Correct use of Menthol

[Dave W]

Greetings . . .

A source of info that has answered a lot of MY questions about menthol can be found at:
http://www.caes.state.ct.us/BeeInformation/BeeFormsandInformation/Menthol.htm

Here are some highlights:
[list]
<LI>Menthol begins to evaporate at approx 70'F.
<LI> Best evaporation is between 80 and 85'F.
<LI> Overwintering bees MUST be treated.
<LI> Temperature outside hive should be at least 65'F. During brood rearing, inside hive temp will be significantly higher, allowing for adequate vaporization.
<LI> Hive should be a MAXIMUM of TWO deep bodies. Smaller the volumn, more effective the treatment.
<LI> Menthol vapors are heavy and will settle down to bottom of hive. ENTRANCE REDUCER should be set to smallest opening to help contain vapors.
<LI>. . . (Close screened bottom board??? DW)
<LI>. . . (Close extra top ventilation??? DW)
<LI> Use 50 grams or ROUNDED 1/3 measuring cup of crystals. Arrange crystals as flat as possible to improve evaporation. Once retrieved, if any crystals remain, they can be reused IF quantity is maintained at 50 grams.
<LI> Bees must inhale menthol CONTINOUSLY for minimum of 15 days.
<LI> Storage should be in an airtight container at temp less than 70'F.

The above info is from The Connecicut Agricultural Experiment Station, dated March 23, 2001.

As a personal note, I have used "daily average temperatures" found at:
http://www.weather.com
to determine MY target date to install menthol (Aug 1 - 89 /76, Aug 21 - 87 / 64).

I was confused by "Ten to twelve weeks after initial treatment remove all Mite-A-Thol", found on instruction sheet supplied w/ packet. Most sources indicate leaving menthol in hive for much shorter period of time. On 9/3/03, I e-mailed Mann Lake Ltd., asking "How long should Mite-A-Thol remain in the hive?". Within minutes, Sherri Hane replied "The minimum treatment period is 28 days and the max is 10-12 weeks. This is to show that you could leave it in without ill effects if you were unable to get back and remove (unlike other treatments which must be limited to prevent resistence)."
Many thanks to Sherri for her help.

Hope this helps a NewBee!
Dave W

[This message has been edited by Dave W (edited September 03, 2003).]

[This message has been edited by Dave W (edited September 03, 2003).]

[This message has been edited by Dave W (edited September 03, 2003).]

[This message has been edited by Dave W (edited September 05, 2003).]

[tarheit]

Actually, it's not true that overwintered bees must be treated with menthol. First, there are other treatments that supposedly work (wintergreen oil and others). Second, depending on your bees (genetics) or level of infestation you may not need to treat at all. New World Carnolians do well without treatment for example.

I have yet to use menthol (though I have used wintergreen oil) and have had very good overwintering success. Much less than most in my area. The highest losses being last winter at 9%, lowest being 0% the year before. And the losses I did have, had nothing to do with mites.

That said. If you have high t mite counts, it can cause large losses and you need to do something before the cold weather hits.

[Robert Brenchley]

I'm in a very different position in the UK where most bees are resistant, but if I had susceptible colonies I'd get rid of them either by requeening (if I spotted it) or letting them die out if I didn't. By treating you're perpetuating strains which aren't viable in the 'real' world.

[Dave W]

Greetings tarheit,

How do I determine my "levels of infestation"?

At what level is treatment needed?

How did you apply the wintergreen that gave you the good results?

When you had losses, what caused them?

thanx,
Dave W

[tarheit]

The level of infestation t mites is difficult to measure because it involves disecting the bees and observing them under a microscope. I belive there are other methods that involve blending a sample of bees, but I'm not familiar with it. Unfortunately I'm not equipt to do any of these tests. I've relied more on the report from the county's inspector that he has found very few t mites in the area.

I have primarily used wintergreen oil in greese patties in the fall after pulling the honey supers. I have also used it in sugar syrup in spring in colonies that seemed to have higher than ordinary varroa counts.

My losses for that past 3 years have been:
2001: One loss, weak hive going into the winter, too few bees and honey. Showed signs of starvation and dysentary.
2002: No losses.
2003: 3 losses. 2 were late swarms and were apparently old queens. Too few bees and were also invaded by a mouse. The cluster in one also was divided in two. The 3rd loss was purely starvation. It was a very strong hive, but moved up and consumed all the honey in the upper hive body and couldn't get back down during our long cold spell last year.

[Robert Brenchley]

Its a very easy dissection, all you do is take a bee, remove the head, pull off the cuticle on the first segment of the thorax (the middle bit where the wings and legs are attached), and look at it under about 10-15x magnfication; a decent handlens will do it. The tracheae are the ropy looking things, which should be white; if they're discoloured it has TM.

------------------
Regards,

Robert Brenchley

RSBrenchley@aol.com
Birmingham UK

[Dave W]

Greetings . . .

A fool-proof method of determining T-mite levels would be to prepare a sample of bees as directed at: http://www.barc.usda.gov/psi/brl/mite-aw.htm and for a FREE test, submit to:
<UL TYPE=SQUARE>Bee Research Labaratory
Bldg 476
BARC-East
Beltsville, MD 20705
[/list]as directed at: http://www.barc.usda.gov/psi/brl/directs.htm

Likelihood of detecting T-mites is higest in fall and winter. A "lab" test BEFORE treating would indicate need for treatment, and a "lab" test AFTER treatment would indicate efficiency of treatment.

Dave W