Beekeepers face a dizzying array of pests, diseases and threats to their livestock. We spend an enormous amount of time battling the varroa mite and being on guard for American Foulbrood disease, nosema, small hive beetle and Africanized honey bees. Fortunately in our region of Western Canada we don’t have the last two problems. Yet.
But among short-term seasonal problems with the potential to be highly destructive, there isn’t a worst pest I’ve encountered than the good ol’ wasp. Varroa? Well, we are learning how to live with it. But when confronted with the old-fashioned yellow jacket or its flying tank cousin, the bald faced hornet, we seem to be unable to deal with such voracious pests.
Neither Amanda nor I care to resort to chemicals to get rid of the wasps. We haven’t been able to find, but one, the nests these gals build. Instead, we resort to closing down the hive entrances to give our bees as much of a fighting chance as possible. If a couple of wasps are able to take out the guard bees, that’s it, Molly. Hive’s a goner.
We have now managed to get a minor handle on the problem. How did we do it? The milk jug trap, modified to account for our local conditions and environment. Let me explain.
We had our first major casualty last week when wasps and hornets, in what seemed like a flash, cleaned out one of our promising hives. It was not for lack of effort in trying to keep these fall pests out of our yards.We could see months ago that this year was going to be particularly bad. Every time we returned from one of our yards with frames of drone comb used as part of our varroa management program, wasps would seek it out almost as soon as we parked the truck.We couldn’t even open a hive for an inspection without it being hit by five or 10 of the marauders.
We hadn’t had the foresight to put out wasp traps early in the year to catch queens before they established populations. That is not a mistake we will make next year. (Here’s a good YouTube synopsis on milk jug methods. Here’s another good site.)
In mid-July we noticed a rise in the wasp population it and started to close down entrances.
On many of our hives we use those long metal mouse guards that can be flipped upside down to keep bees in during transport while still offering them air. We taped down many of the bee ports, leaving six or seven open for the nectar flow.
The problem is complicated by the fact at our new apiary we have a number of small hives and nucs. Nearby there is a huge nest of bald-faced hornets. Those huge black and white hornets are three times the size of a bee, which can be torn apart in the blink of an eye. I can’t find the nest, but I see the carnage everywhere an unsuspecting bee has landed.
Two weeks ago after checking for varroa, I made sure the reducers were all in place. All the hives looked fine.
I came back four days later to find one of our better hives, #41, with a fat new queen and healthy population, completely cleaned out. It was SO dead that every scrap of honey had been cleaned out. When I opened the hive, out flew a cluster of wasps and hornets, freed from having to queue for exit through the now-useless reducer.
We have now gone back and reduced the entrances even further, down to just the width of two bees. It is causing a considerable traffic jam at each entrance, but it also means there’s a phalanx of bees clustered together to ward off marauders.
The other significant thing that has helped has been to bait some wasp pheromones-scented traps with sugar water and lemon grass.
Our earlier milk jug traps, baited with just meat scraps, hadn’t been effective earlier in the summer. But we’re now feeding our hives sugar water and the wasps settle in clouds on any pools we accidentally spill on the truck gate. So we added a fair amount of sugar water to the old jug traps and set them near the hives, and that has done the trick.
The smell of the rotting meat keeps the bees away from the jugs, but the sugar water is like crack to the wasps. We came back yesterday to find the bottom of the jug black with a thick carpet of dead wasps and hornets.