Varroa life cycle

[mwjohnson]

Hello,
I have been searching for varroa life cycle info.
and not doing too well.Does anyone have some good (not TOO technical). thanks.

Also,(this has been driving me nuts)I read someones rhetorical question(wish I could give them proper credit),but it was something like:

"Are the mites we find on our monitor trays the result of better mite fighters,and are we passing by some of our best genetics by breeding only those colonies with low mite loads?"

I find that concept fascinating,IF true I've got one hive with some pretty good genes.

Wondering what you think.

[TwT]

( interesting story from allen dick)is this what you were looking for?

Word is, in a nutshell, that SMR bees are actually hygienic bees, but with an important difference.

SMR bees perform right up there with the HYG strains in standard HYG tests, however, hygienic abilities observed in bees selected for SMR extend beyond simply detecting and removing dead brood. In addition to doing equally well as HYG in detecting and removing dead brood, SMR bees are able to detect, uncap, and remove foundress varroa mites that are laying eggs and reproducing in cells.

This uncapping and removal liberates the foundress, interrupts her reproductive work, and prematurely exposes the undeveloped offspring, resulting in the death of the daughters. The foundress may then enter another cell, but, if she tries to reproduce there, the cycle repeats. Thus SMR greatly reduces mite reproduction, and mites die of old age or accidents without replacing themselves.

The wrinkle is that these bees seem to be much less inclined to uncap and remove foundress mites in sealed brood that are -- for whatever reason -- not laying eggs, and in any hive with varroa, there will be a considerable percentage of mites that non-reproductive, but which are just sitting out the dance in sealed in cells with the pupae.

These non-reproductive mites enter the cell, stay the duration of the capping period, then emerge with the bee.

This subtle fact -- that SMR bees quickly and efficiently remove reproducing mites in brood, but ignore non-reproductive mites in sealed brood --initially escaped researchers, and obscured the strong similarity between SMR and HYG.

Researchers finding and observing the varroa in the sealed brood of such colonies concluded (understandably) that the bees were causing mite non-reproduction, rather than realising that the bees had already located, uncapped and pulled out most of the reproducing foundresses, leaving only the non-reproducing mites. After all, they would pull a frame of brood, brush off the bees, then go to the lab and look at the brood and mites in cells under magnification. Sure there were a few empty cells, but there always are.

They observed that a high percentage of foundress mites discovered in sealed brood were non-reproducing, and that there were fewer mites -- as a percentage of total mite load --in brood than expected. They bred for this characteristic, and actually wound up with an hygienic bee, but one with special abilities -- the ability to sniff out and eject reproducing varroa mites in sealed brood.

Current work -- if I understand correctly -- seems to indicate that SMR and existing HYG cross well, and that the SMR characteristic can be transmitted relatively easily to current HYG stock, so we may see some interesting things in the near future. A name change for SMR may be in the offing as well.

FWIW, preliminary DNA work _seems_ to indicate that just two genes are associated with SMR, but when asked if they are the same genes that are associated with HYG, the answer from those working hard on this problem, seems to be that no one knows yet, and that there is likely more to the whole picture it than just two genes.

I might mention that Dee has been saying for a long time that Lusbys' bees remove varroa foundresses, and that this is a major mechanism in the Lusby success. I think -- correct me if I am wrong -- that she also believes that using small cells (4.9) encourages that trait. I have heard others, here and there, some with small cell and some with ordinary cells, observing varroa removal, too.

This new(?) information is especially interesting for those of us who think we can breed bees by looking at natural drop boards and rejecting hives with big drops. It is not that simple. We could be rejecting the best varroa fighters, using that criterion, if they are, at that moment, combating an infestation originating outside the hive. Observations over a longer period are necessary to get an understanding. (Again, credit to Dee for that).

[Bob Russell]

MW
This site may satisfy your needs.

http://tinyurl.com/6lnhz

[Michael Bush]

Hard to beat that link.

Here's some nice pictures.

http://maarec.cas.psu.edu/pest&disease/sl10.html

Lots of pictures. Just step through it and it goes into the life cycle.

>I think -- correct me if I am wrong -- that she (Dee) also believes that using small cells (4.9) encourages that trait. I have heard others, here and there, some with small cell and some with ordinary cells, observing varroa removal, too.

This increase in chewing out has been reported by many small cell beekeepers.

[mwjohnson]

Thanks for your help, was just about what I was looking for.
Be great to get some of those USDA queens. [img]smile.gif[/img]
Also,I stand corrected about that hive of mine, I checked on them today and that hive was dead, it had 1 1/2 deeps of honey untouched.
I closed the entrances,but wondered if the combs might get moldy? I am wondering if I should bring them home? Would appreciate your ideas on this.
My other colonies seem to be in very good shape,I thought I might divide the honey between my other two colonies when I do my first inspection in early March, but maybe I should freeze it for other uses,like a spring increase?Ideas?
Again,thanks for those links.
--------
Mark Johnson

[Michael Bush]

I would, on a warm day, check on them and put full combs of honey in for empty or mostly empty frames in your other hives. Yes, I'd close them up to keep the mice and robbers out now, and the moths out later.

[Bob Russell]

Mike Johnson and all
Following my reply with the URL to Varroa reproduction it appears your question has not been fully answered.Moving to your mention of the fact are we passing by some of our best genetics.Yes this is very true.The genetics to overcome the varroa are within our bee stocks for the finding and breeding relative to varroa resistance together with high honey production.Many around the world are working on this from different approaches.Once one works with bees that are truly resistant to varroa one makes some amazing observations,particuly so over the last couple of years after nearly 5 years in my own hands on project in New Zealand,which is also the number of years we have had varroa in the North Island of our country. I am now accelerating my own project and will be inviting other beekeepers to become involved.This I will be driving with a magazine publication shortly.