In my former post I wrote: “When I first read that bees don’t uncap and clean out drone pupae, as they do of different reasons with worker pupae, I was a little bit surprised as I saw it ‘all the time’.”
I got this information from a paper by Rémy Vandame, Serge Morand, Marc-E. Colin, Luc P. Belzunces: Parasitism in the social bee Apis mellifera: quantifying costs and benefits of behavioral resistance to Varroa destructor mites, Apidologie 33 (2002) 433–445. In a reference to Rath W., Drescher W. (1990) Response of Apis cerana Fabr. towards brood infested with Varroa jacobsoni Oud. and infestation rate of colonies in Thailand, Apidologie 21, 311–321.
But the findings were made with Apis cerana bees not Apis mellifera. This applied to removal of pupae from cells artificially infested with mites, so these mites had no offspring. Thus it was not ‘true’ VSH tested. http://www.apidologie.org/articles/apido/pdf/2002/05/02.pdf You find it under the subheader 1.2. Removal behavior: “When brood is artificially infested, bees remove only infested worker brood but not infested drone brood (Rath and Drescher, 1990).”
It seems this removal of worker brood (and lack of removal of drone brood) in Cerana bees is not applicable to VSH but to hygienic behavior. If it should be applicable also to VSH in Cerana bees, it opens up for a conclusion that Mellifera bees maybe could be bred to be more resistant to Varroa than Cerana…
Oh, I realized now that Cerana can’t ever uncap a drone pupa, hygienic or VSH, it’s capping is too hard. The drone capping even has a breathing hole. So you can’t compare it with Mellifera really when it comes to uncapping drone brood or not.
Jeffrey Harris found (with Mellifera bees) that VSH is active on drone brood as well, but not as much as on worker brood. http://www.sparc.ars.usda.gov/research/publications/publications.htm?seq_no_115=219999&pf=1 For the full text just register here and download: http://www.researchgate.net/publication/43273071_Effect_of_Brood_Type_on_Varroa-Sensitive_Hygiene_by_Worker_Honey_Bees_(Hymenoptera_Apidae)