Queen Replacement Research Articles

The effects of queen mandibular pheromone on Nosema (Vairimorpha) ceranae infections in caged honey bees

Honey bees utilize queen mandibular pheromone (QMP) for maintaining social hierarchy and colony development. In controlled cage studies, synthetic QMP is often introduced to mimic natural conditions. However, questions have arisen about the effects of QMP on nosema disease studies. This short report identifies significant early-stage suppression effects of QMP on Nosema (Vairimorpha) ceranae infections. QMP was found to significantly lower infection rates below the reported infectious dose for 50 % infectivity (ID50) and to slow disease development in a dose-independent manner. These effects diminished at doses exceeding ID100. We recommend that studies investigating treatment effects using caged bees avoid QMP to ensure unambiguous results. Additionally, employing multiple infectious doses with shorter incubation times would be useful for evaluating other treatments that may have subtle effects. Furthermore, our findings support previous field studies suggesting that queen replacement reduces nosema disease at levels similar to treatment with fumagillin.

High Rates of Honey Bee Colony Losses and Regional Variability in Ethiopia Based on the Standardised COLOSS 2023 Survey.

The COLOSS research association has been assessing honey bee colony losses, associated risk factors and management, focusing on Western countries but with a progressive international expansion. Here, we report the first survey on the loss rates of colonies in 2022/2023 in Ethiopia using COLOSS monitoring survey tools. A face-to-face interview questionnaire survey was conducted on 64 beekeepers selected from Oromia and Tigray regions. This covered 1713 honey bee colonies distributed in 68 apiaries. The percentages of colonies lost were significantly different between Oromia (24.1%) and Tigray (66.4%) regions. Colony losses were attributed as unsolvable queen problems (8% in Oromia; 10% in Tigray), natural disaster (32%; 82%), and empty hives or dead colonies (60%; 8%). The loss rate was significantly affected by queen replacement (p < 0.0001), use of natural comb (p < 0.0001), feed supplementation (p < 0.0001), region (p < 0.0001), varroa treatment (p < 0.0001), colony splitting (p < 0.01), and merging (p < 0.01). Beekeepers in Oromia managed more colonies and implemented improved practices compared to those in Tigray. However, all beekeepers in Oromia detected at least some bees with signs of deformed wing virus, compared to 76% of beekeepers in Tigray. In conclusion, the colony loss rate was significantly different between Oromia and Tigray regions due to differences in natural disasters, management, environment and health factors.

Conflict and conflict resolution in the major transitions.

Conflict and conflict resolution have been argued to be fundamental to the major transitions in evolution. These were key events in life's history in which previously independently living individuals cooperatively formed a higher-level individual, such as a multicellular organism or eusocial colony. Conflict has its central role because, to proceed stably, the evolution of individuality in each major transition required within-individual conflict to be held in check. This review revisits the role of conflict and conflict resolution in the major transitions, addressing recent work arguing for a minor role. Inclusive fitness logic suggests that differences between the kin structures of clones and sexual families support the absence of conflict at the origin of multicellularity but, by contrast, suggest that key conflicts existed at the origin of eusociality. A principal example is conflict over replacing the founding queen (queen replacement). Following the origin of each transition, conflict remained important, because within-individual conflict potentially disrupts the attainment of maximal individuality (organismality) in the system. The conclusion is that conflict remains central to understanding the major transitions, essentially because conflict arises from differences in inclusive fitness optima while conflict resolution can help the system attain a high degree of coincidence of inclusive fitness interests.

Prevalence of Varroa destructor in Honeybee (Apis mellifera) Farms and Varroosis Control Practices in Southern Italy.

The majority of honeybee farms in industrialized countries currently base their Varroa destructor control programs on the use of acaricides in conjunction with other management practices. However, the outcomes of these practices are often misunderstood and have only been studied to a limited extent. Better yields are guaranteed by having hives with low infection levels in the spring. Therefore, it is crucial to understand which beekeeping practices can result in increased control effectiveness. This study aimed to analyze the potential effects of environmental factors and beekeeping practices on the dynamics of V. destructor population. Experimental evidence was obtained by interpolating percentage infestation data from diagnoses conducted on several apiaries in the Calabria region (Southern Italy) with data acquired from a questionnaire on pest control strategies. Data on climatic temperature during the different study periods were also taken into account. The study was conducted over two years and involved 84 Apis mellifera farms. For each apiary, the diagnosis of infestation was made on a minimum of 10 hives. In total, 840 samples of adult honeybees were analyzed in the field to determine the level of infestation. In 2020, 54.7% of the inspected apiaries tested positive for V. destructor, and in 2021, 50% tested positive, according to a study of the field test findings (taking into account a threshold of 3% in July). A significant effect of the number of treatments on parasite prevalence was found. The results showed a significant reduction in the infestation rate in apiaries that received more than two treatments each year. Furthermore, it was shown that management practices, such as drone brood removal and frequent queen replacement, have a statistically significant impact on the infestation rate. The analysis of the questionnaires revealed some critical issues. In particular, only 50% of the interviewed beekeepers diagnosed infestation on samples of adult bees, and only 69% practiced drug rotation. In conclusion, it is only possible to maintain the infestation rate at an acceptable threshold by implementing integrated pest management (IPM) programs and using good beekeeping practices (GBPs).

Epidemiology of the Microsporidium Nosema ceranae in Four Mediterranean Countries.

Simple SummaryNosema ceranae is a highly prevalent intracellular parasite of honey bees’ midgut worldwide. There is a lack of studies addressing the influence of climatic and beekeeping factors on the dynamics of its infection. A long-term study has been carried out in six apiaries in four Mediterranean countries (France, Israel, Portugal, and Spain), monitoring a total of 103 colonies. The lowest prevalence of infection was observed in mainland France, while the highest percentage of infected honey bees per colony was detected in Israel. The location and beekeeping management were shown to influence the infection levels. The percentage of infected honey bees negatively affected the colony strength in the apiaries located in Spain and mainland Portugal, whereas queen replacement had a positive effect on these same apiaries, reducing infection levels. The highest colony losses occurred in mainland France, which had the lowest levels of N. ceranae. It was followed by Spain, an apiary with high levels of N. ceranae, so no correlation between infection and mortality could be established. These results suggest that complementary studies on interactions with other pathogens and honey bee genetics are needed in order to develop management strategies for its control.Nosema ceranae is a highly prevalent intracellular parasite of honey bees’ midgut worldwide. This Microsporidium was monitored during a long-term study to evaluate the infection at apiary and intra-colony levels in six apiaries in four Mediterranean countries (France, Israel, Portugal, and Spain). Parameters on colony strength, honey production, beekeeping management, and climate were also recorded. Except for São Miguel (Azores, Portugal), all apiaries were positive for N. ceranae, with the lowest prevalence in mainland France and the highest intra-colony infection in Israel. A negative correlation between intra-colony infection and colony strength was observed in Spain and mainland Portugal. In these two apiaries, the queen replacement also influenced the infection levels. The highest colony losses occurred in mainland France and Spain, although they did not correlate with the Nosema infection levels, as parasitism was low in France and high in Spain. These results suggest that both the effects and the level of N. ceranae infection depends on location and beekeeping conditions. Further studies on host-parasite coevolution, and perhaps the interactions with other pathogens and the role of honey bee genetics, could assist in understanding the difference between nosemosis disease and infection, to develop appropriate strategies for its control.

Honey bee colony loss rates in 37 countries using the COLOSS survey for winter 2019–2020: the combined effects of operation size, migration and queen replacement

This article presents managed honey bee colony loss rates over winter 2019/20 resulting from using the standardised COLOSS questionnaire in 37 countries. Six countries were from outside Europe, including, for the first time in this series of articles, New Zealand. The 30,491 beekeepers outside New Zealand reported 4.5% of colonies with unsolvable queen problems, 11.1% of colonies dead after winter and 2.6% lost through natural disaster. This gave an overall colony winter loss rate of 18.1%, higher than in the previous year. The winter loss rates varied greatly between countries, from 7.4% to 36.5%. 3216 beekeepers from New Zealand managing 297,345 colonies reported 10.5% losses for their 2019 winter (six months earlier than for other, Northern Hemisphere, countries). We modelled the risk of loss as a dead/empty colony or from unresolvable queen problems, for all countries except New Zealand. Overall, larger beekeeping operations with more than 50 colonies experienced significantly lower losses (p < 0.001). Migration was also highly significant (p < 0.001), with lower loss rates for operations migrating their colonies in the previous season. A higher proportion of new queens reduced the risk of colony winter loss (p < 0.001), suggesting that more queen replacement is better. All three factors, operation size, migration and proportion of young queens, were also included in a multivariable main effects quasi-binomial GLM and all three remained highly significant (p < 0.001). Detailed results for each country and overall are given in a table, and a map shows relative risks of winter loss at the regional level.

Methoxyfenozide has minimal effects on replacement queens but may negatively affect sperm storage

Honey bees are incidentally exposed to pesticides such as the insect growth regulator methoxyfenozide (MEOF) during crop pollination, exposures that extend into the hive via contaminated stored food. We examined the sublethal effects of MEOF-contaminated pollen and queen cell wax on replacement queen development. MEOF-exposed colonies were largely able to produce replacement queens of similar physiological and reproductive quality as unexposed colonies. Newly established queens did not differ in their body mass, ovariole development, or protein and fatty acid contents in their ovaries and fat bodies. MEOF and control queens had similar glandular contents of queen mandibular pheromone (QMP) and queen retinue pheromone (QRP) compounds. However, MEOF queens stored less sperm in their spermathecae than control queens. Given that queen productivity is ultimately limited by sperm availability, MEOF contamination might shorten the functional lifespan of exposed queens.

Aptness of diverse queen cup materials for larval graft acceptance and queen bee emergence in managed honey bee (Apis mellifera) colonies

Artificial queen rearing has changed the beekeeping business in contrast to natural queen replacement, as it provides a newly mated queen into a bee colony, reduces the time between eggs not being laid, and increases the production of young bees in a colony. This study was conducted to investigate the larval acceptance rate grafted in queen cups made from different materials and to find out whether the various materials used for queen cups were suitable for the acceptance of grafted larvae in cell builder colonies. The evaluated materials included fresh bee wax (T1), old bee wax (T2), uncapping bee wax (T3), pure paraffin (T4), 50% paraffin + 50% old bee wax (T5), and brown plastic queen cups (T6) as a control. Results indicated that T3 was the material that most increased the larval acceptance (5.2 ± 0.37), followed by T4 (2.4 ± 0.5), T2 (2.2 ± 0.58), T5 (1.8 ± 0.37), T1 (1.6 ± 0.4), and minimum larval acceptance was in the T6 (1.0 ± 0.4) respectively during the spring season of the year 2020–2021. Similar findings were reported of larval acceptance rate during the spring season of 2021–2022. In addition, the wax material that least affected larval acceptance was the fresh comb bee wax. However, all materials used were coupled with a more larval acceptance rate than the control treatment during both spring seasons of 2020–2021 and 2021–2022. The larval acceptance rate was statistically significant in T3 as a compared to other queen cell cup materials during the both spring seasons (p = 0.001). These findings imply that using different types of bee wax for preparing queen cell cups during larvae grafting, particularly uncapping bee wax, may stimulate and promote grafted larvae acceptance during the queen rearing process.

Sociogenetic structure, reproductive strategies and queen replacement in the erratic ant (Tapinoma erraticum)

AbstractAncestral eusocial insect societies were probably headed by a single and singly mated reproductive queen. However, eusocial Hymenoptera have since secondarily evolved highly diverse mating systems and social structures, which include multiple mating by queens, the coexistence of several reproductive queens within a given colony, and queen replacement over time. Here, we report pronounced plasticity in sociogenetic structure and reproductive strategies in the erratic ant, Tapinoma erraticum. Notably, colonies can be headed by one or several queens. Nestmate queens display a varying degree of genetic relatedness; they range from being unrelated to full sisters to mothers and daughters. Queens mate with one to three males. There is again variability in the degree of relatedness. The queens and their male mate(s) are sometimes related and sometimes unrelated; the same is true for the males that had mated with nestmate queens. Finally, genotypic comparisons between age-based cohorts (i.e. adult workers vs. worker larvae) indicate that new queens, both related and unrelated, appear in established colonies. We suggest that the highly plastic reproductive systems found in T. erraticum might have opened the door evolutionarily to supercoloniality and invasiveness in the genus Tapinoma.

Nutrition induced direct fitness for workers in a primitively eusocial wasp

Eusocial insects are characterised by a reproductive caste differentiation such that egg-laying is restricted to a small number of queens. The majority of the colony members function as non-reproducing workers and gain indirect fitness by rearing the offspring of the reproductives. In primitively eusocial species, some workers can also get direct fitness by sneaking in some eggs in the presence of the queens, replacing the queens and becoming new queens, or initiating new nests. Here we aimed to understand the factors that permit some workers to gain direct fitness and alter the number of workers doing so, using the primitively eusocial wasp Ropalidia marginata. We transplanted 12 naturally occurring colonies into large laboratory cages where there was adequate space for the workers to leave their natal nests and initiate new colonies. We compared six control colonies that we provided with ad libitum food placed near the nest to six test colonies in which we hand-fed the wasps in addition to the ad libitum food. Wasps in test colonies consumed more food, showed more aggression, replaced their queens, and initiated new nests significantly more often than those in control colonies. When considering all 12 colonies, the rates of queen replacement and nest foundation were significantly positively correlated with food consumption rates. The additional nutrition gained by hand-fed wasps appears to help workers in test colonies to develop their ovaries and lay eggs, implying that they are nutritionally castrated in control colonies.

Cultural transmission of vocal dialect in the naked mole-rat.

Naked mole-rats (Heterocephalus glaber) form some of the most cooperative groups in the animal kingdom, living in multigenerational colonies under the control of a single breeding queen. Yet how they maintain this highly organized social structure is unknown. Here we show that the most common naked mole-rat vocalization, the soft chirp, is used to transmit information about group membership, creating distinctive colony dialects. Audio playback experiments demonstrate that individuals make preferential vocal responses to home colony dialects. Pups fostered in foreign colonies in early postnatal life learn the vocal dialect of their adoptive colonies, which suggests vertical transmission and flexibility of vocal signatures. Dialect integrity is partly controlled by the queen: Dialect cohesiveness decreases with queen loss and remerges only with the ascendance of a new queen.

The queen's chirp rules

Animal Culture Naked mole-rats are known for their eusocial lifestyle, living in colonies that consist of many workers and a single breeding queen. Little is known about how individuals within these colonies navigate the many interactions that must occur in such a complex cooperative group. Barker et al. show that calls emitted by individuals, in particular the common “chirp” call, convey information specific to the animal's group (see the Perspective by Buffenstein). Group differences are cultural, rather than genetic, and are related to the queen: Cross-fostered pups adopt their rearing colony's dialects, and dialects change with queen replacement. Science , this issue p. [503][1]; see also p. [461][2] [1]: /lookup/doi/10.1126/science.abc6588 [2]: /lookup/doi/10.1126/science.abf7962

Towards a better knowledge of bee farming operations to provide technical support : farm sustainability, colony and queen replacement strategies and possible consequences on the farming system (DURAPI project)

Towards a better knowledge of bee farming operations to provide technical support : farm sustainability, colony and queen replacement strategies and possible consequences on the farming system (DURAPI project)

Influence of brood pheromone on honey bee colony establishment and queen replacement

There is both anecdotal and empirical evidence to suggest that honey bee queen longevity has decreased in recent years, leading to premature supersedure and queen failure. This is particularly evident when beekeepers create new colonies from packages, where many queens are immediately rejected or replaced after only a few weeks. Relatively little is known about the mechanisms that trigger supersedure in honey bees, although previous studies have shown a strong link with open brood suggesting that brood ester pheromone (BEP) may be involved. We installed new packages into hive equipment with either no treatment (Control), exposure to BEP during package transport and for the first 10 days after installation (BEP), or one frame of open brood (Brood). We found that over the course of the 12-week experiment, Control colonies grew the least, Brood colonies started stronger but leveled off similar to Control colonies, and BEP colonies grew slowly initially but continued positive growth through the end of the experiment. Moreover, we found a highly significant effect of treatment on Outcome—whether the initial queens were immediately Rejected (within 5 weeks), Superseded (after 5 weeks), or Accepted, with Brood, BEP, and Control colonies having 86.7%, 53.3%, and 33.3% acceptance, respectively. Finally, we found that the open-brood:adult-bees ratio significantly diverged 3 weeks prior to queen replacement between accepting and replacing colonies. We suggest that while BEP alone is insufficient to deter premature supersedure, there are clear benefits to queen longevity and package-installation success when establishing new colonies with frames of young brood.

Split sex ratios and genetic relatedness in a primitively eusocial sweat bee

In eusocial Hymenoptera, queens and their helper offspring should favour different sex investment ratios. Queens should prefer a 1:1 investment ratio, as they are equally related to offspring of both sexes (r = 0.5). In contrast, helpers should favour an investment ratio of 3:1 towards the production of female brood. This conflict arises because helpers are more closely related to full sisters (r = 0.75) than brothers (r = 0.25). However, helpers should invest relatively more in male brood if relatedness asymmetry within their colony is reduced. This can occur due to queen replacement after colony orphaning, multiple paternity and the presence of unrelated alien helpers. We analysed an unprecedentedly large number of colonies (n = 109) from a UK population of Lasioglossum malachurum, an obligate eusocial sweat bee, to tease apart the effects of these factors on colony-level investment ratios. We found that multiple paternity, unrelated alien helpers and colony orphaning were all common. Queen-right colonies invested relatively more in females than did orphaned colonies, producing a split sex ratio. However, investment ratios did not change due to multiple paternity or the presence of alien helpers, reducing inclusive fitness pay-offs for helpers. Queen control may also have been important: helpers rarely laid male eggs, and investment in female brood was lower when queens were large relative to their helpers. Genetic relatedness between helpers and the brood that they rear was 0.43 in one year and 0.37 in another year, suggesting that ecological benefits, as well as relatedness benefits, are necessary for the maintenance of helping behaviour.Significance statementHow helping behaviour is maintained in eusocial species is a key topic in evolutionary biology. Colony-level sex investment ratio changes in response to relatedness asymmetries can dramatically influence inclusive fitness benefits for helpers in eusocial Hymenoptera. The extent to which helpers in primitively eusocial colonies can respond adaptively to different sources of variation in relatedness asymmetry is unclear. Using data from 109 colonies of the sweat bee Lasioglossum malachurum, we found that queen loss, but not multiple paternity or the presence of alien helpers, was correlated with colony sex investment ratios. Moreover, we quantified average helper-brood genetic relatedness to test whether it is higher than that predicted under solitary reproduction (r = 0.5). Values equal to and below r = 0.5 suggest that relatedness benefits alone cannot explain the maintenance of helping behaviour. Ecological benefits of group living and/or coercion must also contribute.

An Economic Approach to Assess the Annual Stock in Beekeeping Farms: The Honey Bee Colony Inventory Tool

For beekeepers, the beehive stock represents a fundamental means of ensuring the continuity of their activity, whether they are professionals or hobbyists. The evaluation of this asset for economic purposes requires knowledge of the rhythms and adaptations of honey bee colonies during the annual seasons. As in any breeding activity, it is necessary to establish the numerical and economic size of the species bred. Beekeepers are interested in this evaluation to monitor beehive stock. For keeping economic accounts of stock, a specific tool has been developed and proposed, here called the “Honey Bee Colony Inventory (HBCI)”. The HBCI can be used as either a final or preventive scheme to assess the numbers of honey bee colonies and nuclei, and the mortality rate, in order to calculate the monetary value. This tool allows the strength of honey bee colony stocks to be monitored, including fluctuations throughout the year, and will prove useful for determining solutions to maintain or increase how long stocks last. Data can be registered in countries such as Italy where the veterinary authorities request data on the stock owned and its variations. Due to widespread Varroa mite infestations, in recent years, beekeepers have experimented with a range of different biotechniques that have included queen caging as well as drone and total brood removal. To verify its effectiveness for gathering honey bee colony data, the HBCI was used in nine beekeeping farms applying different biotechniques to control Varroa mites: chemical treatment, total brood removal, queen caging and old queen replacement by royal cell insertion. The results are compared and discussed. Out of the nine farms, seven showed negative monetary value according to the HBCI, as expected, due to multiple factors such as the unfavorable climate trend of 2017 in the studied area. The positive aspect is that the application of this tool will allow farmers to monitor, manage and maintain their beehive stocks.

Honey Bee Queen Replacement: An Analysis of Changes in the Preferences of Polish Beekeepers through Decades.

Simple SummaryIn Poland, there are 1.68 million honey bee (Apis mellifera) colonies. We conducted a survey on honey bee (Apis mellifera) queen management. In the years 1980–2018, questionnaires were sent to beekeepers all over Poland. Questions regarding queen management throughout a single beekeeping season were asked each year: (1) the number of spring bee colonies with which the new season began, (2) the number of queens replaced throughout the season, and (3) the number of newly purchased queens. In total, 2964 questionnaires were selected. We examined the trends by decade timeslot, apiary size, and geographical location. In Poland, it is recommended to replace at least 30% of queens every year. Regardless of the decade and the size of the apiary, on average, above 90% of Polish beekeepers replace old queens with new ones in their colonies. In general, during the observed period, beekeepers replaced almost 52% of their queens, 21% of which were purchased. The involvement of purchased queens in colony management is associated with the size of the apiary, and it significantly grows with the number of colonies in the apiary. The percentage of purchased queens went up in all the voivodeships over time.We conducted a survey on honey bee (Apis mellifera) queen management. Data were collected every year from 1980 to 2018. In total, 2964 questionnaires were collected from all over Poland. We examined the trends by decade timeslot, apiary size, and geographical location. Regardless of the decade and the size of the apiary, on average, above 90% of Polish beekeepers replace old queens with new ones in their colonies. In general, during the observed period, beekeepers replaced almost 52% of their queens, 21% of which were purchased. In the last decade, there was an upward trend in the percentage of beekeepers replacing queens throughout the country. The involvement of purchased queens in colony management is associated with the size of the apiary, and it significantly grows with the number of colonies in the apiary. The percentage of purchased queens went up in all the voivodeships over time. Research and education in this area are needed in order to track the trends and further improve Polish beekeepers’ practices.

High reproductive skew in the Neotropical paper wasp Polistes lanio

Reproductive conflicts are expected in societies where nonbreeding helpers retain the ability to produce offspring. Despite potential competition from reproductively capable nestmates in social wasps, egg laying tends to be monopolised by a single or relatively few queens. Genetic studies on reproductive partitioning in Polistes paper wasps suggest high reproductive skew in the genus. Conflict is thought to be minimal due to nestmate relatedness or the possibility of inheriting a reproductive monopoly on a nest; consequently, there are inclusive fitness opportunities for nonreproductive helpers. However, most studies are limited to temperate wasp species. Given the cosmopolitan distribution of Polistes, genetic data on group conflicts are required for a broader range of tropical species to determine whether these trends apply across climatic zones. We examined female reproductive skew in the Neotropical paper wasp Polistes lanio, genotyping a selection of adults and pupae from established post-emergence nests using single-nucleotide polymorphisms (SNPs). SNP-based pedigree analyses indicate a reproductive monopoly held by a single queen, with queen replacement from natal nestmates and evidence of possible multiple mating. Relatedness between pupal offspring was high (r = 0.71). It is likely that high reproductive skew among females is a founding trait of Polistes societies, conserved among species that have spread into new environments from Indomalayan origins.

A note on genetic parameters and accuracy of estimated breeding values in honey bees

BackgroundIn honey bees, observations are usually made on colonies. The phenotype of a colony is affected by the average breeding value for the worker effect of the thousands of workers in the colony (the worker group) and by the breeding value for the queen effect of the queen of the colony. Because the worker group consists of multiple individuals, interpretation of the variance components and heritabilities of phenotypes observed on the colony and of the accuracy of selection is not straightforward. The additive genetic variance among worker groups depends on the additive genetic relationship between the drone-producing queens (DPQ) that produce the drones that mate with the queen.ResultsHere, we clarify how the relatedness between DPQ affects phenotypic variance, heritability and accuracy of the estimated breeding values of replacement queens. Second, we use simulation to investigate the effect of assumptions about the relatedness between DPQ in the base population on estimates of genetic parameters. Relatedness between DPQ in the base generation may differ considerably between populations because of their history.ConclusionsOur results show that estimates of (co)variance components and derived genetic parameters were seriously biased (25% too high or too low) when assumptions on the relationship between DPQ in the statistical analysis did not agree with reality.

Honey bees consider larval nutritional status rather than genetic relatedness when selecting larvae for emergency queen rearing

In honey bees and many other social insects, production of queens is a vital task, as colony fitness is dependent on queens. The factors considered by honey bee workers in selecting larvae to rear new queens during emergency queen rearing are poorly understood. Identifying these parameters is critical, both in an evolutionary and apicultural context. As female caste development in honey bees is dependent on larval diet (i.e. nutrition), we hypothesized that larval nutritional state is meticulously assessed and used by workers in selection of larvae for queen rearing. To test this hypothesis, we conducted a series of experiments manipulating the nutritional status of one day old larvae by depriving them of brood food for a four-hour period, and then allowing workers to choose larvae for rearing queens from nutritionally deprived and non-deprived larvae. We simultaneously investigated the role of genetic relatedness in selection of larvae for queen rearing. In all the experiments, significantly greater numbers of non-deprived larvae than deprived larvae were selected for queen rearing irrespective of genetic relatedness. Our results demonstrate that honey bees perceive the nutritional state of larvae and use that information when selecting larvae for rearing queens in the natural emergency queen replacement process.