Wednesday, April 20, 2011

Bee Log 56: April 20, 2011

This is what the bottom board on one of our dead hives looked like. It looks pretty much like the bottom boards of the hives that survive. There are a few dead bees there.

We are getting some new hives ready to receive the new packages of bees that we are expecting.

We went into the winter with 19 live hives. 15 of them have died over the winter. I am not sure that I am such a good beekeeper. What did they die of and when did they die? Only one hive died of starvation. All of the other hives had more then enough stores to see them through the winter. Two hives died in the last two weeks. They seem to be victims of CCD or colony collapse disorder. The bees just disappeared leaving behind a bunch of honey, capped brood and no recently dead bee corpses. Several hives died between February 1 and March 1. It was a nasty cold winter and the bees probably had too small a cluster to begin raising the spring bees needed to replace an elderly population of late winter bees. In those hives we found a softball sized cluster of bees all dead.

What will we do differently? We did not treat for either varroa mites or trachea mites last fall. We need to do both. There are some new non-pesticide treatments out that show some promise. One is based on hops and one on formic acid. We have started with the hops treatment. We are also feeding sugar water and pollen substitute. It remains colder than normal in Seattle and the bees are just not getting out much. They need to raise brood this time of year and they must have pollen or pollen substitute for protein.

We hived 8 new packages of bees over the last weekend. We are trying an experiment based on the hypothesis that winter dead-outs are largely caused by a disease or diseases. We placed 4 of the new boxes of bees on frames that had held honey last summer. 4 boxes were placed on new plastic frames painted with a bit of bee's wax from our own hives. We are following the work of Craig Cella of Loganton, PA who described an experiment in the April 2011 American Bee Journal. Any boxes, bases or lids that were reused were dipped in a 10% bleach solution before the bees came. Our test will be a count of the blank cells in the brood nest. A 20 X 20 cell area is marked out and then the empty cells counted. We are curious whether the reused honey super frames will affect the brood.

Beekeepers have been putting new bees on old drawn out frames for many years. Bees seem to like old comb. This gives the bees a head start because they can get right down to the business of raising a family without having to build the house first. Recently, there seems to be some evidence that diseases or something bad for the bees is harbored in the old comb. It is known that the wax is a sponge for pesticides and that the accumulation of pesticides is bad for the bees. Some disease like American foul brood bacteria spores are known to stay on the wax and infected subsequent hives (such hives must be burned). This is not American foul brood. It is not known what causes CCD but putting bees in hives that have died increases mortality. Perhaps our small experiment can help determine if the honey supers are also harboring an agent causing poor brood numbers.

We enter spring a bit chastened by our loss. We feel responsible. We do want to be able to produce honey for the farmers' market. There are 10 more packages of bees coming. That will give us a total of 22 hives placed in 10 locations around the north end of Seattle.