Sunday, April 4, 2010

Gilbert White, Drone Congregation Areas and Varroa Mites - a mixed bag of topics!

Today has been a lovely Easter Sunday, warm, sunny and rather contemplative.

We were discussing Drone Congregation Areas (DCAs) on Friday after inspecting our hives. These are the special areas that Drones go to to 'intercept' Queens that are out on their maiden flights. I'm not sure if anyone really knows why they are where they are, but drones (but not those not from the queen's own hive) congregate in the air and wait around for a passing queen, and then they pounce. Apparently the drones travel farther away from the hive than the queen and this somehow ensures the queen does not mate with a drone from her own hive.

One of the strange and mysterious thing about these areas is that they have been well documented and have been found to stay in a fixed location.  The first DCA to be documented was by Gilbert White in on July 1st 1792...

"There is a natural occurance to be met with upon the highest part of our down on hot summer days, which always amuses me much, without giving me any satisfaction with respect to the cause of it; & that is a loud audible humming of bees in the air, tho’ not one insect is to be seen. This sound is to be heard distinctly the whole common through, from the Money-dells, to Mr White’s avenue-gate. Any person would suppose that a large swarm of bees was in motion, & playing about over his head"

View over Selborne (144K)

Now, Gilbert White lived in Selborne, in Hampshire in England, and is a rather celebrated English Naturalist. He wrote the "Natural History and Antiquities of Selborne" in 1792, and this is one of the few books that has never gone out of print. It really sets the standard for field observation in the English language, and was a major inspiration to Charles Darwin.  Selborne also happens to be about 10 miles from where we live in the UK and is a really lovely village, and probably looks much the same as it did in 1792.

The most amazing thing (at least I think so) is that the DCA Gilbert White first observed, is still active today - more than 217 years later!  That's mind blowing.  I need to find some DCAs in Missouri!

So on to Varroa.  Well, I did a sticky board test yesterday (between 10.30 on April 3rd and 10.30 on April 4th). The result; a grand total of 16 mites stuck down.  My cheat sheet from the University of Minnesota tells me that if the number of mites was about 60 then I should think about treating.  So it seems the varroa in my hive are not in numbers that I need to worry about - at least for now. But I guess another check in a couple of weeks wouldn't harm!

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