Why was fall 2020 different
Fall 2020 was very different than most falls in the Chicagoland area. The video below is a typical scene I see each fall in front of my garage. It shows bees eagerly taking advantage of the September and October blooms. Fall 2020 was no different in that regard. Golden rod and asters offer a last chance for bees to build up winter stores. Typically at end of October the winter cold will sets as each colony settles into their winter cluster.
That isn’t what happened in 2020. If you remember in fall 2019 winter hit hard at the end of October with snow that lasted into December. It was a little colder then usual all that November. In 2020 just the opposite happened. November and early December were unusually warm. This set into place the perfect storm for Varroa Mite migration.
I noticed it with my hives. Unfortunately I didn’t figure it out until it was to late for some colonies. Each year I get better and better at mite control. In 2020 I decided to be very aggressive. In retrospect I may have been to aggressive. Killing an insect that lives on another insect without killing one of them is tricky business. Many mite treatments can be hard on your bees.
Nevertheless, by the end of October I was very pleased with the mite counts throughout the hives. The count was coming up 1 or none. This is what you want to see. I had been diligently balanced resources so each colony had what they needed for honey stores. Things were looking good.
Conditions encouraged robbing behavior…
Unlike most years this past November we were able to go through the hives a couple more times to balance resources and finish moving some of the larger colonies into 2 boxes instead of 3.
The picture to the left shows an event that should have tipped me off to the cascading events that were about to happen everywhere in Chicagoland.
The following example was my first tip-off fall 2020 was going to be a heavy mite migration year.
We were gathering extra frames of honey from hives that were full and giving them to hives that could use a little more. A box of these honey frames had been sitting next to a hive for only about 15 minutes when I noticed that hive now had a cloud of bees around it. Wish I had the taken pictures of that cloud it is quite frightening. Of course there isn’t much time to waste when things like this happen. I typically use a painters tarp to stop the robbing. We only had garbage bags. You have to use what you’ve got there isn’t time to be perfect. No sooner did I cover one hive did the cloud of bees just move to the next. We eventually stopped the robbing. Fortunately it was near the end of day. In all we had to cover 5 different colonies.
Over the course of the next two weeks our hives that were to large to consolidate now consisted of only a queen and about 100 bees. No other dead bees in the hive. Ouch!
This is my speculation. There weren’t flowers available for forage but the weather was excellent for flying. Bees eager to keep storing resources found colonies they could rob but unfortunately for them those weak colonies were full of mites. Mites know when their colony is about to colipase so they hitch a ride to a new colony with stronger healthier bees.
In just a few weeks we lost almost 1/2 of our colonies. Worse fall I’ve ever experienced.
If you feel comfortable, send me a note and share your experiences this past fall. I talked to several beekeepers who lost every hive. One gentlemen had 28 colonies and 14 winter NUCs. All but one vanished. The one that was still alive he had moved to a different area before the end of October.
Not all beekeepers experienced robbing loses.
It wasn’t bad news for everyone. I have one friend with 7 hives still in 3 boxes high, 2 in 2 boxes, and 8 in NUCs. As of Feb 2nd 2021 he still has all his hives alive except for 1.