It looks like that Varroa presence is somehow related with
Chalkbrood development. Hear in Slovenia, and I know the same happened
also in our neighbourhood, we didn't have enlarged problems with
chalkbrood few years after varroa came in our region. Then we had
several years with highly infestation with chalkbrood. Last few years
there are not some much problems with chalkbrood. As I can remember
that happened when we started using fluvalinate strips. I was asking
myself if that could be related with presence of fluvalinate 3 weeks
along in the hive. I've never went in controlled observations of bee
behavior, but that might be interesting. I observed that application
of  essential oils and also fluvalinate into the hive cause induction
of selfgrooming and also allogrooming behavior in bees. As you can
imagine, bee can not be involved in grooming behaviour at the same
time as it inspect brood. With the other words, unusual increase of
frequency of behaviors related with grooming most likely decrease
frequency of comb inspection and cleaning. For this two behaviors
are different motivations and they exclude each other.  It would be
nice that someone would test this hypothesis experimentally.
      By the way, in the first years of varroa infestation we used
 fumigation. This was one day treatments and perhaps this could be
the reason we didn't have problems with chalkbrood.
 
         With regards,
 
                   Janko
 
 
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Dr. Janko Bozic
University of Ljubljana
Biotechnical Faculty, Department of Biology
Vecna pot 111, p.p. 2995
1001 Ljubljana
SLOVENIA
tel. (386) 61-265-584, (386) 61-265-585
fax. (386) 61-273-390
e-mail: [log in to unmask]
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                                SLOVENIA - Homeland of Carniolan Bee