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NEW ZEALAND BEEKEEPER, MAY 2017
So the take-home message is to monitor, monitor, monitor, four to six times a year so you know what’s going in your hives. If you don’t have time to do this, then you’re likely to end up with fewer beehives, and that will be the number you can comfortably manage. A few years ago I was seeing apiaries with large numbers of hives. Seems that these beekeepers have found that an area can only sustain a certain number of hives. Sure, you can feed pollen supplements, but until these can sustain three brood cycles without natural pollen, they are by name a supplement only. We will know when the formulas are right when bumble bees can be raised on it. If you are increasing the numbers of hives per apiary, plant both early and late pollen sources for them. Most of the hives on farmland rely on plantain for autumn brood rearing. Open your eyes. Bees need 45 kilograms of pollen a year and the amount they store in the autumn has a direct bearing on the number of bees they can rear during the winter, unless we all swap to Carniolans. These are very good bees, but not much good if you want large, populated hives early in the season. Some may disagree with this last statement. If you do have a method that works for Carniolans, tell me about it. Wintering Something I missed doing last month is to put insulation under the hive roof. We see the overseas pictures of snow on hive roofs, but between the roof and the hive mat is a polystyrene sheet to hold in the heat. Note that these are not tin roofs. For some reason, hobbyists have copied the commercial beekeepers who migrate hives by using sprung tin roofs. We all used to use telescopic roofs, which provide an overhang and deflect rain off the top supers. Sprung tin roofs allow commercial beekeepers to stack hives close together on trucks but they afford very little insulation, so the bees are constantly using honey as a fuel to generate heat within the cluster. You only need to feel the temperature of sugar syrup in a hive top feeder to realise just how much heat a hive gives off. All this extra work is shortening the lives of your bees. You can provide insulation under a sprung tin roof but a hive strap is required to hold the roof on; otherwise they will blow away in a storm.
The idea is to monitor and find the odd hive that still has high mite numbers and re-treat. It’s a good idea to re-treat
the whole apiary if you find one, as there could be more out there.
Some may choose to use a sugar shake as their monitoring technique, but these don’t work in the damp as the icing sugar doesn’t flow and you have to repeat the shake a number of times to get an accurate count. If you have mesh bottom boards, it’s a lot easier. Grease the bottom slide with a little cooking oil and check in a week or so. Divide the number of mites falling by the days. In all cases, you want less than one mite per 100 bees or less than one mite a day dropping. Then we give a sigh and say that’s done, but it isn’t. Out there will be hives that haven’t been treated, like feral hives from cast swarms that will start dying and your bees, being bees, will scavenge every bit of honey they can find. Unfortunately if they find a hive failing due to mites, most of the mites will hitchhike back to your hive on the robber bees, and in less than a month your hive could be dead. The idea is to monitor and find the odd hive that still has high mite numbers and re-treat. It’s a good idea to re-treat the whole apiary if you find one, as there could be more out there. Resistant mites The most recent Ministry for Primary Industries (MPI) residue report mentioned that amitraz has been found in honey. Amitraz is the chemical in Apivar® but these strips are formulated to give a controlled dose which should be well below threshold levels. Are beekeepers doubling the dose (one strip per five frames of bees is the usual registered use) in order to overcome resistant mites, taking honey from the brood nest that still contains residue from the last treatment, or are some playing with homemade chemical treatments? Beekeepers have to recognise that some strips in some areas just are not performing as efficiently as they used to because mites are gaining resistance to the chemical. Putting in double the number of strips just makes resistance happen a lot faster. Likewise, taking honey out of the brood nest is risky. Apart from having residues in the wax, beekeepers also could be extracting the sugar they fed during the last round, which could make the honey unsaleable due to C4 sugars. Some of us are treating more often with alternative chemicals but still sticking with strips. It could be said that we now using two treatments at once: a fumigant and a chemical treatment. This method, we hope, will delay the resistance problem for a bit. We must all be looking to experimenting with alternative treatments. They aren’t as effective and require more visits, but at least they keep your bees alive. With acids, more is not better. I overdosed a heavily infested apiary with formic acid and killed the open brood that was showing viruses, but also killed three queens. Unless you can find replacement queens at this time of the year, the hives will have to be united with another.
Sprung tin roofs on Jo Telfar's hives in the flood-stricken Waikato, showing hive straps. See front cover for a close-up view. Photo: Jo Telfar.
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