Apiguard Measurement

[sbisme]

Hi All

Apologies if this has been asked before I have done a search but with no success on the answer,

I treated my hive last week with the first treatment of Apiguard due to DWV, now I know there is a calculation for mite before using the treatment to give an estimate of mite in the hive, my question being is there a calculation for the effectiveness of the treatment? Over the last 24 hrs I monitored and cleaned off 17 mites from my board.
Thanks in advance,
Shaun

 

[oliver90owner]

Very simple.

% efficacy is:

Mites killed multiplied by 100 and then divided by the original number present.

Or

100% less the mites remaining, multiplied by 100 and divided by the original number present.

Don't forget 'BODMAS' when doing said calculations.

So you counted 17 in the last 24 hours? The treatment period is? What were killed during the previous 96 hours? What will be killed in the next approx 1000 hours?

I would, frankly, not bother.

 

[sbisme]

Ok thanks for the response

 

[alanf]

I treated my hive last week with the first treatment of Apiguard due to DWV, now I know there is a calculation for mite before using the treatment to give an estimate of mite in the hive, my question being is there a calculation for the effectiveness of the treatment? Over the last 24 hrs I monitored and cleaned off 17 mites from my board.

Nothing wrong with counting if you have the time and inclination. However you do have to understand the limitations. The calculators on the NBU website and elsewhere based on mite drop are for the natural rate of mite death. That is, a population of mites will breed and die at a predictable rate. The assumptions are that the age spread of the mites is even and you see all the dead mites. What can happen is mites get lodged in empty cells, blow off the board, are taken by ants, have ages bunched because of previous brood breaks and lots of other factors. So the calculation is not precise, but a reasonable guess the hive has at least that many mites. Statistically, you get more reliable results if you use periods of several days, and even better if samples from more than one period produce similar results. If the time of year allows drone uncapping that can be useful confirmation, as can sugar rolling.

When you use treatments to kill mites, that's not the natural death rate. One day doesn't mean a great deal. It's the count over a whole treatment period that matters. Mites will die as they emerge from the cells and are exposed to the treatment, which is why most treatments are at least a full mite life cycle, extending to two. As a percentage kill rate, it's the number dead over what you started with as a percentage. But you cannot know the starting numbers precisely. Researchers can estimate the mites after treatment using an additional, different treatment with chemicals not available publicly, lethal rolling or even killing the entire colony. Non of the methods are helpful to a productive colony.

After treatment, the more bee friendly methods of estimating are even more problematic than before because of brood breaks, few drones to uncap, mites arriving from other colonies and the general reduction of brooding going into autumn. The methods are not going to show a clear difference between, say, 80 and 90% effective. Trying to estimate before and then a month later, my hives have drop results with thymol treatments that suggest effectiveness ranging from 50 to 90 percent, and that's probably related to weather and the state of the colony being treated. During treatment, if no mites dropped, they probably didn't need treatment but that's hard to say in advance. If 1000 mites drop then at least the infection is less than it was, but expect to need further treatment later such as oxalic over winter.

 

[sbisme]

Many thanks alanf

 

[midnight sun]

Nothing wrong with counting if you have the time and inclination. However you do have to understand the limitations. The calculators on the NBU website and elsewhere based on mite drop are for the natural rate of mite death. That is, a population of mites will breed and die at a predictable rate. The assumptions are that the age spread of the mites is even and you see all the dead mites. What can happen is mites get lodged in empty cells, blow off the board, are taken by ants, have ages bunched because of previous brood breaks and lots of other factors. So the calculation is not precise, but a reasonable guess the hive has at least that many mites. Statistically, you get more reliable results if you use periods of several days, and even better if samples from more than one period produce similar results. If the time of year allows drone uncapping that can be useful confirmation, as can sugar rolling.

When you use treatments to kill mites, that's not the natural death rate. One day doesn't mean a great deal. It's the count over a whole treatment period that matters. Mites will die as they emerge from the cells and are exposed to the treatment, which is why most treatments are at least a full mite life cycle, extending to two. As a percentage kill rate, it's the number dead over what you started with as a percentage. But you cannot know the starting numbers precisely. Researchers can estimate the mites after treatment using an additional, different treatment with chemicals not available publicly, lethal rolling or even killing the entire colony. Non of the methods are helpful to a productive colony.

After treatment, the more bee friendly methods of estimating are even more problematic than before because of brood breaks, few drones to uncap, mites arriving from other colonies and the general reduction of brooding going into autumn. The methods are not going to show a clear difference between, say, 80 and 90% effective. Trying to estimate before and then a month later, my hives have drop results with thymol treatments that suggest effectiveness ranging from 50 to 90 percent, and that's probably related to weather and the state of the colony being treated. During treatment, if no mites dropped, they probably didn't need treatment but that's hard to say in advance. If 1000 mites drop then at least the infection is less than it was, but expect to need further treatment later such as oxalic over winter.[/QUOTE

Very informative reply! Useful to all.

 

[Ruary]

Apiguard takes some time to kill the mites. The important thing is to do the full treatment that is first tray in for two weeks the second one is added for a further four weeks making a total treatment of six weeks.
Do a mite count after the treatment is complete. It should be Zero.
The one time that I did a daily mite count during treatment I found that it took 21 days for the mite count to start dropping .

 

[sbisme]

Many thanks for the reply Ruary