[Ben Brewcat]

I recently went to a lecture by Dianna Sammataro in which she talked about this very topic. Her recent research is exploring the microflora of the honeybee gut, which includes scores to hundreds of organisms (including fungal organisms like yeasts). These help the bee (just as microbes in our guts do) by producing B vitamins and other compounds that may play important roles in individual and colony health. Fungicides, usually thought to not affect honeybees much, seem to (predictably) be damaging to the bene microbes in bee guts, potentially contributing to nutritive deficiencies. Her presentation showed a couple pallets of colonies in a fog from the fungicide sprayers/generators that were just down the row from them...

Note that there were a lot of "may" and "potentially" caveats in there... it's deliberate . She was at great pains to stress that this is an avenue of investigation at this point. But the premise, to me, is compelling and merits investigation.

 

[Tom G. Laury]

In general, the fungicides are not highly toxic to the bees. However, in the right conditions being sprayed with cold water can drop them to the cold ground where they perish. One exception to this is a formerly common fung. Captan. It will kill the heck out of all the brood.

 

[JohnK and Sheri]

Yes, it is a growing concern, not just for almond pollinators but queen rearing colonies coming back from almonds.where fungicide (Pristine is the one I've heard mentioned) is being used. If fed to the larvae it kills it, so pollen in the combs of queen builders is a serious issue. In the case of pollination colonies, if that pollen can cause losses of brood, it could set a colony way back, while not necessarily causing it to totally collapse. This could happen months later if that pollen were stored and gotten into later.
The fungicide distributors tell the growers it is not toxic: the growers tell the beeks it is not toxic, but there seems to be enough smoke to seriously suspect a fire.

Growers expect a certain frame count going into the groves. Perhaps beeks will need to consider inspections of colonies leaving the groves as well.
Sheri

 

[loggermike]

This will be a good year to look for any effects from fungicide. I think they sprayed around 3 times during bloom.I am finding the hives to be fairly heavy, with an abundance of almond pollen stored around the brood. The hives are looking really good right now

 

[Tom G. Laury]

The Captan kills would be evident while still in the orchard. They threw out piles of pupa.

 

[mbholl]

Used to think of all that stored pollen as a good thing... Now I wonder if it will be something that will be detrimental next fall/winter when the reserves are dug into?

 

[Beeslave]

Captan kills . They threw out piles of pupa.

Are you saying you saw this or if captan was used that is what would have been seen?

 

[Tom G. Laury]

I personally observed this in my own colonies three years in a row in the same orchard. So many dead pupa in the front it looks like flying bees got knocked down, but on closer look it's all pupa. Like all that there were inside. Really ruins the colony. Captan.

 

[JohnK and Sheri]

Tom, that is pretty much identical to what I've heard, but with Pristine being named the culprit: virtually all larvae dumped out in front of the hive, in the orchard. If someone wasn't paying attention it could easily be missed when colonies got scooped back up and sent home. Without seeing the dead pupa and quick decline of the colony, an owner might just figure it had been going backwards for a while and consider himself lucky to get paid on his contract. It is sometimes difficult to connect the dots, especially if one doesn't want to deal with accusations of PPB.

But also reported were more delayed effects on larvae feeding from Pristine sprayed pollen stores, again, with pupa all around the entrance. Devastating enough to any colony but doubly devastating to queen rearers and those who depend on them.
I would imagine queen pricing would take a substantial hike if those colonies had to be quarantined from the valley during almond bloom.

Sheri

 

[Ian]

I spray fungicide on my growing crops, one crop being blooming canola. I have never seen any losses directly related to my applications of fungicides, but I would be able to relate my application to any long term colony depression.

One thing I will pass on, out of all the chemicals I apply fungicides are the hard on the system. They have a binding agent in them that can make a guy ill.

 

[MABee]

My hives were in an orchard that was sprayed 3 times, during the day. Once with Pristine. Like L. Mike, my bees look really good. Guess wait and see.

SIDE NOTE... Give almond growers some credit. They aren't out to kill the bees that are putting food on their tables. All they do is follow the fungicide product label instructions. And if the label says not harmful to bees, then thats all most will ever know. How many beeks are using off label or homemade treatments knowing its not good for bees/queens, but "what else am I supposed to do?"
A lot of growers in my area in the last couple years have tried spraying more at night with the understanding that when the bees are working and you spray them with cold water, its gonna knock them down or send them back to the hive. They know how important the bees are to their bottom line. If anything higher pollination prices make them realize that they need to take care of every little bee in the orchard! But like this year when rain storms were so close together and they have x # of acres to spray with y # of machines with only so many hours of non bee flying time, they start to get nervous and spray during the good bee flying weather! Just insight from the almond grower side in me or my 2 cents worth.

 

[Ramona]

I've been looking at the bee associated microbes for about two years now, ever since I heard that pollen has to ferment to become viable food for bees. Fermented pollen (beebread) boosts the protein content of pollen and supplies necessary substances. The beebread functions not only as food but medicine for the colony.

The fermentation process takes a couple of weeks, beginning with inoculation of the pollen by the bees with unique bacteria from the honey stomach. Fermenting yeasts provide food for more bacteria and eventually lactic acid ends up preserving the pollen creating a "pollen pickle". Because amino acids, vitamins, enzymes, antibiotics, proteins, sterols, etc., are being synthesized and/or released during this process, it's really important that it be allowed to occur uninterrupted. One sterol, 24-methylene chloresterol, is necessary for developing brood . If it is unavailable in the beebread, the bees will pull it from their bodies. After ~ two brood cycles, the bees will run out and be unable to feed the brood properly unless they have an influx of real pollen. Pollen supplement preserved with lactic acid is not the same as real fermented pollen. Any pollen supplement must have at least some (10-15%?) to be effective.

Formic acid, oxalic acid and HFCS all alter the fungal mycroflora of the colony. Balanced fungi are important in disease resistance as some fungi that can cause one bee disease can prevent another. Inhibiting some can open up niches for others to expand. The fungi also synthesize antibiotics and one particular fungus seems to be responsible for synthesizing 24-methlene chloresterol (this seems to happen within an hour or so of the bee collecting?inoculating the pollen).

When we first started looking into the microbes two years ago we immediately thought of the implications of formic acid which on the Miteaway 2 site is described as an anti-microbial. Fungicides also came to mind as a concern. Since then, we've learned that while fungicides are considered OK for bees as they don't outright kill them, they end up highly concentrated in beebread. Even if the grower is extra careful to not spray on open blooms, some fungicides that are labeled as "contact" actually function as "systemic", migrating through the foliage, and can show up in the nectar and pollen 3-5 days after spraying. Before the bees can even gather and inoculate the pollen, the microbes are already inhibited with the fungicides. The yeasts and their byproducts seem to play an extremely important role in the nutrition and "medicinal" value of the beebread to the bees...it makes sense that fungicides could inhibit the fermentation of the yeasts outright.

Because the window of opportunity for larval feeding is so short (6 days) any colonies exposed to fungicides or organic acids could experience glitches in larval development. Those bees suffering from sub-par nutrition and underdeveloped hypophrangeal glands (where brood food comes from) then have to go on to feed a next generation. Small deficiencies over time can have big impacts.

There was a recent discussion on Bee-L about the pollen being so contaminated on crops that beekeepers doing pollination are now feeding pollen patties while the bees are foraging to discourage them from collecting and/or consuming the pollen in the field.

The more we learn about the microbes the more fundamental they appear to be to the working of the bees and the colony. The microbes, bees, flowers and pollen have co-evolved over millions of years to function together in highly specialized ways.

I'm away from my house right now but have a whole file box full of studies that back up everything here. If anyone is interested, I'll be happy to post the titles of relevant studies when I get a chance. There are also pending releases of studies looking specifically at the effect of fungicides on beebread...not sure when they will be out.

Our best hives are far from any agriculture. Our most challenging locations are the ones closest to farms and orchards (not monoculture crops, small operations). This is our observation, not a statistically significant sample.

Ramona

 

[peterloringborst]

I think it is time to reevaluate the effect of fungicides used on blooming crops. Since these don't usually kill bees outright they are allowed. There is mounting evidence that they are harmful to colonies if stored in the hives with pollen

Fungicides usually are not a cause of concern for honey bee poisoning. At labeled field application rates, captan sometimes is associated with larval and pupal mortality. Honey bee broods are lost at a time when the colony population should be expanding. Studies by staff at the USDA Bee Lab in Weslaco, TX, show that honey bee impacts due to captan are related to formulation. These results suggest that it is not the captan itself, but other ingredients in some formulations, that cause developmental problems. These findings are under review for publication.

Iprodione (Rovral) is another fungicide of concern. During studies at University of California–Davis, some honey bee larvae died when exposed to iprodione. Others develop into large, robust pupae that do not develop into adult forms. Other dicarboximide fungicides might affect bees similarly, but such effects have not been determined experimentally.

Fungicides containing captan or iprodione should not be applied to blooming crops during the pollination period.

Certain combinations of demethylation-inhibiting (DMI) fungicides, such as propiconazole (Alamo, Propimax, Quilt), with synthetic pyrethroids, such as lambda-cyhalothrin (Taiga Z, Warrior) have been shown in the laboratory to be more toxic to bees than the insecticide alone (Pilling and Jepson, 1993) because these fungicides reduce the ability of the bee to detoxify the insecticide (Pilling et al., 1995). It is essential that growers read the pesticide label to determine whether specific tank mixes might prove toxic to bees. These problems might also arise if neighboring crops have been treated separately with two materials that can prove hazardous when they are combined.

2010 Pest Management Guide FOR TREE FRUITS IN THE MID-COLUMBIA AREA
Hood River • The Dalles • White Salmon EM 8203-E • Revised January 2010

 

[Action]

Arn't you working in (Spraying) The Orchards you are pollinating?
Jack

My hives were in an orchard that was sprayed 3 times, during the day. Once with Pristine. Like L. Mike, my bees look really good. Guess wait and see.

SIDE NOTE... Give almond growers some credit. They aren't out to kill the bees that are putting food on their tables. All they do is follow the fungicide product label instructions. And if the label says not harmful to bees, then thats all most will ever know. How many beeks are using off label or homemade treatments knowing its not good for bees/queens, but "what else am I supposed to do?"
A lot of growers in my area in the last couple years have tried spraying more at night with the understanding that when the bees are working and you spray them with cold water, its gonna knock them down or send them back to the hive. They know how important the bees are to their bottom line. If anything higher pollination prices make them realize that they need to take care of every little bee in the orchard! But like this year when rain storms were so close together and they have x # of acres to spray with y # of machines with only so many hours of non bee flying time, they start to get nervous and spray during the good bee flying weather! Just insight from the almond grower side in me or my 2 cents worth.

 

[Ian]

>>I think it is time to reevaluate the effect of fungicides used on blooming crops. Si

That is so easy for a beekeeper to say, but tell that to a farmer and they will out right tell you to bugger off.
I know what your saying, and in a way agree, I also would wave a HUGE wand of caution before we go down this path.

Are we not having trouble enough with insecticide poisoning? Here we can directly link improper application to colony death.
Now try to tell a farmer not to apply fungicide?

ya, reevaluate fungicide application,
but lets get some hard science behind us first

 

[Beeslave]

They have a binding agent in them that can make a guy ill.

While I was working the bees in the almonds that were blooming I had no problems(health). One day later that week my sinuses were running and I got a terrible headache. I figured it was from the pollen, and it could have been but I had no problem the previous 4 days. I heard the sprayers working and never thought of that being the cause. Later they got closer to me and a cloud of the spray hit me in the face. That's when I realized I had been working for 4 hrs with the wind blowing the spray from the other side of the grove towards me. I stopped the bee work and went back to the hotel. The next morning the orchard manager told me that the applicator of the fungicide doesn't need to wear a respirator when applying and that was not the cause of me feeling bad. Needless to say I used my own judgement and avoided the turbo sprayers and the drift. No more runny nose or headache. While I was there I made 100 splits. They were made with 1 frame hatching brood with attached bees, 2 frames with honey/pollen and attached bees, plus I shook bees from 3 frames of brood to repopulate deadouts. I figured I shook plenty of bees so when the foragers flew back there would still be enough bees to cover the brood and then some. 50% of those are now empty with abonded brood. I'm not saying the fungicides caused this problem but it has me wondering. I've made plenty of splits this way in WI and never had anything like this happen. The bees will be back to WI this week so I will be able to see for myself what I have to deal with. If a hive is just starting to have some good brood hatching and most of the population consists of foragers that are in the field getting knocked down it can't be good for them.

 

[peterloringborst]

>>I think it is time to reevaluate the effect of fungicides used on blooming crops. Si

That is so easy for a beekeeper to say, but tell that to a farmer and they will out right tell you to bugger off.

ya, reevaluate fungicide application, but lets get some hard science behind us first

If you read the rest of the message, it is clear that Oregon has already revised its recommendations, advising not to apply certain fungicides on blooming plants.

If I was a beekeeper, and pollinated a crop, and the grower told me to bugger off, I would cancel the contract. The main leverage the beekeeper has is the pollination he/she provides.

Meanwhile, regulations on fungicides are based on toxicity studies on adults. If studies show longterm effects, the regs will have to be changed.

Why are they spraying plants in bloom, anyway?

 

[Ian]

Ya, your talking almonds, Im talking canola
farmers who arnt totally dependant dont see pollination as a service, just a side benifet

>>Why are they spraying plants in bloom, anyway?

Most all fungicides are applied during the crop bloom period, reason for the application of the fungicide in the first place, to protect the seed
also some to protect plant

 

[peterloringborst]

>>Why are they spraying plants in bloom, anyway?

Most all fungicides are applied during the crop bloom period, reason for the application of the fungicide in the first place, to protect the seed
also some to protect plant

I still don't get it. Is there seed when the plant is in bloom ???