An informative and sometimes humorous column published in
The New Zealand Beekeeper Journal
Bumble bee numbers have dropped dramatically over the last month and now I’m only seeing the odd queen flying during the middle of the day. Up until last month, they were working dahlias for pollen (they prefer the single-headed variety), but my bees are still continuing to fly on fine days bringing in quite a lot of nectar from banksia, rosemary and other ornamentals in nearby gardens.
The bees are also bringing in a lot of different-coloured pollens from good old gorse in scrub areas and ornamentals like Fatsia japonica, which is flowering just over the fence from the hives. If you stand beside a hive long enough, you will also see the odd bee coming in with propolis packed into the pollen baskets on their hind legs to block up cracks between the supers. Those hives still collecting nectar will also have flying drones.
The warm autumn weather has fooled some of the shrubs on the bush fringe. Kohekohe and tree lucerne have begun flowering but so have the occasional bush lawyer and eucalyptus trees. These are budding up out of season.
With brood rearing reducing, varroa mite numbers are climbing again in some hives to such an extent that the bees are tossing out some shrivelled-up bee bodies; I even saw a mite on the abdomen of a bee fanning at the entrance. If you see mites on the bees, the hive is in real trouble and is in need of immediate treatment. Once a hive has signs of PMS, sacbrood, chalkbrood and shrivelled larvae and bees, it’s hard for it to climb back into good health again. Although the adult bees in the hive may look OK, they have also been affected by varroa and may not be able to produce royal jelly.
The way to recovery is to add a frame or two of emerging brood with bees from a healthy hive. Left on its own, the hive will struggle to get ahead unless it’s in a warm area with winter flowering trees and shrubs that produce good pollen and nectar.
acid treatments that rely on vaporisation (such as thymol-based products and formic acid) less effective unless they are placed directly over the brood nest. Dribbling oxalic acid is relatively effective but it must be delivered warm. Unfortunately, with brood in the hives, it’s going to kill only 50 percent of the mites and the treatment can only be repeated monthly as it is rather acidic on the bees’ stomachs. This type of treatment is best delivered on a fine day when bees are able to fly and defecate away from the hive.
Treating with acids is not as effective as strips so if you don’t think your alternatives are working, resort to strips as the aim is to protect the bees and bring the hive alive and healthy through to spring.
Apparently it’s going to be a rather wet spring in some areas according to forecaster Ken Ring, so plan now for this eventuality. Wet weather puts stress on hives if they can’t get fresh pollen and nectar, which causes nosema to build up in the bees, shortening their lives. Weak colonies (those not filling the box they are in, whether it’s a four-frame nuc or single super) will have a hard time maintaining a compact cluster covering both brood and honey frames.
It’s best to unite any weak hive now unless you can provide a warm environment through the winter, such as a shelter shed with one open side facing the morning sun with early pollen sources nearby. Pack all the nucs together so they share their individual warmth or place the nucs on top of a full-strength hive separated by a split board so the warmth from the bees below passes up into the nuc. You may even consider putting some insulation under the roof of the hive to prevent some of the cluster heat being lost through the roof.
Cold, damp conditions within the hive are more damaging than straight cold. Check that the hive is not building up moisture over the cluster on a cold morning. A little moisture around the edges of the inner cover or split board is OK but the space immediately above the cluster should be dry. If it’s damp, add a little more top ventilation by placing a matchstick on the back of the hive.
Those with top-bar hives should be inspecting them every couple of weeks during the winter on a fine day to see that the cluster is just touching honey frames. If we have a long cold spell, the bees might not break cluster and move back on to the honey frames. You may have to assist them by moving the odd frame forward so that it touches the outside of the cluster. Try not to disturb the bees too much as any bees falling off the combs will be lost to the cold.
Make up and prepare gear for replacement or increase. Check hives after storms. Check to see that your mite treatments have worked. Those beekeepers in the first three years of acute phase of varroa mites can expect your bees to collect honey during the winter from dying feral hives. But there is a downside if this happens as without additional treatments, your hives could also be lost to mite reinvasion.