The warm stretch of weather last week provided an opportunity to look in on the bees. Two of my three hives are doing well, with bees filling at least a full brood super and generally a healthy appearance. The other hive, the one that was strongest last year, is suffering. It appears to have the now all-too-common symptoms of what has been called colony collapse disorder, CCD. A once-thriving colony starts to dwindle. It usually starts with elevated Varroa mite levels showing up on the drop board. The colony enters the winter with good numbers, but a combination of mites, viruses, the fungal Nosema pathogen, and pesticide residues all gang up to reduce the typical bee life span from months to just a few weeks. My experience is that the “hot” problem will vary from year to year. Last year there was no sign of Nosema, but instead evidence of typical viral symptoms. The year before, severe Nosema infections took down two hives. This year I’m not sure of the mix of pathogens that is causing the problem, but suspect both virus and Nosema stress. And invariably, where there are problems there is also a significant number of mites.
Keeping healthy bees is not just about keeping the mites at bay. Bee nutrition is also a factor. Many bees are placed for pollination in large mono-culture crop plantings where there is little variety available to the bees. This can lead to nutritional deficiencies and weakened bee immune systems. Beekeepers often feed sugar syrup (or corn syrup) in the spring to help get the bees going in the spring. To compensate for mono-culture pollen sources, beekeepers will feed pollen substitute patties to the bees. Good bee nutrition requires a wide variety of plant species that supply nectar and pollen. I prefer to leave plenty of honey on my hives so that they don’t need spring feeding, and the backyard hives in Eugene have a plentiful variety of nectar and pollen sources most of the year.
But a bigger problem in the urban setting is pesticide use. The Neonicotinoid family of pesticides are particularly a problem. These are systemic insecticides that attack insect central nervous systems. Systemic insecticides are taken up by the plants and the chemicals end up in the pollen and nectar that the bees collect. Some the Neonics are known to persist for several years before degrading. This is a bad combination for bees. Nerve toxin in the food supply doesn’t help when fighting mites and viruses that the bees have to contend with.
Gardeners can help the bees by planting bee friendly plants, and by just allowing natural weedy areas to go unmowed. Each time a vacant lot is turned into chem-lawn, we lose just a little more of the natural infrastructure that supports all life on this planet. Honey bees are not the only pollinators in trouble.
Coming up in Eugene on February 27th, there will be a great opportunity to get to know more about the plight of the bees. There will be a showing of the film Vanishing of the Bees along with presentations by local experts and beekeepers. I’m going to bring a little of my crimson clover seed to give folks who want to plant some bee forage, and there should be other seed available as well. It’s a chance to learn a little more about the problem insecticides and what we can do about them, and a chance to talk to local beekeepers about how to keep our insect friends flying.