The recent decline in honey bee (Hymenoptera: Apidae) colony health worldwide has had a 18 significant impact on the beekeeping industry as well as on pollination-dependent crop sectors in 19
North America and Europe. The pollinator crisis has been attributed to many environmental and 20
anthropological factors including less nutrient rich agricultural monocultures, pesticide exposure, 21
new parasite and pathogen infestations as well as beekeeper management and weather. Canadian 22
beekeepers have indicated that issues with honey bee queens are the most significant factor 23 affecting their colony health. In Canada, beekeepers manage colony losses by relying on the 24 importation of foreign bees, particularly queens from warmer climates, to lead new replacement 25 colonies. Unfortunately, the risks associated with imported queens include the introduction of 26 new and potentially resistant pests and diseases, undesirable genetics including bees with limited 27 adaptations to Canada's unique climate and bees negatively affected by transportation. Importing 28 a large proportion of our queens each year also creates an unsustainable dependency on foreign 29 bee sources, putting our beekeeping and pollination sectors at an even greater risk in the case of 30 border closures and restrictions. Increasing the domestic supply of queens is one mitigation 31 strategy that could provide Canadian beekeepers, farmers and consumers with a greater level of 32 agricultural stability through locally bred, healthier queens. Our study is the first rigorous 33 analysis of the economic feasibility of Canadian queen production. We present the costs of queen 34 production for three case study operations across Canada over two years as well as the 35 profitability implications. Our results show that for a small to medium sized queen production 36 operation in Canada, producing queen cells and mated queens can be profitable. Using a mated 37 queen market price ranging from $30 to $50, a producer selling mated queens could earn a profit 38 of between $2 and $40 per queen depending on price and the cost structure of his operation. If 39 the producer chose to rear queens for his own operation, the cost savings would also be 40 significant as imported queen prices continue to rise. Our case studies reveal that there is 41 potential for both skilled labour acquisition over time in queen production as well as cost savings 42 from economies of scale. Our queen producers also reduced their production costs by re-using 43 materials year to year. Domestic queen production could be one viable strategy to help address 44 the current pollinator crisis in Canada.
beekeepers reported that queen issues were the most important factor contributing to colony 71 mortality (Fig. 2) . Despite the significant colony losses, beekeepers are able to mitigate high 72 colony mortality by splitting their colonies each spring and installing new queens. These new 73 queens can be reared by the beekeepers themselves, by other local beekeepers or can be 74 imported. Beekeepers can import queens alone, or as package bees, which are comprised of 1-1.5 75 kg of worker bees with a newly-mated queen. 35   1988  1989  1990  1991  1992  1993  1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017 Price per queen ($CDN) small subset of beekeepers. These breeders select for a set of criteria such as honey production, 139 varroa resistance, wintering performance, hygienic behaviour, and/or temperament. Selection 140 usually takes place in the field through specialized phenotypic testing and/or observations of 141 colony performance, however, new laboratory-based testing tools are beginning to reach the 142 market and may soon significantly impact the queen breeding industry in Canada and worldwide 143 (Guarna et al. 2017). These tools would require only a small sample of a colony's workers to be 144 tested for markers corresponding to specific traits, a much less resource intensive selection 145 process. 146 147 As described in Laidlaw and Page (1997) , queen rearing requires that the queen producer follow 148 a generalized breeding procedure. Once the queen and drone mother colonies are selected, a 149 process that can be done by the queen producer or within a separate breeding program which 150 then provides the selected genetics to the queen producing beekeeper who uses a queenless cell 151 starter colony to rear queen cells. One-day-old larvae from the selected mother colony are 152 grafted into queen cups and placed into the cell starter colony for the nurse bees to rear (swarm 153 boxes filled with nurse bees are an alternative to starter colonies used by some Canadian 154 producers). After 24-48 hours, depending on the method, the queen cells are moved into a 155 finishing colony (unless using a combined starter-finisher colony) where they will be reared for 156 eight days until they are ready to be sold as queen cells or introduced into small, queenless 157 colonies (mating nuclei) to be mated. Setting up the mating yard(s) requires a significant labour 158 investment and is a critical component in the queen production process. These steps of queen 159 production result in daughter queens that can be used in the originating operation or sold to other 160 beekeepers (Van Alten et al. 2013). Alternatively, a colony can contribute to the production of 161 mated queens by acting as a drone source colony for mating with virgin queens. For the purpose 162 of this manuscript, a 'queen breeding or production operation' refers to an operation that is 163 involved in queen production regardless of the method used to select breeder queens. We chose three queen breeding operations in Canada each led by an apicultural researcher (with 180 a range of queen production experience) to ensure systematic data collection. Each operation was 181 managed independently and according to the researcher's own set of criteria. The first operation, 182 OP1, was located near Moncton, New Brunswick in Atlantic Canada where historically there has 183 not been a large honey bee queen production industry. OP1 is itself a large beekeeping operation 184 in eastern Canada that produces several hundred splits each summer with a focus to pioneer 185 rigorous breeding research in eastern Canada using a relatively large number of colonies. The 186 operation was led by apicultural researchers with in-depth beekeeping knowledge but limited 187 queen breeding experience. OP2 was located in Lethbridge, in southern Alberta in close 188 proximity to many commercial beekeepers, and where honey bee colonies are frequently used for 189 canola pollination. OP2 collaborated with two commercial beekeepers with large operations but 190 virtually no queen breeding experience. OP2 was led by a researcher with many years of 191 beekeeping experience, including experience with queen rearing and selective breeding. While 192 OP2 had diverse queen production experience, the beekeepers leading OP2 had collectively less 193 experience than OP3 in large scale queen production. to costs specific to rearing and mating queens post cell stage. For the purposes of this queen 215 production study, the costs associated with breeder selection are not included in the production 216 costs. Selection and production are two distinct processes and our focus in this paper is to 217 examine the latter. As well, the opportunity costs incurred by beekeepers who invest their labour 218 and beekeeping resources into queen production at the expense of other beekeeping output is not 219 included in these calculations. 220
For this analysis, we are considering only existing beekeepers as viable players to enter the 222 queen production industry due to the high level of skill and beekeeping experience required for 223 queen production, and thus we assume that these beekeepers will use their current operation's 224 beekeeping equipment such as land, colonies, and bees to conduct their queen rearing. Additional 225 resources used only for cell and queen production including queen rearing materials and feed 226 will be included in the cost analysis for 2018, whereas only additional materials (cell cups, queen 227 cages, feed) that are typically not re-used will be included for year 2. Tables 2a. and 2b. show the 228 inputs and costs associated with cell and queen rearing respectively for all three operations in 229 both years. Table 3 lists pricing and describes the labour activities associated with the labour 230 activity numbers given in tables 2a and 2b. All labour wages are paid at an average of 231 CDN$20/hour to account for both higher skilled labour, less skilled labour and unpaid family 232 labour (Laate 2017 Table 3 24 (1) Table 3 18 (4) We observed a relative consistency of cell and queen material costs across operations and across 249 time which highlights a systematic cell and queen production process for beekeepers rearing 250 queens and suggests that we may be able to extrapolate these results to a wider queen production In 2019, the three breeding operations had a range of overall costs for producing queen cells 290 from $1.18/cell to $4.34/cell and $6.84/mated queen to $13.32/mated queen in addition to the 291 queen cell costs (Table 5) in cell costs from $4.70 down to $1.40 over the same two years. As mentioned earlier, OP3 had 320 higher per cell costs in 2019 due to poor weather, however, additional mated queen costs for 321 2019 for OP3 remained the lowest of the three operations and was even lower than their own 322 additional queen costs in 2018. There were cost reductions for mated queen production between 323 years for all three operations (Fig 5) . 324 325 Figure 4 . Per queen cell cost differential between first two production years. Figure 5 . Per mated queen cost differential between first two production years.
As the queen industry in Canada continues to develop and queen producers gain experience and 330 are able to bring costs down, we are seeing alternative queen rearing practices introduced into 331 operations to improve queen and colony health and reduce costs. Some queen producers in 332 Alberta and across the country have begun to introduce queen cells into queenright colonies 333 (colonies with an existing often older and/or less productive queen). This strategy allows the 334 colony to requeen itself as an alternative to producing or purchasing a mated queen, with the 335 same goal of ultimately building-up a stronger, healthier colony led by a young, healthy queen. 336
Mixed success with requeening was reported in earlier research studying the success of 337 introducing queen cells in queenright colonies (Szabo 1982 , Jay 1981 . However, there is a 338 known positive impact from requeening in terms of decreased winter mortality and increased 339 colony strength particularly when requeening with younger queens (Woyke 1984 , Ricigliano et 340 al. 2018 ), further reducing colony management and replacement costs. It is important that the 341 queen production industry exercise caution, however, in proceeding with this requeening strategy 342 as there is no data to support conclusive positive outcomes (Szabo 1982 requeening is also of critical importance as there would be a gap in the brood cycle of these 344 colonies. This could negatively impact colony size at critical time points such as pollination 345 contracts, honey flows, or population build up going into winter, unless the requeening method 346 prevents the interruption of egg laying in the colony (Forster, 1972) . More research is needed on 347 the biological feasibility and economic efficiency of using cells to requeen queenright colonies. 348 349 Introducing queen cells (whether into queenless or queenright colonies) would mean that in the 350 case of our three case study queen producers, an investment of between $2 and $5 per queen cell 351 would potentially yield a strong colony with desirable genetics, saving the queen producer 352 between 77% (OP3) and 90% (OP1) in queen production costs beyond the cell stage (see total 353 additional cost, table 5). In the case of a beekeeper purchasing cells to re-queen colonies, the 354 savings would also be significant as import queen prices continue to rise (Page 2017). In a 355 theoretical example, a commercial beekeeper with costs similar to OP1, investing $2.50 per 356 successful queen cell with a 5000-colony apiary would be able to re-queen half of his colonies 357 for a total cost of $12,500 compared to spending $54,050 (an additional $41,550 beyond the cell 358 stage) to produce 5000 mated queens or purchasing 5000 queens for a minimum of $200,000 359 ($40 per queen). Alternatively, rather than using their cells or queen in their own operations, 360 queen producers can sell their queen cells and/or mated queens to other beekeepers. In cases of 361 higher overall per cell costs such as in OP2 for 2018, rearing and selling queen cells is less 362 profitable than for OP1 and OP3 due to lower costs, however, for all three operations there are 363 OP2 sees a 60% increase in profits while OP3 experiences a small loss of less than $0.40 386 between the two years ( Figure 7) . It is important to consider that although these costs take into 387 account queen cages, candy and beekeeper labour, they do not include shipping costs as these 388 can be paid by the receiver or the shipper depending on the contractual agreement. grafting and mating success rates, which varied between operations and over time (Table 1 ). 396 on mated queen costs is relatively small, the increase in profits is also small. For an increase in 402 grafting success from 50% to 75% we see a less than 6% increase in profits and for a jump in 403 grafting success from 75% to 100%, we see an increase of less than 3% in mated queen profits. 404
Mating success has a more significant effect on per mated queen profits. Figure 9 shows the 405 impact that the queen's mating success has on profitability of mated queens for OP3, given an 406 average grafting success rate for OP3 of 85% and variable mating success rates that are 407 consistent with our three case studies experiences. A rise in mating success from 60% to 80% 408 results in a 19% profitability increase while an increase from 80% to 100% in mating success 409 results in a 10% rise in profits per mated queen. Our researcher-led case studies had variable 410 mating success rates in 2018, ranging from 67% for OP1 up to 95% for OP3 (Table 1) This detailed economic breakdown of Canadian queen production provides evidence that queen 431 production in Canada has the potential to be profitable even for new producers with variable 432 grafting and mating success, as well as when skilled beekeepers are confronted with poor 433 environmental conditions. Based on our study, the difference between total costs and total 434 revenue in the mated queen market in Canada gives queen producers a reasonable profit by 435 absorbing increased costs resulting from any number of factors including environmental 436 conditions and other externalities. For Canadian beekeepers who rear their own cells and queens, 437 there is great potential for cost savings by requeening their own colonies with queens/cells they 438 produce. Whether the beekeeper uses queen cells or mated queens to requeen existing colonies, 439 there will be significant cost savings by reducing queen purchase costs and simultaneously 440 minimizing importation risks to ultimately reduce colony morbidity and mortality. 441 442 Each queen production operation in Canada will have a unique approach and expertise with 443 queen rearing which will be reflected in its costs and profitability. However, for queen 444 production, the steps taken and the resources used in each of our three case study operations 445 were determined independently by the breeders without consultation and yet there were similar 446 material costs. From 2018 to 2019, grafting success rates increased along with beekeeper 447 experience. Material re-use and economies of scale for labour were also significant factors in 448 cost reduction and profit increases for operations 1 and 2. Operation 3 had a more 449 uncharacteristic progression from 2018 to 2019 as the climate variability in year 2 posed some 450 significant management challenges and resulted in higher overall cell costs. However, while the 451 experienced queen producer in OP3 likely did not benefit from skill acquisition as such, he did 452 have cost savings from re-using materials in 2019. OP3 was also able to use its queen rearing 453 expertise to mitigate any significant profitability impact from the higher cell costs onto the more 454 salient mated queen production costs. The similarities in material costs between operations 455 reflect a common systematic approach to breeding in Canada, allowing us to extrapolate from 456 our costing analysis to a broader representative Canadian small or medium-scale queen producer 457 and conclude that queen production in Canada has the potential for profit and growth. The three 458 operations' results in our study offer evidence that small to medium-scale queen production can 459 be profitable. These results likely provide an upper bound for queen production costs, as large-460 scale commercial queen producers will reap the benefits of even greater economies of scale in 461 their operations, lowering costs even further. 462 463 As experienced beekeepers choose to enter the queen production industry, it is important to 464 consider that first year expenditures are higher than in subsequent years. However, even a newly 465 established queen production operation could be profitable given certain environmental and 466 pricing conditions and a skilled beekeeper with some queen experience. Also, as new selective 467 breeding technologies become available to the wider market, Canadian queen production will 468 yield stronger, more highly selected queens that command higher prices. As queen rearing in 469 Canada continues to proliferate and is shown to be profitable, methods will be streamlined 470 further and the number of queen operations and availability of skilled labour should increase, 471 enabling Canadian beekeepers to play a greater role in contributing to this industry's biological 472 and financial autonomy and sustainability. 