Several years ago, it was common that there were always noticeable, even many bees flying around the ventilation and the door to the extraction room. It has become less and less bees every year. This year there have been virtually none. However wasps have been in abundance. Even though I often walked through the door in July and extracted some of the honey then. And it was no honey flow then.
Last year’s breeding queen no 1 gave many new queens working the colonies this year. That has apparently had a big effect this year. Last year, I used a lot of thymol as wingless bees appeared in many colonies. This year I barely needed to use any thymol at all. I find it hard to draw any other conclusion than that my bees have become more resistant to varroa.
However, there are a few colonies in some apiaries which are close to other Beekeepers bees where the mite level suddenly increased quite some in late July/August onwards for a few weeks. It seems to indicate so-called silent robbery from my colonies from hives that are affected by larger amounts of mites so that they do not maintain a good entrance defense.
Then when I was told about the problems some beekeepers had in Finland with imported Italian bees when it comes to how quick they were to rob and as often as these colonies must be treated against Varroa, I made a connection here.
Bees that are not inclined to rob have less problems with reinvasion of mites. Bees that have less problems with reinvasion can be called more resistant to Varroa.


Another factor that is important for reinvasion is the tendency to return to wrong hive, to drift. I have sold a few queens to countries further south in Europe. I got some feedback recently from a beekeeper in Germany who this year introduced two Elgon queens with differing color, one light and one dark. (One of the features I do not attach great importance to is the color and therefore it can vary a lot.)
Her carniolan bees drift a lot, she has noted. Now she split a hive in two and put the two parts very close together with the entrances adjacent. She noticed that Elgon colony with striped bees contains only striped bees. The hive with without beige striped bees, had only dark bees, no bees with beige stripes. None of these colonies’ bees thus drifted to the neighbor.
It seems that part of the Elgon bees’ better resistance can be explained that they are less inclined to rob and that they drift less.

Factors for reinvasion
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4 thoughts on “Factors for reinvasion

  • September 9, 2016 at 21:30

    Nice and plausible argumentation. Ideally we want to have resistant bees in the end of the day that have no problem with reinvasion, and that get rid of mites very quickly (e.g. like in Africa). But maybe that is the second step of evolution in Europe. At first we need a sufficient stock which survive without treatment.

  • September 14, 2016 at 10:36

    Erik is talking about my two elgon hives and I am able to confirm this.

    Since the carniolan bees which hatched out of the combs the queens were introduced to, are now expired, I observe the colonies are not drifting, as I can see in and out of the hive with the yellow queen. The bees mostly have 2 yellow stripes and a brown spot on their back.
    Remember, they are F1!
    They are very gentle and inquisitive but not at the entrance boards. They are most ferocious if it comes to defense against wasps or foreign bees. The foreigners are carried away.
    My beekeeper friend, who owns the mother colony, tells me the same.

    The only hive in my apiary which has a high mite load is one some primorski bees begged into.
    So I believe Erik is right about this.
    To prevent robbing or being robbed is most important.

  • September 18, 2016 at 06:54

    Italian bees are great brood producers.They don’t care if there is a honey flow on or not. Pretty much they gonna brood until they spent the last drop pf honey in the hive. Large populations push them into robbing, which they are infamous for.
    Drifting is another problem as you noticed. Beehives arranged in long lines will get the most mites on the beginning and the end of the line.

  • September 20, 2016 at 14:23

    Checked the weights of my hives yesterday with cold and rainy weather and the elgons were the only ones which came out to see what`s going on!
    They are alert to environment.
    They are gentle but curious.
    Must be a good trait, too.
    Hopefully. 🙂

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