fumigillin-b drench method
Does anyone use Fumigillin-b in a drench method on a commercial level? If so how do you mix it?
okay, just trying to be funny here, is that like drenching a calf? Do they make tubes small enough? How many litres in the belly?
sorry could not resist, too many years cattle i guess...
i have no answer to your question...sorry
mix one 9.5 bottle to five gallons of syrup, one cup per hive.
How many times do you hit them?
Originally Posted by Keith Jarrett
Well Trevor, the book says 4 times one week apart, but I do mine a couple times ten days apart.
Originally Posted by Trevor Mansell
Trevor, I don't think any of us know, I have had good results at ten days apart.
There have been various opinions about the ideal concentration of the active ingredient in fumagillan syrup for drenching.
Some beekeepers think that an increased concentration above the recommended mixture for non-drench feeding is indicated. Others think the recommended concentration is fine.
I tend to agree with using the recommended mixture, as I really do not know the effects of forcing bees to ingest a concentrated dose.
Are there benefits to increased doses? Or are there toxic effects on the bees subjected to a heavier than normal dose?
Besides being off-label, if there is no proven benefit to using an overly concentrated solution of this expensive (and toxic) drug, why do it?
Theory? Hypothesis? The recommended levels are tested for toxicity and effectiveness. Going outside that band could be risky.
I realise that the argument can be made that with the normal application, the bees are sitting on treated syrup containing a greater total load of the drug which is consumed over a long period and this way, the bees only hold it for a short time, and the total amount of drug is less.
Consider this, though. Drugs are prescribed for a measured dose over a measured time. If taking an antibiotic, you don't just take five pills right now if the doctor says to take one a day for five days. You would possibly be quite sick and probably not get any extra benefit. Fumigillan is normally taken over time, and the drench idea is based on the idea that a quick shot gets most of the disease right off due to the forced ingestion and then subsequent doses are to hit any residual infection that may have been missed and new infection. It is a theory and depends on the true action of the drug. Apparently it works, so the theory may be correct.
With the drench all the bees get some, and right away, since they all clean one another. With normal feeding, maybe only some bees get the full dose, since they are the ones storing it, but eventually all bees get some as the syrup is consumed, so the distribution is slower and not universal or all at once. Perhaps using the standard method, most bees actually get lower doses than those involved in storing it, but over longer time spans, and that lower dose is apparently effective.
Actually, this is an arguement for not using a highly concentrated ration for dosing, since all the bees are being overdosed.
I'd go with the normal mixture, on the label. As for frequency, I don't think it is critical, but the thing to remember is that once damaged, a bee does not recover, even if new damage is prevented, so the idea is to treat over several generations, although I have heard good comments about single treatments.
Last edited by Allen Dick; 01-27-2009 at 09:30 AM.
Thanks, I'll hit them again in 10 days.
Originally Posted by Keith Jarrett
I'm not a large commercial beekeeper but do drench my hives with Fumigillin-b. The mixing ratio that keith stated is how I do it. With my drench gun I'm able to measure amounts being applied and at the end of my gun has a broom spraying pattern.