mites in a cell

[jmgi]

How many mites generally enter a cell at one time to reproduce? John

[sfisher]

I think one female.

[Mike Gillmore]

One mated female.

http://www.ars.usda.gov/services/doc...d=2744&page=14

[beemandan]

I think one female.

One mated female.

Not so fast guys. During spring and summer brooding this may be typical…although not absolute. But as brood production winds down at the end of the season there are often multiple (two and sometimes more) mated female mites entering those limited number of available brood cells. This extra heavy parisitization(?) of overwintering bees is one reason why fall/winter colony collapse from varroa is common.
Also consider…when a single female mite reproduces in a cell, all of her progeny mate with their brother. In that fashion mites are quite inbred. Were it not for those times when multiple foundress mites reproduced in the same cell there would be no sharing of genetic material…..almost certainly dooming the species in the long haul.

[jim lyon]

Also consider…when a single female mite reproduces in a cell, all of her progeny mate with their brother. In that fashion mites are quite inbred. Were it not for those times when multiple foundress mites reproduced in the same cell there would be no sharing of genetic material…..almost certainly dooming the species in the long haul.

That's an interesting perspective Dan and one that makes perfect sense. It always intrigued me that varroa could survive their inbreeding without getting weakened.

[jim lyon]

Let me take this one logical step further. By reducing late summer/fall mite overloads with timely treatments then wouldn't it stand to reason that cross breeding would rarely happen and the mite could suffer as a result?

[beemandan]

cross breeding would rarely happen and the mite could suffer as a result?

If we could only suppress the mite populations in all of the bee colonies...that might help. I'm thinkin' there will always be some untreated and feral colonies and even in the treated, low mite population hives there will probably be a few incidental multifoundress events.
They've survived a gazillion years....I'm guessing that they'll be around in another gazillion.

[jmgi]

beemandan, you must be correct about multiple foundress mites entering a singe cell because in reading Mel Disselkoen he says that is exactly what happens after the brood break when doing splits and they raise a queen, the first new brood is occupied by multiple mites because they are desperate to breed. John

[jim lyon]

I am not quite following the logic of why they would breed any faster in either scenario.

[beemandan]

John,
I think Disselkoen is on-the-money with this.
Even without the brood break there are any number of other conditions that drive the mite/brood issue. This summer when working my hives and removing frames would expose developing drone brood between the boxes, I saw any number of mulifoundress mites on some of those drones. In several I am convinced that I saw three...but because of the disruptive nature of the cell destruction I couldn't be absolutely certain.
In my neck of the woods...the mite populations were substantially higher than I normally see this season. Last winter, I don't believe, most of my hives ever stopped brood production.

This year most have already shutdown......thank goodness!

[jmgi]

Jim, maybe it has something to do with the mite load of 3200 that Mel talked about, at that point if there is a high mite load and not sufficient larval brood of the right age due to decreased brood rearing at the end of the season, or in a brood break scenario, the mites converge on the limited brood in numbers not normally seen. John

[beemandan]

I am not quite following the logic of why they would breed any faster in either scenario.

Jim, If I understand your statement, I don't think it is a question of breeding faster. I think it is an issue of lots of mites looking for somewhere to reproduce, at the same time there aren't many available brood cells for them to use. The result is a higher number of mites/developing bee.
Am I making any sense? (I don't always)

After hitting the enter key....I read John's reply.....what John said.

[jim lyon]

Yeah I can accept that if it is just a population thing. What I was trying to understand was why mites might ignore an uninvaded (if there is such a word) larvae to crowd into another larvae where mites already exist. Dosent it still come down to the fact that mites presumably try to find their own larvae in either scenario? Or put another way wouldn't there be a breeding disadvantage to sharing a larvae with another mated female and not an advantage?

[jmgi]

From what Mel said, when multiple mites(he said four or more)enter a cell it is unsustainable for the mites, they all die from lack of food and the larva itself dies from being depleted. This is another reason that the brood break helps so much, the mites self destruct by being greedy little things. John

[beemandan]

Dosent it still come down to the fact that mites presumably try to find their own larvae in either scenario?

A couple of things come to my mind. First...there may not be any mechanism for them to determine that a cell has already been invaded. I really don't know.
Secondly...if there are 2000 mites actively looking for brood cells and only 1500 brood cells of the right age......

[jim lyon]

I think we are in agreement on this. I initially thought you were saying that Mel was claiming there was a breeding advantage for multiple mites to share a larvae. As it relates to what we have done we have used an oxalic trickle at 20 days on nuc yards for a few years but stopped the past few years as it appeared mite numbers in the spring were so low we were killing very few mites and I was worried that OA might affect a newly mated queen just getting started. If your mite loads are high, though, it might be the lesser of two evils.

[beemandan]

I was worried that OA might affect a newly mated queen just getting started. If your mite loads are high, though, it might be the lesser of two evils.

I am planning to try hopguard for this purpose this upcoming spring. I'm not sure it will help but if it meets the manufacturers claims...it shouldn't hurt.

[jmgi]

beemandan, as someone who doesn't treat-yet, I thought that mite loads are low in spring and grow as the season progresses, so why would you treat in spring with hopguard as you were saying? Or do you normally treat spring and fall regardless of mite load? John

[jim lyon]

beemandan, as someone who doesn't treat-yet, I thought that mite loads are low in spring and grow as the season progresses, so why would you treat in spring with hopguard as you were saying? Or do you normally treat spring and fall regardless of mite load? John

There should be far fewer mites in the spring than the fall but it all gets down to how low you were able to get them last fall. That's the beauty of a well timed OA treatment.

[beemandan]

With the products (apiguard, apilife var) I'd usually use for mites result in a significant disruption in the colony and so, in the past, I've always thought that a springtime treatment caused more trouble than it solved. But after this year....I've had second thoughts. I lost some hives during the summer that were surely mite caused. By the time I realized how bad they were, it was too late to help them. And although most of my hives got an unscheduled midsummer treatment and did well, I suspect that they would have been even better if they had started the season with a lower mite load. In my mind, if hopguard genuinely isn't significantly disruptive to the hive....it is worth a try.