Back in early October we did one last check of our bee hives. One of our hives was doing phenomenal. Lots of brood, lots of food for the winter. But one thing that was kind of bothering me was that there was a bunch of supersedure cells. At first I was thinking they were getting ready to swarm which is odd because of the time of year or that there was something wrong with the queen, however based on her brood pattern things seemed healthy.
However, not 3 weeks later we noticed a large drop in activity in that hive almost overnight. We thought maybe it was because it was colder and they were staying in the hive to regulate the temperature. Plus we were still seeing some bees come and go.
We went in this past week just to check the hive only to find the colony had completely collapsed. Not only that, but there was a very large pile of dead bees in front of the hive. I’m kicking myself now for not following my gut early on and checking them. If I had I would have been able to send in a sample of the dead bees and a sample of pollen to determine what had killed them. However, I have my suspicions and they are pretty strong.
The amount of supersedure cells, the nearly overnight collapse of what seemed like a healthy colony and the pile of dead bees outside of the hive point to pesticide poisoning. There are a number of pesticides that are very toxic to honeybees but are commonly used in urban areas such as malathion and Sevin (along with many others that can be used specifically for bees such as Spectracide Bug Stop). Even organic pesticides, such as Permethrin, can create problems for bees as it is highly toxic to them. We avoid the use of pesticides (except for regular Sluggo which is non-toxic to non-target species) but since bees travel up to 3 miles away there just isn’t any way to control their exposure.
Unfortunately pesticides can dissipate fairly quickly so it’s too late to test the pollen.
So if you’re concerned about the plight of pollinators double check that bottle of pesticide’s active ingredient before you spray it.