We have made the final steps in putting the bees away for winter. We tend to try get these tasks done a bit earlier than most folks in our area, I like to allow the bees a couple weeks to get any cracks in the hives propolized to their liking before the weather gets cold enough to keep them in cluster all day. We have had good success wintering small colonies in our 4 way mating nucs over the years we have been using them, and this year we have another experiment in wintering happening. While touring the tradeshow at Apimondia, I saw the Lyson Mini Plus mating nuc, and really liked the concept. These are a styrofoam box that holds 6 frames, the frames are half length medium depth. The bottom has an entrance on two sides and the unit comes with a follower board that allows us to use it as 2 units of 3 frames during queen mating season, then remove the follower and build a colony to fill 6 frames for wintering. The unit comes with a top feeder that’s divided so you can use it to feed 2 units thru the summer and then top up the whole unit with winter stores when fall rolls around. The photo is one of these units just before I put the lid on to do the final close for winter. I ordered 5 after Apimonidia to try these out this year. They worked well for us this season, so much so that I’ve ordered 20 more. One of the best things about them, I dont have to build any custom equipment for these units. They come complete with feeders and frames, lid, bottom board and the box for 6 frames, along with the follower that can split it into two units.

A virtual presentation for the Comox Valley Bee Club for the April 2020 virtual meeting. In years gone past we had some things that were normal, and they just happened year over year. Winter weather was predictable, in the interior of the province we would have the occaisional cold snap, and once in a while a blizzard. On the coast we had one more weather item to add into the list, a howling southeast wind that originated in the vicinity of Hawaii and came off the Pacific ocean loaded with moisture would produce torrential rains which we effectively called the Pineapple Express. I guess times have changed, and weather folks are dreaming up new names constantly for the same old stuff we’ve seen all our lives. There is the ‘Arctic Blast’, the ‘Polar Vortex’ and the ‘Atmoshperic River’. Beekeeping is much the same, old terms will get new names, the current buzz is ‘social distance’. As we come into the latter part of April I have worked hard to keep the news of pandemic away from my bees. Wifi in the bee yard has been disconnected, power turned off to the plugs at the scale so there is no extra light, and the bees will go to bed early. The problem still exists tho, they can fly, and thru the day they do fly out to go grocery shopping, fetch water, and do all the normal humdrum things required to continue living and raising brood. And while they do all these normal day to day things, some will come into contact with other bees that have been infected with the Varroa Virus. When that happens, it is inevitable that eventually that virus will come home with one of them and begin spreading thru the colony. Varroa virus attacks the young, and starts by attacking the brood before it has even had a chance to emerge. Varroa virus can propogate to pandemic situations in a matter of weeks, and has been known to kill off entire bee yards in a matter of 6 or 8 weeks when beekeepers are not tending the bees properly. African and Russian sourced bees have learned how to use the concept of social distancing to help deal with the Varro virus, while Italian and Carnolian bees do use social distancing to some extent, not nearly as much or as effectively as bees like scutellata. So how do bees accomplish this task? It begins when the queen will decree the colony must practise social distancing. The queen will gather up about half of the bees and they will move off to a spot at least 2 meters away from the hive, often a tree branch, while they wait to see if the hive has truely been infected. The expectation is the medical staff (those folks in the funny white suits with the bee proof hat) will arrive shortly and test the hive to see if it has been infected with the Varroa Virus. It’s a 2 minute test involving a bottle of alchohol, and results are available immediately. If the test result is positive, then the hive will be put under quarantine and the bees out on the tree branch will have to go find a new home. For people, 14 day quarantine is not a big deal, so they will just hang around till they can go home again. For the honeybee it’s different, a 14 day quarantine is a third of a lifetime, so they wont stick around waiting for the all clear to return home, they will head off and find a new place to call home. Scutellata take this concept to an even higher level, rather than find a place to build a new home, they will as often as not just find an existing hive then take over. When the bees decide on their own that it is necessary to begin practising social distance that presents a number of issues for the beekeeper. First off, we don’t really like to see half of the bees fly away to a new home, that involves losing a lot of bees. The second part of this, as often as not, those bees will not find a hollow tree like it shows in all the books and cartoons. Reality is more like what you see on the 628DirtRooster channel on Youtube, bees neatly setting up house in the walls and eaves of somebody else’s house. Reference the paragraph above, wifi turned off in the bee yard, I absolutely do NOT want my bees to see those videos and start getting bright ideas. So therefore as a beekeeper I will help my bees to practise social distance without becoming a nuisance in my neighbors walls. There are many ways I can accomplish this goal without allowing the bees to use the fly away method. If I analyze what happens when the bees do this on thier own, we see two distinct changes in the makeup of the colony. First, it’s now much smaller so the focus will be back on raising brood, and secondly, the bees have separated the queen from the brood. This also makes a lot of sense, in the hive the queen is the ‘purveyor of everything’ and the brood is most susceptible to damage from the varroa virus, so it makes sense to separate them. The first, and easiest way to accomplish our goal, is to simply preempt the queens decree. I can walk up to the hive and take one of the boxes, place it on a bottom board 2 meters away ensuring that box has at least half of the brood, and both boxes have eggs. This method is easy, and I dont have to find queens or any other difficult beekeeping tasks, just move a box then walk away. The sudden and rapid drop in population will cause the bees to become so worried about making new brood, they wont worry about the varroa virus for a while. One of the boxes will be in an absolute panic and start raising a new queen. the main drawback to this method is, it virtually guarantees the bees will make no surplus honey over the spring flows, and one of the boxes will likely not have enough bees to be productive over the summer fireweed flows. On the bright side, one box will have a fresh young queen and will likely be in great condition for the winter come fall. Does the walk away help control the varroa virus? Not really, it just spreads it between the new boxes just like the bees. BUT, the box that makes a new queen does present an opportunity for the beekeeper. 28 days after the walk away, one box will have a fresh young queen just starting to lay, and no capped brood in the box. That’s a pretty good opportunity to use your oxalic acid vaporizer. Another method that is commonly used to enforce social distancing with honeybees is called the ‘cut down’. Similar to the walk away, but it does require one to do some beekeeping tasks like ‘find the queen’. To accomplish the cut down, go thru the colony and find the frame with the queen and place it in a nuc box sitting on a bottom board at least 2 meters distant from the original colony. To this nuc box add one more frame with capped brood, and a frame with pollen and honey, leaving all the rest in the original location. The theory is, with most of the workforce left in the original location and now queen laying, the bees can all focus on hauling in nectar and making a large honey crop. Literature tells us, the cut down is best done about a week before the onset of main flow. I’m sure it works really well for folks that have a crystal ball and can tell exactly when we are a week away from the flow starting. I’ve had a hive on a scale for some number of years, and I can say with absolute certainty, correct timing 3 out of 6 years for our place would be to cut down on April 15, and on the other years, correct timing would have been on May 15. My conclusion, getting the timing exactly right, it’s a coin toss. But with that said, I do use the cut down for a different situation. When we find a colony making queen cells, we will take the queen and a frame of brood to start a nuc. Some colonies make a good honey crop when we do this. Other times, I guess the bees find the social distancing away from the queen to cause anxiety and loneliness so they dont do much in the way of gathering nectar and making honey. As far as controlling the varroa virus, cut down provides the same opportunity as the walk away in one of the boxes, fresh young queen just starting to lay, and no capped brood, an ideal time to use the vaporizer. So far, all of the methods presented to assist your bees with the practise of social distancing tend to focus on population reduction, but they dont do much for distancing the queen from the brood. Another method that appears to be popular online, altho I will admit to never having tried it myself, directly addresses the issue of distancing the queen from the brood. For this method, colloquially referred to as a ‘fly back’ online, one starts by picking up the entire colony and moving it to a location at least 2 meters distant from where it currently sits, then place a new bottom board with an empty box in the spot you took the hive away from. Now go thru the original hive, find the frame with the queen and move it into the new empty box. To the new box you now add a frame feeder, and fill it with fresh new undrawn frames. Finally put a pollen patty on it and then the lid. This is best done early in the day. The theory now is, the non flying house bees will stay with the brood in the old box at the new location. The flying foragers will fly out to get stuff, then go back to the place they were oriented, now containing the new box with queen and empty frames. The bees will react with ‘OMG we have swarmed, I need to start making new comb’. The bees will immediaely use the syrup in the feed to get to work making new comb, and the queen will lay in it as fast as they make it. That’s the theory, I’ve never tried it myself, but I may experiment with a fly back style this summer just to see how well it does work. All of the methods of assisting bees with social distancing presented so far have the side effect of creating a new colony, similar to how it would play out if the bees were left to do it on thier own. Not all of us want new colonies, and some are not allowed to have more colonies in the yard, be it a municipal ordinance or a spousal ordinance, end result is the same. Is it possible to assist our bees with social distancing in a manner that does not create new colonies? The answer is yes, and there are multiple ways to accomplish this task. The simplest and easiest way to make sure the queen is not coming in contact with the brood, is to kill the queen. Yes, it’s a drastic method, but it is very effective. The colony will begin new queen cells almost immediately. In 4 weeks you should have a fresh young laying queen. If you time killing the queen to be a week before the flow, many would expect a great honey crop as the bees have no open brood to tend thru the flow while making a queen, so they should make honey and a queen. My own experience with hives where queens were killed or removed, bees tend to make honey OR a queen, not honey AND a queen. In 10 years of keeping bees, only once has a queenless colony made a decent honey crop for us while raising a queen. As far as how this method helps with varroa virus, as above, it doesn’t do much to deal with the varroa other than create an opportunity for you to put a vaporizer into a colony that has no capped brood. So now another method to separate the queen and brood to manage social distancing, but without creating a new colony. Start by setting an empty box beside your existing colony. Go thru the colony and move brood frames into the empty box. While doing this, ensure the queen is not moved, she must stay in the original box. Once done, re-assemble the original box adding frames as required. Place a queen excluder over the original box, then two empty honey supers, then another queen excluder. Now place the box with all the open brood above that excluder and ensure there is an entrance available for the top box. Expectation is, foragers continue to come and go out of the original entrance. Nurse bees will gravitate up to the top box where the open brood is. After a day, queen pheremone will be almost non existant in the top box, nurse bees up there will start to raise a queen. Foraging force will continue to come and go as per nomal, the queen in the bottom will be laying. In the bottom brood nest, population is reduced so the queen will no longer have a desire to trigger that social distancing. The workforce is unaffected so they should contine working on putting honey into those supers. In the top box, the nurse bees will raise a new queen separate from the nest down below, she will go out the top entrance when it’s time to mate, then when she returns she will start a brood nest in the top box. Once there is a brood nest started in that top box, beekeeper needs to go to the bottom box, kill the queen, then move the new brood nest to the bottom. This method is good for keeping the colony full size, raising a new queen and producing a honey crop. Do not leave it to long with both queens laying, as the older one will almost certainly decide to invoke social distancing on her own if left to long. This method is no help and possibly detrimental with respect to dealing with the varroa virus. These are my thoughts for this month. We can try shelter our bees from all the news these days, but the virus is pervasive, and within a month social distancing will be come the trend amongst our honeybees, just as it is for all the people today. We are not going to prevent them from getting that message. The best we can do is assist them with the process so our bees can all practise social distancing without becomiing a pest in the neighborhood. This month is about helping our bees to be socially responsible as they begin their fight to flatten the curve with varroa virus. Next month we will start discussing vaccinations for our colonies unaffected, and treatments for those that test positive.

This morning I spent a bit of time cleaning up graphs for the scale hive. In order to get a better year over year comparison, I added an offset to the 2018 data so that it has a similar starting point to prior years. 2018 data is now a different color from the rest, and the graph is a better year over year comparison as they start at a similar point. We have had a few problems with this colony this spring. The first issue came about thanks to a 4 legged critter, not completely sure what kind of critter knocked it off the stand on the night of April 24. I suspect it was a small bear as we spotted a bear in the chicken feed next door that evening. It was a little one that scampered up a tree when I went over to lock up chickens for the night. The next morning, hive on the scale was tipped over. That bear was small enough to squeeze under the gate leading into the back lot. We had the hive fully strapped so it didn’t get in, but, the whole hive was laying on it’s side on the ground. On the morning of May 3 we once again found it tipped over, so I set up an electric fence around that stand. All the rest of our hives are strapped to the stands so they cannot be knocked off, but I cant do that with the hive on the scale and still get proper weight data, so another fence was the only option left. Considering how badly this colony has been disrupted thru the spring, it’s been doing well. I added another empty drawn super yesterday because all of the supers that were on top were heavy with nectar. Currently configured with a double deep for the brood nest and 4 drawn supers above an excluder. Historical data shows we should have a considerable flow running for at least another two weeks, the thimbleberries have started to bloom and after thimbles we expect raspberries to start blooming.

Any beekeeper that has kept bees for a number of seasons will understand and know, there comes a time when your colony requires assistance in dealing with varroa, or the colony will die. This is a sad fact of modern beekeeping, but, if we are going to apply good animal husbandry concepts to our bee stock, there are times when it’s necessary to intervene and try keep our stock healthy. To begin with, when modelling mite interventions (Treatments), I have chosen two of the common organic acid methods to introduce as tools for managing mites. Formic Flash:- The formic flash treatment is one commonly used in our area, it’s a single day application of formic acid to the colony. The benefit of the formic acid treatment over others, it will apparently effect mites under cappings as well as phoretic mites. One can read endlessly about efficacy, and eventually you realize, the numbers quoted in different sources are all over the map. I have chosen to model the formic flash treatment with a very high efficacy level, not because I believe it is this high, but to show how even with high efficacy on a treatment, an out of control mite population will still kill the hive even after a mite treatment is applied. For the purposes of this model, the formic flash treatment kills 90% of the mites under cappings and those in a phoretic state. This is a highly effective mite kill. But a huge caveat, reading at Randy Oliver’s site at scientific beekeeping, he tried multiple rounds of formic flash to try improve mite kill. A second round of formic a week after the first resulted in a dead colony. Reference available here. Oxalic Acid Vapour:- The Oxalic Acid Vapour treatment is less effective than the formic treatment in that it only affects phoretic mites. Easily applied on a small scale using a wand style vaporizer that takes about 5 minutes per colony for a full treatment, or using a blower style of vaporizer that takes about a minute per hive when doing larger numbers. The OAV treatment puts oxalic acid crystals in the hive which work for about 24 hours killing phoretic mites. Literature suggests this treatment is about 95% effective, in that when properly applied it will kill 95% of the mites. As it lasts over roughly 24 hours, for the purposes of modelling, we kill off 95% of phoretic mites on the day it is applied, and also get 95% of the mites emerging over the next 24 hours. The OAV treatment only gets phoretic mites, and one strategy to help with this problem that I’ve read about online a number of times is folks are trying 3 treatments a week apart with the expectation this will get all of the mites thru a brood cycle. That would be true if the mite brood cycle turns over on a weekly basis, but, it doesn’t, it turns over on a 5 day period, the amount of time a mite remains phoretic. I added two more OAV options to the model, one of them applies 3 treatments at a 1 week interval, and another that applies 4 treatments at 5 day intervals. for those with a small number of hives, these may be viable options for mite control. If your colony count is such that you cant get thru them all in 5 days of work, then these become less viable options.

So the bee population model is more or less complete, but it still is not representative of the real world. Out here in the real world, we have the varroa mite. To properly model the growth of varroa within a colony, we first need to understand the life cycle of this critter. After reading endlessly in various literature on the subject, my conclusion is, the life cycle of the mite is fairly well understood, and is dramatically effected by what type of cell a given foundress mite enters. We need some numbers to realistically place timeframes on varroa development, a good reference is found here.

The phoretic period may last 4.5 to 11 days when brood is present in the hive or as long as five to six months during the winter when no brood is present in the hive. Consequently, female mites living when brood is present in the colony have an average life expectancy of 27 days, yet in the absence of brood, they may live for many months.

To get a handle on the reproductive success of those mites, another quote from the same article

Considering mortality in brood cells and improper mating, the average foundress mite produces about one offspring per worker cell she enters, and about two offspring per drone cell. Drones take longer to develop so more mites are produced in drone cells.

To try model these numbers is fairly strait forward. When a mite emerges we keep them in a phoretic state for 4 days. Starting on day 5, we assume that half of the mites available for going into cells will successfully find their way into a cell to try and reproduce. A fertile varroa mite going into a worker cell will produce one offspring, so two mites will emerge. That original foundress has been under the cap for 10 days and spent 5 days phoretic, so is now 15 days old, and after another 5 days of phoretic behaviour will enter another cell, so we have two fertile mites entering worker cells at this time. 10 days later we will have 4 mites emerge, but the original foundress is now fully aged and dies of age. The net result is, after two varroa brood cycles in worker brood, a single foundress mite has resulted in 3 mites in the colony. Things change when there is drone brood available, literature suggests the varroa much prefer to hop into a drone cell over a worker cell. When a varroa mite enters the drone cell, she remains under the cap for 14 days, and will produce two viable daughters. After a phoretic period, all 3 of these mites will enter drone cells, and all 3 produce 2 more viable daughters, for a total of 9 mites emerging on the second round. At this time the original foundress mite dies of age, but leaves behind 8 viable mites as daughters and grand daughters. As this math shows, there are two very distinctly different details when comparing the varroa life cycle to the honeybee life cycle. The bee population is based on a single queen laying eggs, and will grow in a linear fashion limited by the rate of egg laying of the queen when not limited by temperatures for brood incubation. The varro life cycle is shorter, and not limited by a single queen laying eggs, it grows exponentially rather than linearly because all fertile varroa mites are producing offspring. To model varroa growth, we know the mites prefer a drone cell so it would be easy to just place all of the fertile varroa into drone cells when they are available, but, this is not realistic. There are 10 worker cells open on capping day for every drone cell that is open, not all of the varroa will find a drone cell. To account for this, we have prefererred drones when it’s time for varroa to enter cells, but assume only half of them find a drone cell, the other half entering cells will end up in a worker cell. This is the basis on which the varroa growth has been incorporated into the colony growth model. Introducing varroa into the colony growth model does introduce another new concept, that of the ‘sick bee’. We know that bee virus are vectored by the varroa mite, and a colony with extremely high varroa levels will show lots of sick bees in the form of deformed wing virus and other inflictions. To account for this, a new type of bee has been incorporated into the population model, the ‘sick bee’. Any bee emerging from a cell that was populated with a varroa mite during the brood development is not placed in the normal bee population to graduate from nurse to wax maker and on up to forager. Instead, they are placed into the ‘sick bee’ population, ie, deformed wing etc. I cant find any suitable references in the literature to suggest how long a sick bee will live, but, we chose a rather arbitrary ‘it make sense to me’ way of handling the sick bees. If the bee is inflicted with deformed wing, it can still manage to crawl around on the frames, clean cells, etc. Where trouble begins for that bee is when the time comes to orient and graduate to foraging, instead of flying out of the hive, it ends up crawling out because it cant fly. Once a sick bee crawls out of the hive, it’s gone, so we have arbitrarily set the numbers so that sick bees crawl out and die at an age of 25 days, shortly after they should have graduated from being a house bee to a foraging bee. The final tweak to the handling of varroa and sick bees came from a comment I saw in an online video by Jamie Ellis from the University of Florida. His comment was, when varroa population gets large, some cells will end up with two or more varroa feeding on the pupae in that cells. With two or more varroa feeding on a pupae, that bee will be dead or very close to it when it emerges. This final detail explains one symptom we often see when a hive crashes due to varroa load, we see numerous bees that were in the process of emerging and never completely got out of the cell when doing the post mortem. After adding this little bit into the math for handling varroa populations as they explode, the graphs mimic almost perfectly what we see from hives crashing due to varroa loads.

The first run at modeling bee colony population growth through a season was meant to validate some of the math and get a rough idea of how it would all work. Once the framework was in place the job becomes one of accounting for more details. The single biggest detail missing from the original math set was incorporating drones into the colony growth. Much of the reading I’ve done both online and in books, many folks tend to view drones in a colony as a waste of resources, they produce no honey and do no work in the colony. All they do is eat, and fly out. This view may be correct for folks that have an outlook of ‘honey produced this season’ and they buy in all the queens they need over time. But if we raise our own stock and have an outlook that looks beyond the results of this year, the drone population we raise in this season is a very important component of our results the following season. Those drones will mate with the queens we raise this season, so they are providing half of the genetic input to our bee population next year. So while some folks view drones as a drag on the colony, my own person view is, our drone crop this year is responsible for a good honey crop next year. Another place where drones actually help the colony is during the spring buildup. While the drones are out flying during the day, overnight they are in the cluster, and that cluster is incubating the early brood rounds when nights are cold. The drone population can and does help incubating brood overnight. The drones live on a different life cycle as compared to the worker bees, and it is very important to model this different cycle correctly. A drone egg is laid, then emerges as a larvae 3 and a half days later, just like the worker bee. The drone cell is capped on day 10, so it sits open for a day longer than a worker, then emerges on day 24. This is a critical difference as the drone cell is capped for 14 days vs the 11 days for which a worker is capped. After the drones emerge, they spend a week or two hardening and maturing in the colony before they start making regular afternoon flights to the drone congregation area. This is another important detail, because it tells us about our ability to successfully mate a new queen. You cannot successfully mate a new queen till a couple weeks after you see the first drones on frames in the colony. So, when do the bees start raising drones ? Just about everything I’ve read on the subject suggests that the bees will start raising drones later than when they start raising workers during the early spring buildup. But this is not what we see in our hives here in Campbell River. Our bees typically start the first round of brood in the mid February timeframe, and that’s about the time we will start to consider spring feed in the form of patties. We dont normally go deep into the hives lifting frames to inspect until mid to late March. On the late March first inspection, we often see some drones walking on the frames, not a lot, but there are some. If we do the math on drone development time, seeing drones on the frames in mid March suggests they were laid as eggs in mid to late February. I am convinced the first drone eggs are indeed placed in cells as soon as the first round of replacement bees is started. How many drones do the bees raise ? Again, reading literature provides a wide range of numbers, really depends on ‘which book did you read’ to get a handle on that number. I’ve seen numbers as low as 5 percent, and as high as 20 percent. Our own experience in looking at colonies where we place a drone frame, bees tend to fill one side completely, and the second side partially, which works out to approximately 10 percent of the brood is drone cells. Another detail that we need to account for is drone eviction. It’s well known, as we get into the later part of the season, worker bees evict the drones from the colony. With no basis other than ‘it makes sense’, we need to consider another important date then when modelling hive populations. If the bees are evicting the living drones on a given date, when did the queen stop laying eggs in drone cells ? It takes 24 days for a drone to develop from egg to emerging bee, so it does make sense to assume that no more eggs are placed in drone cells when we are 24 days before the date at which the bees will evict drones. After going over all of the numbers I’ve seen over time, and trying to make a realistic mathematical model for colony development, I chose to model drones by having the queen place 10% of the eggs into drone cells while she is laying eggs, and stops laying in drone cells 24 days prior to the date when the bees evict the drones. The way eviction is modelled, on days after the start of the eviction process, half of the remaining drone population gets evicted from the colony, resulting in a drone population that declines rapidly once eviction starts.

So Ian is showing the work in progress hive model on Youtube now. Find it here:- Hive model We have seen in numerous presentations the population dynamics chart originally produced by Randy Oliver with respect to bee population growth and dynamics in a healthy bee colony. It was a bit inspiring, but, we wanted something that would allow us to modify the start conditions and see how different start conditions would change the dynamics. Honeybee duties are based on the age of the bee, there is a pretty good description found on Wikipedia. The way the calculations work is strait forward. The starting population is distributed by age based on the start condition. A package is an even spread of bees of all ages. A wintered unit starts out with all winter bees, and a nuc starts with a population of all house bees, along with the number of brood frames selected, with the brood spread evenly over all ages. When the simulation runs, the date is advanced one day at a time, and all the bees / brood are aged by a day, then tally up how many in each age group to plot population of that group. During the process realistic restrictions are incorporated, ie the queen doesn’t lay more eggs than the current population can support for feeding and incubating brood. Some assumptions are made during the simulation. It is assumed the bees will have all the necessary protein and carbohydrates available for feeding the brood, if not available naturally then they should be beekeeper provided. It is also assumed there is always enough comb available for eggs to be laid at the best rate the queen is capable of. During the buildup, it’s also assumed that a queen doesn’t go from 0 to thousands of eggs overnight, it takes time for the rate of eggs laid to ramp up. An arbitrary number was chosen, on any given day queen will be capable of at least a couple hundred eggs, and the rate of eggs being laid can increase by 25% day over day, so when the simulation first starts, there is a ramp on the rate of eggs going into cells. Winter bees are a special case, and there is really no good numbers available in literature for modelling the winter honeybees. But we can make some intelligent guesses. Looking at the division of labour by age, bees are nursing brood from ages 3 thru 11 days for a total of 8 days. Larvae is open from day 3 thru 8 for a total of 6 days, so the ratio of nurse bees to open larvae is 4/3 in a hive with a steady state population at maximum potential. During the fall slowdown there is a period where the ratio of nurses to open larvae gets much larger, so we have a surplus of nurse bees that have the body fats of the freshly emerged bees, but are not expending them nursing new larvae. These are the bees we allocate to the ‘winter bees’ population. Conversly in the spring, when winter bees are pressed into nursing duty, that starts the aging clock for them to age out on the normal bee age cycle. During spring buildup, the way this is modelled, when there is a shortage of nurse bees for the open larvae, bees are taken from the winter bees category and placed into the nurse bee role at age of 4 day, and then allowed to age out in the normal progression. Ofc, we all know, there is bee die-off thru the winter, not all of the winter bees survive thru till the spring. Again, to simulate this I have found no strong references in the literature for death rates, so we go back to our own experience and look at what we’ve seen in colonies in our back lot. My best guesstimate for that is, winter bees die off at approximately 10% per month. On the ‘To-Do’ list. The next addition will be modelling growth of the drone population along with the worker bees. When that’s done, plan is to home in on the biology of varroa mites, and introduce a varroa mite population that runs in conjunction with the bee population model.