Issue |
Apidologie
Volume 34, Number 1, January-February 2003
|
|
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Page(s) | 11 - 17 | |
DOI | https://doi.org/10.1051/apido:2002042 |
DOI: 10.1051/apido:2002042
Rapid determination of the numbers of Varroa destructor, a parasitic mite of the honey bee, Apis mellifera, on sticky-board collection devices
Nicholas W. Calderone and Sisi LinDepartment of Entomology, Comstock Hall, Cornell University, Ithaca, NY 14853, USA
(Received 21 May 2001; revised 25 March 2002; accepted 18 April 2002)
Abstract
We collected mites on boards coated with Vaseline; then, Vaseline,
mites and debris were removed and solvent processed. Three weights were
obtained for each sample: (1) weight after processing (pre-cleaned
weight = W
); (2) weight after removing most remaining contaminants
(partially cleaned weight = W
); and (3) weight after removing all
remaining contaminants (clean weight = W
). The regression of the actual
number of mites on W
was significant (
P < 0.0001). Therefore, we evaluated
the usefulness of W
and W
as surrogates for W
because they are easier to obtain. Concordance correlation coefficients (
rc)
for W
with both W
and W
were
< 0.80;
therefore, correction factors for the two surrogates were calculated by dividing
the average value of Wcln by: (1) the average value of Wpre, or (2) the average
value of W
. W
and W
were adjusted
by multiplying them by the appropriate factor. The
rc values for corrected
data were
> 0.99. Our method lets us obtain an accurate estimate of the
number of mites in 20-30 min, regardless of the number present, and is useful
when the number of mites on a board
> 4 500. Our method also avoids the loss
of precision that occurs with sub-sampling.
Key words: Varroa destructor / Apis mellifera / population estimation
Correspondence and reprints: Nicholas W. Calderone
e-mail: nwc4@cornell.edu
© INRA, EDP Sciences, DIB, AGIB 2003