December 19, 2006

Diary of the bee hives 2005

February 2005
Spring is unusually advanced. The first daffodils were seen in flower nearby on 10 January. The first celandines were seen in the village on 6 February. On sunny days and with snowdrop and crocus adding to the pollen supplied by gorse the bees are out in number. On 3 February foragers were seen returning at a rate of 77/min to one hive, and, surprisingly, drones were seen at the entrances to two colonies. Other colony foraging rates ranged from 8 to 47/min. Pollen loads were off white (snowdrop) or orange (crocus, gorse). Routine hefting (weighing the hives) was carried out through the winter about a third of the way through each month. The results for remaining stores are shown on the graph below. On average the colonies have used about 10 pounds of stores since the autumn. This compares favourably with their consumption of 15 pounds during the whole of the previous winter. Two colonies were each given 2 pounds of candy as a precaution because their stores started the winter lower than the rest and were reaching an unsafe level. Wild cherry is now in flower in the locality. First celandine flowers seen on 6 February.

25 March
First chiffchaff heard in song.

29 April 2005
Early March brought a cold windy spell with night temperatures below freezing. This proved more than many colonies in the district could stand. Indeed, one experienced beekeeper lost six out of eight colonies at one location due to starvation. It was not that the hives were short of honey stores but rather that the weather was so cold (snow on 8 April) that the cluster could not move a few inches to the plentiful remaining stores. Despite the relatively mild winter overall, when the hives were opened for the first time in April many beekeepers reported higher than average losses. The main causes were wasps in Autumn 2004, mice getting in past inadequate mouse guards and poor mating of queens in the cold wet weather towards the end of the previous summer. No reports were heard of Varroa mites being the cause of losses despite the move away from synthetic pyrethroids amongst the beekeepers in this locality. The author's winter losses of colonies were 25%, i.e. exceptionally high. The cause was probably poorly mated queens. One was a swarm which appeared to do well early last summer but by September failed to take down the pre-winter syrup feed in the normal way, suggesting a poor queen. The other still had bees when the hives were first opened on 22 April but there was no sign of a queen.

Furthermore, there were two small patches of drone brood, apparently dead, suggesting that the failing colony had triggered drone-laying workers. But taken over two seasons, colony losses are averaging 15%, which is nearly double the UK average. At the 22 April inspection , after moving comes between colonies to even them up, the colonies had brood on 4 frames on average. This shows only half the rate of colony build-up compared with the same date in 2004. Again, the weather is the most likely reason for the delay. Varroa mite drop over a period of seven days was sampled through the open mesh floors onto boards coated with petroleum jelly. The counts ranged from 0 to 1 mites per day per hive. It appears that the oxalic acid treatment in the winter was highly successful and the decision was taken not to give a Spring treatment for Varroa this year. This entails some risk of colony collapse before the end of the season but if the mite drops are monitored at regular intervals, any unacceptable mite burdens can be reduced by dusting with icing sugar. It would not be acceptable to use a thymol based treatment during the period of honey storing as even minute traces of thymol can produce a noticeable impairment of flavour. Foraging this season compared with last is shown below together with ambient temperature. Bees returning to the hive are counted over a period of one minute. They could have left the hive for any number of purposes: e.g. fetching nectar, pollen, propolis or water; clearing flights (defecation); scouting for forage; carrying away dead bees and detritus. The activity at the hive entrance is a good clue to what is going on inside. Purposeful activity with a lot of traffic both ways in sunny weather and pollen loads on returning bees is a healthy sign. Foraging is only moderately correlated with the ambient temperature. Other factors include what forage is available and whether it is sunny, overcast, raining or windy.

From mid-March to mid-April last year foraging was much more vigorous than at the corresponding period this year. This reflects the slow build up of brood in the colonies this year. The 2004 plot shoes a close correspondence with the ambient temperature. With the improvement in the weather towards the end of April there was a corresponding increase in foraging, exceeding last years averages for that time. The plants attracting the bees in the garden are currently azaleas and acer.

16 May
Hawthorn just coming into blossom a few hundred yards from the apiary. Routine inspections this year have been greatly speeded up by having a portable tape recorder in the top pocket of the overalls. This allows more detail to recorded and shortens hive open times.

6 June
Artificial swarmed two colonies which were showing advanced signs of swarming. The method used was that of Adrian Waring in Better Beginnings for Beekeepers. To a fresh brood box with 10 frames of foundation was added a frame of young brood in the middle. All bees were shaken into this box from the parent box  (using an empty super as funnel), except frames with queen cells, which were brushed. Placed parent box over queen excluder over bees for two hours, then moved the parent box, now repopulated with workers to the top of the supers and left overnight. Next morning, removed parent colony, now queenless, to new floor, stand and roof a metre to one side. The following day the parent colonies were removed to their new locations resulting in four colonies in all. Note that this method avoids having to find the queen.

21 June
First bramble pollen seen coming in.

28 June
Spring honey harvest of 20 pounds. The fifth swarm of the year was taken today. Swarms were used either to strengthen failing colonies or start new ones.

6 July
One of the queenless colonies from 6 June had a laying queen by 6 July. The other had queen cells but was in a weak condition and was therefore united over newspaper with a stronger colony. Apiary inspection by the government's local bee inspector. No bee health problems observed.

5 September
Bees foraging a mile away to a large stand of Japanese knotweed and Himalayan balsam. Foraging rates were as high as in July -- i.e. more than 120 bees returning per minute to over half of the hives. Bees also visiting borage about half a mile away.

10 September
First ivy pollen seen coming in and honey bees seen on ivy about two hundred yards from the apiary.

17 September
Knotweed flow almost over.

22 September
Sixth swarm of year found a few yards away from the apiary under a bush. This had clearly escaped notice at emergence and had already formed a well developed colony with brood and honey. Judging by its size it probably had emerged in early September, i.e. a time when one is normally not expecting swarms to emerge. After cutting away branches and twigs, the comb was taken and placed inside openable plastic frames in a brood box. The colony was fed but did not appear to do well. It was eventually united over newspaper with another weak colony (7 October). The colonies were combined the following day after the newspaper appeared to have been eaten through in places but fighting broke out leading to several hundred bees. The colony eventually died out.

2 October
Ivy flow at its peak. About half the hives foraging at >120/min (bees returning) and mean returning rate about 75/min.

12 November
Bees foraging to mahonia in garden where apiary is situated.

15 November
Honeybees seen on fuscia about half a mile from the apiary.

Harvest
With a relatively dry May-July (2.5 inches per month) and a cool August (average 18.5 C) local beekeepers reported a relatively poor season. However, the author's was about average (34 lbs honey per National hive).

Varroa
Oxalic acid treatment was given on 30 December 2004. The resulting mite drop was 410 measured over 3 days. The colonies were clearly quite badly infested but by 22 April (see above) were still almost clear of mites. By 21 May the average mite drop had increased to 1.5 per hive per day with two hives showing zero. On 25 June it was 0.8; 26 July, 1.0; 25 August, 10.6. All hives were treated with thymol up to mid-September. The highest mite drop was 1614 mites collected over 9 days after adding thymol to one colony. The treatment comprised 5 g thymol crystals dissolved in 7 g used vegetable cooking oil absorbed in two kitchen tissues opened out over the brood nest. The Varroa sampling boards were put in to help retain the vapour. The thymol is dissolved by gentle heating and only enough is made for the immediate treatments. The mixture is dispensed from a shampoo bottle in weighed doses into the folded tissues and transported to the apiary between sheets of aluminium foil. There was a significant number of dead bees (average 40) and pupae fragments in front of hives after these treatments. In future treatments the dose was adjusted to 4 g dissolved in 12 g oil. This was much better tolerated.

Feeding for winter
As low residual stores the previous winter (2004-5) had necessitated the feeding of candy to some hives in March the policy this year was to feed to a total of 35 pounds of stores going into winter. This was done by weighing all hives and after allowing for woodwork and bees calculating the stores deficit and the corresponding amount of syrup to feed. The amounts of 2:1 syrup (1 kg sugar in 600 ml water) actually fed ranged from 3.5 to 8.5 litres. The mean calculated weight of stores from hefting the hives at the back with a 60 pounds spring balance was 34 pounds.