Mite load level to trigger treatments?

[Wisnewbee]

It seems the infestation level (mite load) at which treatment should be applied has changed over the years. The information depends on the time of season, migratory or stationary operation and the county or country giving the recommendation. I've read in the past that if you have a 10% mite load (adjusted for mites under cappings, not just mites on bees) you should be treating. The information I've come across lately has a much lower threshold for treatment, in the 2-3% range (adjusted for brood mite load). In a perfect world we would endevor to always keep the mite load as low as possible, but in the real world at what mite load do you feel the need to take action? 1%, 2%, 5%? Spring, summer, fall treatments and loads. I'm putting this post here to get the commercial guy's take on reality.

Wisnewbee

[BMAC]

If you count more than 5 mites in a random sampling treat at absolute next opportunity.

[AstroBee]

If you count more than 5 mites in a random sampling treat at absolute next opportunity.

Using what procedure?

[BMAC]

I always use eather rolls. I suppose it probably doesnt matter. 300 bee sample taken from the BROOD.

[Wisnewbee]

So doing the math. ((Mite count/3)*2)= 3.3% mite load. This allows for mites on capped brood. If there was no brood present then the math would work out as (mite count/3) = 1.66% mite load. Is this at anytime of the year? I've also heard and read you will get a higher count using an ether roll vs a powdered sugar roll. Have you seen a difference?

Wisnewbee

[jim lyon]

I like to see under 1% (3 per 1/2 cup 300 bee sample) in the early spring. Later in the summer anything under 4% is acceptable but evidence that you will need a treatment fairly soon. Over 5% is getting dangerous. Post treatment you would like to see under 1% again and ideally some negatives

[Wisnewbee]

Jim, when you say some negatives, I'm assuming you're talking about the number of mites on a sticky board, pretreatment drop rate vs post treatment drop rate. Am I right? I can't see how you'd get a negative number doing a roll test. For your 300 bee count are you using powdered sugar, ether, or something else? Alcohol?

When you say a 1% load (3 per 1/2 cup 300 bee sample), I take it you're not adjusting for mites on capped brood. I thought the math was something like this; ((mite count/3)*2) to allow for mites on brood. That would double your numbers. ????

Wisnewbee

[Matt Beekman]

I like to see under 1% (3 per 1/2 cup 300 bee sample) in the early spring. Later in the summer anything under 4% is acceptable but evidence that you will need a treatment fairly soon. Over 5% is getting dangerous. Post treatment you would like to see under 1% again and ideally some negatives

Solid advice!

[jim lyon]

Jim, when you say some negatives, I'm assuming you're talking about the number of mites on a sticky board, pretreatment drop rate vs post treatment drop rate. Am I right? I can't see how you'd get a negative number doing a roll test. For your 300 bee count are you using powdered sugar, ether, or something else? Alcohol?

When you say a 1% load (3 per 1/2 cup 300 bee sample), I take it you're not adjusting for mites on capped brood. I thought the math was something like this; ((mite count/3)*2) to allow for mites on brood. That would double your numbers. ????

Wisnewbee

I am doing ether rolls though there are certainly other methods such as alcohol washes or sugar shakes will work as well. I spend at least a good minute shaking and rolling them before I feel that I have dislodged most of them. You can count the mites on the side of the jar or I prefer to dump the bees add a little water and count the "floaties". About the only time I will use a sticky board is to monitor mite drop after a treatment. I am aware that brood greatly skews your counts which is a big reason why those elevated late summer counts are so much worse than the numbers indicate. With less and less brood your mite numbers can quickly overwhelm hives. In other words if you are seeing double digit numbers late in the summer and still have considerable brood in the hive you better look out.
The "negative" terminology simply means that no mites were found in the sample.

[Ian]

Wisnewbee, my suggestion is exactly what Jim said,

>>I like to see under 1% (3 per 1/2 cup 300 bee sample) in the early spring. Later in the summer anything under 4% is acceptable but evidence that you will need a treatment fairly soon. Over 5% is getting dangerous. Post treatment you would like to see under 1% again and ideally some negatives<<

But I think 4% is too high for a fall time mite load, if I'm seeing anything around the 2.5-3% range, Im going.

It use to be a 5% rule, but now with deformed wing virus it seems if there is any type of mite load, the hives will dwindle to viral loads

[Honey-4-All]

The data keeps saying that the threshold number is way lower than has been generally accepted. A hive with 2-3 % at its peak at any time of the year is more likely to cross the safety line and pass to the ranks of the dead out pile if it gets any worse. If the mites don't get them by themselves the holes drilled by the "more than 3% gang" will surely help all the other problems out there make a move which will lead to their demise.

[camero7]

It use to be a 5% rule, but now with deformed wing virus it seems if there is any type of mite load, the hives will dwindle to viral loads

[Wisnewbee]

I'd like to thank everyone who provided valueable information on an evolving topic.

Wisnewbee