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Amanda's Beekeeping Notes February 2019


Amanda's Beekeeping Notes February 2019

Beekeeping notes from Amanda Millar

Winter care:

Apart from the usual things like making sure the entrance is clear of dead bees, the hives are still intact, dry and not blown over, hefting for stores is very important.  If you are unsure it will not hurt the colony to raise the crown board briefly on a mild, low-wind day to check they have stores nearby.  Small colonies may not be able expand the cluster to access more stores resulting in isolation starvation even if they have plenty in the hive, so be prepared to move a frame of stores closer to the cluster if necessary.  If worried, you can also put some fondant in a plastic container inverted over the crown board hole over the cluster and check fortnightly that it has not dried out or all been eaten. Dried fondant is easy to recognize, pitted and pocked with holes. See photo. It has been mild up until recently and they will, ironically, have been using more stores than if in a tight quiet cluster as the bees have been more active and probably been raising brood all winter  (although I know two of mine were brood-free before Christmas). The large colonies will have eaten more and they are the ones at risk of starvation. Unfortunately, the indications are that we are to have a few weeks of cold wintery weather just as the brood area is beginning to expand. They will benefit from extra insulation now, if not already, on the crownboard.

Fondant_dried_and_pitted_AM_Feb19  
Dried pitted fondant  

If you are suffering from bee-withdrawal symptoms over winter then put your inserts under the mesh floor to see what they are doing without disturbing them (see ‘Reading the insert’ article for interpretation of results) and start preparing for the spring. Make up frames (leaving the wax foundation until nearer the time), get on top of any cleaning not already done and have some clean floors and crownboards ready for the first spring inspection, which could be early March. Decide which colonies did best last year and which to rear queens from this year and brush up on your preferred queen rearing techniques and swarm prevention and control theory.

Reading the insert
Reading the insert

Last month I explained how I treated for the first time with Oxalic Acid Vapourisation (OAV) at 5 day intervals. I have now finished; most, but not all, have reduced their mites to an acceptable level, but also because the weather is now too cold (it is not recommended below 4 degrees) and the queens will now be increasing their laying and most varroa will be safe in sealed brood cells.  Because I did not wish to disturb the bees by removing any sealed brood, and after reading the research thoroughly, I was expecting to do more than one treatment. As I was keen to understand the efficacy and how many mites were present/dropped, I counted every day. I shall not be undertaking such compulsive counting next year I assure you!

Of my 15 colonies only 12 required OAV, the rest had a daily mite drop of less than 1 mite per day.  Of these 12, two (2 and 9) had little or no brood and dropped 173 and 643 after the first 5 days; I treated again and they dropped 70 and 69 in a further 5 days. I monitored for a further 5 days and they only dropped 15 and 1 in this time. I am not yet sure how long it will take to reach the background drop but it seems to be about a fortnight. Four colonies (1, 5, 10, S1) I started later, having seen the results on the colonies with the highest pre-treatment drops. These only had time for two or three treatments but they still dropped totals of between 437 and 1025 mites so it should have helped them.

Four colonies required 4 treatments. The worst one dropped over 2700 mites over the 4 treatments.  The life cycle of the mites indicates 15 days (ie 3 treatments) should expose all the phoretic mites at some stage and the treatment is supposed to be over 95% effective on phoretic mites.  So I should have been seeing a drastic reduction in mites on the fourth treatment rather than the 315-390 I found at the Divisional apiary.  This I do not yet understand. 

I found most mites were dropped on the first and second days after treatment, perhaps half this in the third and fourth days, and much less on the fifth day. In a third of the colonies, more mites were dropped on the second day, the rest dropped more on the first day. A third of them dropped more mites on their second treatment than their first, but most dropped slightly fewer in their third or fourth treatments, however this is likely to have more to do with when the influx of varroa arrived in October.  I suspect it was an invasion lasting several weeks judging from the varroa drop while I was doing icing sugar dusting during that time.  A summary of my ‘plan’ for next year’s OAV based on the results of this experiment are as follows. After assessing by daily drop if >1/day, or icing sugar >10 after an hour, I shall OAV.  As my mite bombs seem to strike in late October I shall start in mid-late November in case some need 4 treatments.  This timing should get the unwanted mites away from the bees as soon as possible to reduce disease risk, also before the weather turns difficult and before the queen increases laying in early January. I will do it above 6° C so the cluster is not too tight and it is less disturbing for them and do it before they start flying in the morning so the odd flying bees are not blocked out if it is cool. If more than 100 drop after 5 days I shall treat again. A colony with little or no brood will need at most 2 treatments.

I am very pleased with the results so far and any time they are broodless (swarms, artificial swarms etc) I shall give them an OA Vap and with a bit of luck I will not have to do so much dusting this year! As far as their general health appears after these treatments, they look very good. No dead outside, only a couple of dead bees on a couple of floors, all have been flying when the temperature is above 6 degrees; so looking much better than this time last year

This chart shows the total drop after 5 days from the treatment date indicated (in bold black). The green figures are total mite drops in a further 5 days from the date given, without any treatment.  (I allowed myself a break over Christmas from visiting the Divisional apiary!) I was concerned with the continuing high drops mid Jan in a couple of colonies at home when most of the others had reduced to single figures, so while it was mild I dusted three (light black) and did OAV on colony 1, which should have had 4 treatments in a row. Colony 10 should have had another treatment in December but it is too late now.

Colony

1

2

4

5

8

9

10

BH1

BH2

BH3

BH4

Treatment date

                     

7.12.18

             

204

507

116

798

12.12.18

 

643

468

 

808

173

 

198

402

219

999

17.12.18

194

69

241

175

200

70

 

80

258

98

560

22.12.18

465

1

411

331

126

15

472

14

77

9

127

27.12.18

366

 

190

119

6

 

202

3

315

7

391

1.1.19

41

 

30

33

0

 

25

2

1

1

13

6.1.19

44

 

28

12

   

24

3

0

1

3

12.1.19

39

 

24

23

   

16

0

0

1

 

14.1.19 Dust

51

 

18

     

60

       

14.1.19 OAV

193

                   

 

 

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