As Sid has mentioned, the sure diagnosis of acarine requires examination of
the prothoracic tracheae.
When tracheal mites first appeared on the scene here in NY, back in the
'80's, we saw large-scale colony losses during the winters. In fact it was
difficult to keep established apiaries going, as so many colonies became
decimated. Though I did not perform dissections or have bees sent to a lab
for analysis, the symptoms were quite marked, including large numbers of
dead bees fully clogging the entrances, and clusters which appeared to have
"exploded" (scattered through the hive, no tight cluster despite cold
temperatures). Often there would be practically no bees left in the hives
at all, and the majority of the winter stores still remaining.
Added to this, crawling bees all over the ground before the hives were
common, sometimes even in cold weather. Some colonies would pull through
to spring with tiny clusters, and I remember arriving at certain yards in
springtime and finding crawling bees scattered across the ground many yards
from the apiary. The "K-wing" appearance would be obvious on many of the
crawlers.
These symptoms occurred during the first few years of the acarine problem here.
I have not noticed them over the past 4-5 years, and wintering success has
vastly improved. I no longer expect to find colonies showing these
symptoms, and hopefully the susceptible stock has been weeded out over the
years. It certainly was disheartening to have to clean out so many heavy
but dead hives every spring.
Question is, were these telltale signs of acarine infestation, or maybe
signs of secondary infections (nosema or ?) which occurred due to the
stress caused by acarine? Or in other words, can a high tm infestation
exist without those symptoms, and could there be other symptoms pointing to
acarine?
We seem to have gotten over that hurdle, anyway, even if it took a number
of years. In the meantime, of course the ugly varroa showed up, and it has
been another novel problem to deal with...!
Regards,
JG
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