Dennis Murrell on Condensation

Dennis had a post on his site with a very interesting look at the importance of condensation in the hive. His site no longer seems to be up, but an archived copy of his site is still available.

With American beekeepers in particular, the idea of upper entrances for ventilation is very popular. What Dennis observed while using a water feeder inside a hive by placing a plexiglas cover on top of his hive, seems to go against that practice.

He observed that very little condensation occured during the winter.  A good deal of condensation did occur during the spring and fall, but the bees quickly made use of this. His feeling was that this saved them the work of collecting water from outside the hive, and provided a needed water source for his bees when an external source was not necessarily available.

Will his ideas work for you in your climate? I don't know, but I do feel the topic of ventialtion and upper entrances probably deserves a little more thought and consideration than most bee books suggest.

Feeding, particularly at the end of season when there could be a lack of natural forage can set off robbing behaviour. For this reason it's best to feed on the top of the hive and just a little before sunset.

This year I added either empty hive boxes or ekes on top of the hives to make space for a plastic food container that is fitted with a wooden raft. The inspiration for which comes from this page which outlines a few different feeder setups.

This is what it looks like in action:

honeybees feeding in a simple top feeder

Apart from robbing behaviour, the other reason for which it is preferred to feed bees at the end of the day is that it makes the hive go absolutely nuts. It seems that once a few bees discover this sudden source of sweetness they go tell their friends. Naturally other bees will want in on the action and set off to look for this great source of forage. It should not be unexpected that they will look for food outside of the hive, that is, after all, where they usually look for nectar sources. Very quickly orientation flights will commence and the bees will scour the immediate area for the food source which is actually inside their hive.

You can see in the above video that they will also be attracted to the smallest gaps around the feeder even if they are not big enough for them to get through.

I personally feel it's best to avoid feeding all together if you can, however if you must feed, then feeding small amounts in the late evening is best. This is a particularly pertinent consideration for urban beekeepers. Though the mass amounts of bees searching the area for non-existent flowers may not act aggressively towards people, it is one of the situations where your neighbours are more likely to come into contact with your bees. In one case, when I returned 24 hours after feeding, they still had some syrup left in the feeder and they were still sending out foragers to find flowers. Upon arrival at the apiary, while I was still 75 meters away and two stories down from the hives, I already had a few bees buzzing around me.

The following video of the hive entrance starts right after the colony had been given feed. Each five second clip shows what the entrance looked like at one minute intervals. So by the end of the video you see what was happening roughly 18 minutes after feeding.



Do small cells help bees cope with Varroa? A review

In 2011 David Heaf put together a fairly comprehensive review of different scientific studies on the usefulness of using small cell comb as a varroa control. While a few studies found positive results, particularly when africanized bees were used, the majority of the studies did not find small cell beneficial against varroa. Of course some questions still remain.

Terrible VarroaPhoto by: Shawn Caza / CC: Attribution-NonCommercial-ShareAlike License

The classic, and still the most definitive text on the subject is 'Swarming Its Control and Prevention' by L. E. Snelgrove.

Snelgrove's recommended approach to swarm prevention involves keeping lots of space in the brood box for the queen to lay. Once queen cells are observed, his strategy involves separating the flying bees from the house bees. To achieve this separation, he designed what is now called the Snelgrove board, a simple yet clever piece of equipment that allows you to divide bees within the same hive.

The result of using a Snelgrove board is basically an artificial swarm or split, however, his approach allows for a little more flexibility, particularly if increases are not desired and you plan on recombining the split later. On the downside, you do need to spend a little time opening and closing entrances a few different times over the course of a number of days.

Queen cells
Queen cells on a new foundationless comb. Via flickr

In addition to his own method, the 112 page book also provides the authors opinion on the pros and cons of other swarm control approaches.

Caution. Those tempted to avert swarming by the destruction of queen cells should pay special attention to the comments on pg. 57 of Snelgrove's book. He observed that after queen cells are destroyed one may find new capped queen cells as soon as four days later since the bees may use existing young worker larvae to replace the damaged cells.

This blog post on swarm prevention by Michael Bush is a quick and simple explanation of the behaviour leading up to a swarm and what you can do to prevent swarming.

Essentially, Mr.Bush is also all about keeping the brood box open and giving the bees enough space up to the point where you see queen cells. You need to keep an eye out for backfilling. This means checking if the size of the brood nest is diminishing as a result of the colony filling cells where brood has emerged with nectar. As an example, the following photo shows a large section of nectar in the middle of a brood frame

backfilling the broodnest

Keep in mind that you may see a similar behaviour during an intense flow. The bees may initially store nectar quickly in any available cell. They will then move it up above the brood shortly afterwards. So some nectar near brood isn't necessarily anything to worry about, but If they don't move it upwards, then you should expect queen cells are coming.

Tips. You may also want to consider if there's anything you can do to help the bees cure the nectar into honey faster (As moisture is evaporated from nectar it requires less storage space). Many will tell you to increase upper ventilation during a flow, while a few might tell you otherwise.

If the bees are backfilling during the reproductive swarm period, it is suggested to create space in the brood nest itself. Simply adding honey supers may not be enough as the bees may need more brood space rather than honey space.

Once you see queen cells or eggs in queen cups, decide if they are swarm rather than supercedure cells. As I keep hives in urban areas where a swarm can be particularly unwelcome by neighbours, I tend to error on the side of caution and always assume it's a swarm cell.

Egg in a queen cup

Caution. Once swarm cells are laid in, splitting, or artificial swarming, is the most effective recourse remaining to prevent a swarm. At this point it becomes extremely difficult to simply change the mind of your bees by simply adding more space.

Here's a video of a Michael Bush giving a lecture on the subject:


A few years ago Dave Barr introduced me to the concept of Growing degree days(GDD), a calculation of accumulated heat that helps you to predict the blossoming of plants and trees with pretty good accuracy. It's no subsititute for physically looking around you and taking note of what is in bloom, but following the GDD might help predict the timing of flows and corresponding seasonal bee behaviour.

See wikipedia for a detailed explanation on how the calculation is made and flowering time of various plants.

Use this calculator to check the GDD for your area. All GDD references are given using base 10 throughout the rest of this post.

The spring has been excessively warm this year in Toronto. We jumped up to 25 C GDD in the last week. The average for this time of year is 0 C GDD and in 2010, which seemed like a warm early spring at the time, we were only at 3.5 C GDD. Normally this might be a bit early for silver/freeman maples, but just as you would expect from our current GDD, they are just finishing their bloom

freeman maple and native bee

and the native collettes have emerged in time to profit from them and mate:

What I have noticed over the past few years is that bees will start returning to the hive with full pollen baskets as the growing degree days rise just above 0 C.

full pollen basket on honey bee

One of the more detailed theories on bee behaviour in early spring I've been able to find is on Michael Bush's site. It attempts to relate certain changes in hive behaviour to bloom times. You may be in a different region than Michael, and things may progress at an unusual rate this year, but I think it will be interesting to keep an eye out for any of the correlations he mentions in the next month or two.


- If the brood nest starts contracting before the peak of the apple blossoms - they may be switching from buildup to swarm preparation. Look for backfilling, or patches of nectar surrounded by brood like in the photo below.

backfilling the broodnest

- When the Black locust blooms (140 C-160 C GDD) should be the start of the main flow and the interest in initiating a swarming should be reduced.

- Established colonies start making white wax shortly afterwards.

My hypothesis is, that for here in Ontario, around 70-100 C GDD might be a good time to look for the first signs of swarming preperation, with Queen eggs most likely appearing around 115-160 C GDD. However, I imagine with the large amount of stores the bees still have after what was a mild winter, they could run out of space even before this.

Update 2012: Short mild winter, I saw the first queen egg in one of my hives at 64.5 GDD. You can get a quick peek of it behind the bees:

The first swarm in my area was a few days later at 65.5 GDD or about three weeks after the dandelions first bloom, two weeks after the apples and at about the time the lilac trees were in bloom.

forsythia swarm

2013: I observed eggs and larvae in queen cups at 88.5 GDD. A little under a week after the apple blooms, two weeks after the dandelions and about the time the lillacs bloomed, but it's possible they were supercedure cells. It was a cool and wet spring, and I'm not sure there was very many reproductive swarms. I did find a feral colony that had moved in sometime before 95 GDD, but the first report of an actual swarm in the area did not come till around 265 GDD.

2014: Very, very cold winter, with a long cool spring. First report of a queen cell came from a friend around 50 GDD at the time the apple bloom started and two weeks after the dandelions. The first swarm report I heard reported came four weeks later at 252 GDD, about a week after the black locust bloom.


The Biology and Managment of colonies in Winter

This excellent document from the Canadian Association of Professional Apiculturalists provides a quick and clear overview of honey bee behaviour over the winter months including changes in the hive correlated to specific temperatures.

The graph of colony metabolic rate seems particularly useful for estimating honey consumption over the cool months

After hearing a variety of ideas on how this years mild winter might have affected the bees it was nice to find some quantitative data on the subject.

It also offers some thoughts on dealing with moisture in the hive and comparisons of solar versus insulated hive wraps for winter.

Last week we were called to collect a swarm.

Right away we noticed a few indications that led us to believe the swarm was queenless:

  1. There was no single cluster. Bees were on the ground in two different locations and there were a few up in a tree.

  2. The bees were spread out and fanning. While it was hot, it's likely they were searching for queen scent rather than trying to keep cool. Even once we got them into a nuc box they spread out over the available surface of the box rather than clustering.

  3. They became very interested in the bee gloves of my friend John and actually started running en masse towards him when he first started looking for a queen.(You can see this in the video. Unfortunetly it's a little obscured as some bees had also become very interested in my camera at the same time.) I don't expect the residual bee smells on the gloves and camera would have been nearly as interesting if they had a queen giving them the pheremones they were really after.

We collected the bees and joined them with one of our weaker colonies. The colony we joined it with was a split with an old queen removed from a hive that had supersedure cells. We placed the swarm on top in a seperate box with a sheet of newspaper inbetween. Five days later we opened the hive to discover: the bees had already eaten two holes through the paper, one dead queen being mobbed by bees and one healthy looking queen going about her business.

We couldn't believe it. We searched for other explanations. Is it possible a virgin queen drifted back to the wrong hive from the other half of the split? Seems unlikely. So maybe the swarm did have a queen afterall. Upon reviewing the video again, I noticed relatively few bees fanning at the begining as compared with the end when some bees were already placed in a nuc box. Perhaps that should have been seen as sign the bees were just trying to keep cool vs. actually wondering about the current location of their queen?

Lesson? Check and double check when there is any doubt about a queens existence.