My understanding of the research published about the effect of varroa
infestations on drones is that mites have an effect on the number of drones
that reach sexual maturity, on the flight performance of mature drones, but
not necessarily on sperm quality and quantity. Therefore, while the number
of drone colonies needs to be increased to ensure an adequate number of
drones make it and don't succumb to what Lipinski calls 'oxidative stress',
the quality of the mating should be unaffected. The question is, by how much
should they be increased? Larry Connor's Bee Culture article a couple of
years back was very useful in telling us how to do the sums, but makes the
assumption that all the drones produced are 'consumed' by mating. Drones are
supposed to be potential mates for as long as their flight performance lasts
undiminished and they can stay competitive. So the related question is, how
long is that? What is the lifespan of these competitive but (as yet) unmated
drones and how much can/do they contribute to a 'reserve' bolstering the
number being produced 'fresh' on a daily basis? Does anyone know if Duay,
DeJong & Engles 'flying power' bioassay was used to study the competitive
fitness of old drones?


References.
Connor, How many drone colonies do you need? Bee Culture, November 2003.
Collins & Pettis, Effect of Varroa infestation on semen quality. ABJ, Aug
2001, pp590-592.
Duay, DeJong, & Engels, Decreased flight performance and sperm production in
drones of the honeybee... Genetics and Molecular Research Vol 1(3): 227-232.
Lipinski & Zoltowska. Preliminary evidence associating oxidative strees in
honeybee drone brood with Varroa destructor, Journal of Apicultural
Research, July 2005, pp126-128.

Dave Black
Otanewainuku, New Zealand.

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