Colony Population Research Articles

Stray Cat Colonies Lacking Health Surveillance and Management Pose Infection Pressure for Aelurostrongylus abstrusus on Sympatric Domestic and Wild Felids

The prevalence of respiratory nematodes in domestic animals has increased in Europe in recent decades. Aelurostrongylus abstrusus is the most common parasitic nematode of the respiratory tract in felids, and an increase in its prevalence has been suggested in different European countries including Spain, with values ranging from 0% to 30%. The Baermann technique was used to detect metastrongyloid larvae in 93 faecal samples from cats living in colonies (n = 29), cats living in shelters (n = 30), and owned cats (n = 34). Eleven cats (11.2%) were infected by A. abstrusus, the only species detected. The prevalence in colony cats (34.5%, 10/29) was significantly higher than the 3.3% (1/30) prevalence in shelter cats. Conversely, A. abstrusus was not found in any of the owned cats. The results can be representative of other areas in the Mediterranean basin, indicating the need to improve feline management and knowledge about the distribution and abundance of this parasite through geographically wider studies in Spain. This study emphasizes the importance of deworming domestic cats, especially those from street and rural environments or with outdoor lifestyles. The results also urge the need for population and health control of street cat colonies. Incorporating a deworming protocol in the current trapping–neutering–release campaigns for cat population control will be essential.

A comprehensive epidemiological approach documenting an outbreak of H5N1 highly pathogenic avian influenza virus clade 2.3.4.4b among gulls, terns, and harbor seals in the Northeastern Pacific.

Highly pathogenic avian influenza viruses (HPAIV) H5N1 clade 2.3.4.4b continue to have unprecedented global impacts on wild birds and mammals, with especially significant mortality observed in colonial surface-nesting seabirds and in some marine mammal species. In July of 2023 H5N1 HPAIV 2.3.4.4b was detected in Caspian terns nesting on Rat Island, Washington USA. An estimated 1,800-1,900 adult terns populated the breeding colony, based on aerial photographs taken at the start of the outbreak. On a near-weekly basis throughout July and August, we counted and removed carcasses, euthanized moribund birds, and collected swab and tissue samples for diagnostic testing and next-generation sequencing. We directly counted 1,101 dead Caspian tern adults and 520 dead chicks, indicating a minimum 56% loss of the adult colony population and potential impacts to reproductive success. Combining the observed mortality on Rat Island with HPAI-related Caspian tern deaths recorded elsewhere in Washington and Oregon, we estimate that 10-14% of the Pacific Flyway population was lost in the summer of 2023. Comparatively few adult Glaucous-winged gulls (hybrids) nesting on Rat Island died (~3% of the local population), although gull chick mortality was high. Sixteen harbor seals in the immediate or nearby area stranded during the outbreak, and H5N1 HPAIV was detected in brain and/or lung tissue of five seals. These cases are the first known detections of HPAIV in a marine mammal on the Pacific coast of North America. Phylogenetic analyses support the occurrence of at least three independent avian-mammalian virus spillover events (tern or gull to harbor seal). Whole genome sequencing indicated that H5N1 HPAIV may have been introduced to Washington from Caspian terns in Oregon. Ongoing monitoring and surveillance for H5N1 HPAIV in the marine environment is necessary to understand the epidemiology of this virus, assess conservation impacts to susceptible species, and provide support for data-driven management and response actions.

The life history of harvester ant colonies.

A long-term study of a population of desert seed-eating ant colonies of the red harvester ant, Pogonomyrmex barbatus, in New Mexico, USA, shows that a colony can live for 20-30 years-the lifespan of its founding queen. A colony's collective behaviour shifts in the course of its life history. These changes, generated by social interactions within the colony, adjust the behaviour of the colony as it grows older and larger, in response to its environment and neighbouring colonies. A worker lives only a year and performs different tasks as it ages, in response to interactions with other workers and the local surroundings. A colony's behaviour changes-becoming more stable and consistent-as the colony grows older, with more ants to participate in social interactions. A neighbourhood of colonies, often of similar age, grows old together. Colonies differ in how they regulate foraging behaviour collectively to manage water loss. These differences influence how foragers of neighbouring colonies partition foraging area. In a harsh but stable environment, the gradual behavioural shifts over a colony's lifespan allow it to adjust to slow changes in the composition of its neighbourhood and in environmental conditions.This article is part of the discussion meeting issue 'Understanding age and society using natural populations'.

Leveraging transcriptome sequence read archives for virus detection in wild and colony populations of triatomines (Hemiptera: Reduviidae: Triatominae)

Triatomines are infamous as vectors of the parasite Trypanosoma cruzi, the causative agent of Chagas disease. However, climate-driven range expansion and urbanization adaptation of triatomine populations, coupled with their highly diverse feeding strategies (vertebrate haematophagy, kleptohaematophagy, and coprophagy), and has elevated interest in triatomines as potential arboviral vectors. Information on the triatomine virome is scant, with prior records including only eight insect-specific viruses: Triatoma virus (TrV) and Rhodnius prolixus viruses 1–7. Here, we leverage publicly available transcriptome datasets to assess viral diversity in 122 wild and colony kissing bugs representing eight species from six countries. In total, six viruses were detected (including Rhodnius prolixus viruses 4–6), and TrV was detected in almost half of all screened triatomines. This is the first report of TrV in Triatoma brasiliensis and in members of the genus Mepraia (M. gajardoi, M. spinolai, and M. parapatrica), and this effort has vastly expanded the publicly available genomic resources of TrV, adding 39 genome sequences to the single genome sequence currently available in the GenBank database. Furthermore, two additional viruses—Meccus longipennis virus 1 and Drosophila melanogaster Nora virus—are herein reported for the first time from kissing bugs. Meccus longipennis virus 1 was detected in Triatoma infestans from Argentina, Brazil, Chile, and Peru, and Drosophila melanogaster Nora virus was found in T. infestans from Argentina. Our results illustrate the advantage and utility of low-cost transcriptome data mining for the discovery of known and novel arboviruses in triatomines and other potential insect vectors.

Pre-extension Demonstration and Evaluation of Top Feeder Honeybee Feeding Technology at Wolmera Woreda, Oromia Region

To maintain optimum honeybee colony population during dearth of floral resources, feeding of honeybee colonies with supplementary feeds is important. This research activity is conducted with the main objectives to evaluate and demonstrate top feeder technology under farmers’ management and create awareness on the importance of the technology. As to the method, selection of demonstration sites and farmers was purposive due to the reason that the evaluation of the technology requires modern box hive and experience on this hive. Two demonstration sites at two Village Administrations selected and Farmers research groups were used for technology evaluation. One FRG which contain 10-15 beekeepers strengthened at each demonstration site and group apiaries of FRG members used as centers of learning and technology evaluation. At each sites, farmers, development agents and experts trained and experimental colonies established. Honeybee colony follow up and technology evaluation activities undertaken in partnership with these FRG members, development agents and experts. As to the result, by using top feeder, the beekeeper can feed many colonies in short period of time. The average time taken to feed one honeybee colony using top feeder was only 55.85 seconds where as it was 107.26 seconds using plastic bucket under farmer’s management. Moreover, feeding using top feeder also reduced honeybee colonies disturbance during time of feeding. In conclusion, technologies like top feeder that saves beekeepers time and also reduce disturbances of honeybee colony are critical for our beekeepers. Therefore, it is suggested to further pre scale up the technology in other areas

Right-Wing Extremism and Terrorism with Roots In (Neo)Colonization

Many Western countries and their citizens react to right-wing extremism as if it were a coup against the democratic rule of law. This article explores the reasons for this. It does so as follows. First, by outlining what is meant by right-wing extremism. But also by addressing the theories that right-wing extremists use to support their ideology of destruction and subversion. Second, this article examines the numbers of right-wing extremists in Europe and in the European Parliament. In this European Parliament, right-wing extremists have become a party that cannot be ignored. In fact, even Hungary's far-right prime minister, Viktor Orbán, is now taking over the EU presidency for six months. Third, this article addresses the threat of right-wing extremist terrorism. This is done on the basis of a number of states that oppress citizens in their own and neighboring countries, invoking the adage: "one's own country and one's own people come first. Russia and Israel are the two countries most often mentioned. Attention is also paid to individual Western far-right terrorists who target Muslims, sub-Saharan Africans, and the "leftist" elite. Their far-right ideology is strongly discussed in this article. Fourth, we test the hypothesis that the ancestors of right-wing extremists had their first experiences with dismissing the other as inferior and inferior in the former Western colonies. In doing so, we do not close our eyes to neocolonial behavior. The elaboration of this hypothesis is that they treat immigrants, refugees and expatriates in the same way as their ancestors did in the former colonies on the African, Asian and American continents. Isolation, exploitation, enslavement, plundering, looting and torture, as well as genocidal wars, were the order of the day. Epigenetics shows that the distinction between genotype and phenotype is based on genotypic changes due to phenotypic conditions. In short, poor living conditions due to institutional racism, stress, pollution, overcrowding and deprivation lead to negative genetic changes. The victims of epigenetic transformation are mainly immigrants, refugees and expatriates in Western countries and the original populations in the former Western colonies. Finally, this article shows that it is a significant number of immigrants, refugees, and expatriates who are told by right-wing extremists that they are not welcome in their continent, country, province, neighborhood, and street. With God's evidence, this article shows that human beings were not created to fight each other with fire and sword.

Sacbrood viruses and select Lake Sinai virus variants dominated Apis mellifera colonies symptomatic for European foulbrood.

European foulbrood (EFB) is a prevalent disease in the European honey bee (Apis mellifera) in the United States, which can lead to colony decline and collapse. The bacterial components of EFB are well-studied, but the diversity of viral infections within infected colonies has not been explored. In this study, we use meta-transcriptomics sequencing of 12 honey bee hives, symptomatic (+, n = 6) and asymptomatic (-, n = 6) for EFB, to investigate viral infection associated with the disease. We assembled 41 viral genomes, belonging to three families (Iflaviridae, Dicistroviridae, and Sinhaliviridae), all previously reported in honey bees, including Lake Sinai virus, deformed wing virus, sacbrood virus, Black queen cell virus, and Israeli acute paralysis virus. In colonies with severe EFB, we observed a higher occurrence of viral genomes (34 genomes) in contrast to fewer recovered from healthy colonies (seven genomes) and a complete absence of Dicistroviridae genomes.We observed specific Lake Sinai virus clades associated exclusively with EFB + or EFB - colonies, in addition to EFB-afflicted colonies that exhibited an increase in relative abundance of sacbrood viruses. Multivariate analyses highlighted that a combination of site and EFB disease status influenced RNA virome composition, while EFB status alone did not significantly impact it, presenting a challenge for comparisons between colonies kept in different yards. These findings contribute to the understanding of viral dynamics in honey bee colonies compromised by EFB and underscore the need for future investigations to consider viral composition when investigating EFB.IMPORTANCEThis study on the viromes of honey bee colonies affected by European foulbrood (EFB) sheds light on the dynamics of viral populations in bee colonies in the context of a prevalent bacterial brood disease. The identification of distinct Lake Sinai virus and sacbrood virus clades associated with colonies affected by severe EFB suggests a potential connection between viral composition and disease status, emphasizing the need for further investigation into the role of viruses during EFB infection. The observed increase in sacbrood viruses during EFB infection suggests a potential viral dysbiosis, with potential implications for honey bee brood health. These findings contribute valuable insights related to beekeeping practices, offering a foundation for future research aimed at understanding and mitigating the impact of bacterial and viral infection in commercial honey bee operations and the management of EFB.

Colonial Ascidian Populations at Inshore Coral Reefs of Norfolk Island, South Pacific

Subtropical coral reefs such as the lagoonal reefs of Norfolk Island in the remote South Pacific are vastly understudied, with many benthic species unrecorded in the scientific literature. Here we report on ascidian populations from 2021 to 2023 at Norfolk Islands inshore reefs. Quantitative assessments spanning that period were conducted to assess ascidian presence, cover, and benthic interactions. We show ascidian cover remained persistently low and stable across the lagoonal reefs during the study period. We find adjacent reef site, Cemetery Bay showed variation in ascidian cover over time, where we measure a 3.2-fold increase in cover over 2 years. Ascidians were associated primarily with sand and sediment substrates at all reef locations. Recorded interactions between hard corals and ascidians were low. This study provides valuable insights into the population dynamics of ascidians within subtropical reef ecosystems. Ongoing ascidian population monitoring can provide a comprehensive understanding of ascidian dynamics whilst also providing insight of theimpact of anthropogenic stressors on benthic communities. Together, this can aid in informing management and conservation strategies for subtropical reefs.

Varroa destructor control strategies in Apis mellifera colonies: a meta-analysis and systematic revision on natural compounds efficacy

The parasitic mite Varroa destructor is a sanitary threat to beekeeping and causes significant losses in honey bee colonies. Thus, different acaricides have been applied as a strategy to control this disease. In the context of Integrated Pest Management, acaricides based on natural compounds, such as organic acids and essentials oils, are chosen by beekeepers to minimize negative effects on colonies and hive products. Considering the variety of natural active ingredients reported to have varroacidal activity and their different application systems, the aim of this work was to synthesize and quantify scientific knowledge on the acaricide performance of natural compounds to control V. destructor populations in Apis mellifera colonies. A systematic revision and a meta-analysis on the percentage of efficacy published for these formulations were conducted by selecting articles published between 2002 and 2022. According to our results, most publications investigated the efficacy of natural compounds in temperate climates and in European honey bee colonies since Varroa control is practically compulsory under these conditions. Thymol (THY) showed higher estimated efficacy compared to oxalic and formic acids (FA) and other essential oils (EOs). Variable efficacies were found in colonies treated with the natural compounds considered in this study according to different doses and application methods. The high between-study heterogeneity found in this revision might be explained by several factors, including the number of colonies and intra-apiary variation. As such, standardized protocols for field assays are key to improving efficacy evaluation. In addition, methodological implications are discussed.

Formation of Virginian opposition to the Stamp Act of 1765

The article analyzes the reaction of the House of Burgesses of Virginia and the colonial public to the adoption of the Stamp Act of 1765. The subject of the study is specific measures of Virginian legislators that were aimed at forming protest sentiments towards the new tax. The object of the study is the political background of the adoption of the stamp tax and its connection with the desire of the British authorities to cover the national debt at the expense of new sources. Special attention is paid to the study of specific initiatives of Virginian legislators who managed to turn the campaign for the repeal of the Stamp Act into a protest of the broad masses of the colony's population. Special role is given to the consideration of some documentary sources that help to form a comprehensive picture of the development of opposition sentiments in Virginia in 1765. The study reflects the reaction of the Virginia Legislative Assembly to the adoption of the Stamp Act of 1765, which showed the presence of a certain parity between radically minded members of the assembly and supporters of a moderate and balanced reaction to changes in tax legislation. An important circumstance reflected in the study is the reaction to the adoption of the Stamp Act of 1765 by the wealthiest families of Virginia, which demonstrated their real control not only over the opposition, but also over the entire political process of the province as a whole.

Remote sensing of emperor penguin abundance and breeding success

Emperor penguins (Aptenodytes forsteri) are under increasing environmental pressure. Monitoring colony size and population trends of this Antarctic seabird relies primarily on satellite imagery recorded near the end of the breeding season, when light conditions levels are sufficient to capture images, but colony occupancy is highly variable. To correct population estimates for this variability, we develop a phenological model that can predict the number of breeding pairs and fledging chicks, as well as key phenological events such as arrival, hatching and foraging times, from as few as six data points from a single season. The ability to extrapolate occupancy from sparse data makes the model particularly useful for monitoring remotely sensed animal colonies where ground-based population estimates are rare or unavailable.

АДАПТИВНИЙ ПІДХІД ДО ВИЗНАЧЕННЯ СТАНУ ВУЛИКА ЗА ДОПОМОГОЮ НЕЙРОННИХ МЕРЕЖ ТА АНАЛІЗУ АУДІО

Problem statement. Monitoring the queen bee is crucial for the health and produc-tivity of a bee colony. The queen plays a vital role in reproduction and maintaining the colony's population. Utilizing neural networks, such as CNNs along with sound analysis, can be a valuable tool for monitoring queen bees and assessing their behavior and health within the hive. Purpose. Finding the best way to preprocess audio data and review it is an important task that, if performed well, will help to track the bee hive population and its health state in general. Related work. With the development of deep learning, several studies were done on their application along with sound analysis in bee hive state identi-fication, such as swarming or bee queen detection. Materials and methods. A public la-beled dataset “To bee or not to bee” with bee hive sounds was used for training. It was split by source and then cut into pieces 4 seconds each. Then, CNN models were trained using different audio feature extraction methods, such as MFCCs and STFT. First, it was trained on a first audio set, and then trained models were utilized to analyze their per-formance on the evaluation set of the second audio set. Results and discussion. According to the training and evaluation results, MFCCs-based models have given constant good results, and when used on a limited audio dataset, pre-trained model showed better per-formance than the one trained from zero. Conclusions. The experiment showed that MFCCs is a better performant feature extraction method for a task of the bee hive sounds analysis and bee queen presence identification. Also, even though training a model on a full audio set results in better performance, pre-trained models can detect a bee queen absence in another hive even after an additional training on a limited audio dataset.

AN ADAPTIVE APPROACH TO THE BEE HIVE STATE IDENTIFICATION USING NEURAL NETWORKS AND AUDIO ANALYSIS

Monitoring the queen bee is crucial for the health and productivity of a bee colony. The queen plays a vital role in reproduction and maintaining the colony's population. Utilizing neural networks, such as CNNs along with sound analysis, can be a valuable tool for monitoring queen bees and assessing their behavior and health within the hive. Finding the best way to preprocess audio data and review it is an important task that, if performed well, will help to track the bee hive population and its health state in general. According to the training and evaluation results, MFCCs-based models have given constant good results, and when used on a limited audio dataset, pre-trained model showed better performance than the one trained from zero.

Warmer autumns and winters could reduce honey bee overwintering survival with potential risks for pollination services

Honey bees and other pollinators are critical for food production and nutritional security but face multiple survival challenges. The effect of climate change on honey bee colony losses is only recently being explored. While correlations between higher winter temperatures and greater colony losses have been noted, the impacts of warmer autumn and winter temperatures on colony population dynamics and age structure as an underlying cause of reduced colony survival have not been examined. Focusing on the Pacific Northwest US, our objectives were to (a) quantify the effect of warmer autumns and winters on honey bee foraging activity, the age structure of the overwintering cluster, and spring colony losses, and (b) evaluate indoor cold storage as a management strategy to mitigate the negative impacts of climate change. We perform simulations using the VARROAPOP population dynamics model driven by future climate projections to address these objectives. Results indicate that expanding geographic areas will have warmer autumns and winters extending honey bee flight times. Our simulations support the hypothesis that late-season flight alters the overwintering colony age structure, skews the population towards older bees, and leads to greater risks of colony failure in the spring. Management intervention by moving colonies to cold storage facilities for overwintering has the potential to reduce honey bee colony losses. However, critical gaps remain in how to optimize winter management strategies to improve the survival of overwintering colonies in different locations and conditions. It is imperative that we bridge the gaps to sustain honey bees and the beekeeping industry and ensure food and nutritional security.

Beyond the dominant narratives: Identifying Indigenous and African individuals in Quebec St-Lawrence Valley colonial cemeteries by three-dimensional morphometrical analysis of the temporal bone

In Quebec, written accounts of free or enslaved Indigenous and African individuals during colonial times are few and limited. Three-dimensional geometric morphometric methods applied on 214 temporal bones individuals are used to explore intra-cemetery population variation throughout three centuries (1683–1878), to identify plausible non-European or admixed individuals. First, Principal Component Analysis (PCA) was generated from populations originated from Africa, North-America (Indigenous) and Europe where colonial cemeteries are projected to assess their degree of overlap with the reference groups. Second, Discriminant Function Analysis (DFA) based on typicality probabilities also allowed to assign unknown individuals to the three reference groups. Our results highlighted discrepancy between PCA and DFA. With the PCA, Quebec colonial groups overlap with the Europeans except for three individuals. For the DFA, 64 % (n = 136) were classified as typical to one group and 36 % as atypical (n = 77). Most were European, (82 %; n = 112), followed by those as Indigenous (7 %; n = 10), intermediate between Africans and Indigenous (6 %; n = 8) and Africans (5 %; n = 7). Compared with previous research, one individual from the first Protestant cemeteries of St-Matthew in Quebec could be assessed as plausible African or admixed origin. Two others need further analysis: one from St-Matthew and one from the first Catholic cemetery of Notre-Dame in Montreal. Finally, in response to dominant narratives that focused mainly on Euro-colonists, this research provided for the first time a new snapshot of several colonial population diversity in Quebec, underlining the presence of marginalized groups -especially those of African origin, who are absent from the archaeological reports under study.

The characteristics of differentiated yeast subpopulations depend on their lifestyle and available nutrients

Yeast populations can undergo diversification during their growth and ageing, leading to the formation of different cell-types. Differentiation into two major subpopulations, differing in cell size and density and exhibiting distinct physiological and metabolic properties, was described in planktonic liquid cultures and in populations of colonies growing on semisolid surfaces. Here, we compare stress resistance, metabolism and expression of marker genes in seven differentiated cell subpopulations emerging during cultivation in liquid fermentative or respiratory media and during colony development on the same type of solid media. The results show that the more-dense cell subpopulations are more stress resistant than the less-dense subpopulations under all cultivation conditions tested. On the other hand, respiratory capacity, enzymatic activities and marker gene expression differed more between subpopulations. These characteristics are more influenced by the lifestyle of the population (colony vs. planktonic cultivation) and the medium composition. Only in the population growing in liquid respiratory medium, two subpopulations do not form as in the other conditions tested, but all cells exhibit a range of characteristics of the more-dense subpopulations. This suggests that signals for cell differentiation may be triggered by prior metabolic reprogramming or by an unknown signal from the structured environment in the colony.

CHARACTERISTICS OF PH AND NUMBER OF MICROBES IN THE RETICULUM, OMASUM AND ABOMASUM OF BALI CATTLE

Bali cattle are native Indonesian cattle germplasm which must be preserved and cultivated. The research aims to determine the pH characteristics and number of microbes in the reticulum, omasum and abomasum of Bali cattle. The research sample was the stomach contents of the reticulum, omasum and abomasum of clinically healthy Bali cattle slaughtered at the slaughterhouse, Pesanggaran, Denpasar. Samples were taken aseptically from 30 cows. This research is observational with a cross-sectional study design. The number of bacterial and fungal colony populations was calculated using the pour plate method on nutrient agar plates and Sabouraud dextrose agar plates, respectively. The population of Enterobacteriaceae bacterial colonies was counted using the scatter method on Eosin Methylen Blue agar plates. pH measurements in cow stomach contents were carried out using pH indicator strips. The research data were analyzed descriptively. The results showed that the average pH of the reticulum, omasum and abomasum were 7,66; 6,50 and 5,26. The average total bacteria or ALTB in the reticulum, omasum and abomasum were 18,53 x 106 CFU/gr, 21,43 x 106 CFU/gr and 26,73 x 106 CFU/gr; the fungal population was 7,10 x 105 CFU/gr, 4,56 x 105 CFU/gr and 2,83 x 105 CFU/gr; Coliform counts were 60,03 x 103 CFU/gr, 57,70 x 103 CFU/gr and 61,60 x 103 CFU/gr; the number of non-Coliforms was 49,00 x 103 CFU/gr, 45,53 x 103 CFU/gr and 41,46 x 103 CFU/gr, the number of E.coli respectively 20,70 x 103 CFU/gr, 22, 83 x 103 CFU/gr and 22,86 x 103 CFU/gr.

Thinking inside the box: Restoring the propolis envelope facilitates honey bee social immunity.

When wild honey bee colonies (Apis mellifera) nest in hollow tree cavities, they coat the rough cavity walls with a continuous layer of propolis, a substance comprised primarily of plant resins. Studies have shown that the resulting "propolis envelope" leads to both individual- and colony-level health benefits. Unfortunately, the smooth wooden boxes most commonly used in beekeeping do little to stimulate propolis collection. As a result, most managed bees live in hives that are propolis-poor. In this study, we assessed different surface texture treatments (rough wood boxes, boxes outfitted with propolis traps, and standard, smooth wood boxes) in terms of their ability to stimulate propolis collection, and we examined the effect of propolis on colony health, pathogen loads, immune gene expression, bacterial gene expression, survivorship, and honey production in both stationary and migratory beekeeping contexts. We found that rough wood boxes are the most effective box type for stimulating propolis deposition. Although the use of rough wood boxes did not improve colony survivorship overall, Melissococcus plutonius detections via gene expression were significantly lower in rough wood boxes, and viral loads for multiple viruses tended to decrease as propolis deposition increased. By the end of year one, honey bee populations in migratory rough box colonies were also significantly larger than those in migratory control colonies. The use of rough wood boxes did correspond with decreased honey production in year one migratory colonies but had no effect during year two. Finally, in both stationary and migratory operations, propolis deposition was correlated with a seasonal decrease and/or stabilization in the expression of multiple immune and bacterial genes, suggesting that propolis-rich environments contribute to hive homeostasis. These findings provide support for the practical implementation of rough box hives as a means to enhance propolis collection and colony health in multiple beekeeping contexts.

Honey bee colony population annual dynamics in northern Ethiopia’s semi-arid region, Tigray

Beekeepers around the world have been experiencing seasonal colony losses which differ with the scale of beekeeping operations and countries. This survey provides a glimpse of annual colony dynamics among smallholder beekeepers in three areas of northern Ethiopia. Data were collected using an interview questionnaire regarding annual colony in-(out)flow through swarming, splitting, purchasing, selling and losses. In total, 120 beekeepers were included, managing 266 colonies at the time of the interview. The beekeepers stocked their colonies through artificial splitting, natural swarming and buying, and de-stocked due to selling and losses. The overall percentage of total annual managed colonies lost was 15.7%, and the loss rates significantly differed from 9% to 19.5% between areas. Swarm production positively correlated with the number of colonies managed in fixed-comb hives and the number of colonies sold, which is consistent with traditional beekeepers in this area using swarm production and marketing as an income source. On the other hand, the number of colonies lost was also related to colonies produced through swarming and splitting, which may indicate the production of weak colonies. Although the lowland area showed the highest mean annual loss, the number of colonies lost and colony loss rates per household did not differ significantly between areas. Future studies should identify the causes of colony losses and sustainable management strategies.

Colony level fitness analysis identifies a trade-off between population growth rate and dauer yield in Caenorhabditis elegans

BackgroundIn the evolution from unicellular to multicellular life forms, natural selection favored reduced cell proliferation and even programmed cell death if this increased organismal fitness. Could reduced individual fertility or even programmed organismal death similarly increase the fitness of colonies of closely-related metazoan organisms? This possibility is at least consistent with evolutionary theory, and has been supported by computer modelling. Caenorhabditis elegans has a boom and bust life history, where populations of nematodes that are sometimes near clonal subsist on and consume food patches, and then generate dauer larva dispersal propagules. A recent study of an in silico model of C. elegans predicted that one determinant of colony fitness (measured as dauer yield) is minimization of futile food consumption (i.e. that which does not contribute to dauer yield). One way to achieve this is to optimize colony population structure by adjustment of individual fertility.ResultsHere we describe development of a C. elegans colony fitness assay, and its use to investigate the effect of altering population structure on colony fitness after population bust. Fitness metrics measured were speed of dauer production, and dauer yield, an indirect measure of efficiency of resource utilization (i.e. conversion of food into dauers). We find that with increasing founder number, speed of dauer production increases (due to earlier bust) but dauer yield rises and falls. In addition, some dauer recovery was detected soon after the post-colony bust peak of dauer yield, suggesting possible bet hedging among dauers.ConclusionsThese results suggest the presence of a fitness trade-off at colony level between speed and efficiency of resource utilization in C. elegans. They also provide indirect evidence that population structure is a determinant of colony level fitness, potentially by affecting level of futile food consumption.