I have a suspicion that one of our hives might be suffering from nosemea. The first somewhat warm day yesterday brought all hives activity. It was only 30? but they were still flying nonetheless. One in particular has an unusual amount of bee poop out front. It?s not going to warm up enough for us to feed sugar syrup for several more weeks. Is there any sort of treatment that can be done now?
First off, advice against treating for nosema without a confirmed diagnosis. Take samples and check under a microscope.
Nowadays, you will often find that a bunch of poop does not mean nosema at all.
HP, is there a treatment for Nosema cerena? Please correct my spelling if needed.??
I am not aware of proven approved prescribed treatment for nosema ceranae. Though, beekeepers being beekeepers there is probably some backwoods concoction cooked up somewhere out there.
Quote from: TheHoneyPump on March 08, 2019, 11:06:29 PM
I am not aware of proven approved prescribed treatment for nosema ceranae. Though, beekeepers being beekeepers there is probably some backwoods concoction cooked up somewhere out there.
Is there anyone here that might have a "concoction cooked up somewhere out there." as I quote HP. I for one would like to be informed. I do know that there are several beekeepers on videos which use essential oils for this problem, these guys are breeders at that. But,I have never heard of any of them claiming that this will work for both types of Nosema. But at the same time they have all, of whom I have studied, state, Nosema period. So ?? Hum....
[attachment=0][/attachment]
Electron pic of ceranae:
Mr. Ben, I believe HP is our forum expert on nosema. I know of no one else that scopes and does spore counts as HP.
Nosema ceranae is just plain weird. Check out the above pic: has 6 legs,[i think they are legs] filaments, looks like a mite, 1000 times smaller than a mite, reproduces like bacteria with mother cell dividing into two daughter cells but also reproduces spores like a fungus which it is,,, well sorta. Ceranae is classified as a fungus but unlike any I have ever seen. Just plain weird, breaks all the typical fungus criteria. Known to infect honey bees only with similar fungi bombi that infect only bumble bees.
Under a typical light microscope, nosema likes like translucent jelly beans, but unbelievably tiny as 400X is required for contrast.
No doubt that Mr Claude is one of our premier experts here, so I listen closely to an expert as himself and Mr Bush as well as others here. whom I have confidence in. Even Mr Claude, (HP) left room for the possiability that "I am not aware of proven approved prescribed treatment for nosema ceranae. Though, beekeepers being beekeepers there is probably some backwoods concoction cooked up somewhere out there."
So I ask an honest question to an honest statement which was furnished by one of our experts. To obtain knodlege, we must ask honest, legitimate questions. We must be inquisitive don't you agree? The picture that you posted is an awesome one. And I appreciate your thought and update on this problem. The beekeeper of 2019 has much more to deal with in the way of pest and other ailments that was not present just a few years ago, even though this one might have been. I am glad that you and some of the more experienced beekeepers had the opportunity to enjoy the golden days of beekeeping just a couple generations ago.. must have been awesome! Tell us about it !!
Phil, you ask the right questions, you are way ahead of the typical beek with a single year of experience, I mean WAY ahead.
I deal with nosema by requeening, apis which leaves visible drown splatter and ceranae is just a big mystery to me as I know of no visable or signs for detection. I clean hive bodies that have splatter with vinegar which I read kills the spores. In 2018, I saw no issues with nosema, in 2017 I did have splatter, cleaned and requeened. I just discovered a dead out in my apiary that had small amounts of brown splatter on the inner cover????
Certainly other beeks on this forum have relevant knowledge as well, regarding nosema, but only HP is serious enough to scope and count spores to my knowledge.
As a kid, in Houston Texas, beekeeping in the 1960?s was a piece of cake. Let bees alone and extract honey, no problems that I ever detected. Never lost a hive, never saw abscond, never treated, never a problem, just place a hive within reach of flowers and nature took care of everything. I do remember seeing my bees dragging out one wax moth larva once. Honey bees were completely self supporting without need of any intervention. The 10 frame langstrof deep with one super and full of bees delivered was $35.00 that my Dad kindly took care of the $. The original hive was painted silver. I have not seen a silver hive body since.
Nosema apis pic from the net.
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Thank you Mr Van for the kind words of encouragement. Thinking of the sixties beekeeping days leave me in wonder! I can't imagine not having to worry wirh the mites that we have today, let alone Small Hive Beetles. I will say, as I have said before I am greatful to each of you, which have taken the time to answer my many many questions and the time to teach me,'as well as others here. Borrowing your words,
Blessings
Ben,
Nosema apis is no longer a problem since nosema ceranae came on the scene. I believe n ceranae may kill/eat n apis. I used to have a micro scope with a 400 x power. We would remove the abdomens of about 10 bees and grind them up and put the slurry under the microscope. You could count the number of ceranae in a ring to determine the infestation load.
Jim
Quote from: van from Arkansas on March 09, 2019, 07:16:02 PM
Nosema apis pic from the net.
[attachment=0][/attachment]
Wow, what a mess!
Quote from: sawdstmakr on March 09, 2019, 08:36:26 PM
Ben,
Nosema apis is no longer a problem since nosema ceranae came on the scene. I believe n ceranae may kill/eat n apis. I used to have a micro scope with a 400 x power. We would remove the abdomens of about 10 bees and grind them up and put the slurry under the microscope. You could count the number of ceranae in a ring to determine the infestation load.
Jim
You are a very knowledgeable man Jim. That is very interesting. We are blessed to have you here! Let me ask you. How long have you been keeping bees? 🐝
"Under a typical light microscope, nosema likes like translucent jelly beans, but unbelievably tiny as 400X is required for contrast."
Mr Van sir, I am looking into this deeper, and you are right this is weird fungus. Looks like a live (something).
Quote from: Ben Framed on March 10, 2019, 01:16:21 AM
Quote from: sawdstmakr on March 09, 2019, 08:36:26 PM
Ben,
Nosema apis is no longer a problem since nosema ceranae came on the scene. I believe n ceranae may kill/eat n apis. I used to have a micro scope with a 400 x power. We would remove the abdomens of about 10 bees and grind them up and put the slurry under the microscope. You could count the number of ceranae in a ring to determine the infestation load.
Jim
You are a very knowledgeable man Jim. That is very interesting. We are blessed to have you here! Let me ask you. How long have you been keeping bees? 🐝
I started in 2010. My wife bought me 2 Beekeeping books for my birthday and within a month I had 2 hives.
Jim
Quote from: sawdstmakr on March 10, 2019, 08:23:55 AM
Quote from: Ben Framed on March 10, 2019, 01:16:21 AM
Quote from: sawdstmakr on March 09, 2019, 08:36:26 PM
Ben,
Nosema apis is no longer a problem since nosema ceranae came on the scene. I believe n ceranae may kill/eat n apis. I used to have a micro scope with a 400 x power. We would remove the abdomens of about 10 bees and grind them up and put the slurry under the microscope. You could count the number of ceranae in a ring to determine the infestation load.
Jim
You are a very knowledgeable man Jim. That is very interesting. We are blessed to have you here! Let me ask you. How long have you been keeping bees? 🐝
I started in 2010. My wife bought me 2 Beekeeping books for my birthday and within a month I had 2 hives.
Jim
It didn't take you long to become addicted. 😊 That was a fast transition! My first hives were aquired by the cutout route. I have read some of your cut out topics here.
The microscope is an essential tool in the beekeeper?s toolbox. It is part of the pest and disease management program. Much of what you would do with your own scope, and alot more, is done by your area inspector and supporting lab. All you have to do is ask them. The difference is time to results. There is of course delay to sending samples out. As opposed to putting your own eyes on the microbes in the truck in the beeyard.
Have been using the scope for 40+ years. Always amazed at what is seen and often the results taking us in a different corrective direction than what one would first think and do without the data. In the early years we counted spores. That did not last long. We look for diagnosis levels of: -none, -some, -ohoh now what, -kill it now.
With regards to nosema. I am admittedly a studious follower of Randy Oliver?s nosema series on scientificbeekeeping.com It is is upwards of 17+ articles now and ongoing. I encourage everyone to go there and absorb.
My experience and comfort level with the most troublesome little critters can be summarized as:
- nosema apis, calm casual walk in the park
- nosema apis+ceranae. Frustrating. Lagging colonies. Survive but do not really thrive. Appear as lazy bees. Constantly shows potential in showing of a good brood nest. Yet never really gets going. Stays same all summer or dwindles ever so slowly.
- nosema ceranae, low to moderate infection. Business as usual, though overall production forecast is going to be down for the year.
- nosema ceranae, heavy infection. Where did all my bees go?!!!
- varroa mite. My mood gets edgy in spring and fall. Yet calm overall
- varroa mite + either nosema. Hive/Apiary Catastrophe. Dead bees walking. Recovery impossible. End the suffering. Terminate now.
Nosema is a gut parasite that sucks energy and efficiency out of the bee and by extension the overall super-organism that we call the hive.
General guidelines of managing this pest, the basics, are:
- keep the hive well fed. Ensure it is never ever food stressed. Prompt application of protein supplements and syrup.
- dead out equipment needs to be quarantined and handled as contagious, which it is. Clean in a quarantined area away from other equipment. Clean over a drop sheet or tarp. When done roll up the tarp with everything on it and the bags of scrapings. Setup a barrel or pit and burn it all.
- cleaning tools go into a bucket of cleaning vinegar. This is double/triple strength white vinegar. Eg Alleys. Found on the shelf at your hardware store.
- cleaned equipment is stacked, shrink wrapped, and fumigated with acetic acid (vinegar), same stuff, Alleys. Extreme infections, equipment is mist sprayed. Set on sunny side of the building and left for at least a week. It can then be reused.
- if radiation services are available and accessible, highly recommend to setup a program to cycle a percentage of your equipment through it on a rolling annual basis. This eliminates the countless more and other microbes and chemicals that affect hive health.
I hope that is fairly straight forward and clear.
Hope that helps!
Having said all that and getting back to the dysentery. A poopy hive in does NOT mean nosema. Most often the issues is prolonged confinement combined with old or poor quality feed. The bees have belly-aches because the food they have is tainted. Aka mild food poisoning.
Like stomaching a toasted slice of moldy bread or cutting a slice off of fresh loaf out of the oven.
Always ensure the food the bees have is of good quality before thinking they are diseased. If you have a scope, and a keen eye, it may be possible to pickup on what is in the food causing them problems.
Alot to take in. I will stop there.
Happy beekeeping!
HP - that is outstandingly well written! Thank you for taking the time!
A question - in the case of nosema apis+ceranae - I have a hive that matches your description. 7 med frames of brood at every inspection. A good nectar flow has been on since early Jan, and all other hives are booming. Yet this hive has seemingly less bees each month. Will re-Queening solve the problem?
I had planned on re-Queening this hive as soon as I've grown some queens (which has been delayed due to 7 weeks of rain and low 50'sF temps). This week it warms to 70 deg F and I am planning to make several swarm-prevention split. Queens would of course be ready in 4 weeks or so.
I've also thought of removing (and freezing) the brood, killing the 2ND yr queen, and introducing a frame of eggs - using this hive as a starter Nuc.
However - if the disease would be passed down, all of this would be pointless. Assuming of course, that this is in fact the problem.
Your thoughts on this?
Thank you
Alan
HP - I should also add:
I thought the problem was with the queen. This hive is the 2nd genetic line that I have. This hive was started from a frame of brood in March 2018. It climbed to 3 med 8 frame boxes by fall. Nov showed it to have the highest mite count of all 4 hives. I treated OAV thru Dec. All other hives have bounced back amazingly well! In truth this is the 1st time in my 4 years (attempting beekeeping) that I've entered the spring with healthy hives - and it has been a shock to see how fast they can grow. All but this one ... I had assumed the queen was poorly mated, or had other health issues, but the brood patterns are solid - wall to wall. But in 2 months time - my other hives have gone from a few frames to 4 full boxes each, and this one has yet to start filling the 2nd box ....
I should also add - this hive had a dysentery problem last May, shortly after becoming Queenright. Bee poop all over the outside. Bees dragging themselves along pooping. Inspection revealed a lack of stores. Adding 2 frames of capped honey with some pollen, fixed the problem and the hive bounced back nicely at that time. ... as previously stated, I'm in a steep learning curve ...
Any time you confine bees they get dysentery. That doesn?t equate to nosema.
As far as fumidil, first, it is no longer available. Second, it makes them more susceptible to nosema because it kills the bacteria that forms th gut lining in the bees. Third, it causes birth defects in mammals which is why it is illegal to use in most of the world.
http://www.bushfarms.com/beesnosema.htm
Quote from: CoolBees on March 10, 2019, 03:51:08 PM
HP - that is outstandingly well written! Thank you for taking the time!
A question - in the case of nosema apis+ceranae - I have a hive that matches your description. 7 med frames of brood at every inspection. A good nectar flow has been on since early Jan, and all other hives are booming. Yet this hive has seemingly less bees each month. Will re-Queening solve the problem?
I had planned on re-Queening this hive as soon as I've grown some queens (which has been delayed due to 7 weeks of rain and low 50'sF temps). This week it warms to 70 deg F and I am planning to make several swarm-prevention split. Queens would of course be ready in 4 weeks or so.
I've also thought of removing (and freezing) the brood, killing the 2ND yr queen, and introducing a frame of eggs - using this hive as a starter Nuc.
However - if the disease would be passed down, all of this would be pointless. Assuming of course, that this is in fact the problem.
Your thoughts on this?
Thank you
Alan
Suggestion would be to confirm your suspicions first by sampling. If you see nosema in the microscope, combining with your observations of high mite load, inspections, and performance. Then that hive should be taken down promptly, killed. This could be the dead bees walking scenario. It may have a multitude of compounding problems, and perhaps nosema on its own would be the least of its troubles. When it is decided to terminate a sick hive. The process is this: Do not shake it out in the bee yard. Do not let the bees go anywhere. Do not transfer brood or comb hoping to save their efforts. Consider the equipment and all the bees within as contaminated. Bag it in the evening and contain it. Remove and cleanup the equipment as described. Then you can startup a new hive in that equipment when your new queens are ready and you are making splits. Make a very very strong split into the refurbished equipment, combining bees and brood from multiple hives. Et Voila, a new rocket of a hive that will still make you a crop this year. You are at the perfect time of the year to do this. You can sample and let the scope tell you. Or perhaps just combine the observations you already have; previous problems, the mite factor, and since you are dealing with only one hive - just take it out now. Nothing is to be lost and everything to be gained at this time of the year. It can be a tough decision to take out a hive. It is helpful if you think about what is best for the bees, not what is best for your wants and efforts.
The alternative is to hold on to hope and nurse it. That is the frustrating route that always ends in heartbreaking disappointment. Maybe they just need another week. Or another week. Awe man, they are so close ... maybe one more week. No. It is spring. It is the time the hive should be prolific and explosive. If it is lagging far behind the others, there is an issue to be investigated, data gathered, and dealt with promptly while you have the resources and energies available from the other colonies to do something about it.
I always advise against re-queening as an approach to fixing a diseased or pest ridden hive. A sick hive is a sick HIVE not a sick queen. Deal with the hive as a whole, holistically. Deal with the queen as an individual. Re-queen for sake of keeping the genetics wanted and to keep the queen age across the apiary young and vigorous. Replace old or defective/failing queens. Replace queens of mean or wimpy/dainty genetics.
Re-queening a sick hive is like installing one shiny new chrome lug nut when the wheel alignment is off, the rim is bent, the steel belt wires are poking out of the bald tire, and the tire has hardly any air pressure in it.
imho.
Hope that helps!
.
TheHoneyPump- "The microscope is an essential tool in the beekeeper?s toolbox."
I am not attempting to hi-jack the thread. Just a quick question please for you, Mr Van or anyone else who does AI-II. Is the 400X good for both processes, I am considering the purchase and it would be nice if one microscope could be used for both purposes.
Thanks, Phillip
Phil, For II one needs a stereo microscope 8X. Mine is a Nikon 80-8 mag. Some use jewelers glasses.
For nosema 400X light microscope. Mine is a Zeiss, medical grade, 40X to 1,000X with oil condenser. One does not need a Zeiss for bee work.
Two completely different scopes.
Thanks Mr Van that helps..
Phillip
> A sick hive is a sick HIVE not a sick queen
But often a sick colony is sick because of their genetics.
Amen, Mr. Bush. That is why I requeen and have not ever attempt to treat dysentery issues. Fungicides are nasty, just plain poison and certainly play havoc on the good bacteria in the bee gut as stated by Bush.
Interesting that i never saw dysentery when young and raising bees. May be part to location: Houston Texas mild winters that seldom see frost so the bees were not confined in winter like most places.
We get nosaema when the bees feed late in the season when there is a lot of moisture in the air at night. This tend to show up weeks after the bees have been collecting high moisture nectar.
For us a shift to warmer areas, especially on to bare sandy soil seems to help, an increase in nutrition also seems to help.
We don't change queens or treat, just a better environment, also affected hives are packed down to the brood box and even pack out the brood box to reduce area needed to keep warm.
For confirming Nosema, you don't need to use a microscope, you can see it by the color and by the pattern (line oft dots, runny and a distjnct brown).
But using the microscope is the better way.
Treating is very easy, the main criteria is to make sure that all sources for reinfection are cleared and that you stimulate brood rearing.
Just wait until you start to hit about 46f, then feed liquid 1:1 treated with bleach. In the 2nd or 3rd flying day in a row, you bring a new hive, with foundation. Now all brood and clean combs get moved into the Nlnew box with the brood enclosed by at least one sheet if foundation (foundation firces the bees to build combs and thus raising the ammount of feed used, and also confines the brood onto a distinct area, that the bees can care for quite easy). All honey combs geht removed.
Now continue to feed 1:1.
The old hive needs to be cleaned, burn the inside and outside with a torch after scraping.
The frames that you took out of the hives are getting melted and the frames cooked in 6% soda or 2% NaOH.
While doing this, you have to be honest to yourself. Don't try to keep any stores that you take out of the hive or keep any dark combs. The reason is, that you else will spread the diseases and continue to lose hives, cause of this.
To limit the problems with diseases in the future, feed at least a Fallon of thymolised sugar syrup in fall and rotate a lot of combs out of your operation. Try to replace brood combs every two years and don't use dark combs in supers (gives better quality honey and those combs are seeing many hives, better not use them to spread diseases).
Quote from: robirot on March 12, 2019, 03:26:08 AM
For confirming Nosema, you don't need to use a microscope, you can see it by the color and by the pattern (line oft dots, runny and a distjnct brown).
But using the microscope is the better way.
Treating is very easy, the main criteria is to make sure that all sources for reinfection are cleared and that you stimulate brood rearing.
Just wait until you start to hit about 46f, then feed liquid 1:1 treated with bleach. In the 2nd or 3rd flying day in a row, you bring a new hive, with foundation. Now all brood and clean combs get moved into the Nlnew box with the brood enclosed by at least one sheet if foundation (foundation firces the bees to build combs and thus raising the ammount of feed used, and also confines the brood onto a distinct area, that the bees can care for quite easy). All honey combs geht removed.
Now continue to feed 1:1.
The old hive needs to be cleaned, burn the inside and outside with a torch after scraping.
The frames that you took out of the hives are getting melted and the frames cooked in 6% soda or 2% NaOH.
While doing this, you have to be honest to yourself. Don't try to keep any stores that you take out of the hive or keep any dark combs. The reason is, that you else will spread the diseases and continue to lose hives, cause of this.
To limit the problems with diseases in the future, feed at least a Fallon of thymolised sugar syrup in fall and rotate a lot of combs out of your operation. Try to replace brood combs every two years and don't use dark combs in supers (gives better quality honey and those combs are seeing many hives, better not use them to spread diseases).
Thank you for the information. Just for educational purposes, what about the wax? Could it be boiled and thus kill any nosema?
Yes, reworking into foundation is no problem
>Could it be boiled and thus kill any nosema?
If you are concerned about nosema spores, keep in mind that Nosema cerana has displaced Nosema apis and Nosema cerana spores are killed by freezing. I've never done anything for Nosema and APHIS does counts on my colonies every year and find a Nosema count of zero. I'm sure some of the issue of Nosema has to do with climate.
Thank you both robirot and Mr Bush for the previous post. Glad to hear both your responses. I hope my bees never get this nosema. I am trying to know what to do in the case that they do get it. If I was on a scale such as TheHoneyPump, I would do as he does in such a case. I would not want to dally around with such a problem where livelyhood was involved. But as a hobbiest, who theoretically has more time to devote to each hive. I might try and save them. So, if a person wants to save the wax from a hive with this problem. He could freeze the wax and then boil the wax and that should do it. This has been a good topic and good post made in my opinion. Thanks all. Phillip
Mr Claude, your post #16 & 17 were totally outstanding. I hope it's not against the rules here, and if it is Jim please scold me now. I have made a habit of printing such post, (articles), for my personal use fo future references. How could we not appreciate such bee knodlege that borders brilliance. You folks are true Blessing for beginners as well as professional beekeepers, I am sure! Thanks all of you !!
Sincerely, Phillip
Quote from: Michael Bush on March 12, 2019, 09:29:53 AM
>Could it be boiled and thus kill any nosema?
If you are concerned about nosema spores, keep in mind that Nosema cerana has displaced Nosema apis and Nosema cerana spores are killed by freezing. I've never done anything for Nosema and APHIS does counts on my colonies every year and find a Nosema count of zero. I'm sure some of the issue of Nosema has to do with climate.
Occurring to UC Davis Entomology Dept: nosema spores less than 10,000 are counted as zero or NONE DETECTED, ND. The nosema article is presented below:
Causative Agent
Diagnosing and Treating Nosema Disease Eric C. Mussen, Extension Apiculturist, UC Davis ? 3/11/11
Nosema disease in U.S. honey bees is caused by one of two (or both) fungi named Nosema apis and Nosema ceranae. Nosema species are obligate, fungus-like, intra-cellular parasites that are limited to specific hosts species. Nosema apis and N. ceranae cannot be reared in laboratory culture, as is possible with most bacteria and other fungi. They can multiply in living honey bee midgut, and perhaps other, cells. There is evidence that, like Nosema bombi in bumble bees, the N. ceranae may infect other honey bee tissues, but that remains to be substantiated.
Life Cycle
When a bee ingests Nosema spores, the spores are filtered out of the honey sac by the proventricular valve and released into the midgut. The exact physical and chemical conditions of the honey bee midgut stimulate germination. The organism penetrates a midgut cell and grows by absorbing nutrients from that cell. The parasite increases in size until it is large enough to divide in half. Each new parasite continues this multiplication process until the nutrients in the cell begin to become exhausted. That stimulus triggers sporulation. Depending upon the species of Nosema, approximately 100 spores can begin to develop as early as four days post-infection or up to nine days later. Some of the early, thin walled spores appear to germinate inside the infected cells, sending their polar filaments into adjacent cells. In this manner, they can make their way through the body cavity, infecting other tissues, at least in bumble bees. The nutrient- depleted host cells rupture. Environmentally resistant, thick walled spores are released into the midgut lumen to start the process, again, or be excreted to the outside. Heavily infected worker honey bees can contain an excess of 50 million spores. Damaged intestinal tissue is subject to secondary infections and "dysentery" (brown diarrhea spots on the combs and exterior of the hive) is a common sign of infection with Nosema apis, but not seen with N. ceranae. N. apis infected bees also defecate inside the hive, contaminating combs with millions of infectious spores.
Effects on Colony
Nosema infections have specific negative effects on honey bees. Worker bees that ingest spores when they are less than a week old normally do not digest food well and are not capable of producing brood food secretions. Infected bees tend to skip the brood rearing phase of life and become foragers at very young ages. Their life spans can be reduced up to 78%. Young queens that ingest Nosema apis spores normally are superseded within a month. In climates where winter prohibits supersedures for many months, colonies often go queenless and dwindle away in early spring. Experience in Minnesota suggests that an average of one million or more N. apis spores per bee can lead to increased winter losses. When high percentages of workers are infected and spore counts exceed ten million spores per bee, significant numbers of colonies will die or lose queens during the winter. With Nosema apis, this spike in the level of infection
normally occurrs in early spring, then ?goes away? as the weather improves and the bees defecate outside the hive. With Nosema ceranae having become the dominant species, infection and spore levels can be elevated all year. All levels of infection led to very slow spring build up with Nosema apis, even when forage and temperatures were ideal. Frequently, reduced honey yields followed this poor population build up. In Spain, year ?round infections with Nosema ceranae did not seem to interfere with spring build up and swarming, but were found to lead to very high percentages of lost colonies during summer and through to the next spring.
Diagnosis
Nosema disease is difficult to diagnose without using laboratory equipment. Pulling the last abdominal segments from a bee usually will remove the intestinal tract intact. According to some authors, a healthy midgut is tan in color, with concentric constrictions. An infected midgut will become swollen, whitish and lose its visible constrictions. There is so much variation that this method of diagnosis really cannot be trusted. Besides, other causes of dysentery, such as ingesting honeydew, fermented syrups, indigestible sugars in cola syrups, molasses and kitchen corn syrups can result in similar intestinal changes.
Scientists use a specific methodology to determine levels of infestation. Known numbers of severed abdomens are homogenized, using a mortar and pestle. The homogenate is sieved through two layers of cheesecloth into calibrated centrifuge tubes. The tubes are spun in a clinical centrifuge at 600 rpm for six minutes to drive the spores to the bottom of the tubes. The liquid (supernatant) is poured off (decanted) and the plug (pellet) at the bottom is resuspended in a specific volume of water (final calculation is spores in one ml water per bee). The plug is broken up well (resuspended) by sucking the water in and out many times through a small-tipped disposable pipette. Then a small droplet of the suspension is placed on a blood cell counting chamber (hemocytometer). The number of spores counted over certain areas of the chamber grid can be converted to millions of spores per bee. If infection levels are below 10,000 spores per bee, no spores will be seen over the entire grid and the diagnosis is determined to be ?not detected? or ?ND.? That does not mean that there is no infection.
Treating Infected Colonies
Medicating for Nosema apis is based on the most appropriate times to prevent comb contamination and development of disease in bees that clean up fecal deposits from combs while expanding the brood nest. Later in the summer, when bees are defecating outside the hive, N. apis usually cannot be detected. A few bees are infected all year, but only the diseased late season bees are of consequence. When they develop high levels of infection, they defecate on the combs in October, November and December, then die.
Brood rearing never ceases in many parts of California over the winter, but as the days begin to lengthen in late December, the bees are stimulated to pick up the pace. Availability of nectars and pollens, along with warming temperatures, accelerate brood rearing. It is at this time that many bees "cleaning and polishing" cells, in anticipation of egg laying, become inoculated. How severe the disease will get in the colony population depends upon the initial spore load
(amount of contamination) and how much of the time the bees are confined to the hive by non- flight weather. So, Nosema apis levels can vary significantly from year to year.
In order to "cover the bases" in Minnesota, if a colony population had one million or more spores per bee in April, we fed it two gallons of fumagillin-medicated, heavy (two parts sugar : one part water) syrup the following September. If we had to "feed for weight," that was done earlier, so that the early syrup could be "ripened" and stored before the medicated syrup was applied. If the medicated syrup is mixed with other, unripened syrup, it can be diluted to ineffective concentrations. We anticipated that the medicated syrup would be consumed throughout the winter. Spore deposition on combs in early winter would be reduced and the parasite could not reproduce in medicated bees that became inoculated in the spring. The syrup would be consumed, totally, long before the bees produced any honey.
Although we have not conducted the experiments, it is likely that two gallons of medicated syrup may not be required in most of California. Nosema apis levels were not as high in California as they were in Minnesota. Combs should not be so badly contaminated during the winter months, since intermittent flight is possible. Therefore, first treatments with medicated syrup should coincide well with the normal practice of providing colonies with "stimulative" syrup and pollen substitute feeding in late December and January. A gallon, or so, of medicated syrup should provide protection against Nosema apis until the bees are flying well in March and April. Heavy nectar flows from Manzanita, Eucalyptus, mustard and radish might dilute the medication significantly, as would later feeding with non-medicated syrup.
Medicating for Nosema ceranae is going to be different. For one thing, fumagillin no longer is available as Fumidil-B?. A Canadian company, Medivet, sells the product as Fumigilin-B?. The new fumagillin mixes more readily into solution and it appears to be less stable in solution, if the label instructions are correct. The label suggests using the antibiotic in the fall, as always has been the ractice at that time of year for nosema control. Since N. ceranae tends to persist throughout the year, the label calls for increasing the dosage level, and feeding repeatedly in small amounts of sugar syrup, in the spring. Beyond that, Spanish researchers have found that N. ceranae-infected bees tend not to take medicated syrup from feeders, so they had to pour the syrup over the bees (called ?drench?), down between the frames, to make them consume the medication.
Expected Results of Treatment
Beekeepers who have fed fumagillin to field colonies years ago had noted significant differences in colony build up. In fact, many of them stopped using fumagillin. The colonies built up too quickly and swarm control became nearly impossible. With so many colonies succumbing to CCD at this time, I doubt that swarm control will be a major issue any longer.
Decontamination of Equipment
The spores of both nosema species are susceptible to irradiation or fumigation with glacial acetic acid (details in The Hive and the Honey Bee). Otherwise the spores of apparently Europe-originated N. apis are very resistant to the elements, except sunshine, and persist for
many years. Nosema ceranae, on the other hand, originated in tropical Asia, and its spores are susceptible to weather, especially cold weather. The spores can be killed by refrigeration or by freezing. If possibly spore-contaminated combs are placed in a freezer and left there until it is certain that all materials in the combs have reached freezing temperatures (honey holds a lot of heat for quite a while), N. ceranae spores, all life stages of greater wax moth, all stages of small hive beetle, and other little critters that tend to get into stored combs will be eliminated.
I am happy to discuss Nosema, its consequences in colonies, and treatments. I can be reached by telephone at: (530) 752-0472 or by email at:
[email protected]. Copies of this "Bee Brief" can be downloaded at: http://entomology.ucdavis.edu/facutly/mussen/beebriefs/index.cfm.