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Abstarct Fumagilin-B is used to treat nosema infection in honey bee colonies; however, it is unclear whether treatment consistently reduces Vairimorpha ceranae (Fries et al.) abundance and improves colony strength and survival in the Canadian Prairies. This study assessed spring and fall fumagillin treatments on nosema abundance, colony strength, and mortality in 2 different beekeeping regions within Alberta, using both indoor and outdoor wintering management at each site. We compared 4 fumagillin treatments: Spring-only, Fall-only, Spring-and-Fall, and Control (no treatment). The spring treatment dose was ~68 mg/colony, whereas the fall treatment dose was 120 or 48 mg/colony, depending on the year. We found that the colonies were infected predominately with V. ceranae, with V. apis (Zander) present only in mixed infections in a subset of colonies. Although treatment in either the spring or fall did reduce nosema abundance in the short term, it did not eliminate the infection, making continued monitoring necessary. Colony strength was improved by spring treatment in some locations but not consistently, possibly due to the treatment timing or low dose. The combined spring and fall treatment increased colony survival over winter in one of 2 yr. Wintering method did not interact with treatment to affect nosema abundance in the spring. There does not appear to be a significant residual benefit of fall treatment as it did not reduce spring nosema abundance or increase colony population. Therefore, spring treatment should be applied to reduce spring V. ceranae abundance rather than relying on residual efficacy from previous fall treatments.

Canadian beekeepers faced widespread levels of high honey bee colony mortality over the winter of 2021/2022, with an average winter loss of 45%. To understand the economic impact of winter colony mortality in Canada and the beekeeping management strategies used to mitigate these losses, we develop a profit model of commercial beekeeping operations in Alberta, Canada. Our model shows that for operations engaging in commercial pollination as well as honey production (compared to honey production alone), per colony profit is higher and operations are better able to withstand fluctuations in exogenous variables such as prices and environmental factors affecting productivity including winter mortality rates. The results also suggest that beekeeping operations that replace winter colony losses with splits instead of package bees accrue higher per colony profit than those importing packages to replace losses. Further, operations that produce their own queens to use in their replacement splits, accrue even higher profit. Our results demonstrate that the profitability of beekeeping operations is dependent on several factors including winter mortality rates, colony replacement strategies, and the diversification of revenue sources. Beekeepers who are not as susceptible to price and risk fluctuations in international markets and imported bee risks accrue more consistently positive profits.

Adequate nutrition is required to support productive honey bee colonies, therefore beekeepers supplement colonies with additional protein at targeted time points. We tested the effects of commercially available protein feeds in spring, in advance of colonies being used for hybrid canola pollination. The feed treatments across the three-year study included the following patty types: Global 15% pollen, Global 0% pollen, Bee Pollen-Ate, FeedBee, and Healthy Bees, as well as an unsupplemented control in year two of the study only. The amount of feed consumed varied among colonies, treatments, date, and year. Similarly, there were also differences in feed efficiency (bees reared per gram of feed consumed), likely due to the relative availability of external forage sources to supplement the feed provided. Unsupplemented colonies were able to rear less brood, and subsequently had fewer adult bees than supplemented colonies, in an apiary where pollen was not abundant. Differences in consumption among treatments often failed to translate in to differences in amount of brood reared or subsequent adult population. All the protein feed treatments contained all ten amino acids essential to honey bees, however lysine and arginine were below the optimal proportion required for growth in all patties except the FeedBee patty. The amount of protein and amount and types of sugars and fats in the products also varied among product type and batch. The results of this study demonstrate a benefit to supplementary spring protein feeding to increase honey bee colony populations in advance of a summer pollination market.

The ideal-free distribution and central-place foraging are important ecological models that can explain the distribution of foraging organisms in their environment. However, this model ignores distance-based foraging costs from a central place (hive, nest), whereas central-place foraging ignores competition. Different foraging currencies and cooperation between foragers also create different optimal distributions of foragers, but are limited to a simple two-patch model. We present a hybrid model of the ideal-free distribution that uses realistic competitive effects although accounting for distance-based foraging, and test it using honey bees (Apis mellifera L.) foraging in canola fields (Brassica napus L.). Our simulations show that foragers maximizing efficiency (energy profits ÷losses) prioritize distance to their aggregation more than those maximizing net-rate (energy profits ÷time), and that social foragers move to more distant patches to maximize group benefits, meaning that social foragers do not approach an ideal-free distribution. Simulated efficiency-maximizers had a hump-shaped relationship of trip times with distance, spending shorter amounts of time in both nearby and far-away patches. Canola fields were far more attractive to simulated foragers than semi-natural areas, suggesting limited foraging on semi-natural lands during the bloom period of canola. Finally, we found that the observed distribution of honey bees in canola fields most closely resembled the optimal distribution of solitary efficiency-maximizers. Our model has both theoretical and practical uses, as it allows us to model central-place forager distributions in complex landscapes as well as providing information on appropriate hive stocking rates for agricultural pollination.

To gauge the impact of COVID-19 on the Canadian beekeeping sector, we conducted a survey of over 200 beekeepers in the fall of 2020. Our survey results show Canadian beekeepers faced two major challenges: 1) disrupted importation of honey bees (Hymenoptera: Apidae) (queen and bulk bees) that maintain populations; and 2) disrupted arrival of temporary foreign workers (TFWs). Disruptions in the arrival of bees and labor resulted in fewer colonies and less colony management, culminating in higher costs and lower productivity. Using the survey data, we develop a profitability analysis to estimate the impact of these disruptions on colony profit. Our results suggest that a disruption in either foreign worker or bee arrival allows beekeepers to compensate and while colony profits are lower, they remain positive. When both honey bee and foreign workers arrivals are disrupted for a beekeeper, even when the beekeeper experiences less significant colony health and cost impacts, a colony with a single pollination contract is no longer profitable, and a colony with two pollination contracts has significantly reduced profitability. As COVID-19 disruptions from 2020 and into 2021 become more significant to long-term colony health and more costly to a beekeeping operation, economic losses could threaten the industry’s viability as well as the sustainability of pollination-dependent crop sectors across the country. The economic and agricultural impacts from the COVID-19 pandemic have exposed a vulnerability within Canada’s beekeeping industry stemming from its dependency on imported labor and bees. Travel disruptions and border closures pose an ongoing threat to Canadian agriculture and apiculture in 2021 and highlight the need for Canada’s beekeeping industry to strengthen domestic supply chains to minimize future risks.

Social organisms combat pathogens through individual innate immune responses or through social immunity—behaviors among individuals that limit pathogen transmission within groups. Although we have a relatively detailed understanding of the genetics and evolution of the innate immune system of animals, we know little about social immunity. Addressing this knowledge gap is crucial for understanding how life-history traits influence immunity, and identifying if trade-offs exist between innate and social immunity. Hygienic behavior in the Western honey bee, Apis mellifera, provides an excellent model for investigating the genetics and evolution of social immunity in animals. This heritable, colony-level behavior is performed by nurse bees when they detect and remove infected or dead brood from the colony. We sequenced 125 haploid genomes from two artificially selected highly hygienic populations and a baseline unselected population. Genomic contrasts allowed us to identify a minimum of 73 genes tentatively associated with hygienic behavior. Many genes were within previously discovered QTLs associated with hygienic behavior and were predictive of hygienic behavior within the unselected population. These genes were often involved in neuronal development and sensory perception in solitary insects. We found that genes associated with hygienic behavior have evidence of positive selection within honey bees (Apis), supporting the hypothesis that social immunity contributes to fitness. Our results indicate that genes influencing developmental neurobiology and behavior in solitary insects may have been co-opted to give rise to a novel and adaptive social immune phenotype in honey bees.

The epidemiology of Nosema spp. in honey bees, Apis mellifera, may be affected by winter conditions as cold temperatures and differing wintering methods (indoor and outdoor) provide varying levels of temperature stress and defecation flight opportunities. Across the Canadian Prairies, including Alberta, the length and severity of winter vary among geographic locations. This study investigates the seasonal pattern of Nosema abundance in two Alberta locations using indoor and outdoor wintering methods and its impact on bee population, survival, and commercial viability. This study found that N. ceranae had a distinct seasonal pattern in Alberta, with high spore abundance in spring, declining to low levels in the summer and fall. The results showed that fall Nosema monitoring might not be the best indicator of treatment needs or future colony health outcomes. There was no clear pattern for differences in N. ceranae abundance by location or wintering method. However, wintering method affected survival with colonies wintered indoors having lower mortality and more rapid spring population build-up than outdoor-wintered colonies. The results suggest that the existing Nosema threshold should be reinvestigated with wintering method in mind to provide more favorable outcomes for beekeepers. Average Nosema abundance in the spring was a significant predictor of end-of-study winter colony mortality, highlighting the importance of spring Nosema monitoring and treatments.

The recent decline in honey bee (Hymenoptera: Apidae) colony health worldwide has had a significant impact on the beekeeping industry as well as on pollination-dependent crop sectors in North America and Europe. The pollinator crisis has been attributed to many environmental and anthropological factors including less nutrient rich agricultural monocultures, pesticide exposure, new parasite and pathogen infestations as well as beekeeper management and weather. Canadian beekeepers have indicated that issues with honey bee queens are the most significant factor affecting their colony health. In Canada, beekeepers manage colony losses by relying on the importation of foreign bees, particularly queens from warmer climates, to lead new replacement colonies. Unfortunately, the risks associated with imported queens include the introduction of new and potentially resistant pests and diseases, undesirable genetics including bees with limited adaptations to Canada’s unique climate and bees negatively affected by transportation. Importing a large proportion of our queens each year also creates an unsustainable dependency on foreign bee sources, putting our beekeeping and pollination sectors at an even greater risk in the case of border closures and restrictions. Increasing the domestic supply of queens is one mitigation strategy that could provide Canadian beekeepers, farmers and consumers with a greater level of agricultural stability through locally bred, healthier queens. Our study is the first rigorous analysis of the economic feasibility of Canadian queen production. We present the costs of queen production for three case study operations across Canada over two years as well as the profitability implications. Our results show that for a small to medium sized queen production operation in Canada, producing queen cells and mated queens can be profitable. Using a mated queen market price ranging from $30 to $50, a producer selling mated queens could earn a profit of between $2 and $40 per queen depending on price and the cost structure of his operation. If the producer chose to rear queens for his own operation, the cost savings would also be significant as imported queen prices continue to rise. Our case studies reveal that there is potential for both skilled labour acquisition over time in queen production as well as cost savings from economies of scale. Our queen producers also reduced their production costs by re-using materials year to year. Domestic queen production could be one viable strategy to help address the current pollinator crisis in Canada.

The development of new treatments for castrate resistant prostate cancer (CRPC) must address such challenges as intrinsic tumor heterogeneity and phenotypic plasticity. Combined PTEN/TP53 alterations represent a major genotype of CRPC (25–30%) and are associated with poor outcomes. Using tumor-derived, castration-resistant Pten/Tp53 null luminal prostate cells for comprehensive, high-throughput, mechanism-based screening, we identified several vulnerabilities among >1900 compounds, including inhibitors of: PI3K/AKT/mTOR, the proteasome, the cell cycle, heat shock proteins, DNA repair, NFκB, MAPK, and epigenetic modifiers. HSP90 inhibitors were one of the most active compound classes in the screen and have clinical potential for use in drug combinations to enhance efficacy and delay the development of resistance. To inform future design of rational drug combinations, we tested ganetespib, a potent second-generation HSP90 inhibitor, as a single agent in multiple CRPC genotypes and phenotypes. Ganetespib decreased growth of endogenous Pten/Tp53 null tumors, confirming therapeutic activity in situ. Fifteen human CRPC LuCaP PDX-derived organoid models were assayed for responses to 110 drugs, and HSP90 inhibitors (ganetespib and onalespib) were among the select group of drugs (75% of models) at high potency (IC50

We compare two different sizes of honey bee colony units: singles (one brood chamber) and doubles (two brood chambers) in hybrid seed canola pollination in southern Alberta in 2014 and 2015. Currently, canola seed production companies only contract double-brood chamber units to pollinate canola in southern Alberta, but it may be advantageous to the industry if singles could also be contracted for pollination, as they are in many other crops. To evaluate the differences between the colony units, we measured population size, nectar and pollen foraging, nectar and pollen load weights, pollen collection, and honey production. The colony populations of both the single- and double-brood chamber hives in this study were highly variable. In 2015, there was no difference between the single- and the double-brood chamber colonies in adult bee populations, and the singles had more sealed brood than did the double-brood chamber colonies. Our findings indicate that in comparison to doubles, on a per-frame basis, singles yield more pollen, more nectar foragers, similar or more pollen foragers, and similar amounts of honey. Therefore, we conclude that singles could be used to provide the same level of pollination services as doubles currently do in hybrid seed canola pollination, and growers should focus on receiving healthy populous colonies, regardless of the number of brood boxes.

Hybrid canola seed production is an important pollination market in Canada; typically both honey bees (Apis mellifera L. (Hymenoptera: Apidae)) and Alfalfa Leafcutting bees (Megachile rotundata Fab. (Hymenoptera: Megachilidae)) are concurrently managed to ensure pollination in this high-value crop. Beekeepers are paid to provide pollination services, and the colonies also produce a honey crop from the canola. Pollen availability from male-fertile plants is carefully managed in this crop to provide an abundance of pollen to fertilize male-sterile (‘female’) plants. This abundance of pollen represents an underutilized resource for beekeepers, and an opportunity to diversify the hive-products produced for market in this management system. We used a commercial-style pollen trap to collect pollen from colonies twice weekly for the duration of canola pollination, and compared the honey production and amount of sealed brood in colonies with pollen traps to those without pollen traps. We found that while pollen trapping reduced honey production, there was no negative impact on brood production, and at current market prices, the per-hive revenue was higher in colonies from which pollen was trapped. Pollen trapping honey bee colonies in the context of hybrid canola pollination, therefore, offers beekeepers an opportunity to diversify their products and increase their revenue.

Insect pollination of flowers should change the within-season allocation of resources in plants. But the nature of this life-history response, particularly regarding allocation to roots, photosynthetic structures, and flowers, is empirically unresolved. This study uses a greenhouse experiment to investigate the effect of insect pollination on the reproductive output of 23 varieties of a globally important crop—canola (Brassica napus). Overall, insect pollination modified the functional characteristics (flower timing & effort, plant size & shape, seed packaging, root biomass) of canola, increasing seed production and quality, and pollinator dependence. Reproductive output and pollinator dependence were defined by strong trait trade-offs, which ranged from more pollinator-dependent plants favouring early reproductive effort, to less pollinator-dependent plants favouring a prolonged phenology with smaller plant size and lower seed quality. Seed production decreased with pollinator dependence in the absence of pollinators. The agricultural preference for hybrid varieties will increase seed production compared to open-pollinated varieties, but, even so, pollinators typically enhance seed production of both types. Our study elucidates how insect pollination alters the character and function of a globally important crop, supporting optimization of yield via intensification of insect pollination, and highlights the beneficial effects of insect pollination early in the season.

We present a novel way to select for highly polygenic traits. For millennia, humans have used observable phenotypes to selectively breed stronger or more productive livestock and crops. Selection on genotype, using single-nucleotide polymorphisms (SNPs) and genome profiling, is also now applied broadly in livestock breeding programs; however, selection on protein/peptide or mRNA expression markers has not yet been proven useful. Here we demonstrate the utility of protein markers to select for disease-resistant hygienic behavior in the European honey bee (Apis mellifera L.). Robust, mechanistically-linked protein expression markers, by integrating cis- and trans- effects from many genomic loci, may overcome limitations of genomic markers to allow for selection. After three generations of selection, the resulting marker-selected stock outperformed an unselected benchmark stock in terms of hygienic behavior, and had improved survival when challenged with a bacterial disease or a parasitic mite, similar to bees selected using a phenotype–based assessment for this trait. This is the first demonstration of the efficacy of protein markers for industrial selective breeding in any agricultural species, plant or animal.

We examined whether alfalfa leafcutting bees (ALCB, Megachille rotundata) experienced a higher incidence of seven viruses commonly found honey bees (Apis mellifera) when placed alongside honey bees for hybrid canola seed pollination. Although two viruses – sacbrood virus (SBV) and deformed wing virus (DWV) – were detected in ALCB adults, their presence appeared independent of whether honey bees were present in the same field or not. A further survey of viruses among ALCB adults in three different alfalfa seed growing regions in Western Canada confirmed the ubiquity of sacbrood virus (SBV) as well as the infrequent presence of acute bee paralysis virus (ABPV), both of which had not been previously reported on ALCB. Moreover, SBV and ABPV were detected in the cocoon stage and only in one region. Co-infection among pools of ALCB adults with both of these viruses was more closely correlated with decreasing levels of cocoon viability than infection levels in cocoons themselves. This research suggests ongoing viral transmission between honey bees and ALCB in the same fields is likely low but that co-infection with these viruses may lower ALCB productivity.

We present a novel way to select for highly polygenic traits. For millennia, humans have used observable phenotypes to selectively breed stronger or more productive livestock and crops. Selection on genotype, using single-nucleotide polymorphisms (SNPs) and quantitative trait loci (QTLs), is also now applied broadly in livestock breeding programs; however, selection on protein or mRNA expression markers have not been proved useful yet. Here we demonstrate the utility of protein markers to select for disease-resistant behaviour in the European honey bees (Apis melliferaL.). Robust, mechanistically-linked protein expression markers, by integrating cis and trans effects from many genomic loci, may overcome limitations of genomic markers to allow for selection. After three generations of selection, the resulting stock performed as well or better than bees selected using phenotype–based assessment of this trait, when challenged with disease. This is the first demonstration of the efficacy of protein markers for selective breeding in any agricultural species, plant or animal.Significance statementThe honey bee has been in the news a lot recently, largely because of world-wide die-offs due to the parasitic Varroa mite, which is becoming resistant to the chemical controls the bee industry uses. In this study, we show that robust expression biomarkers of a disease-resistance trait can be used, in an out-bred population, to select for that trait. After three generations of selection, the resulting stock performed as well or better than bees selected using the phenotypic best method for assessing this trait when challenged with disease. This is the first demonstration of an expression marker for selective breeding in any agricultural species, plant or animal. This also represents a completely novel way to select for highly polygenic traits.

Environmental changes threaten plant-pollinator mutualisms and their critical ecosystem service. Drivers such as land use, invasions and climate change can affect pollinator diversity or species encounter rates. However, nitrogen deposition, climate warming and CO2 enrichment could interact to disrupt this crucial mutualism by altering plant chemistry in ways that alter floral attractiveness or even nutritional rewards for pollinators. Using a pumpkin model system, we show that these drivers non-additively affect flower morphology, phenology, flower sex ratios and nectar chemistry (sugar and amino acids), thereby altering the attractiveness of nectar to bumble bee pollinators and reducing worker longevity. Alarmingly, bees were attracted to, and consumed more, nectar from a treatment that reduced their survival by 22%. Thus, three of the five major drivers of global environmental change have previously unknown interactive effects on plant-pollinator mutualisms that could not be predicted from studies of individual drivers in isolation.

The effect of stream riparian condition on invertebrate drift was examined in headwater streams of the Torpy River in north-central British Columbia, Canada. Forest harvesting provided the opportunity to examine drift within control streams (i.e., within intact forest), streams with 10 m foliated reserve strips, streams with 10 m defoliated riparian reserve strips, and streams without riparian reserve strips (i.e., clear cut to the stream bank). The density (concentration) of aquatic invertebrates (individuals m−3) in the drift was significantly lower in streams with 10 m riparian reserves compared to control streams (P 10 m defoliated > 10 m foliated). There was significantly more aquatic drift in downstream vs. upstream locations of control streams, but this pattern was reversed for harvested streams (P = 0.51) leading to a significant interaction term in the analysis (P = 0.046; which indicates that the upstream-downstream comparison differed significantly between control and treatment streams in this double-control design). These types of changes in the drift of aquatic and terrestrial invertebrates are known to affect stream ecosystems through trophic interactions among periphyton, benthic grazers, and fish. Consequently, both the quantity and quality of riparian reserve strips must be considered for the effective mitigation of forestry practices.

We examined the effect of larval and adult nutrition on worker honey bee (Apis mellifera L.) ovary development. Workers were fed high or low-pollen diets as larvae, and high or low-protein diets as adults. Workers fed low-protein diets at both life stages had the lowest levels of ovary development, followed by those fed high-protein diets as larvae and low- quality diets as adults, and then those fed diets poor in protein as larvae but high as adults. Workers fed high-protein diets at both life stages had the highest levels of ovary development. The increases in ovary development due to improved dietary protein in the larval and adult life stages were additive. Adult diet also had an effect on body mass. The results demonstrate that both carry-over of larval reserves and nutrients acquired in the adult life stage are important to ovary development in worker honey bees. Carry-over from larval development, however, appears to be less important to adult fecundity than is adult nutrition. Seasonal trends in worker ovary development and mass were examined throughout the brood rearing season. Worker ovary development was lowest in spring, highest in mid-summer, and intermediate in fall.

In most social insect colonies, workers do not attempt to lay eggs in the presence of a queen. However, in the honey bee (Apis mellifera), a rare phenotype occurs in which workers activate their ovaries and lay large numbers of male eggs despite the presence of a fecund queen. We examined the proximate mechanisms by which this ‘anarchistic’ behaviour is expressed. We tested the effects of brood and queen pheromones on retinue attraction and worker ovary activation using caged worker bees. We found no difference between the anarchistic and wild type queen pheromones in the retinue response elicited in either wild type or anarchistic workers. Further, we found that anarchistic queens produce a pheromone blend that is as effective at inhibiting ovary activation as the wild type queen pheromone. However, anarchistic workers are less inhibited by queen pheromones than their wild type counterparts, in a dose-dependent manner. These results show that the anarchistic phenomenon is not due to changes in the production of queen pheromones, but rather is due in part to a shift in the worker response to these queen-produced signals. In addition, we demonstrate the dose-dependent nature of the effect of queen pheromones on honey bee worker ovary activation.

Anarchistic honey bees are a line developed by recurrent selection in which workers frequently lay eggs. In unselected colonies, workers refrain from reproduction in response to pheromonal signals that indicate the presence of brood and a queen. We show that queen type (anarchistic or wild type) has no effect on rates of ovary activation of anarchistic or wild type workers. In addition, we show that an important component of the queen’s signalling system, the queen mandibular gland pheromone, is similar in wild type and anarchistic queens. Anarchistic larvae do not inhibit worker ovary development to the same degree as wild type larvae, however all colonies in this experiment contained only wild type larvae. Anarchistic workers had greater rates of ovary activation than wild type workers in colonies headed by either queen type. We therefore conclude that there must be differences in the transmission or reception of queen pheromones, or worker sensitivity to these compounds. These results clearly demonstrate that anarchy is a complex syndrome, not simply the result of reduced pheromone production by anarchist queens and larvae.

SUMMARYHoney bee (Apis mellifera) queen mandibular pheromone (QMP) influences many aspects of worker behaviour and physiology. We observed that synthetic QMP seems to calm colonies and reduce stinging, suggesting a role for QMP in managing colony defensive behaviour. We assessed defensive responses of colonies that were queenright, queenless or supplemented with two forms of synthetic QMP (liquid QMP on glass slides or Bee Boost® synthetic lures) by counting stings on a leather patch and the number of responder bees at colony entrances. Colonies with queens showed decreased defensive behaviour when exposed to liquid QMP; colonies without queens and exposed to liquid QMP had no change in the number of stings but a decrease in the number of guard bees. Bee Boost had no effect on colony defensive behaviour in colonies with or without queens. The ability to reduce defensive behaviour with QMP could have positive implications for commercial beekeeping, especially in context with Africanized bees, should an eff...

Commercial greenhouses require high densities of managed bumble bee (Bombus occidentalis Greene, 1858 and Bombus impatiens Cresson, 1863) colonies to pollinate crops such as tomatoes (Lycopersicon esculentum Miller). We examined drifting, a behavioural consequence of introducing closely aggregated colonies into greenhouse habitats, to determine possible explanations for observed drifting frequencies. Bee drift is normally associated with increased individual mortality and disease transfer between colonies. In this study, individual bees frequently drifted into and remained within foreign colonies. More drifting bees were found in colonies with higher worker and brood populations and greater pollen stores. Increased intracolony aggressive interactions were not associated with a higher number of drifting bees. Drifting bees had a significantly greater number of mature eggs in their ovaries than did resident worker bees residing in colonies hosting drifters, suggesting that drifting could potentially increase the fitness of individual worker bees and may not be solely a function of disorientation and (or) nectar robbing. Taken together, our results suggest that drifting of workers into foreign colonies within greenhouses may demonstrate a predisposition to social parasitism. This selfish worker reproduction challenges our previous understanding of social insect societies as being cooperative societies.

Honeybees, in addition to the economically important hive products they produce, are valuable pollinators of both agricultural crops and natural ecosystems. Environmental changes will affect populations of honeybees through changes to available floral and nesting resources, and the distribution and virulence of parasites and pathogens. Drivers of environmental change alter the timing and abundance of flowers, as well as the amount and quality of nectar and pollen produced, thus affecting both the survival of honeybee colonies and the economic viability of beekeeping operations. Geographic distributions of Apis species and sub-species, and important bee diseases and parasites will shift as climates change, exposing honeybees to novel parasites and pathogens. The plasticity and genetic variability of Apis mellifera make it less vulnerable to climate change than more specialised species, and natural or directed selection can be used to derive bees suited to new environmental conditions; however, beekeepers must vigilantly monitor colony health, forage availability, and adaptively manage their colonies.

The effects of lineatin enantiomer ratios, lineatin release rate, and trap length on catches and the flight periods of three sympatric species of Trypodendron Stephens were investigated in field bioassays using multiple-funnel traps. The ambrosia beetle, Trypodendron betulae Swaine, was caught in similar numbers in baited traps and blank control traps, showing that this species does not respond to lineatin. Our results confirmed that Trypodendron lineatum (Olivier) is attracted only to (+)-lineatin. Trypodendron rufitarsus (Kirby) and Trypodendron retusum (LeConte) were shown to utilize lineatin and like T. lineatum were caught only when (+)-lineatin was present. These results indicate that lineatin does not govern reproductive isolation among these three species. There was no effect by (+)-lineatin release rate within the range tested. The flight of T. rufitarsus commenced earlier and ceased before the peak of the T. lineatum flight, suggesting that temporal separation may be an important component of reproductive isolation between these two species. The flight period of T. retusum was similar to that of T. lineatum. Host odours may aid in reproductive isolation of these two species. Enantiomer blend did not significantly affect sex ratio in any species; however, sex ratio differed among species, indicating that different species responded differently to the traps or that natural sex ratios differ. Catches of T. rufitarsus and T. retusum increased with trap length when pheromone release per trap was held constant and when release was held constant relative to trap length. Trap length and release rate did not affect sex ratio.

Both enantiomers of the aggregation pheromone lineatin were obtained in very high enantiomeric purity by preparative chiral liquid chromatography on microcrystalline cellulose triacetate. Catches of the striped ambrosia beetle, Trypodendron lineatum, in multiple-funnel traps baited with lineatin enatiomer ratios (plus/minus) of 100 : 0, 75 : 25, 50 : 50, 25 : 75, and 0 : 100, demonstrated that (+)-lineatin is the only active enantiomer in interior British Columbia, where two other Trypodendron species are sympatric. In additional experiments using (±)-lineatin, catches of both sexes increased significantly with trap length, either at a constant pheromone dose per trap, or a constant dose per four-funnel unit, up to 16 funnels per trap. When trap length was held constant at eight funnels, increasing the lineatin dose fourfold had no effect on trap catches.

A key characteristic of eusocial species is reproductive division of labour. Honey bee colonies typically have a single reproductive queen and thousands of sterile workers. Adult queens differ dramatically from workers in anatomy, physiology, behaviour and lifespan. Young female workers can activate their ovaries and initiate egg laying; these 'reproductive' workers differ from sterile workers in anatomy, physiology, and behaviour. These differences, however, are on a much smaller scale than those observed between the queen and worker castes. Here, we use microarrays to monitor expression patterns of several thousand genes in the brains of same-aged virgin queens, sterile workers, and reproductive workers. We found large differences in expression between queens and both worker groups (~2000 genes), and much smaller differences between sterile and reproductive workers (221 genes). The expression patterns of these 221 genes in reproductive workers are more queen-like, and may represent a core group of genes associated with reproductive physiology. Furthermore, queens and reproductive workers preferentially up-regulate genes associated with the nurse bee behavioural state, which supports the hypothesis of an evolutionary link between worker division of labour and molecular pathways related to reproduction. Finally, several functional groups of genes associated with longevity in other species are significantly up-regulated in queens. Identifying the genes that underlie the differences between queens, sterile workers, and reproductive workers will allow us to begin to characterize the molecular mechanisms underlying the evolution of social behaviour and large-scale remodelling of gene networks associated with polyphenisms.

We report results that address a long-standing controversy in honey bee biology, the identity of the queen-produced compounds that inhibit worker honey bee ovary development. As the honey bee is the only organism for which identities have been proposed for any pheromone that regulates reproduction, the resolution of its identity is of broad significance. We examined the effects of synthetic honey bee queen mandibular pheromone (QMP), four newly identified queen retinue pheromone components, and whole-queen extracts on the ovary development of caged worker bees. The newly identified compounds did not inhibit worker ovary development alone, nor did they improve the efficacy of QMP when applied in combination. QMP was as effective as queen extracts at ovary regulation. Caged workers in the QMP and queen extract treatments had better developed ovaries than did workers remaining in queenright colonies. We conclude that QMP is responsible for the ovary-regulating pheromonal capability of queens from European-derived Apis mellifera subspecies.

Epithelial ovarian cancer (OVCA) accounts for 90% of all ovarian cancers and is the most lethal gynecological cancer. The vast majorities of OVCA cases are diagnosed at advanced stage and have pelvic involvement extending to the abdomen and/or lymph nodes (stage III), or distal organs such as liver, lungs and spleen (stage IV). The five-year survival rate for late stage disease is less than 25%. Although peritoneal dissemination and correlative parenchymal metastases frequently occur, little is known about the properties of OVCA cells contributing to this malignant biology. Further understanding of OVCA metastasis may shed light on disease prevention and treatment. We previously documented a significant correlation between peritoneal OVCA tumor burden and serum S100A6 concentration in an animal model of OVCA carcinomatosis. This was further substantiated by evidence of prominent S100A6 expression in patient OVCA tissues, as well as increased S100A6 in sera from a separate late stage OVCA patient cohort. Yet, the biological function of S100A6 is not well defined. Immunofluorescent labeling (IF) of S100A6 in SKOV3 epithelial OVCA cells revealed a diffuse expression in various sub-cellular compartments, including nuclei, nuclear envelop, cytoplasm, and interestingly, phyllopodia; among which, the nuclear and phyllopodia localization were most prominent. The presence of S100A6 at phyllopodia suggested a role for S100A6 in cell motility. To test an association of S100A6 in cell mobility and tumor growth, S100A6 expression was knocked down in SKOV3 cells (stable, KD), using siRNA expressing vector pSuper (Oligoengine). These KD cells showed diminished S100A6 overall by IF, yet the subcellular distribution of S100A6 was not altered; conspicuous nuclear and phyllopodial localization remained. S100A6 KD cells exhibited decreased cell mobility in a wound healing assay in vitro. KD cells were less mobile when evaluated in a migration assay, both under unstimulated culture conditions and in response to EGF chemotaxis. To test the effect of altered S100A6 expression on tumor malignancy and growth, S100A6 KD cells expressing luciferase were compared to parental SKOV cells and SKOV cells expressing control non-targeting siRNA (control), for up to 4 weeks in vivo following intraperitoneal injection. When photon flux from luciferase activity was quantified twice a week from xenografts, growth of control and parental SKOV3 cells was comparable, in contrast to KD cells, which grew significantly slower. Necropsy at 4 weeks after cell inoculation revealed reduced or grossly unapparent tumor burden in mice receiving KD cells, as compared to controls, thereby corroborating the imaging findings. In summary, elevated S100A6 may augment ability of OVCA cells to colonize and spread in the peritoneum, contributing to malignancy of OVCA cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5296.