Varroa Resistant Honey Bees

April 2023

The website was launched at the BBKA Spring Convention  21st-23rd April 2023.

Our intention is that this is just the start and more info will be updated as it appears, depending what the UK beekeepers want. We have tried our best but please bear with us as we will be working hard to sort out any dead links or initial bugs.

1740 visitors in first week

Testimonials

Tom Seeley states "an extremely valuable website"

Randy Oliver states "Wonderful website"

Spring Update 2023

Steve Riley, Westerham Beekeepers:

Spring is an excellent time to review how colonies have over-wintered.  Are they bursting out of the crown boards and full of vigour?  Or are mite counts too high and the colony struggling?

Requeening “Varroa Susceptible” colonies

Some colonies exhibit many of the traits of resistant bees, such as uncapping, recapping and chewing out infected pupae, but not enough hygienic behaviour to confer longer-term resistance.  Typically, they have over-wintered ok but now have high mite drops (10-20 per day).  We requeen those colonies from the best stocks (0-5 mites per day).  Doing this early enough in the season allows the new queen’s offspring to get on top of the varroa load and, ideally, before the drones are flying from the weaker colonies.  The spring review is a tough call, and your judgement improves with experience.  But removing bees with low defences to varroa very quickly improves the mix in your apiary and local area.  Take the same beekeeper actions as one would to a mean, defensive colony.

Using the swarming process for “Bees’ Choice” queens

Blackthorn, Hawthorn and Horse Chestnut trees provide large amounts of the spring pollen and nectar flow in the west Kent / east Surrey area.  By the end of May, most of the colonies have 2-4 supers on and artificial swarming has taken place. The laying queens are moved to nucs with a couple of frames of brood and stores.  This leaves the main colony to produce superb queen cells, selected by the bees, from a strong constituency of nurse bees, whilst the foraging force remains in place to capture the pollen and nectar flows.  Once sealed, the queen cells are carefully cut out and put into roller cages in an incubator at 35°C to hatch.

This gives us an excellent source of virgin queens, with varroa resistant traits, that are adapted to our local conditions.  They are used to make up nucs, re-queen or share around the area with like-minded beekeepers.  It’s a totally sustainable apiary, not needing to buy in queens and in control of the desired traits.

Rhona Toft-Foragers Bee & Honey Co. 

Writing this at the end of May in warm sunshine, the very wet start to the season seems like a long time ago. We had very few dry days in the whole of March and well into April which reduced the foraging opportunities for our bees. Temperatures were also below average meaning that early season inspections were fewer than normal. Spring normally comes early to this part of Worcestershire, and we have come to expect colonies to expand rapidly in March and April. The cool wet Spring this year led to a much steadier expansion in most colonies with many still having ivy honey in the brood box. The ivy honey did cause us problems in the Autumn, and I was not happy to see so much in brood boxes in the Spring but it turned out to be useful food in the cool, wet Spring. Our colonies are deliberately diverse, and some will come out of the winter really strong while others can look quite small. I have learned not to right-off these small colonies as many have the capacity to catch-up and now have 3 supers of Spring honey.  There were, however, more small colonies this Spring than we have come to expect, and I think that it relates back to too much ivy honey in the brood boxes last September when Winter bees should have been raised. Every year is different and new challenges continue to appear.

We have oil seed rape around several apiaries this year, but the cool Spring temperatures meant that the nectar flow was slow until mid-May. With cool weather in the long range forecast we decided not to chase the early Spring honey and instead put more colonies onto double broods (or even a triple for one) to get well drawn brood combs and hopefully reduce swarming. It would also make splitting colonies easier. Most of our colonies are on single, National brood boxes, most of the time. In mid-May the warm weather coincided with the Horse Chestnut and Hawthorn flowering and with soil moisture levels still good, the nectar flooded in. The steadier nectar flow earlier in the spring and extra brood space meant that we had little early season swarming but when the weather did warm up in mid-May, many colonies started swarm preparations and we had many calls about swarms that thankfully were not ours.

For those colonies that needed swarm control, putting the old Queen in a nuc is our preferred method. The remaining colony can then be left to finish their queen cells and if it is a colony that we like, we may then split the colony into nucs or harvest spare queen cells for use in requeening others. All other queen cells will be removed to prevent casts. The nuc method does involve more equipment than a vertical split but works well for us. We are now seeing the 1st newly mated queens of 2023 which is always a pleasure. Hopefully they will have the desirable characteristics of Varroa resistance, good temperament, and good overwintering that we are after.

We have been raising more drones this year than we have done for a few years. We seemed to fall out of the habit of putting a shallow frame in the brood box to allow drone comb to be built underneath. We also tried whole brood frames with drone foundation. When we were in our early years of managing without Varroacides, we used this drone comb to monitor and trap Varroa. Those colonies with low Varroa got to keep their drones to pass on their genes while those with high mite numbers didn't. Both methods worked but it is always good to try something new so this year we are trying foundation-less frames. We have only tried these frames in a few selected colonies to boost the population of drones from good colonies. So far, we have discovered that a bit more careful frame handling is required compared with previous methods!

Joe Ibbertson 

A particularly unusual spring here. Cold, cloudy weather was dominant right into the Oil Seed Rape (OSR) flowering period. Most colonies were on occasion still breaking into winter stores in April and eating whatever they managed to bring in. My management system is to retain the first super with the colony always (once they have built up to that point). I feel this prudent approach came in to its own this year as not a single colony came close to starvation despite conditions.

In comparison to last year, OSR planting was minimal locally. True to nature colonies followed the flowering of the hawthorn to really take off and of course, want to swarm. The odd start to the year continued as colonies produced only a few Queen cells for swarming, in a way I would typically class as supersedure cells. Timing and conditions suggest do otherwise and swarming has been prolific this year, catching many beekeepers off guard.

 After the video release of Zach Lamas’s research showing that Varroa mite aggregate on adult drones our small team has been doing its best to observe uncapping/recapping/removal behaviour directed toward drone brood, potentially as an important part of their resistant abilities. I have long seen the external evidence of drone removal and am now more observant of these behaviours targeted toward drone cells on the comb. An outing with our associations ex-education officer provided a nice opportunity to take a closer look at a colony in its third year. A ‘casual’ count of 36 mites in 35 days and not a sign of DWV afflicted bees. Incredulously we watched two workers actively remove a drone, usurping a mite in the process and a third worker removing the pupae’s antenna during the activity (you will often find antennae on the bottom boards in responsive colonies). In another colony at the same apiary, I came across hatched Queen cells which had been ‘recapped’, with the ‘lid’ still open and attached. A first for me!

Two of the colonies in my furthest out apiary looked less vibrant than I would expect to see at initial inspections but appear to be doing well now. I will consider a possible requeening as the season continues. Nearly all my managed colonies successfully came through this winter and my loss rate was 4.5%. The free-living colonies I monitor had a winter survival of above 90% and there appears to be little difference between tree, log, insulated and standard National hives in terms of survivorship and swarming response. The excessive heat and huge Ivy flow of last year also seems not to have made an impact locally. As with many things in beekeeping, we end with more questions than answers.

Stephen Martin

During spring a major new study was published “Scaramella et al. (2023) Host brood traits, independent of adult behaviours, reduce Varroa destructor mite reproduction in resistant honeybee populations, International Journal for Parasitology, online first.”This new study suggests that in varroa resistance the workers do not have any role to play, this was inferred since the infertility levels of covered and uncovered cells were the same in their experimental setup. That is since the covered cells workers were unable to access the cells you may expect higher infertility levels. However, to me the experiment appears flawed since the actions of the ‘workers’ removing infested cells in the many months before the experiment was conducted would have already reduced the colony level of mite fertility i.e. increased their levels of infertility. So, the only thing covering the brood does is to increase the sample size since the infested cells removed in the uncovered section during the experiment cannot be removed if covered. Which is the case. Therefore, claiming the workers are not important is wrong, in fact worker behaviour removing infested worker brood is the key (Grindrod & Martin, 2021). I am currently contacting the papers authors to see if I have missed something, and I will update the website if I get any new insights.