoons in this:

http://www.crownbees.com/crown-bees/...idity-chamber/

I didn't use that last year, but I wouldn't think a slight bit of humidity would hurt the cocoons as long as it was not excessive.

I'd be interested to hear how you deal with with predatory wasps.

[cpm]

They seem pretty tolerant of high humidity, at least for a while. I had mine in the crisper and actually found a layer of mould growing on them. Yet my hatch rate was as good as ever (close to 90%).

[Stromnessbees]

Don't forget that low level neonicotinoid pesticide damage usually doesn't show any immediate symptoms. If the bees have collected contaminated pollen and reared their larvae on it these larve will have a compromised immune system and probably some damage to the central nervous system which makes them helpless against varroa and other parasites.

In honeybees it has been observed that in areas with sublethal level of neonicotinoid poisoning colonies keep replacing their queens continuously as the queen larvae cannot fully develop in presence of these toxins - the beekeeper observes continuous supercedure and doesn't get to harvest much honey.

[kincade]

CPM, never found mold on mine. Utah is a desert so the humidity is exceptionally low here. I was hoping the humidity tray would help with that.

Strom, thanks for the observation. I actually wondered about neo pesticides but I'm not sure anyone around here uses anything like that. It's mostly lawn care products and such (and they DO use a ton of these). However, your post is a bit confusing to me. I think you have Mason bees confused with Honeybees as to my knowledge varroa are not an issue with Mason bees (no brood cycle, no larvae for 28 days, etc). But I can see how any kind of poisoning would render the larvae much worse off.

[Stromnessbees]

When I mentioned varroa I was refering to this sentence:

I haven't seen any birds around the boxes, and both our honeybee hives are thriving so far with no evidence of pesticide poisoning.

I can imagine that any type of bees that is reared under the influence of sublethal doses of neonicotinoids would have reduced lifespan, reduced immunity and reduced resistance to parasites.

Furthermore, in honeybees many instances of continuous supercedure have been observed, which indicates that pesticide-compromised queens have inadequate pheromone systems.

[jonathan]

Early supersedure of queens is more likely to be associated with nosema levels as there is literature going back several decades documenting this.

https://w3.avignon.inra.fr/dspace/handle/2174/442

[Stromnessbees]

Early supersedure of queens is more likely to be associated with nosema levels as there is literature going back several decades documenting this.

https://w3.avignon.inra.fr/dspace/handle/2174/442

What's going on here, are you tracking me?
Since when have you been interested in mason bees?
Or are you just here to defend the pesticides again?

Do I have to add 'tracking' to this list?

Methods employed by a certain group of posters who have nothing better to do than to defend the latest pesticides:

Strategy No. 1: write nonsensical or distractive posts in order to make the thread boring and uninteresting to any genuine beekeeper who is interested in making honey and keeping his bees healthy. - Please notice that these posters are working as a team, boosting each other and driving the thread away from its original intention.

A second strategy is to make the pesticide-sceptic look ridiculous, foolish, fanatical, an outsider or - a favourite - calling him a conspiracy theorist. They will also try to associate him with unpopular persons or movements.

A third strategy is to baffle the genuine reader with science: they claim that if you haven't read certain scientific papers from beginning to end you can't take part in the discussion, they make you feel inferior. - Not-so-subtle psychology being used here in order to frustrate you and to scare you away from the real issues.


Once you know the game you will laugh about it every time you see the team in action!

[rwurster]

I missed your post earlier. There's an entomologist who has a strategy for keeping losses due to parasitic wasps to a minimum. I'm pretty tired but I'll browse my bookmarks for it and post the link. It has worked well for me.

[beewest]

In my opinion, regardless to what anybody says I strongly believe the use of cardboard tubes alone is not suitable material to protect the mason bees from mono parasitic wasp. In my 14 year experience raising mason bees the best overall protection is achieved by drilling 3/8 holes in wood trays and either inserts an Easy-Tear tube or do your non-glue paper liners. With this method only 1 or 2 % of the cocoons are lost. Believe me I know the fillings when one find the best cocoons have been taken by this parasite. If our friend KINCADE wishes I will send him one of this tray, so to have a better idea of what I am talking about. (Free as show and tell)

[Omie]

I am having a pretty good year for my mason bees- mostly horn-faced and blue orchard.

http://youtu.be/JxdwuHQLboQ

http://youtu.be/6Pk8CYvGR4c

I lost some cocoons in the stored paper tubes...some pollen mites, some black mold. But in general I have 3 times as many live nesting bees now as I had last year, so I consider it a successful year.

[Gyozu]

I use wood blocks with parchment paper liners. the holes are oversize so the paper gets wound up to make the tubes the right size. There are about 3-4 wraps to make the tube.

The tubes are longer than the block so I bend down the end and screw on a plywood back. It was leaving a gap for the wasps to get in and I would see about 15 tubes suffer wasp damage due to the access this gap provided. I stopped this by making sure the tubes only stuck out 1/2 and wrapping the seem with electrical tape. That cut loss to about zero.

I'm trying grooved trays this year and we will see.

[kincade]

Rwurster, I'd love to know what your technique is. Mono is a huge problem here. As beewest alluded to, cardboard isn't enough to discourage the mono wasps in these parts. I lost nearly all my tubes last year that were in cardboard, and even some in the kraft cardboard tubes. Only the reeds seemed to keep the wasps at bay.

Beewest, I'd love to try one of those trays. I'm in the states though, so shipping might be prohibitive?

Omie, your houses look GREAT! I'd call that an amazing year. I ended up with only 31 filled reeds, even less than last year. After 2 years in a row, I'm wondering if there is something here that is preventing the masons from thriving.

Gyozu, I'd love to see pictures of your blocks. I may try grooved trays next year if I decide to pursue this farther. But I don't believe whatever is killing my Mason bees is related to their nesting material. Something either happened last summer or while they overwintered to prevent them from emerging. Over 1/2 of my cocoons never hatched, and the queens that did fly seemed very short lived.

I have wondered if the warm snap this spring did something to them. last spring was cold and rainy. this spring we had 90* days in March, and I'm wondering if it was TOO warm for them and they died in their coccoons?

[Gyozu]

Gyozu, I'd love to see pictures of your blocks. I may try grooved trays next year if I decide to pursue this farther. But I don't believe whatever is killing my Mason bees is related to their nesting material. Something either happened last summer or while they overwintered to prevent them from emerging. Over 1/2 of my cocoons never hatched, and the queens that did fly seemed very short lived.

Here is a link to some Bee block photos from 2011 and 2012. If I get about 8 cocoons/ tube, I'm going to have a boatload of them next year.

http://s164.photobucket.com/albums/u...0Bee%20Blocks/

I won't know how the trays did till next year. Besides cocoons, I will be interested in how much time it takes to turn around the trays.

It has been strange around here. Almost no bumble bees and last year they were everywhere.

[kincade]

Very nice. I'm interested to hear how your grooved blocks do. I like the idea of using milk cartons for emergence boxes. What is the purpose of the foam in the emergence boxes?

[Gyozu]

Very nice. I'm interested to hear how your grooved blocks do. I like the idea of using milk cartons for emergence boxes. What is the purpose of the foam in the emergence boxes?

To tell the truth, I can't remember. Might have been to load the cocoons into the milk box.

This year I used Small priority mail boxes with a couple of holes in them and taped shut. Stacked them 4 high in the bucket and added cardboard seperators between each layer for a rainshield/porch area.



Click to enlarge.

[Omie]

Omie, your houses look GREAT! I'd call that an amazing year. I ended up with only 31 filled reeds, even less than last year. After 2 years in a row, I'm wondering if there is something here that is preventing the masons from thriving.
I have wondered if the warm snap this spring did something to them. last spring was cold and rainy. this spring we had 90* days in March, and I'm wondering if it was TOO warm for them and they died in their coccoons?

Kincaid, thank you! I'm very proud of the simple yet beautiful boxes my husband made for me, and the ease with which I can now merely load the 6 pineapple juice cans in them and fill with straws. The box hold 6 cans which hold 75 tubes each- a total of 450 straws. This setup has proved so successful for me that my population has more than doubled each year. I have set myself a limit of 2 such boxes on my porch, because I realize the forage/food supply in any given spot is not unlimited. I like to think some of my bees wind up finding nesting further out in various directions, thereby expanding their range and population outward from my 'home spot'.
This past week there were SO many mason bees (horn-faced and blue orchard) filling up the tubes that they were literally almost out of tubes in the first box of 450 straws. We put up a second identical box underneath the first box, and I only put about 250 new straws in it. I hadn't even finished placing the straws in the new cans when females were already flying their way past me standing in front of the box and choosing new straws and getting to work in them! They were so enthusiastic that they were literally going into the straws that I was adjusting the position of with my hands. So I'm hoping the new straws will be enough for them.

To tell the truth, I can't remember. Might have been to load the cocoons into the milk box.
This year I used Small priority mail boxes with a couple of holes in them and taped shut. Stacked them 4 high in the bucket and added cardboard seperators between each layer for a rainshield/porch area.

Gyozu- I love your milk carton emergence box idea- thanks, will use it next year!

Question for all- in an emergence box, is it better to put the little escape holes near the top of the box, or at the bottom? (Better in terms of letting them out but discouraging them from trying to get back in to nest in the old straws)