Up till now anyway, this colony of bees (and their ancestors forming this colony’s ancestor colonies) that has lived in a wall since several colony generations, has never been treated with any kind of chemicals ever, against Varroa mites or anything else.
June 29 last year I caught a swarm that came from this wall in a non-heated old house. (http://www.elgon.es/diary/?p=515) Towards the outside of the wall from the bees they had no insulation whatsoever. Just a thin board of wood. At the inside though a thick log wall.
For a couple of years there’s been an Elgon apiary 3 km away (2 miles). But the bee colony has been longer than that in the wall. Further back in time the closest apiary was 6 km (4 miles) away. At that time the Varroa mite had not arrived to these bees. For many years this colony has swarmed every year.
The swarm I caught was not big, but it had an egglaying queen and built up strength well enough to winter safely. To help it make a lot of brood I provided it with a shallow super above an excluder. I shouldn’t have done that I think as it was too easy for me to just take away this honey super when it was time to prepare the colony for winter. That is stressful time.
Now the bees hadn’t much honey left so I gave them 20 kg (44 pounds) of sugar in sucrose solution. If I hadn’t taken the small amount of honey it would have had about 10 kg (22 pounds) of honey for winter storage. Seeing how the colony behaved I think it would have made it well through winter with that amount. My first colony ever in 1974 had about that amount its first winter.
I saw no wingless bees during the season last year, so they got no Thymol against mites. I didn’t then have any quick way to measure the mite population (but here is at least one: http://www.elgon.es/diary/?p=354) And as I mentioned it was stressful times for me.
The queen stopped laying entirely in late summer. In November I saw through the plastic sheet used as kind of inner cover that the bees was sitting tight together like vacuum-packed peanuts.
About 10 March this year when the bees had their main cleansing flight after winter the cluster had spread out and filled more room than in November. It was very few dead bees on the bottom board. And not one defecate spot at the entrance.
These bees seems at least to be more winter hardy and be more Varroa resistant than common beekeepers’ bees, which have not been selected for Varroa resistance.
A possible scenario
A swarm of Elgon bees flying from the Elgon beekeeper 6 km away finds the cavity in the wall. Varroa mites havn’t arrived yet to the area. No beekeeper robs the honey or exchanges it for sugar. The cavity is not bigger than maximum two big boxes a beekeeper uses. The amount of brood can’t be as big as in a beekeepers hive. And the restricted area makes the volume finally too small for the bees (no beekeeper puts on boxes) and they swarm, every year mostly. Insulation is almost none. No beekeeper renews the wax and the bees build what they want when it comes to for example cell sizes. The Elgon beekeeper used small cell size to begin with. Here the cell sizes may become still smaller due to cocoon residues.
The bees adapt to the new environment now when they are on their own, like they were before there were any beekeepers around. In this adaption process the epigenetic process is most important, at least at first. The different environment created by a different “hive”, different food (more natural) and different cell sizes (also still smaller) gives a different chemical environment of many aspects. For example the different cell sizes give somewhat different food for the larvae, amount and probably composition also. This results in switching off some genes and turning on others in the DNA. Disturbing chemicals like pesticides and treatments in the hive can hinder this epigenetic process. But not for this swarm. It lived in a non-farming area and no beekeeper put chemicals in their hive.
There were no neighbor bees. Thus no bad influences from non-resistant bees drifting into their hive and no reinvasion of mites.
When the Varroa mites arrived the drones that became “fathers” were those that the mites didn’t parasitize. Maybe they avoided those drone larvae. And also those drones that were parasitized but were not as affected as others, became “fathers”. Thus also an adaption for resistance took place with a change of the DNA. Natural selection thus took place.
As the colony swarms every year there is a break in the brood production. This hinders the reproduction of mites. Also there is both an epigenetic and a genetic adaption with the new generation.
The smaller cells give less attractive food for the mites. They get less fertile on larvae in smaller cells. http://www.elgon.es/diary/?p=596
Drone cells get smaller in colonies on smaller worker brood cells. With smaller worker brood cells you get worker bees that get more hygienic. http://medycynawet.edu.pl/index.php/component/content/article/336-summary-201412/5234-summary-med-weter-70-12-774-776-2014 or http://alturl.com/a8scb Small cell beekeepers, including me, reports a widespread occurrence of uncapping and chewing out of capped brood in both worker and drone brood parasitized by mites. http://www.elgon.es/diary/?p=544 But VSH is said sometimes to not occur on drone brood. But those bees are kept on large cells. At least it doesn’t occur as much in drone brood. But it is observed quite a lot sometimes in small cell colonies as mites are observed to be much more common there in drone brood than in worker brood. http://resistantbees.com/blog/?page_id=2471
What happen with feral bees in a beekeeper’s hive?
If a swarm from feral bees end up in a beekeeper’s hive with large cell size, the environment changes and a “reverted” epigenetic process takes place. If there are more bee colonies in the apiary or close by all bees will be drifting (as is common) in all colonies and be mixed more or less. If these other bees have no or very little resistance against Varroa they will have a negative impact on the more resistant feral bees. These were enough resistant in the wall. Are they enough resistant now in this beekeeper’s hive? Maybe not.
If the feral swarm ends up in a beekeeper’s hive with small cell size, and there are neighboring bees that have substantial resistance against the mite, it may be that this swarm will do very well fighting the mites. Especially if there are no or very few bees around that can’t make life miserable for Varroa mites.
What will happen with my feral bees? Will they continue to be treatment free?