Number Of Queens Research Articles

Determination of colony characteristics and suitability for mass production of native Bombus terrestris L. population in the Central Black Sea coast region

In this study, two successive generations of queens belonging to a native Bombus terrestris population in the Central Black Sea Region of Türkiye were reared under controlled laboratory conditions to examine its developmental characteristics and suitability for mass production. The first generation was formed by a hundred Bombus terrestris queens which were caught from native fauna in Ordu Province, Türkiye. Young queens and males produced at the end of the life cycle in different colonies of first generation were mated in laboratory conditions. Mated queens were placed in a refrigerated incubator for their two months diapause period. After the diapause period, all queens were raised under the same conditions, and second generation colonies were reared. Some characters such as first egg-laying time, the timing of switch point, the timing of competition point, and total numbers of individuals produced in colonies of the first and second generation were determined. In these characteristics, the total numbers of workers and queens were found to be statistically significant between generations (p < 0.05). According to the findings of this study, some of the features such as first egglaying time, the timing of switch point, and the number of young queens produced may be unsatisfactory for mass production.

Decoupled evolution of mating biology and social structure in Acromyrmex leaf-cutting ants

Insect societies vary greatly in their social structure, mating biology, and life history. Polygyny, the presence of multiple reproductive queens in a single colony, and polyandry, multiple mating by females, both increase the genetic variability in colonies of eusocial organisms, resulting in potential reproductive conflicts. The co-occurrence of polygyny and polyandry in a single species is rarely observed across eusocial insects, and these traits have been found to be negatively correlated in ants. Acromyrmex leaf-cutting ants are well-suited for investigating the evolution of complex mating strategies because both polygyny and polyandry co-occur in this genus. We used microsatellite markers and parentage inference in five South American Acromyrmex species to study how different selective pressures influence the evolution of polygyny and polyandry. We show that Acromyrmex species exhibit independent variation in mating biology and social structure, and polygyny and polyandry are not necessarily negatively correlated within genera. One species, Acromyrmex lobicornis, displays a significantly lower mating frequency compared to others, while another species, A. lundii, appears to have reverted to obligate monogyny. These variations appear to have a small impact on average intra-colonial relatedness, although the biological significance of such a small effect size is unclear. All species show significant reproductive skew between patrilines, but there was no significant difference in reproductive skew between any of the sampled species. We find that the evolution of social structure and mating biology appear to follow independent evolutionary trajectories in different species. Finally, we discuss the evolutionary implications that mating biology and social structure have on life history evolution in Acromyrmex leaf-cutting ants.Significance statementMany species of eusocial insects have colonies with multiple queens (polygyny), or queens mating with multiple males (polyandry). Both behaviors generate potentially beneficial genetic diversity in ant colonies as well as reproductive conflict. The co-occurrence of both polygyny and polyandry in a single species is only known from few ant species. Leaf-cutting ants have both multi-queen colonies and multiply mated queens, providing a well-suited system for studying the co-evolutionary dynamics between mating behavior and genetic diversity in colonies of eusocial insects. We used microsatellite markers to infer the socio-reproductive behavior in five South American leaf-cutter ant species. We found that variation in genetic diversity in colonies was directly associated with the mating frequencies of queens, but not with the number of queens in a colony. We suggest that multi-queen nesting and mating frequency evolve independently of one another, indicating that behavioral and ecological factors other than genetic diversity contribute to the evolution of complex mating behaviors in leaf-cutting ants.

Pollen and landscape diversity as well as wax moth depredation determine reproductive success of bumblebees in agricultural landscapes

Bumblebees are important pollinators in agricultural landscapes that are facing global declines. Main pressures include food scarcity mainly due to the reduction of semi-natural habitats (SNH) and parasite-induced vulnerability. Even though intensive agricultural landscapes are poor habitats for bumblebees, the cultivation of mass-flowering crops (MFC) can provide a high amount of floral resources and therefore can promote pollinators. In contrary to SNH, which provide a high diversity of floral resources, MFC provide only monofloral, short-term and unbalanced resources for bees. We explored the direct and indirect effects of landscape composition (proportions of MFC, SNH, urban areas), landscape diversity, diversity of pollen diets and wax moth depredation on the growth and reproductive success of bumblebee colonies. We placed 44 experimental Bombus terrestris L. colonies in 22 agricultural landscapes. The study landscapes represented gradients of the cover of SNH, urban areas and oilseed rape (OSR) and differed in the availability of the mid-season flowering MFC faba bean (Vicia faba L.). We recorded colony growth and reproductive success of the bumblebee colonies, diversity of collected pollen types and depredation by the specialized wax moth Aphomia sociella L. We found no effects of landscape composition or landscape diversity on the diversity of pollen collected by the bees. However, we found a positive effect of landscape diversity on the reproductive success of bumblebees. Moreover, pollen diversity and the availability of faba bean interacted and resulted in higher numbers of young queens in landscapes without faba bean. In addition, colonies that collected a higher pollen diversity had a reduced A. sociella depredation. Increased parasitism had a cascading negative effect on the reproductive success of bumblebees by limiting colony growth. Our study showed that high landscape diversity and diverse pollen diets can enhance the reproductive success of bumblebees. A diverse diet even mitigated depredation by wax moths. To sustain vital bumblebee populations and their pollination services, diverse and floral rich habitat types should be conserved or restored in agricultural landscapes.

Cooperation by ant queens during colony-founding perpetuates alternative forms of social organization

Key social traits, like queen number in eusocial insect colonies, have long been considered plastic, but the recent finding that colony social organization is under strict genetic control in multiple ant lineages challenges this view. This begs the question of which hardwired behavioral mechanism(s) generate alternative forms of social organization during colony development. We addressed this question in the Alpine silver ant, Formica selysi, a species with two social forms determined by a supergene. Queens that carry exclusively the M haplotype are produced by and live in monogyne (= single-queen) colonies, whereas queens that carry at least one copy of the P haplotype are produced by and live in polygyne (= multiple-queen) colonies. With extensive field samplings and laboratory experiments, we show that both types of queens successfully establish colonies independently, without being accompanied by workers, but that they do so in contrasting ways. Monogyne queens were generally intolerant of other queens and founded colonies solitarily, whereas polygyne queens were mutually attracted to each other and mainly founded colonies cooperatively. These associations persisted for months after worker emergence, suggesting that cooperative colony-founding leads to permanent multiple queening. Overall, our study shows that queens of each social form found colonies independently in the field but that P-carrying queens are more likely to cooperate, thereby contributing to perpetuate alternative forms of social organization.Significance statementUnderstanding the genetic and behavioral underpinnings of social organization is a major goal in evolutionary biology. Recent studies have shown that colony social organization is controlled by supergenes in multiple ant lineages. But the behavioral processes linking the genotype of a queen to the type of colony she will form remain largely unknown. Here, we show that in Alpine silver ants, alternative supergene genotypes are associated with different levels of social attraction and tolerance in young queens. These hardwired differences in social traits make queens carrying the P supergene haplotype more prone to cooperate and form durable associations during independent colony-founding. These findings help explain how genetic variants induce alternative forms of social organization during the ontogeny of a colony. They also illustrate how simple phenotypic differences at the individual level can result in large differences at higher levels of organization.

Linked supergenes underlie split sex ratio and social organization in an ant

Sexually reproducing organisms usually invest equally in male and female offspring. Deviations from this pattern have led researchers to new discoveries in the study of parent-offspring conflict, genomic conflict, and cooperative breeding. Some social insect species exhibit the unusual population-level pattern of split sex ratio, wherein some colonies specialize in the production of future queens and others specialize in the production of males. Theoretical work predicted that worker control of sex ratio and variation in relatedness asymmetry among colonies would cause each colony to specialize in the production of one sex. While some empirical tests supported theoretical predictions, others deviated from them, leaving many questions about how split sex ratio emerges. One factor yet to be investigated is whether colony sex ratio may be influenced by the genotypes of queens or workers. Here, we sequence the genomes of 138 Formica glacialis workers from 34 male-producing and 34 gyne-producing colonies to determine whether split sex ratio is under genetic control. We identify a supergene spanning 5.5 Mbp that is closely associated with sex allocation in this system. Strikingly, this supergene is adjacent to another supergene spanning 5 Mbp that is associated with variation in colony queen number. We identify a similar pattern in a second related species, Formica podzolica. The discovery that split sex ratio is determined, at least in part, by a supergene in two species opens future research on the evolutionary drivers of split sex ratio.

Development of an Application for Interactive Research and Analysis of the N-Queens Problem

This paper presents a study on the N-Queens Problem. Different approaches to its solution discussed in the scientific literature are analyzed. The implementation of an algorithm based on the backtracking method is also presented. The algorithm is optimized to find solutions in a specific subset of configurations among all possible ones. With this approach, the computational complexity of the algorithm is reduced from exponential to quadratic. In this way, the algorithm finds all possible solutions in a shorter time: fundamental and their symmetrical equivalents. The methodology for conducting the experiments is presented. The purpose of the study, the tasks to be performed, and the conditions for conducting the experiments are presented as well. In connection with the research, an application that implements the presented algorithm has been developed. This application generated all the results obtained in this study. The experimental results show that with a linear increase in the number of queens (equivalent to a quadratic increase in the number of fields on the board, the number of recursive calls made by the algorithm increases exponentially. Similarly, the number of possible solutions, as well as the execution time of the algorithm (in the different modes of the application - internal, interactive, and combined), also increases exponentially. However, the algorithm's execution time in the internal mode is significantly shorter than in the other two modes - interactive and combined. The future guidelines for the study are presented.

The maintenance of polymorphism in an ancient social supergene.

Supergenes, regions of the genome with suppressed recombination between sets of functional mutations, contribute to the evolution of complex phenotypes in diverse systems. Excluding sex chromosomes, most supergenes discovered so far appear to be young, being found in one species or a few closely related species. Here, we investigate how a chromosome harbouring an ancient supergene has evolved over about 30million years (Ma). The Formica supergene underlies variation in colony queen number in at least five species. We expand previous analyses of sequence divergence on this chromosome to encompass about 90species spanning the Formica phylogeny. Within the nonrecombining region, the gene knockout contains 22single nucleotide polymorphisms (SNPs) that are consistently differentiated between two alternative supergene haplotypes in divergent European Formica species, and we show that these same SNPs are present in most Formica clades. In these clades, including an early diverging Nearctic Formica clade, individuals with alternative genotypes at knockout also have higher differentiation in other portions of this chromosome. We identify hotspots of SNPs along this chromosome that are present in multiple Formica clades to detect genes that may have contributed to the emergence and maintenance of the genetic polymorphism. Finally, we infer three gene duplications on one haplotype, based on apparent heterozygosity within these genes in the genomes of haploid males. This study strengthens the evidence that this supergene originated early in the evolution of Formica and that just a few loci in this large region of suppressed recombination retain strongly differentiated alleles across contemporary Formica lineages.

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.

Colony structure, population structure, and sharing of foraging trees in the ant Myrmecia nigriceps (Hymenoptera: Formicidae)

Foraging ants face many dangers in search of food and often need to defend their prey to ensure the colony’s survival, although ants may also follow a peaceful foraging strategy. A non-aggressive approach is seen in the Australian bull ant Myrmecia nigriceps, in that workers of neighboring nests sometimes share foraging trees. In this study, we observed 31 nests at Mount Majura Nature Reserve in Canberra (Australia), 12 of which shared a foraging tree with at least one other nest in at least one of three nights. We genotyped 360 individuals at five published microsatellite loci and further established a set of nine polymorphic loci for M. nigriceps. Our results revealed a significant correlation between tree sharing and geographical distance between nests. We found no correlation between internest relatedness and tree sharing, geographical distance between nests and internest relatedness, and intranest relatedness and tree sharing. We further investigated the colony structure of M. nigriceps. All colonies were monodomous; the number of queens per colony ranged from one to two, and the number of fathers from one to three. No instances of worker drifting were found in this study.

Foraging for the fungus: why do Acromyrmex subterraneus (Formicidae) queens need to forage during the nest foundation phase?

1. Semiclaustral ant queens must pay the price of foraging to guarantee their survival and also that of their brood through the nest foundation phase. For leaf‐cutting ant species, the challenge is even greater, as they also need to cultivate their symbiont fungus.2. We hypothesised that suppressing foraging activity could reflect in larger offspring and higher survival, as queens would be entirely dedicated to rearing the brood and initial fungus.3. By providing easy access to leaves or completely denying it, we evaluated how foraging runs interfere in Acromyrmex subterraneus queens' survival, productivity, and variation of body mass components.4. Three foraging conditions were simulated: Starved – no leaves, Spoiled – leaves inside the nest chamber, and Walker – leaves 3 m away from the nest chamber. We registered the number of dead queens, offspring, weight of the fungus garden, fresh and lean dry mass of the queens, as well as their lipid and water contents.5. Survival of Starved queens, which did not oviposit, was lower than that of Spoiled and Walker queens, although weight loss, water content, and lean dry mass were similar. While lipid content reduction was similar for Spoiled and Walker queens, the former had more larvae and pupae, and a heavier fungus garden than the latter, suggesting a greater rearing effort of Spoiled queens toward them both.6. The simulated foraging conditions provided novel data for a semiclaustral leaf‐cutting ant species that evidences that fungus garden cultivation is definitively the main driving force for the colony founding success.

Queens Independence Separation on Rectangular Chessboards

The famous eight queens problem with non-attacking queens placement on an 8 x 8 chessboard was first posed in the year 1848. The queens separation problem is the legal placement of the fewest number of pawns with the maximum number of independent queens placed on an N x N board which results in a separated board. Here a legal placement is defined as the separation of attacking queens by pawns. Using this concept, the current study extends the queens separation problem onto the rectangular board M x N, (M&lt;N), to result in a separated board with the maximum number of independent queens. The research work here first describes the M+k queens separation with k=1 pawn and continue to find for any k. Then it focuses on finding the symmetric solutions of the M+k queens separation with k pawns.

Social insect colonies are more likely to accept unrelated queens when they come with workers

Abstract Relatedness underlies the evolution of reproductive altruism, yet eusocial insect colonies occasionally accept unrelated reproductive queens. Why would workers living in colonies with related queens accept unrelated ones, when they do not gain indirect fitness through their reproduction? To understand this seemingly paradox, we investigated whether acceptance of unrelated queens by workers is an incidental phenomenon resulting from failure to recognize non-nestmate queens, or whether it is adaptively favored in contexts where cooperation is preferable to rejection. Our study system is the socially polymorphic Alpine silver ant, Formica selysi. Within populations, some colonies have a single queen, and others have multiple, sometimes unrelated, breeding queens. Social organization is determined by a supergene with two haplotypes. In a first experiment, we investigated whether the number of reproductive queens living in colonies affects the ability of workers at rejecting alien queens, as multiple matrilines within colonies could increase colony odor diversity and reduce workers’ recognition abilities. As workers rejected all alien queens, independently of the number of queens heading their colony, we then investigated whether their acceptance is flexible and favored in specific conditions. We found that workers frequently accepted alien queens when these queens came with a workforce. Our results show that workers flexibly adjust their acceptance of alien queens according to the situation. We discuss how this conditional acceptance of unrelated queens may be adaptive by providing benefits through increased colony size and/or genetic diversity, and by avoiding rejection costs linked to fighting.

The Chess Board Independent Domatic Number Of Queen Graph

The independent domatic queen number of a graph Q n is the maximum number of pairwise disjoint minimum independent queen dominating sets of P n and it is denoted by i d(Q n ) while maximum independent domatic queen number is denoted by I d(Q n ). We discuss about in this paper the independent (maximum independent) domatic number of queen graph Q n on n × n chess board.

Oocyte resorption in termite queens: Seasonal dynamics and controlling factors

Female insects can resorb their oocytes that could not be oviposited. Oocyte resorption is proposed to be an adaptive mechanism to optimize fitness in hostile environments, recouping resources that might otherwise be lost. Social insects have developed reproductive division of labor, wherein a small number of queens are devoted to egg production. Matured queens are highly specialized in reproduction and are largely dependent on nestmate workers for their nourishment. Therefore, oocyte resorption in the queens should be influenced by social factors such as the amount of available workforce, as well as external and abiotic factors. In this study, we investigated the seasonal dynamics and regulation factors of oocyte resorption in actively reproducing termite queens. We continuously collected the field-nests of the subterranean termite Reticulitermes speratus and demonstrated that queens frequently resorbed their oocytes in late summer, even though it is one of the most productive seasons in this species. On the other hand, our laboratory experiment showed that oocyte resorption itself was strongly induced regardless of the season. We also found that the rate of oocyte resorption was influenced by colony size (the number of attending workers). These results suggest that termite queens seasonally resorb their oocytes, yet oocyte resorption itself is regulated by social factors rather than by seasonal factors. Our study provides a unique insight into the regulation of reproduction in social insects.

Solution to n-Queens Problem: Heuristic Approach

Finding non-backtracking solutions to n-queens problems, has been very challenging. Several researchers have attempting to find non-backtracking solutions to n-queens problem, although, some of them recorded huge successes in their researches, but none of them have attempting using the implications of even and odd n-queens, to find solutions to the n-queens problem. In this paper, an attempt was made to extract patterns created from even-numbered n-queens and odd-numbered n-queens placements on the chessboard. The research started from experimenting the placements of non-attacking queens for 4-queens, 16-queens, 32-queens and n-queens. After the experimenting with the placements of different number of queens on the chessboard, it was revealed that even-numbered and odd-numbered queens, have pattern of placement of queens. The results of this research work show how to start and finish placements of queens on the chessboard, depending on whether the n number of queens are either even or odd, using heuristic approach.

Social organization and the evolution of life-history traits in two queen morphs of the ant Temnothorax rugatulus.

During the evolution of social insects, not only did life-history traits diverge, with queens becoming highly fecund and long lived compared with their sterile workers, but also individual traits lost their importance compared with colony-level traits. In solitary animals, fecundity is largely influenced by female size, whereas in eusocial insects, colony size and queen number can affect the egg-laying rate. Here, we focused on the ant Temnothorax rugatulus, which exhibits two queen morphs varying in size and reproductive strategy, correlating with their colony's social organization. We experimentally tested the influence of social structure, colony and body size on queen fecundity and investigated links between body size, metabolic rate and survival under paraquat-induced oxidative stress. To gain insight into the molecular physiology underlying the alternative reproductive strategies, we analysed fat body transcriptomes. Per-queen egg production was lower in polygynous colonies when fecundity was limited by worker care. Colony size was a determinant of fecundity rather than body size or queen number, highlighting the super-organismal properties of these societies. The smaller microgynes were more frequently fed by workers and exhibited an increase in metabolic activity, yet they were similarly resistant to oxidative stress. Small queens differentially expressed metabolic genes in the fat body, indicating that shifts in molecular physiology and resource availability allow microgyne queens to compensate for their small size with a more active metabolism without paying increased mortality costs. We provide novel insights into how life-history traits and their associations were modified during social evolution and adapted to queen reproductive strategies.

The plasticity of lifespan in social insects.

One of the central questions of ageing research is why lifespans of organisms differ so tremendously among related taxa and, even more surprising, among members of the same species. Social insects provide a particularly pronounced example for this. Here, we review previously published information on lifespan plasticity in social insects and provide new data on worker lifespan in the ant Cardiocondyla obscurior, which because of its relatively short lifespan is a convenient model to study ageing. We show that individual lifespan may vary within species with several reproductive and social traits, such as egg-laying rate, queen number, task, colony size and colony composition. For example, in Cardiocondyla, highly fecund queens live longer than reproductively less active queens, and workers tend to live longer when transferred into a novel social environment or, as we show with new data, into small colonies. We hypothesize that this plasticity of lifespan serves to maximize the reproductive output of the colony as a whole and thus the inclusive fitness of all individuals. The underlying mechanisms that link the social environment or reproductive status with lifespan are currently unresolved. Several studies in honeybees and ants indicate an involvement of nutrient-sensing pathways, but the details appear to differ among species. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'

Influence of the Number of Queens on Nest Establishment: Native and Invasive Ant Species.

Simple SummaryNest establishment is a critical stage of the ant life cycle because it determines the chances of colony success. Here, we study the effect of different numbers of queens (i.e., one or six) on the position of queens and workers inside and outside the artificial nests of an invasive (Linepithema humile) and Mediterranean native (Tapinoma nigerrimum) species. Our results suggest that queens in nests with six queens entered the nest faster than single queens. Similarly, during nest establishment, workers in nests with six queens entered the nest faster, with this effect being more pronounced for the native species. Once nests were established, fewer workers were engaged in outside-nest tasks in nests with six queens. This was especially true for workers of the native species engaged in patrolling. These results suggest that the number of queens can influence both queen and worker behavior, and that invasive and native species have different responses.As a critical stage in the life cycle of ant colonies, nest establishment depends on external and internal factors. This study investigates the effect of the number of queens on queen and worker behavior during nest establishment in invasive Argentine ants (Linepitema humile) and native Mediterranean Tapinoma nigerrimum. We set up experimental colonies with the same number of workers but with one or six queens. At different time points, we recorded the positions of queens and workers inside and outside the nest. Our results highlight the influence of the number of queens on the position of queens and workers with between-species differences. Queens of both species entered the nests more quickly when there were six queens. During nest establishment, more workers were inside nests with six queens for both species, with this effect being greater for T. nigerrimum. Once nests were established, fewer workers of both species were engaged in nest maintenance and feeding in nests with six queens; T. nigerrimum had fewer workers engaged in patrolling. These results suggest that the number of queens is a key factor driving queen and worker behavior during and after nest establishment with different species responses.

Net benefits of a mutualism: Influence of the quality of extrafloral nectar on the colony fitness of a mutualistic ant

AbstractAimExtrafloral nectar, a carbohydrate‐rich liquid, is the main plant‐based resource offered in exchange for ant protection. The positive results of this protection provided by ants are widely studied and supported; however, studies showing the benefits that ants and their colonies have from the resources offered by plants such as extrafloral nectar are scarce. Here, we evaluated how extrafloral nectar and artificial food resources with different nutrient concentration benefit short‐ and long‐term Camponotus crassus colony fitness (number and weight of individuals) and survival.MethodsWe conducted two sets of experiments: (1) in the field we attached artificial ant nests to plants with clogged and unclogged extrafloral nectaries; and (2) in the laboratory we offered artificial food resources with different carbohydrate–protein ratios to ant colonies. With these experiments, we evaluated the number and weight of queens, adult workers, pupae, larvae, and eggs, as well as the survival probability of the colonies.ResultsIn the first experiment, the short‐term provision of extrafloral nectar resulted in a larger number and weight of individuals with access to this resource. In the second experiment, regardless of time, the supply of more concentrated carbohydrate and nitrogen food increased ant colony fitness and survival. Conclusion: We provided new evidence that extrafloral nectar significantly benefits ant colonies. Our results corroborate the assertion that these relationships are reciprocally beneficial.

Art Gallery Problem with Rook and Queen Vision

How many chess rooks or queens does it take to guard all squares of a given polyomino, the union of square tiles from a square grid? This question is a version of the art gallery problem in which the guards can “see” whichever squares the rook or queen attacks. We show that lfloor {frac{n}{2}} rfloor rooks or lfloor {frac{n}{3}} rfloor queens are sufficient and sometimes necessary to guard a polyomino with n tiles. We then prove that finding the minimum number of rooks or queens needed to guard a polyomino is NP-hard. These results also apply to d-dimensional rooks and queens on d-dimensional polycubes. Finally, we use bipartite matching theorems to describe sets of non-attacking rooks on polyominoes.