Mites too old to reproduce???

[Dave W]

In the April 07 issue of ABJ on page 321, is this seemingly profound statement, “If you start these new colonies w/ queen cells, many of the varroa mites in that sealed brood will be too old to reproduce by the time the new queen’s brood is at the right stage for an infestation”.

This statement clearly defines why making splits reduces the presence of Varroa, something I’ve pondered.

In reviewing Varroa biology as defined in Mites of the Honey Bee, Webster/Delaplane explain that while in the cell, the spermathecae of mature female mites are filled by mating multiple times w/ their brother. Soon after mating is completed the sperm transport system in the female degenerates thereby preventing any future mating. Newly fertilized females cannot lay fertilized eggs immediately since the final stages of spermatogenesis occur in the female reproductive system, taking 4-13 days depending on the maturity of the female.

When the bee emerges from the cell, these mated mites leave the cell and become phoretic on other adult bees. When brood is present, phoretic periods of between 4.5 to 11 days have been recorded but must exceed months (5-6?) during the winter broodless period. In the lab, mites have been observed to live for up to 80-100 day while reproducing.

My question is about being “too old to reproduce”, can someone please explain?

[George Fergusson]

In the April 07 issue of ABJ on page 321, is this seemingly profound statement, “If you start these new colonies w/ queen cells, many of the varroa mites in that sealed brood will be too old to reproduce by the time the new queen’s brood is at the right stage for an infestation”.

This statement clearly defines why making splits reduces the presence of Varroa, something I’ve pondered.

Depriving the bees (and hence the varroa mites) of a brood cycle has an obvious and predictable effect: less bees (and mites) than there would have been if there had been no break in the brood cycle.

I'm not aware of any evidence that mites will lose their reproductive window of opportunity just because they've been on-hold for a few weeks or even a month unless they were scheduled to die of old age anyways. Statistically this would likely happen to some percentage of mites.

In reviewing Varroa biology as defined in Mites of the Honey Bee, Webster/Delaplane explain that while in the cell, the spermathecae of mature female mites are filled by mating multiple times w/ their brother. Soon after mating is completed the sperm transport system in the female degenerates thereby preventing any future mating. Newly fertilized females cannot lay fertilized eggs immediately since the final stages of spermatogenesis occur in the female reproductive system, taking 4-13 days depending on the maturity of the female.

That all sounds correct as per my understanding, for what it's worth.

When the bee emerges from the cell, these mated mites leave the cell and become phoretic on other adult bees. When brood is present, phoretic periods of between 4.5 to 11 days have been recorded but must exceed months (5-6?) during the winter broodless period. In the lab, mites have been observed to live for up to 80-100 day while reproducing.

Again, correct as per my understanding. I also understand from my reading that mites can reproduce approximately 3 times.

My question is about being “too old to reproduce”, can someone please explain?

No. I can't explain that statement except to suggest they're talking about a Foundress mite (i.e., the mother that enters a cell to reproduce) might have another cell-laying experience in her future of which she would be deprived if there were a break in the brood cycle because she would die of old age before having the opportunity to enter a cell to breed. I would expect that some small segment of the mite population might fit this description.

[George Fergusson]

Gee Dave... I've been thinking about this off and on most of the afternoon. At first glance I figured your initial quote was just bogus, I mean what were they thinking? Then as I was replying the possibilities began to percolate, then finally on my way home the real effect of breaking the brood cycle on mite population hit me. Not only are you shorting all the mites a reproductive cycle, you're going to lose those almost-dead mites, the ones that have maybe one more reproduction cycle left in them. They're going to die off before they get a chance to lay eggs one last time.

Now I don't know much about mite population age distribution. I don't really recall ever reading much about it either but clearly in a hive you're going to have mites with varying ages ranging from very young (just emerged) to very old (almost dead). I wonder, what percentage of the mites have a low reproductive potential, and is it a constant percentage of the population?

[Dave W]

Hmmmm . . . I love it when ONE question creates TWO.

[Michael Palmer]

Dewey Caron said something at our winter meeting. We were discussing smr bees, and how they keep the mite load down. He mentioned that after 3 or 4 attempts, the female mite would be too old to reproduce.

[gardenbees]

I was contemplating splitting my two hives after the honey flow and treating all of them with powdered sugar at that time. Sounds like from the above discussion that it would be a one, two punch for the mites. Breaking the brood cycle and knocking off the mites that are waiting around to breed after the new queen is laying. Theresa.

[George Fergusson]

>it would be a one, two punch for the mites.

Yes, and a cheap shot at that, below the belt