During our Apivox Varroa Eliminator project, we are constantly trying to identify the relationship between the state of the bee colony and the population of Varroa mites parasitizing in it. One of the important observations is the relationship between the temperature in the "streets" of the bee nest in spring and the growth of the amount of mites drop.
It is believed, and we in principle agree with this, that the free fall of the mites is proportional to the size of the mite's population. We believe that this relationship is quantitatively much more complex than scientists believe, but in general it is so ...
Thus, with a number of simplifications and assumptions, we will also assume that the stable growth of free fall of the mites tells us about the growth of the tick population, and its stable decrease, about the process of reducing the size of the mite's population. In our opinion, the stable amount of the mites falling freely on the sticky board indicates some stabilization in the development of the mite's population.
In
order to understand the state of the bee colony and the presence of brood in
it, temperature sensors were placed in the center of all the
"streets" between the frames of the experimental colony. Our results
provided data for building the chart, which
you can see below. The measurement range is from
So, what dependencies do we see ...
1) At the end of September, the drop in
temperature in the "streets" led to the complete impossibility of
laying eggs by the queen, and, accordingly, to the complete cessation of
reproduction of the mites. The mites drop began to decline, because most of the
old mites, according to our data, die during the reproduction process. The quantity of the mites starting to stabilize.
2) Since January, when the outside
temperatures became positive or slightly negative, about 2 "streets"
of the nest were heated by bees to the temperatures above 32-33C, which allow
the queen to lay eggs. This led to the beginning of the renewal of the mites
population. At the same time, the mites drop did not grow much, since the
quantity of the brood was not big.
3) From March 26, when sufficiently high
positive outside temperatures were established, the bees switched to stable
heating of seven or eight "streets" of the nest to the temperatures
of 33-35C. This led to the possibility of brood rearing in the cells of
these frames. This led to a steady
increase of the mite's population, which received a lot of space for multiple,
unlimited growth. This led to the death of old females during the reproduction
process and to increase of falling mites.
4) In May, the family went into the state of preparation for swarming. The temperature at the periphery of the nest has significantly increased to 33-35C. This allowed the bees to lay drone brood and queen cells at the periphery of the nest. The mites population received at its disposal not only a huge amount of brood of worker bees, but also drone brood. The growth of the population accelerated many times, bringing the family in early June to collapse ... The growth of the mites population was accompanied by a corresponding fall of young immature mites and dying founding females to sticky board...
The graph clearly shows the point of the beginning of the growth of the mites population (arrow) corresponding to stable heating of more than half of the frames of the nest , which corresponds to the appearance of brood of worker bees in them.
Thus, we can state that:
1.
The appearance in the nest of bees in winter at least one "street"
with a temperature above + 30C indicates the beginning of the recovery of the
mites population.
2.
The presence in the nest of bees in the spring of more than half of the
"streets", heated for more than 32-33C can be a sign of the beginning
of active reproduction of the mites in the brood of worker bees. From this
point on, the mites population begin to grow rapidly.
3. A rise in temperature at the periphery of the nest to 33-35C means the beginning of the mass laying of drone brood and a catastrophic increase in the populations of Varroa mites.
Thus,
there is a direct and almost linear relationship between the increase in the
number of heated nesting frames and the growth of both mites drop and the mites
population itself in the bee colony. For beekeepers, this can be an indicator
for determining the stages of the fight against Varroa mites in bee colonies of
their apiaries.
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