 LETTER TO THE EDITORÂ
In reference to Chalkbrood Explained, in last month’s Advocate. I have a different theory on why we are seeing more Chalkbrood present, (Ascosphaera apis).
Dr Mark Goodwin is correct that chalkbrood mainly shows in times of bee stress, mostly during the spring. After the initial introduction in Northland, it took only about three years before beekeepers were seeing it all over the country. It was particularly noticeable in mellifera mellifera (European dark bee) feral colonies. Some I removed from buildings had a 50% infection. Varroa arrived and within three years most of the ferals were gone and so were the black bees. Selective breeding (breeding from colonies with no infection) saw chalkbrood basically disappear.
About five years ago, I started seeing chalkbrood in some Wellington hives. These were hives I requeened with South Island queens, yet the beekeepers supplying the queens were not seeing chalkbrood in their colonies.
A few years later I heard a report from the Wairarapa that two of the three breeder queens from the South Island breeding programme came down with chalkbrood after their introduction.
In the Wellington Beekeepers Association hives this spring we had three colonies out of 16 showing chalkbrood. I have also seen it this season in two of my nucs (two out of the 20 I made to requeen colonies). I removed the heavily effected brood frames, combined these nucs and put in a virgin queen. Normally the bees will clean everything out of brood frames in preparation of the new queen beginning to lay, so most of the mummies should be removed.
Requeening of colonies with locally produced queens greatly assists, but you can sometimes see the odd chalkbrood larvae in the brood frames right through the season. Initially I thought the queens I was getting may have had a weakness for chalkbrood, but hearing that this was happening with other South Island queens, perhaps this indicates that the Wellington area had somehow become infected with a different variant of chalkbrood and that it had spread. Chalkbrood being endemic to New Zealand is unlikely to be tested at MPI's lab, unless there is funding for such a project.
Nature doesn't stand still.
-Frank Lindsay, Wellington.
Ministry for Primary Industries senior scientist Dr Richard Hall contributes:Â We had never looked at characterising chalkbrood; but it is something that had definitely been on our radar. It was something that Hayley Pragert and I had considered as a project task in the past. You will remember we looked at DWV-A (which we have in NZ) and DWV-B (which we did not find). A similar thing could be done for chalkbrood, it is a just a time/resource matter when doing such work. I will keep this idea in mind.
