Intrigued. This is the most concise summary of what I've found, which
clearly indicates that Africanized hybrids are healthier, even in managed
apiaries, and can co-exist with varroa. The European honey bees in Chili,
and Argentina may be at a significant threat, versus the healthy colonies
in Venezuela and Brazil.
From my previous reference, there's no doubt increased swarming, smaller
nest sizes bolster feral colonies survival rates. However, this is not the
protective factor in managed apiaries, in large nest sizes. The hygienic
behavior of Afrianized hybrids represents a great deal of potential benefit
for commercial operations in the US. We do not have to selectively breed
for varroa resistance. Instead, focus those efforts on less aggressive
Africanized queens, and integrating the Africanized genetics into
commercial operations (my personal opinion))).
*Artificial infestation of bee colonies with adult varroa females in Sao
Paolo, Brazil, hasshowed that Africanized bee workers were almost eight
fold more efficient in getting rid ofthe mites on their bodies compared to
pure Italian bee workers (Moretto et al. 1991).According to Moretto (1997),
artificially infested Africanized bees reacted to the presenceof varroa
from the very beginning of infestation. Strong body movements involving
theabdomen, legs and mandibles were performed by the infested workers. The
movementsexecuted by infested workers permitted nearby workers to identify
the varroa on theirbody.*
https://link.springer.com/article/10.1007/s10493-009-9325-4
There's evidence to suggest that the particular climate makes a difference
in varroa resistance of Afrianized hybrids:
*On the other hand, in evaluatingthe infestation levels in the Forest Zone
of the state of MinasGerais, a region with a tropical climate with
temperaturesvarying from 14 to 26ÂșC during the year (Koeppen
climateclassification), Bacha Junior et al. (2009) found an averagevalue of
7.8% during the summer. Apparently, there is greatvariation in the
infestation rates of this mite according to theregion of the country and
the respective climate (Moretto,1997).*
https://www.alice.cnptia.embrapa.br/alice/handle/doc/1006569
*The natural resistance of Africanized honeybees(AHB) to Varroa mites has
been well documentedin Venezuela and Brazil (Casanova 2000;Moretto 2002;
Junkes et al. 2007). The hygienicand grooming behaviors of these bees have
beenconsidered a key factor in disease resistance(CorrĂȘa-Marques et al.
2000; Invernizzi et al2016). Likewise, Principal et al. (2004)
andPiccirillo and Gonzalez (1995) have reported thatinfestation rates were
low in AHB colonies,allowing beekeeping without the need of treatmentsfor
varroosis. Currently, Varroa infestationin Venezuela is not considered a
serious problem(Principal, pers. commun.).*
https://link.springer.com/article/10.1007/s13592-016-0445-7
***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html
|