Large Colony Size Research Articles

Chromosome-scale genome assembly of the hunt bumble bee, Bombus huntii Greene, 1860, a species of agricultural interest.

The Hunt bumble bee, Bombus huntii, is a widely distributed pollinator in western North America. The species produces large colony sizes in captive rearing conditions, experiences low parasite and pathogen loads, and has been demonstrated to be an effective pollinator of tomatoes grown in controlled environment agriculture systems. These desirable traits have galvanized producer efforts to develop commercial Bombus huntii colonies for growers to deliver pollination services to crops. To better understand Bombus huntii biology and support population genetic studies and breeding decisions, we sequenced and assembled the Bombus huntii genome from a single haploid male. High-fidelity sequencing of the entire genome using PacBio, along with HiC sequencing, led to a comprehensive contig assembly of high continuity. This assembly was further organized into a chromosomal arrangement, successfully identifying 18 chromosomes spread across the 317.4 Mb assembly with a BUSCO score indicating 97.6% completeness. Synteny analysis demonstrates shared chromosome number (n = 18) with Bombus terrestris, a species belonging to a different subgenus, matching the expectation that presence of 18 haploid chromosomes is an ancestral trait at least between the subgenera Pyrobombus and Bombus sensu stricto. In conclusion, the assembly outcome, alongside the minimal tissue sampled destructively, showcases efficient techniques for producing a comprehensive, highly contiguous genome.

The Impact of Avian Haemosporidian Infection on Feather Quality and Feather Growth Rate of Migratory Passerines.

Bird feathers have several functions, including flight, insulation, communication, and camouflage. Since feathers degrade over time, birds need to moult regularly to maintain these functions. However, environmental factors like food scarcity, stress, and parasite infections can affect feather quality and moult speed. This study examined the impact of avian haemosporidian infection and uropygial gland volume, as well as feather quality and feather growth rate in two migratory hirundine species captured in southwestern Spain-the house martin (Delichon urbicum) and sand martin (Riparia riparia). Our findings showed that the prevalence of infection varied among species, with house martins having the highest rates, possibly due to their larger colony size. Moreover, haemosporidian infection had a different impact on each species; infected house martins exhibited lower feather quality than healthy individuals, although this outcome was not observed in sand martins. Furthermore, no effect of infection on feather growth rate was observed in both hirundinids. Additionally, feather growth rate only correlated positively with feather quality in house martins. Finally, no link was observed between uropygial gland volume and feather quality or feather growth rate in any of the species in this study. These findings highlight the effect of haemosporidian infections on the plumage of migratory birds, marking, for the first time, how avian haemosporidian infection is shown to adversely impact feather quality. Even so, further research is needed to explore these relationships more deeply.

Review and meta-analysis of correlates of home range size in bats

Abstract Home range is an ecological concept that affects many aspects of the life of vertebrates and hence understanding how it varies between species is crucial. Mammalian home range size has been linked to body size and diet, but these studies were based predominantly on terrestrial species and most specifically excluded bats. As the only group of flying mammals, bats experience distinctly different constraints on movement, and hence home range. However, despite their diversity, relatively little is known about the home ranges of bats, and this is the first global review assessing correlates of their home range size. Our hypothesis is that home range will be impacted by different ecological conditions experienced by the bats and by the biological traits of the bats themselves. We performed a meta-analysis based on published data for 81 bat species to identify variables that contribute most to home range size. Sex, wing loading, functional group, colony size, dietary class, distance from the equator (latitudinal region), habitat type, and the interaction between habitat type and latitudinal region were all important explanatory variables. Wing loading was positively correlated with home range size—while females, open-air foragers, large colony sizes, and bats in temperate regions consistently had large home ranges. Understanding the correlates of home range has important implications, for example, for bat conservation and for assessing the risk of spillover of zoonotic pathogens from bats to humans and livestock.

First characterisation and conservation needs of a large maternity colony of lesser horseshoe bats (Rhinolophus hipposideros) in Aljezur, Portugal

A new maternity colony of lesser horseshoe bats (Rhinolophus hipposideros) was found and described in an abandoned building in Aljezur, Portugal. Between June 25 and July 4, 2022, we conducted emergence and juvenile counts, took light intensity measurements during emergence times and evaluated microclimatic conditions inside the roost, namely temperature and relative humidity. Moreover, we took ultrasound recordings in the open and performed transects to locate foraging areas and commuting corridors. We found the colony amounted to at least 501 individuals (371 adults and 130 juveniles), currently the largest known in Portugal and one of the biggest in Europe. Sixteen matching echolocation calls were recorded away from the colony near a water reservoir, a probable foraging area together with the Vale da Telha valley connecting the roost to the water body, which may also serve as a commuting corridor. Considering the threatened conservation status of the lesser horseshoe bat, the large colony size and its lack of protection, we proposed several conservation measures aimed at preserving the colony. We hope our recommendations will be included in the management plan currently being prepared for the Natura 2000 site Costa Sudoeste. Following up on this research, a radio-tracking study would definitively confirm the bats’ movements and foraging grounds.

Biology of the southern giant hornet, Vespa soror: nest architecture, morphological differences among castes, and the genetic structure of colonies.

Giant hornets in the genus Vespa are apex predators that are known throughout Asia for their exceptional size and devastating group attacks on social insect colonies. The giant hornets include Vespa mandarinia, a well-studied and widespread temperate species, and Vespa soror, a poorly known sister species that is limited to subtropical and tropical regions of Southeast Asia. Both species have been recently documented on the west coast of North America, raising urgent questions about their potential impact in novel ecosystems. To better understand the biology of V. soror, we describe the nest architecture, caste morphology, and genetic structure of colonies collected in Vietnam. Comparisons of colony metrics between the two giant hornet species suggest important differences that are likely a consequence of the relatively warmer climate in which V. soror occurs. Like V. mandarinia, V. soror constructs large, underground nests of partially enveloped horizontal combs. However, compared to temperate V. mandarinia colonies, the longer nesting period of subtropical V. soror colonies likely resulted in relatively larger colony sizes and nests by the end of their annual cycle. Vespa soror workers and gynes were larger than males, distinguishable based on wing shape and body size (total length and measures of six body parts), and equivalent in size to female castes of V. mandarinia. We genotyped colony members from three mature nests, which revealed that males and females were offspring of singly mated queens. Two colonies were monogynous, but one colony was comprised of two unrelated matrilines. Polygyny has not been observed for V. mandarinia, but is more common in tropical hornet species. Our study sheds light on essential details about the biology of an understudied species of giant hornet, whose populous colonies and long nesting period suggest the potential for substantial ecological impact wherever they occur.

The Space Environment Activates Capsular Polysaccharide Production in Lacticaseibacillus rhamnosus Probio-M9 by Mutating the wze (ywqD) Gene.

The study of microorganisms in outer space has focused mainly on investigating phenotypic changes in microbial pathogens induced by factors encountered in space. This study aimed to investigate the effect of space exposure on a probiotic bacterium, Lacticaseibacillus rhamnosus Probio-M9. Probio-M9 cells were exposed to space in a spaceflight. Interestingly, our results showed that a substantial proportion of space-exposed mutants (35/100) exhibited a ropy phenotype, characterized by their larger colony sizes and an acquired ability to produce capsular polysaccharide (CPS), compared with the original Probio-M9 or the ground control isolates without space exposure. Whole-genome sequencing analyses on both the Illumina and PacBio platforms revealed a skewed distribution of single nucleotide polymorphisms (12/89 [13.5%]) toward the CPS gene cluster, particularly in the wze (ywqD) gene. The wze gene encodes a putative tyrosine-protein kinase that regulates CPS expression through substrate phosphorylation. Transcriptomics analysis of two space-exposed ropy mutants revealed increased expression in the wze gene relative to a ground control isolate. Finally, we showed that the acquired ropy phenotype (CPS-producing ability) and space-induced genomic changes could be stably inherited. Our findings confirmed that the wze gene directly influences the capacity for CPS production in Probio-M9, and space mutagenesis is a potential strategy for inducing stable physiological changes in probiotics. IMPORTANCE This work investigated the effect of space exposure on a probiotic bacterium, Lacticaseibacillus rhamnosus Probio-M9. Interestingly, the space-exposed bacteria became capable of producing capsular polysaccharide (CPS). Some probiotic-derived CPSs have nutraceutical potential and bioactive properties. They also enhance the survival of probiotics through the gastrointestinal transit and ultimately strengthen the probiotic effects. Space mutagenesis seems to be a promising strategy for inducing stable changes in probiotics, and the obtained high-CPS-yielding mutants are valuable resources for future applications.

Introducing Cyanodorina gen. nov. and Cyanodorina ovale sp. nov. (Microcystaceae, Chroococcales), a Novel Coccoid Cyanobacterium Isolated from Caohai Lake in China Based on a Polyphasic Approach

The Chroococcales is one of the least studied cyanobacterial orders comprising the non-baeocyte-producing coccoids cyanobacteria with stacked and fasciculated thylakoids. During a survey of aquatic biodiversity in Caohai Lake in Guizhou Province, China, a coccoid-like cyanobacterium was isolated. It was characterized using a polyphasic approach, based on morphology, electron microscopy, and molecular phylogenetic analyses. This species’ colonies exhibited morphological similarity to those of Microcystis species but differed in their larger colony sizes and widely oval cells. The 16S rRNA gene sequence of this species had the maximum homology, corresponding to 93.10%, to that of the genus Microcystis. The results of 16S rRNA gene threshold value and 16S rRNA phylogenetic analyses confirmed that the studied species belongs to the family Microcystaceae but is phylogenetically distinct from the other species of Microcystaceae. Furthermore, The D1–D1′, Box–B helix, and V3 helix of the 16S–23S ITS region were also different from those previously described in Microcystaceae taxa. Combining the morphological, ecological, and molecular features of the coccoid-like cyanobacterium, we here propose the establishment of the Cyanodorina gen. nov. and the Cyanodorina ovale sp. nov.

The potential and realized foraging movements of bees are differentially determined by body size and sociality.

Reversing biodiversity declines requires a better understanding of organismal mobility, as movement processes dictate the scale at which species interact with the environment. Previous studies have demonstrated that species foraging ranges, and therefore, habitat use increases with body size. Yet, foraging ranges are also affected by other life-history traits, such as sociality, which influence the need of and ability to detect resources. We evaluated the effect of body size and sociality on potential and realized foraging ranges using a compiled dataset of 383 measurements for 81 bee species. Potential ranges were larger than realized ranges and increased more steeply with body size. Highly eusocial species had larger realized foraging ranges than primitively eusocial or solitary taxa. We contend that potential ranges describe species movement capabilities, whereas realized ranges depict how foraging movements result from interactions between species traits and environmental conditions. Furthermore, the complex communication strategies and large colony sizes in highly eusocial species may facilitate foraging over wider areas in response to resource depletion. Our findings should contribute to a greater understanding of landscape ecology and conservation, as traits that influence movement mediate species vulnerability to habitat loss and fragmentation.

Ant phylogenomics reveals a natural selection hotspot preceding the origin of complex eusociality

The evolution of eusociality has allowed ants to become one of the most conspicuous and ecologically dominant groups of organisms in the world. A large majority of the current ∼14,000 ant species belong to the formicoids,1 a clade of nine subfamilies that exhibit the most extreme forms of reproductive division of labor, large colony size,2 worker polymorphism,3 and extended queen longevity.4 The eight remaining non-formicoid subfamilies are less well studied, with few genomes having been sequenced so far and unclear phylogenetic relationships.5 By sequencing 65 genomes, we provide a robust phylogeny of the 17 ant subfamilies, retrieving high support to the controversial leptanillomorph clade (Leptanillinae and Martialinae) as the sister group to all other extant ants. Moreover, our genomic analyses revealed that the emergence of the formicoids was accompanied by an elevated number of positive selection events. Importantly, the top three gene functions under selection are linked to key features of complex eusociality, with histone acetylation being implicated in caste differentiation, gene silencing by RNA in worker sterility, and autophagy in longevity. These results show that the key pathways associated with eusociality have been under strong selection during the Cretaceous, suggesting that the molecular foundations of complex eusociality may have evolved rapidly in less than 20 Ma.

Five decades of misunderstanding in the social Hymenoptera: a review and meta-analysis of Michener's paradox.

ABSTRACTIn a much‐cited 1964 paper entitled “Reproductive efficiency in relation to colony size in hymenopterous societies,” Charles Michener investigated the correlation between a colony's size and its reproductive efficiency – the ability of its adult females to produce reproductives, measured as per‐capita output. Based on his analysis of published data from destructively sampled colonies in 18 species, he reported that in most of these species efficiency decreased with increasing colony size. His conclusion that efficiency is higher in smaller groups has since gained widespread acceptance. But it created a seeming paradox: how can natural selection maintain social behaviour when a female apparently enjoys her highest per‐capita output by working alone? Here we treat Michener's pattern as a hypothesis and perform the first large‐scale test of its prediction across the eusocial Hymenoptera. Because data on actual output of reproductives were not available for most species, Michener used various proxies, such as nest size, numbers of brood, or amounts of stored food. We show that for each of Michener's data sets the reported decline in per‐capita productivity can be explained by factors other than decreasing efficiency, calling into question his conclusion that declining efficiency is the cause of the pattern. The most prominent cause of bias is the failure of the proxy to capture all forms of output in which the colony invests during the course of its ontogeny. Other biasing factors include seasonal effects and a variety of methodological flaws in the data sets he used. We then summarize the results of 215 data sets drawn from post‐1964 studies of 80 species in 33 genera that better control for these factors. Of these, 163 data sets are included in two meta‐analyses that statistically synthesize the available data on the relationship between colony size and efficiency, accounting for variable sample sizes and non‐independence among the data sets. The overall effect, and those for most taxonomic subgroups, indicates no loss of efficiency with increasing colony size. Two exceptional taxa, the halictid bees and independent‐founding paper wasps, show negative trends consistent with the Michener hypothesis in some species. We conclude that in most species, particularly those with large colony sizes, the hypothesis of decreasing efficiency with increasing colony size is not supported. Finally, we explore potential mechanisms through which the level of efficiency can decrease, be maintained, or even increase, as colonies increase in size.

Seasonal Phenology and Colony Longevity Patterns in a Predatory Social Wasp

Social wasps play critical ecological roles in an ecosystem, providing a diversity of services and some disservices. Yellowjacket wasps (Vespula spp.) in particular are well known for shaping arthropod communities via predation and competition for resources. In part due to their sociality and large colony sizes, Vespula can have a profound ecological impact on local communities. Such effects can be magnified when colonies exhibit a perennial life history, in which a colony will overwinter, persist for more than one year, and become orders of magnitude larger in size compared to typical annual colonies. Despite growing interest in the factors that influence colony success, we currently lack the ability to predict when yellowjackets may have a high-abundance or outbreak year. This highlights the need for a critical understanding of the phenological patterns of foraging activity, colony distribution, and senescence. Here, we quantify the seasonal activity and foraging rates of 123 colonies of the western yellowjacket, V. pensylvanica, in its native range over 4 consecutive years. Average colony longevity was about 1 month longer than previously reported for this species, and colonies with later peaks in activity and higher average traffic rates persisted longer into the winter. Longer-lived colonies tended to cluster together within a year, but not between years. We found 3 perennial colonies (2.4% of all colonies), and they exhibited tenfold higher peak traffic rates compared to annual colonies. By identifying temporal and spatial patterns in survivorship and colony longevity, we gain insight into the factors associated with prolonged survival time and increased likelihood of overwintering in yellowjacket wasps.

The benefits of being big and diverse: early colony survival in harvester ants.

In sessile organisms such as plants and benthic invertebrates, founding propagules typically suffer extremely high rates of mortality due to both extrinsic and intrinsic factors. Many social insect species share similarities with these groups, but factors influencing early colony survival are relatively unstudied. We used a field experiment to measure the importance of environmental quality relative to intrinsic colony properties in the harvester ant, Pogonomyrmex occidentalis, by monitoring the survival of 584 experimental colonies. We measured survival of transplanted colonies over four months in each of three years (2014-2016) at a site in western Colorado. Colony survival was primarily determined by colony features. Multiple mating by the queen and larger colony size at the time of transplant increased survival, but queen size, maternal lineage and the composition of plant species in the vicinity of the colony did not. Food supplementation increased survival significantly when natural food was scarce, but was not consistently beneficial, in contrast to predictions. Our results emphasize the general importance of rapid growth and early attainment of large size in the survival of sessile species. However, attributes specific to ants that are a consequence of their sociality also strongly affected survival. Colonies with multiply-mated queens were more likely to survive over a wide range of circumstances, highlighting the importance of this trait even at the early stages of colony life.

Sharing roosts but not ectoparasites: high host-specificity in bat flies and wing mites of Miniopterus schreibersii and Rhinolophus ferrumequinum (Mammalia: Chiroptera)

Schreiber's bent-winged bat Miniopterus schreibersii and the greater horseshoe bat Rhinolophus ferrumequinum are widespread and common cavernicolous species across southern Europe that host numerous specialized ectoparasite species. The objective of this study was to characterize the species assemblage, genetic diversity, and host specificity of bat flies (Nycteribiidae, Diptera) and wing mites (Spinturnicidae, Acari) found on these bat hosts in Serbia and Bosnia and Herzegovina. Notably, while bat flies lay puparia on the cave walls and can thus be transmitted indirectly, wing mites require direct body contact for transmission. Morphological identification and sequencing of a 710-bp fragment of cytochrome oxidase I gene of 207 bat flies yielded 4 species, 3 on M. schreibersii and 1 on R. ferrumequinum. Sequencing of a 460-bp small subunit ribosomal RNA fragment, in all 190 collected wing mites revealed 2 species, 1 per host. In no case was a parasite associated with 1 host found on the other host. Species and genetic diversity of flies were higher in M. schreibersii, likely reflecting their host's larger colony sizes and migratory potential. Mite species of both hosts showed similarly low diversity, likely due to their faster life history and lower winter survival. Our findings highlight a remarkably high host-specificity and segregation of ectoparasite species despite direct contact among their hosts in the roost, suggesting a defined host preference in the investigated ectoparasite species. Furthermore, the differences in ectoparasite genetic diversity exemplify the interplay between host and parasite life histories in shaping parasite population genetic structure.

Important ecosystem function, low redundancy and high vulnerability: The trifecta argument for protecting the Great Barrier Reef's tabular Acropora

AbstractIdentifying organisms that play an important role in maintaining ecosystem function is a key aspect of resilience‐based management. For Australia's Great Barrier Reef (GBR), we found that the recovery ability of shallow exposed fore‐reefs is more than 14 times higher when tabular Acropora are present. The disproportionate role that tabular Acropora play appears to be driven by a combination of traits including high recruitment, high growth rate and, importantly, large maximum colony sizes. Despite this key role, tabular Acropora are highly sensitive to most pressures. We compile evidence suggesting that if tabular corals were to decline or disappear on the GBR, the potential for reef recovery on exposed fore‐reefs would be considerably slowed. We then consider the merits of placing special emphasis on the protection of tabular Acropora within the management of the GBR. Importantly, we recognise that an analysis of costs and benefits of such recognition is vital before any change is implemented. Actions might include targeted crown‐of‐thorns starfish control, anchoring restrictions and protection for tabular corals on reefs identified as essential for their larval dispersal. In addition, targeted communications about the critical importance of these highly recognisable corals may boost community support and participation in their protection.

Rapid Population Decline of the Pillar Coral Dendrogyra cylindrus Along the Florida Reef Tract

Coral reefs worldwide are in a state of decline, but the population status and impacts of stressors for rare species are generally not well documented using broad-scale monitoring protocols. We fate-tracked all known colonies of the pillar coral, Dendrogyra cylindrus, on the Florida Reef Tract (FRT) from 2013 to 2020 to assess population condition and trend, and to document the relative impacts of chronic and acute stressors. Large average colony size, an absence of juveniles, and large geographic distances between genotypes suggest that the Florida D. cylindrus population has been reproductively extinct for decades. During the study period, low-intensity chronic stressors were balanced by regrowth, while back-to-back years of coral bleaching and thermally-exacerbated disease led to declines that the subsequent recovery rates suggest would require 11 uninterrupted years to overcome. The most recent stressor on Florida’s D. cylindrus population is “stony coral tissue loss disease” (SCTLD). Following the appearance of the disease in Florida in 2014, unrecoverable losses occurred within the D. cylindrus population as tissue, colonies, and whole genotypes suffered complete mortality. Losses of 94% of coral tissue, 93% of colonies, and 86% of genotypes between 2014 and the end of 2020 have led to functional extinction of D. cylindrus on the FRT.

Predicting ecological impacts of invasive termites.

There are 28 invasive termite species, most belong to two families, the Kalotermitidae (esp. Cryptotermes spp.) and Rhinotermitidae (esp. Coptotermes spp.). Six invasive termite species are known to have spread into natural habitats, but little direct research has been conducted into their ecological impacts. Predictions based on indirect research (natural durability of commercial wood species) suggest fast-growing, pioneer tree species with low density wood, perhaps notably legumes, are most vulnerable to invasive termites, but even slow growing climax tree species may succumb. Cryptotermes will likely have less ecological impact, due to small colonies attacking dead branch stubs in the canopy. Coptotermes will likely have greater impact, due to large colony sizes and nesting in living trees, which they hollow out and can kill. There are no studies of invasive termites on native termites, other wood-eating insects, or predators, such as ants, showing considerable scope for future research.

In-vitro effectiveness test of leaf extract of cattapa and derris to control anthracnose in chili

Anthracnose disease (Colletotrichum capsici) is one of the main problem in the cultivation of chili. This study was aimed to discover about the extract of leaf extract of cattapa (Terminalia catappa L) and leaf extract of derris (Derris elliptica) against the growth of Colletotrichum capsici causes anthracnosis in chilli. The study was conducted at the Mycology Laboratory of Institute Vegetables Research Indonesia, on July - September 2018. The study used a randomized design complete (CRD) with nine treatments and three replications. The treatment consisted of: leaf extract of derris (0.5%; 1.0%; 1.5%; 2.0%), leaf extract of cattapa (0.5%; 1.0%; 1.5%; 2.0%), and control (without treatment). The result showed that the leaf extract of derris more effective to suppress the conidial production of C. capsici. Development of colonies diameter leaf extract of derris was relatively smaller (3.24-4.31 cm), while for the treatment of leaf extract of cattapa showed larger colony size (6.02-6.82 cm).

No specialist pheromone‐ignoring ants in Lasius niger

In insect societies, the balance between exploitation of known resources and exploration of new ones is important to ensure sufficient resources. Mass recruiting ants, such as Lasius niger, use pheromone trails to recruit nestmates to a newly discovered food source. Pheromone following, however, shows characteristic non‐following (lapse) rates among different species, with ∼20% of L. niger foragers ignoring pheromone. These characteristic lapse rates might simply be ‘noise’, or they might indicate a subset of specialised explorative foragers, a scouting caste, that consistently ignores pheromone in order to explore. Here we show pheromone ignoring is not a repeatable behaviour in L. niger foragers – ants who did not follow a trail were no more likely to ignore it again an hour later than ants which did follow it. Our findings suggest that there is no subset of specialised pheromone‐ignoring L. niger foragers. This may be due to their moderate colony size and strong reliance on individual memories: species with larger colony sizes or a weaker reliance on private information (i.e. memory) may have specialist non‐followers. Our work raises the question: what is a scout ant? We encourage future research to investigate the presence of a scouting caste in other ant species using our straightforward methodology, as a social information‐ignoring caste may be rarer than expected.

Short Communication: Antibacterial potential of Actinomycetes isolated from mangrove sediment in Tanjung Api-Api, South Sumatra, Indonesia

Abstract. Rozirwan, Muda HI, Ulqodry TZ. 2020. Short Communication: Antibacterial potential of Actinomycetes isolated from mangrove sediment in Tanjung Api-Api, South Sumatra, Indonesia. Biodiversitas 21: 5723-5728. Actinomycetes play an important role in the decomposition process of organic matter in mangrove sediments. This study was carried out to identify and evaluate the antagonistic activity of actinomycetes from mangrove sediment against Escherichia coli and Staphylococcus aureus. Identification of actinomycetes was performed based on morphological dan physiological characters. The antagonistic test was carried out against Escherichia coli and Staphylococcus aureus. A total of ten isolates had been successfully isolated and grouped into eight genera, including; Oerskovia H1, Micrococcus H2, Nocardia H3, Sporichtya H5, Corynebacterium H6, Jonesia H7, Actinomyces H10, and Streptomyces H8, H11, H12. Actinomycetes from mangrove sediment were gram-positive bacillus. The shape of the colony varied from circular to filamentous and irregular, with medium and large colony sizes. The colony appears white or yellow. The surface is convex and flat, aerobes and facultative anaerobes; capable of fermenting glucose. Five isolates have very strong growth inhibition activity against E. coli: Nocardia H3 (27.81mm ± 1.39), Actinomycetes H10 (27.75mm ± 2.48), Corynebacterium H6 (27.69mm ± 2.39), Micrococcus H2 (18.55mm ± 2.44), and Streptomyces H8 (17.92mm ± 2.70) while Streptomyces H8 (24.83mm ± 2.08), and Actinomycetes H10 (16.06mm ± 2.49) were active against S. aureus.

Non-Inseminated Queens Have Worker-Like Behaviors in Colonies of Fungus-Growing Ants, Mycetomoellerius turrifex Wheeler (Attini, Hymenoptera)

In eusocial Hymenoptera such as ants, bees, and wasps, the queen numbers are fundamentally important to maintain the social systems. In Texas, USA, a fungus growing ant, Mycetomoellerius turrifex Wheeler (1903) (the genus name was changed from Trachymyrmex to Mycetomoellerius in 2019 (Solomon et al., 2019)) was observed to have several non-inseminated queens that wandered outside the nest long after the mating season. However, the evolutionary and ecological factors causing the occurrence of such non-inseminated queens are still unclear. Thus, I examined the worker-like behaviors of non-inseminated queens of M. turrifex in Texas. Fifteen ant colonies were collected over three years, between 1999 and 2001. The frequencies of non-inseminated queens, workers, and broods, as well as the depths of nest chambers, were observed in each collecting year. In Nov. 1999 and May 2000, multiple nests contained queens that did not mate with males within their nests. These nests had a relatively larger colony size than those collected in Oct. 2001. Conversely, the colonies collected in Oct. 2001 were completely monogynous, i.e., there were no non-inseminated queens in the nests. Behavioral observations of each female revealed that the non-inseminated queensbehaved significantly differently from the workers and the inseminated queens. The behaviors that distinguished different female castes were mutualistic fungus garden care, digging of nest floors, guarding, and resting in the nest. These data suggest that queens failed to mate due to severe environmental fluctuations in southern Texas, but were accepted by the colony as a temporary labor force.