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Fumagilin Drench

4690 Views 7 Replies 3 Participants Last post by  Beeslave
Disclaimer: I am not an expert and this is info passed on to me....

I asked about this over on Bee-L and a few of those memebers discussed this with me through personal emails instead of posting it on the forum. There are alot of different variables that need to be considered depending on how high of spore counts you have, how much time you have before placing honeysupers on, are the bees so bad they are not taking syrup, etc.

U.S. measurements:
Single drench(1 cup) treatment-4.5 g powder per colony(not active ingredient measurement)
2 treatments-2.25 g per treatment
3 treatments-2 g per treatment
4 treatments-1.5 g per treatment

If the spore counts are high do a strong dose the first time and follow up 2-3 more treatments of the lighter dose.

Using the 2 treatment schedule- 450g fumagilin(4g short of the 454g bottle) mixed in 13 gallons of syrup solution will provide 1 treatment(2.25g fumagilin powder) for around 200 colonies.

Same as above but broke down to a smaller batch-112.5 g fumagilin mixed with 3.25 gallons will give 1 treatment to around 50 colonies.

This is what I am doing-I have a 6 gallon bucket with a line where 3.25 gallons is. I mix(paint mixer on a cordless drill) the 112.5 g with 3 qts water in a seperate bucket(2 gal). I then poor the fumagilin water mix into my pail with the 3.25 gallon mark. I then fill with HFCS 55 to the line and mix well. I have a veggie can with a bunch of holes drilled in the bottom nailed to a stick. It is attached to the side stick at an angle so when I stand upright with the can close to the hive top it is level. I have another small can nailed to a stick for dipping out of the pail. That can has a notch cut out of the top of it to pour from that allows me to only have 1 cup solution inside of it. I put the drench can over the colony and pour from the dipping can into it while moving the drench can around to spread the solution evenly over the bees. Myself and a helper(all he did was open and close colonies) drenched 448 hives that were divided in 2 yards 5 miles apart in 5 hrs. It takes longer to remove the lid and put it back on then it does to drench. I mix each batch on the spot. I had spore count avg of 15.1 million per bee from 15 sample hives so I am doing the 2 treatment ratio 3 times.

Like I said in the beginning-I am not an expert but this is what I am doing. I will send bee sample out again from the same colonies that were sampled from the first time to see what the spore counts are after treatments.
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Thank you for the new link and your data!
This was sent to me in an email off list from Bee-L-It makes it all confusing when trying to figure what is the best and most efficient wasy to go:

Here are three one time treatments for bees with high spore loads.

1 9.5 gram bottle in 33 gallons of syrup. One cup dribbled over the bees ( source a 13,000 hive operation in California) . Used three times a year for two years without problems.

1- 9.5 gram bottle in 5 gallons of syrup ( source -name withheld- a California commercial beekeeper which posts on beesource) one cup dribbled once three times a year.

one quarter of a 9.5 gram bottle in 3 gallons of sucrose ( -name withheld- used for three years without problems)
one cup per hive. Have used a cup a week for three weeks without bee problems other than bees crashing from nosema. I used controls the first year and saw no bee death problems.

Tests by Abbot labs on fumigillin showed increasing the dosage did not harm bees.

So if you think your bees will last three weeks then use the formula of 1.5g per hive with 3 treatments 1 week apart. If hives are crashing then I would give a strong dose right away. *Then* maybe a couple light doses.

Nosema ceranae may indeed be only part of the issue like Jerry says. The road back when nosema loads are high is slow and the road is paved with dead and weak hives. At times the hives will appear better as the spring and summer flows come on only to crash in fall.
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Sunday, April 18, 2010

I competed the 2nd application of the 1/2 cup strong drench which is 4 oz/hive to a group of hives that are going through testing.
No noticeable mortality.
I noticed some queen death on weaker colonies. Could have been something else but only 3 out of 156 hives.

I also drenched the whole top of the hive. I was given directions to avoid drenching the brood but I did. I noticed a little brood mortality but minimal. That could be something else also but that was only in some of the really strong hives that are being knocked down to prevent swarming.
any updates, have you tested any to see if the drench is helping? thanks
You will notice that other bee diseases are considered
Here's some data that Randy Oliver has on his web site:

Mean survival of colonies (arbitrarily set at 4 frames or stronger) at April 3 was 50%. Highest survival (88%) was in the pollen substitute/fumagillin group; lowest survivals were in the untreated controls (38%) and in the bleach treatment (25%). The data of this trial are shown in the Appendix.

The colonies showing the least amount of strength loss from December 15 to February 25 were the group fed pollen substitute plus fumagillin. By April 3, mean colony strength had generally rebounded to approximately their starting strength for most groups. The notable exceptions were the pollen substitute/fumagillin group, whose mean strength increased by 227%, and the bleach group, which had only recovered 64% of their original strength.

On the average, 3 colonies in each group of 8 were over 8 frames on April 8. Only two groups were marginally better (to 4 colonies out of 8)—the pollen substitute/fumagillin and HoneyBHealthy. However, two of the HoneyBHealthy colonies had started at 10 frames, so I don’t feel that HoneyBHealthy’s performance in this regard was notable.

Dr. Nancy Ostiguy generously volunteered to have a student perform nosema spore counts of the bee samples. Unfortunately, they were not complete by the time of this progress report.

The great variability of colony performance likely precludes any statistical significance, but I will run statistics when the spore counts are completed.

In April, I spot-checked a large proportion of the surviving colonies for nosema levels. The majority were still infected in the range of a few million spores per bee. I only found one colony that had few spores. Despite this infection, most of the colonies that survived the winter went on to produce honey, and in several cases, to produce swarms. The bees in the swarms that I captured all ran at infection levels of a few million spores per bee.

However, not all colonies built up. Several colonies continued to dwindle, or stayed stuck at about 4 frames for most of the season. I could not find any correlation between colony strength and buildup and nosema levels. The one observation that stood out was that those colonies that did not build up generally had spotty brood, and sick larvae and pupae. The symptoms were generally EFB-like, or sacbrood-like, but it isn’t clear that those diseases were actually the cause.

I sent samples of sick bees to Dr. Jay Evans at USDA, Dr. Nancy Ostiguy at Penn State, Dr. Michelle Flenniken at U.C. Davis, and Dr. Jerry Bromenshenk/Dave Wicks at BVS. The three report results back to date are shown below.

Results from Dr. Jay Evans
Sample 1 Sacbrood virus, possible N. apis
Sample 2 none
Sample 3 ABPV, BQCV, EFB
Sample 4 low sacbrood, low AFB
Sample 5 low sacbrood, EFB, Nos. ceranae
Sample 6 BQCV, Nos. ceran
Sample 7 BQCV, DWV, IAPV, Nos. ceranae
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At the end of next week I will be sending samples out again to see if there was a drop in spore count and how much. I wanted to wait 2 wks after the last drench before testing.

If observations can be used as a determination of the effectiveness I would have to say it helped but it is still to early to be sure.
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