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Simple Summary: Ant gardens (AGs) constitute a sophisticated example of mutualism between ants and plants (myrmecochory), characterized by intricate interspecific relationships with vascular epiphytes. Our main aim was to characterize the epiphytes and their associated ants in the Tingana Reserve in San Martín, situated at 800 m. a.s.l. This unique and humid ecosystem, distinguished by its altitude and microclimate, is home to a diverse array of plant species, including aguaje (Mauritia flexuosa). The area falls within the distribution range of Neotropical AGs, and our results highlight the ecological significance of ant specificity in seed dispersal among the epiphytes of the Mauritia flexuosa peat swamp forest in Peruvian ecosystems. Mutualisms characterized by reciprocal benefits between species are a fundamental relationship of tropical ecosystems. Ant Gardens (AGs) represent an interesting ant-plant mutualism, involving specialized interactions between vascular epiphytes and ants. While this relationship has been extensively studied in various tropical regions, the available information on Peruvian ecosystems is limited. The objective of this study was to identify the ant and epiphyte species that constitute AGs. From February 2023 to January 2024, a study was conducted on two 50 × 10 m transects within the Mauritia flexuosa peat swamp forest, located within the Water Association Aguajal Renacal del Alto Mayo (ADECARAM) Tingana in San Martín, Peru. A total of 69 ant gardens were documented, comprising 18 phorophyte species, 19 epiphyte species, and three ant species. The results demonstrated that neither the height nor the diameter at breast height (DBH) of phorophytes exhibited a statistically significant correlation with the number of AGs per host. However, a positive correlation was observed between the length and width of the AGs and the number of ants per AG. The findings of this study contribute to the understanding of AG mutualism in Peruvian ecosystems. [ABSTRACT FROM AUTHOR]

Simple Summary: Ongoing climate change has led to increased insect damage to maize and the mycotoxigenic fungal infestation and subsequent mycotoxin contamination of maize meant for food and feed. A field study was conducted in two regions in Kenya to see how different maize–legume cropping systems affect the arthropod taxa that were most prevalent on maize at the flowering and grain-filling stages, the arthropods that were most damaging, those that could potentially disperse mycotoxigenic fungi on pre-harvest maize, and the aflatoxin contamination of the grain. Our work revealed that the main herbivore in maize is the fall armyworm (FAW), which was prevalent in both regions but was significantly diminished by the push–pull cropping system. The presence of Aspergillus and Fusarium verticillioides on the exoskeleton of maize weevils, sap beetles, earwigs, and carpenter ants suggests a potential passive dispersal of the fungi in pre-harvest maize. The fungi have previously been isolated from maize from the two regions of Kenya. They are associated with the production of aflatoxins and fumonisins, which present a serious hazard to human and animal health. To reduce maize contamination with mycotoxigenic fungi, farmers can apply targeted insect management strategies, including intercropping and push–pull technology. Maize productivity has remained low and has worsened in the wake of a changing climate, resulting in new invasive pests, with pests that were earlier designated as minor becoming major and with pathogens being transported by pests and/or entering their feeding sites. A study was conducted in 2021 in the Kisumu and Makueni counties, Kenya, to determine how different maize cropping systems affect insect diversity, insect damage to maize, and insects' ability to spread mycotoxigenic fungi in pre-harvest maize. The field experiments used a randomized complete block design, with the four treatments being maize monocrop, maize intercropped with beans, maize–bean intercrop with the addition of Trichoderma harzianum at planting, and push–pull technology. The FAW, Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae), was the most damaging pest in the two regions. The push–pull and the maize–bean intercropping technologies significantly reduced the maize foliage and ear damage caused by the FAW. Beetles passively spread mycotoxigenic Aspergillus spp. and Fusarium verticillioides on pre-harvest maize. Maize weevils, namely, Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae), and Carpophilus dimidiatus Fabricius, 1792 (Coleoptera: Nitidulidae), earwigs, namely, Forficula spp. L. (Dermaptera: Forficulidae), and carpenter ants, namely, Camponotus spp. L. (Hymenoptera: Formicidae) carried the highest number of spores on their exoskeletons. This study stresses the role of insects in the spread of fungi on pre-harvest maize and their possible control by intercropping and other cropping technologies. [ABSTRACT FROM AUTHOR]

We provide evidence that Camponotus chilensis (Spinola) visit flowers of the Radal tree (Lomatia hirsuta Diels ex J.F.Macbr.), possibly acting as pollinators of this important tree of the Proteaceae family in the Andean Patagonian forests of Argentina. We found several ant workers transporting pollen from different trees during the blooming season. Pollen transported by workers varied in amount, with some individuals observed fully coated with pollen grains. This note constitutes the first observation of ant activity on the flowers of this plant species and also the first potential example of a tree pollinated by ants in the Neotropics. This note highlights the importance of natural history data in the emergent study field of ant‐pollination. [ABSTRACT FROM AUTHOR]

ABSTRACT The intricate web of interactions in nature has led to unexpected partnerships between plants and animals, greatly influencing ecosystem dynamics. In this discussion, we'll explore the Pollination Syndrome Hypothesis and consider a scenario where a partnership with unexpected pollinators emerges. We suggest that ant pollination has been largely overlooked, but ants can surprisingly play a crucial role and have a history of success in pollinating dry system plants. We will present both negative and positive aspects that must be observed in ant‐pollination syndrome. Additionally, we aim to explore the often‐underestimated phenomenon of ant pollination and the overlooked tiny, discreet, unnoticed flowers found in our fields and forests, especially in dry ecosystems, savannas and mountain fields, which may hold numerous undiscovered secrets about these interactions. We encourage young biologists to engage in natural history observations and to perform manipulative experiments directly in the field to understand the true nature of these successful ant‐pollinations. [ABSTRACT FROM AUTHOR]

Quantifying the degree of ecological specialization of animals is essential for understanding the evolution of resource use in changing environments. Stable isotope analysis (SIA) is a powerful tool for investigating the ecological niches of animals and providing insights into their diet. This study focused on the ecological role of two coastal species of ants, Camponotus morosus and Dorymyrmex goetschi, in Chile. Their seasonal isotopic niches were characterised using carbon (δ13C) and nitrogen (δ15N) analysis. This was done on El Tabito Beach, a coastal area with a pronounced seasonality. The results indicated unique niches for each species and variation between them across seasons. While C. morosus maintained a consistent niche breadth throughout the year, D. goetschi displayed a narrower niche in summer. Our analyses showed that terrestrial-derived carbon constituted the primary food resource for both species of ants, with a slight increase in the marine component in summer. Overall, the results highlight seasonal variations in isotopic signatures, niche breadth, and diet composition and underscore the importance of considering temporal dynamics in ant ecology and, in particular, in trophic interactions. [ABSTRACT FROM AUTHOR]

Two new species of Myrmozercon, M. serratus sp. nov. and M. spatulatus sp. nov., are described based on adults and deutonymphs collected in association with ants in Mexico. They represent the first records of this genus from the Neotropic s.s. faunal region. Both new species are associated with hosts in the genus Camponotus from the same small area of a coastal lagoon, which share the same nesting habit preferences, providing strong evidence for host specificity. All but one colony of C. atriceps hosted mites, whereas they occurred in only half of the colonies of C. rectangularis. There was a significant positive correlation between the abundance of C. atriceps sexual ants and the abundance of mites. We summarize the known host associations for the genus Myrmozercon and discuss host specificity. Larvae of both mite species were collected on the wings of males and gynes suggesting that egg laying occurs on the hosts reproductive caste. Two hypotheses explaining this observation are discussed, larvae may be phoretic on winged sexuals, favoring mite co-dispersal with hosts, or larvae reside on the alates as a refuge from predation. [ABSTRACT FROM AUTHOR]

Two species may share a mutualistic interaction if the benefits gained by the interaction outweigh the costs incurred. In this study, we tested experimentally how the identity of ants (pinned) and floral visitors of an extrafloral nectary (EFN)-bearing plant can affect plant fitness. We quantified ant activity and floral visitor visitation overlap over time, floral visitor behaviour, amount of floral resources collected, and plant fitness as influenced by the ant species identity in an EFN-bearing plant from Brazilian Cerrado savanna, Qualea multiflora (Vochysiaceae). We found that: (i) ant activity and floral visitation overlap greatly in time; (ii) floral visitors vary in their response to the presence of ants; (iii) different ant species have different impacts on floral visitors; (iv) ants affected the amount of floral resources collected by pollinators, but their levels were contingent on ant identity; and (v) plant fitness components (fruit production, seed weight, and seed size) were most strongly affected by the largest and most aggressive ant species. Our results suggest that the balance of the trade-off between the beneficial effects of ant protection against herbivorous insects and the negative consequences for plant fitness by deterring pollinators depends on the species identity of both the ants and the floral visitors to the plant. [ABSTRACT FROM AUTHOR]

Simple Summary: Ants are highly adaptable insects that thrive in a variety of climates and habitats worldwide. This study examines how climate and habitat influence the morphological traits of the ant species Camponotus japonicus across 22 sites in mainland China. These sites represent three climate zones and three habitat types. Our analysis shows that both climate and habitat significantly shape the ants' morphological traits. Specifically, ants in mid-temperate farmlands exhibit more constrained morphological traits, while those in sparse woodlands show greater variation. Urban parks present a stable environment with less morphological variation. Temperature, precipitation, humidity, and altitude were found to be closely linked to these morphological traits. This research enhances our understanding of how ants adapt to environmental changes through morphological variation and underscores their critical ecological roles in various ecosystems. Ants are a highly adaptable group of insects that have globally established themselves in diverse climates and habitats. This study investigates the influence of climate and habitat on the morphological traits of Camponotus japonicus across 22 sites in mainland China. These sites span three climate zones (mid-temperate, warm temperate, and subtropical) and three habitat types (urban parks, farmlands, and sparse woodlands). Principal component analysis (PCA) was used to determine the principal axis of morphological variation, while hypervolume analysis and centroid distance calculation were used to verify the environmental filtering hypothesis and the optimal transfer hypothesis. The results support both hypotheses showing that climate and habitat significantly affect the morphological space of C. japonicus workers. In particular, the morphological space is more constrained in mid-temperate farmlands, while workers in sparse woodlands exhibit greater morphological variation. In contrast, urban parks are characterized by higher stability and reduced morphological differences. Additionally, robust regression analysis reveals that environmental factors such as temperature, precipitation, humidity, and altitude are closely linked to the morphological traits of the workers. Understanding how ant morphology responds to external environmental changes enhances our understanding of their adaptability and their essential ecological roles across various ecosystems. [ABSTRACT FROM AUTHOR]

Mimicry, that is, the imitation of any unpalatable or defensive species by another, has been of central interest to evolutionary research since Darwin's lifetime. Two ant species, Camponotus guanchus Santschi, 1908 and Crematogaster alluaudi Emery, 1893, endemic to the Canary Islands, occur in two color‐morphs: While the head of workers is always reddish and the gaster blackish, the mesosoma (inclusive waist) is either fully reddish or fully blackish. In addition to the obvious morphological and coloration similarities, we provide evidence of mimicry: (i) Ca. guanchus was found only within the area of Cr. alluaudi. (ii) Color morphs are geographically non‐randomly distributed: Workers of both species from 16 localities of syntopic occurrences shared in eight cases a blackish and in eight cases a reddish mesosoma. Hence, Ca. guanchus mimics both local color‐morphs of Cr. alluaudi. We consider a fascinating analogy with the Mediterranean mimicry system in Camponotus lateralis (Olivier, 1792) and its model species of the Crematogaster scutellaris (Olivier, 1792) group on an island scale. Additionally, we present two endemic bug species, Perenotus stysi (Ribes et al., 2008) and P. malobae Roca‐Cusachs & Goula, 2016, as mimics of those Cr. alluaudi workers having a reddish mesosoma. Our distribution, coloration, frequency, and behavioral data as well as the analogy with Ca. lateralis and the Cr. scutellaris group suggest a Batesian‐mimicry system in which Ca. guanchus, Perenotus stysi, and P. malobae mimic the unpalatable and aggressive Cr. alluaudi as an antipredator adaptation. [ABSTRACT FROM AUTHOR]

Objectives: Ants are ecologically dominant insects in most terrestrial ecosystems, with more than 14,000 extant species in about 340 genera recorded to date. However, genomic resources are still scarce for most species, especially for species endemic in East or Southeast Asia, limiting the study of phylogeny, speciation and adaptation of this evolutionarily successful animal lineage. Here, we assemble and annotate the genomes of Odontoponera transversa and Camponotus friedae, two ant species with a natural distribution in China, to facilitate future study of ant evolution. Data description: We obtained a total of 16 Gb and 51 Gb PacBio HiFi data for O. transversa and C. friedae, respectively, which were assembled into the draft genomes of 339 Mb for O. transversa and 233 Mb for C. friedae. Genome assessments by multiple metrics showed good completeness and high accuracy of the two assemblies. Gene annotations assisted by RNA-seq data yielded a comparable number of protein-coding genes in the two genomes (10,892 for O. transversa and 11,296 for C. friedae), while repeat annotations revealed a remarkable difference of repeat content between these two ant species (149.4 Mb for O. transversa versus 49.7 Mb for C. friedae). Besides, complete mitochondrial genomes for the two species were assembled and annotated. [ABSTRACT FROM AUTHOR]

The ant Crematogaster scutellaris, distributed across the western Mediterranean region and east to the west Balkans, is a visual mimicry model for various other organisms, including different other species of ants. It is an ecologically and behaviorally dominant species, foraging through large permanent trails that workers pugnaciously defend by biting and spraying a toxic secretion. Here we report on two interesting novelties discovered by monitoring Cr. scutellaris foraging trails in Tunisia: first, we present the first records of the mimicking ant Colobopsis imitans in the country, filling a distribution gap and confirming a previous biogeographic hypothesis; second, we identified the miridMimocoris rugicollis, whose brachypterous females are known as myrmecomorphs, as a mimic of Cr. scutellaris. Both Co. imitans and M. rugicollis were observed following or stationing near Cr. scutellaris trails, often in the presence of another mimicking ant, Camponotus lateralis. Still little is known about the ecology and behavior of most Cr. scutellaris mimics, with some species still undescribed. Further research is needed to investigate the evolutionary pressures shaping this adaptation. [ABSTRACT FROM AUTHOR]

Mimicry, the superficial resemblance between organisms of two or more species, is considered a textbook example for natural selection, for which it is assumed that predators are important selective agents. Ant mimicking spiders have received considerable attention in studies on mimicry because they include examples with remarkable, species‐specific morphological adaptations. Ant‐like behaviours such as erratic locomotory patterns, abdomen bobbing and vertical movements of the first or second pair of legs to imitate antennal movements, are assumed to have evolved before morphological mimicry and may be considered adaptations to general ant resemblance. Species‐specific behavioural ant mimicry (behaviour that is only observed in specific ants and imitated by their mimics) was very rarely documented and ant resembling behaviour that repels predator attacks has not been confirmed yet. In this study we report and discuss such species‐specific behaviour, a spray display (SD), in the castianeirine spiders Myrmecotypus iguazu (a morphologically accurate mimic of the carpenter ant Camponotus sericeiventris), and M. tahyinandu (a morphologically accurate mimic of C. crassus). The SD consisted of the raising of the cephalothorax and moving of the abdomen ventrally under the cephalothorax, pointing the apex forward, and holding the antennae (ant) or first pair of legs (spiders) at an angle of about 45°–120°. The morphological adaptations that are required to perform the SD and the lack of an alternative explanation for the purpose of this display suggest that the SD has evolved to enhance both general behavioural and morphologically accurate ant resemblance. The two observed Myrmecotypus species may be considered the behaviorally most accurate ant‐resembling spiders known to date, as the SD may provide protection against spider‐ and ant‐eating predators at a point in predator interactions where other myrmecomorph spiders may abandon their ant‐resembling behaviour. [ABSTRACT FROM AUTHOR]

Caste polymorphs of the ant Camponotus compressus (Fabricius, 1798) are distinct by their morphology and life styles; the two distinct castes are largely nocturnal and rely on their visual sensory system to interpret their temporal niches. The compound eyes of the castes were explored through Light and Scanning Electron Microscopy (SEM) in order to delineate cast specific organisation and adaptations of the compound eye. The findings reveal that major workers of C. compressus possess a more sophisticated visual system in terms of its morphological features along with optical properties that enhances a better vision, which includes a greater number of ommatidia and high ommatidial density, a higher ommatidial diameter, low inter ommatidial angle and a more efficient pupillary mechanism to counter conditions where ambient light levels are high. This underlines the dependence of scouts (major workers) on visual system and the foragers on olfactory system in the species. [ABSTRACT FROM AUTHOR]

Spiders usually show Batesian mimicry with different model ant species. There are no specific study of ant mimicking spiders and their association with model ants from North-Eastern part of India. In this study, from the campus of Gauhati University, Assam, we recorded total eleven ant-mimicking spiders of which two are new records from India and seven are new records from North-East India. We noticed the model-mimic association of Myrmarachne melanocephala with Tetraponera rufonigra, Myrmarachne cornuta with Tetraponera allaborans, Myrmaplata plataleoides with Camponotus compressus, Myrmarachne acromegalis with Polyrhachis laevissima, Myrmaplata aureonigra with P. laevissima and Polyrhachis dives, Cambalida flavipes with Camponotus compressus and Apochinomma elongatum with Tetraponera nigra. Four unidentified Mymarachne sp. were found mimicking the ant species namely Camponotus parius, Technomyrmex albipes, Polyrhachis tibialis and Dolichoderus moggridgei. The work will open a new window for future studies to explore the ant's and spider's diversity and their co-evolutionary interactions for avoiding predator, deceive other individuals etc. [ABSTRACT FROM AUTHOR]

Synthesis of the Alibertia edulis (Rubiaceae) interaction with the ant Camponotus rufipes. The nectary in the flowers and later in the apex of the fruit (pericalpial nectary) offers resources for the ants during the reproductive season of Alibertia. These ants are recognized for holding an aggressive behavior that might protect the plant from herbivores and fruit predators. When the fruit is ripe, the interaction ends until the next reproduction season for Alibertia edulis. [Display omitted] • Considering the phenological, anatomical and histochemical tests, we describe a new association between the plant Alibertia edulis and the ant Camponotus rufipes, both widely spread Cerrado species. • The plant structure involved in the interaction is a pericarpial nectary. • The interaction occurs during the fruit ripening phase, in which pericarpial nectaries in unripe fruits are secreting sugar. When the fruit is completely ripe, in the peak of the rainy season, the interaction ends until the next reproduction season for Alibertia. Plant-ant interaction in savanna ecosystems is an iconic example of species mutualism. In Cerrado, Brazilian savanna, it is common to find this type of interaction mediated by the offer of extrafloral rewards. This study described a new plant-ant interaction for the tree Alibertia edulis (Rubiaceae) and the ant species Camponotus rufipes and elucidated the main structure involved in the interaction. To do so, (i) we monitored the phenology of A. edulis , (ii) recorded the ant species visitation, and, (iii) collected fruits in different stages of development to perform anatomical and histochemical trials to characterize the structures and chemical components related to the secreted substances - which could be responsible for attracting the ants. Ants' visitation starts at the beginning of fruit development and stops when they are completely ripe. An extrafloral nectary – pericarpical nectary - on the top of the fruits was identified and described for the first time in the Alibertia edulis , derived from the flower structure, which remains to exude (sugar components) during the fruit development. Based on these results, C. rufipes , known for being an aggressive ant, may play a role in protecting fruits against predation until they are completely ripe and the seeds are ready to be dispersed. During seed dispersal, the fruits reduce the production of nectar, signaling the end of the partnership with the ants until the next reproductive season. Here, we shed light and bring new insights into a new plant-ant interaction for a widely spread tree and ant species. [ABSTRACT FROM AUTHOR]

Extrafloral nectaried plants and myrmecophytes offer resources to ants that engage in protective mutualisms. The role of different ant species in herbivore deterrence has long been analyzed by using insect baits, and ants are regarded as effective plant guards if they attack the insects. Here, by performing a literature review, we conducted a comparative investigation on which ants display aggression toward experimental prey, which ants are better plant guards, and which plants (extrafloral nectaried plants or myrmecophytes) are better defended by ants. Data revealed that studies evaluating ant aggression toward insect baits have been performed on 37 extrafloral nectaried plant species and 19 myrmecophytes, and have involved over 30 genera of ants. Extrafloral nectaried plants and myrmecophytes rely on specific ant fauna to defend them from herbivores. In extrafloral nectaried plants, Camponotus and Crematogaster were regarded as the best plant protectors, as they attacked insects in nearly all plants. In myrmecophytes, Azteca, Pheidole, and Pseudomyrmex were the most important insect attackers. Myrmecophytes were better protected by ants, as all insects were attacked; in extrafloral nectaried plants, some ants failed to attack the insects. Plants are patrolled by several different ants, but there is a core of ants that excel in protection, and this varies according to plant type (extrafloral nectaried plants and myrmecophytes). With this knowledge, it may be possible to label different ants as effective plant guards, to anticipate their effects on plant performance, and even to understand their potential role as biological control agents. [ABSTRACT FROM AUTHOR]

Ants have been widely used as bioindicators of natural and disturbed environments. In Argentine Chaco Seco, ants represent an important part of the total biodiversity and fulfil various functions in forest ecosystems. With the aim of evaluating β diversity and identifying indicator ants, surveys were carried out in three types of implanted forests: Neltuma alba (mesquite), Eucalyptus tereticornis (eucalyptus) and mixed forests without intervention for 50 years, mainly composed of Ceiba speciosa and Phoenix canariensis, located at the Fernández Experimental Station of the Catholic University of Santiago del Estero. The samplings were carried out in spring, summer and autumn, between 2019 and 2022, using pitfall traps that remained active for 24 h. The abundance and composition of Formicidae at each site and season were evaluated using the Jaccard similarity index and generalized linear mixed models. A total of 7366 individuals grouped into 28 species belonging to 6 Formicidae subfamilies were identified. Some species were present at all sites and seasons, with Solenopsis saevissima, Camponotus mus and Pheidole bergii being the most abundant in the mesquite, eucalyptus and mixed stands, respectively. In addition, three exclusive species of N. alba, two of E. tereticornis and one of the mixed stand were identified. Furthermore, it was observed that the myrmecological composition varied seasonally, mainly during autumn. These results demonstrate that due to the characteristics of each site, representative groups of ants can be found for each that could be used as indicators of each type of environment and that the temporal variation of the communities is favored by the diversification of the habitats, which offer different resources during each season of the year, increasing the turnover rate. [ABSTRACT FROM AUTHOR]

Camponotus japonicus (Hymenoptera: Formicidae) is an omnivorous social insect which builds sizable colonies in sparse woodlands or cropland and spreads across multiple climatic zones in the Chinese mainland. This study aims to reveal the role of climate changes and geological events in driving the genetic structure of social insect populations by investigating the phylogenetics and historical demography of C. japonicus in the Chinese mainland. Phylogenetic analyses were conducted based on the mitochondria DNA dataset using MrBayes and IQ‐TREE. We constructed a haplotype network, calculated analyses of molecular variance, estimated the divergence time, and reconstructed the maximum clade credibility tree. Mismatch distribution and Bayesian skyline plots were used to infer historical population fluctuations. Additionally, ecological niche modeling was employed to predict the potential distribution of the species during the present, mid‐holocene, and last glacial maximum periods in the Chinese mainland. The phylogenetic tree and median‐joining network analyses support the presence of four distinct lineages in C. japonicus. These lineages exhibit significant genetic differentiation and limited gene flow. The divergence among the four lineages began in the early Pleistocene, approximately 1.41 million years ago (Ma). Subsequently, the central lineage diverged from both the northern and southern lineages around 1.16 Ma, while the northern and southern lineages diverged from each other at approximately 1.07 Ma. Population expansion was observed in the southern, central, and northern lineages prior to the last glacial maximum, while the Yunnan‐Sichuan lineage experienced a slight increase in population size in more recent times. The predicted distribution of the species corresponds well with the actual distribution. Furthermore, the current suitable habitat areas in northern Xinjiang, southern Tibet, and the southeast coastal regions have significantly decreased compared to the last glacial maximum and the mid‐holocene periods. Our results suggest that climate oscillations and geological events play an important role in driving genetic patterns and differentiation of C. japonicus. Mountain barriers isolate populations from each other, hinder the flow of genes, and effectively prevent the spread of this species. But at the same time, it also formed refugia at low altitudes areas such as Qinling‐Bashan Mountains and Yanshan‐Taihang Mountains and provide suitable habitats during glaciation. This study provides a good model for understanding how complex climate changes and geological events affect population genetic differentiation of social insects in the Chinese mainland. [ABSTRACT FROM AUTHOR]

The Galápagos ant fauna has long been understudied, with the last taxonomic summary being published almost a century ago. Here, a comprehensive and updated overview of the known ant species of the Galápagos Islands is provided with updated species distributions. The list is based on an extensive review of literature, the identification of more than 382,000 specimens deposited in different entomological collections, and recent expeditions to the islands. The ant fauna is composed of five subfamilies (Dolichoderinae, Dorylinae, Formicinae, Myrmicinae, and Ponerinae), 22 genera, 50 species, and 25 subspecies, although three species (Crematogaster crinosa Mayr, 1862, Camponotus senex (Smith, 1858), and Solenopsis saevissima (Smith, 1855)) are considered dubious records. Finally, an illustrated identification key of the species found in the archipelago is presented. [ABSTRACT FROM AUTHOR]

The ants of the volcanic caldera of Mt. Melibengoy in the Allah Valley Watershed Forest Reserve (AVWFR), are surveyed, principally by opportunistic collecting. We report 87 ant species representing 33 genera in six subfamilies. We also report three new species records for the Philippines in addition to 13 new distributional records for Mindanao Island. The new Philippine species records are: Cataulacus granulatus (Latreille, 1802); Myrmecina yamanei Okido, Ogata and Hosoishi, 2016; and Pheidole quadrensis Forel, 1900. The new Mindanao distributional records are Camponotus nigricans Roger, 1863; Camponotus variegatus crassinodis Forel, 1892; CrematogastersubcircularisMayr, 1879; Parasyscia rufithorax (Wheeler & Chapman, 1925); Pheidole cariniceps Eguchi, 2001; Ph. hortensis Forel, 1913; Ph. spinicornis Eguchi, 2001; Polyrhachis dives F. Smith, 1857; Po. illaudata Walker, 1859; Po. rastellata (Latreille, 1802); Po. thrinax Roger, 1863; Proceratium papuanum Emery, 1897; and Strumigenys theia Bolton, 2000. The high diversity of ants detected by opportunistic hand collecting suggests that a more intensive survey, using a variety of collecting techniques, will very likely discover more new species and new distributional records from Mt. Melibengoy. The very diverse native ant community also provides as basis for the high conservation priority of the AVWFR. The knowledge gap of Mindanao ant diversity and its affinity to Bornean ant diversity are briefly discussed. [ABSTRACT FROM AUTHOR]

Camponotus herculeanus (Linnaeus, 1758) was rediscovered in Belgium near Ouren. Throughout the spring and summer of 2023, workers were collected on multiple occasions in a Picea abies stand near the Belgian-German boarder. [ABSTRACT FROM AUTHOR]

We conducted laboratory experiments using Japanese carpenter ants (Camponotus japonicus) to investigate whether movement during visual learning can influence the learning performance of ant foragers. We performed three different experiments. In the first experiment, the ants could move freely in a straight maze during the visual learning. The ants in the experiments two and three were fixed to a certain position during the visual learning training. A distinct difference between these two experiments was that the ants in one experiment could perceive an approaching visual stimulus during the training, although they were fixed. After training phases, a Y-maze test was performed. One arm of the Y-maze had a visual stimulus presented to the ants during the training. We found that the ants in the first experiment showed rapid learning and correctly selected the landmark arm. However, the ants in the experiments two and three did not exhibit any preference for the chosen arm. Interestingly, we found differences in the time spent around a certain location in the Y-maze between the experiments two and three. These results suggest that movement during visual learning may influence the rapid learning of ant foragers. [ABSTRACT FROM AUTHOR]

Carpenter ants in the genus Camponotus are large, conspicuous ants that are abundant and ecologically influential in many terrestrial ecosystems. The bicolored carpenter ant, Camponotus vicinus Mayr, is distributed across a wide range of elevations and latitudes in western North America, where it is a prominent scavenger and predator. Here, we present a high-quality genome assembly of C. vicinus from a sample collected in Sonoma County, California, near the type locality of the species. This genome assembly consists of 38 scaffolds spanning 302.74 Mb, with contig N50 of 15.9 Mb, scaffold N50 of 19.9 Mb, and BUSCO completeness of 99.2%. This genome sequence will be a valuable resource for exploring the evolutionary ecology of C. vicinus and carpenter ants generally. It also provides an important tool for clarifying cryptic diversity within the C. vicinus species complex, a genetically diverse set of populations, some of which are quite localized and of conservation interest. [ABSTRACT FROM AUTHOR]

As the only direct records of the history of evolution, it is critical to determine the geological source of biota-bearing fossils. Through the application of synchrotron-radiation micro-computed tomography (SR-µ-CT), Fourier-transformed infrared-spectroscopy (FT-IR), visual evaluation of ultraviolet fluorescence (UV-VS), radiocarbon dating (14C quantification), and historical sleuthing, we were able to identify and sort 161 (83 Baltic amber, 71 Copal and 7 Kauri gum pieces) individually numbered and largely mislabeled pieces of East African Defaunation resin (~145 years old) and copal (~390 years old), as well as Baltic amber (~35 million years old) from the Phyletisches Museum collection. Based on this collection, we define two new species: ‡Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov. (Psocodea: Amphientomidae, copal) and †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. (Coleoptera: Mordellidae, Baltic amber). For selected taxa, we provide systematic reviews of the fossil record, including: Amphientomidae, for which we provide a key to all species of Amphientomum, extant and extinct, and recognize the junior synonymy of Am. ectostriolatum Li, 2002 (an unjustified emendation) under Am. ectostriolate Li, 1999 (syn. nov.); the fossil ant genus †Yantaromyrmex and the clades Dorylinae, Plagiolepidini, Camponotus, Crematogaster, and Pheidole (Formicidae); the Nevrorthidae (Neuroptera); and Doliopygus (Coleoptera: Curculionidae: Platypodinae). We synonymize Palaeoseopsis Enderlein, 1925 with Amphientomum Pictet, 1854, syn. nov. and transfer one species from Amphientomum, forming Lithoseopsis indentatum (Turner, 1975), comb. nov. To prevent the uncritical usage of unidentifiable fossils attributed to Camponotus for macroevolutionary analysis, we transfer 29 species to the form genus †Camponotites Steinbach, 1967, which we consider to be most useful as incertae sedis in the Formicinae. We treat †Ctt. ullrichi (Bachmayer, 1960), comb. nov. as unidentifiable hence invalid stat. nov. We also transfer †Ca. mengei Mayr, 1868 and its junior synonym †Ca. igneus Mayr, 1868 to a new genus, †Eocamponotus Boudinot, gen. nov. , which is incertae sedis in the Camponotini. Concluding our revision of Camponotus fossils, we transfer †Ca. palaeopterus (Zhang, 1989) to Liometopum (Dolichoderinae), resulting in †L. palaeopterum comb. nov. and the junior synonymy of †Shanwangella Zhang, 1989, syn. nov. under Liometopum Mayr, 1861. Because the type specimens of the genera †Palaeosminthurus Pierce & Gibron, 1962, stat. rev. and †Pseudocamponotus Carpenter, 1930 are unidentifiable due to poor preservation, we consider these taxa unidentifiable hence invalid stat. nov. To avoid unsupported use of the available fossils names attributed to Crematogaster for divergence dating calibration points, we transfer three species to a new collective taxon that is incertae sedis in Myrmicinae, †Incertogaster Boudinot, gen. nov. , forming †In. aurora (LaPolla & Greenwalt, 2015), †In. praecursor (Emery, 1891), comb. nov. , and †In. primitiva (Radchenko & Dlussky, 2019), comb. nov. Finally, we transfer †Ph. cordata (Holl, 1829) back to Pheidole, and designate a neotype from our copal collection based on all available evidence. All new species plus the neotype of ‡Ph. cordata are depicted with 3D cybertypes from our µ-CT scan data. We introduce the convention of a double dagger symbol (‡) to indicate fossils in copal or Defaunation resin, as these may yet be extant. To further contextualize our results, we provide a discussion of amber history and classification, as well as the Kleinkuhren locality, to which multiple specimens were attributed. We conclude with conspecti on key biological problems and increasing potential of µ-CT for phylogenetic paleontology. [ABSTRACT FROM AUTHOR]

Effective coordination of group actions underlies the success of group-living organisms. Recent studies of animal personality have shown that groups composed of individuals with different behavioral propensities can outperform uniform groups in a range of different tasks, but we have only a rudimentary understanding of how differences in individual behavior influence the behavior of the group as a whole. In this study, we use natural variation in behavioral propensity among morphologically distinct worker castes of the small carpenter ant Camponotus yamaokai to shed new light on this. Iterative testing indicated that ants displayed consistent behavioral differences among individuals and between castes, with major workers exhibiting a lower exploratory tendency than minors. By constructing groups of different caste composition and quantifying their performance in the task of colony emigration, we show that group performance is an asymmetric humped function of caste ratio, with optimal performance achieved by groups with natural caste ratios. Using a simulation model based on our empirical data, we demonstrate that interindividual differences in social attraction and exploratory tendency are sufficient to explain the observed patterns. Our results provide new insights into how group performance in collective tasks can vary with group composition. [ABSTRACT FROM AUTHOR]

Ants often interact aggressively for resources (e.g. nest sites and food) with members of their own or another species. In these competitive interactions, dominant ant species exert a strong influence on ant species coexistence and plant‐associated arthropod community structure. However, few studies have experimentally manipulated the relative abundance of dominant ant species on plants, preventing a mechanistic understanding of the effects of ant competitive interactions on ant community structure as well as on their interactions with other insects, particularly mutualistic hemipterans. In this study, we performed a field experiment in a tropical dry forest in Brazil to investigate the effects of two dominant ant species (Camponotus crassus and Cephalotes pusillus) on the structure ant communities and the abundance of the ant‐tended hemipteran Enchenopa brasiliensis in Solanum lycocarpum plants. For this, we identified and quantified all ant species foraging on plants and estimated the number of egg masses, nymphs and adults of the mutualistic hemipteran before and after experimentally removing nests of both two dominant ant species. Our results showed that removal of C. pusillus nests significantly changed ant community structure, whereas removal of C. crassus nests did not. We also found that nest removal of both dominant ant species had significant effects on hemipteran abundance. In particular, plants generally hosted more hemipteran eggs, nymphs and adults after (vs before) nest removal of both dominant ant species. Overall, this study demonstrates that dominant ant species can play a pivotal role in structuring ant communities and the interactions between ants and honeydew‐producing hemipteran insects. [ABSTRACT FROM AUTHOR]

A study was conducted to document nest intruders in newly divided colonies of stingless bees. The nature of the damage, the sequence of activities after colony division, and task allocation in the colony were studied. Three insect invaders - solitary resin bees (Megachile disjuncta, M. cephalotes), ants (Oecophylla smaragdina and Camponotus sp.) and spiders belonging to the family Salticidae and Lycosidae invaded the colonies during the earlier stages of division. The mean number of resin bees and ant invasions was significantly higher during the first week after division. Spiders invaded the hives and formed webs during the second week after division, resin and honey resources are robbed by resin bees and ants. Nest entrance closure was observed at 4.37±0.74 days after colony division guard bee activity from 6.13±1.24 days and foraging activity from 10.63±1.06 days after division. Observations on the task allocation framework after colony division indicated that 69% of bees were involved in hive entrance repair, 18% in colony architecture development, and 13% in tending to newly emerged bees from brood cells. The bees built a complex nest entrance, guarded activity and demonstrated nest closure behaviour in order to protect the nest against intruders. The results of the study are of prime importance for beekeepers to learn how to watch for hive intruders during colony division and to understand the adaptive defence mechanism to protect colonies. [ABSTRACT FROM AUTHOR]

Mutualism between ants and honeydew-producing hemipterans is a highly successful evolutionary innovation that attains the status of ecological keystone across many terrestrial ecosystems, involving a multitude of actors through direct or cascading effects. In these relationships, ants often protect their hemipteran partners against their arthropod natural enemies, sometimes interfering with the biological control of pest species. However, the dynamics of these interactions are highly variable based on the specific identity of all the actors involved, and baseline data remain scarce. We performed a field experiment exposing colonies of the walnut aphid Panaphis juglandis attended by five European ant species (Camponotus piceus , Ca. vagus , Crematogaster scutellaris , Dolichoderus quadripunctatus , Lasius emarginatus) to a native and an exotic lady beetle (Adalia bipunctata and Harmonia axyridis), documenting the behavioural interactions between these insects and the performance of ants in the protection of the aphids. Our results reveal a significant behavioural diversity among the ant species involved, with D. quadripunctatus and L. emarginatus being the most aggressive and having the best performance as aphid defenders, and Ca. piceus being least effective and often fleeing away. Cr. scutellaris displayed a rare rescue behaviour attempting to pull away the aphids that the lady beetles grabbed. On the other hand, behavioural responses to A. bipunctata and H. axyridis were similar. Further investigations are needed to understand the eco-ethological implications of these differences, while a better understanding of ant behavioural diversity may help refine biological control strategies. [ABSTRACT FROM AUTHOR]

Ergatandromorphs are examples of genetic chimeras found in ants, in which they exhibit features of both minor workers and males. In this study, we report a lateral ergatandromorph of Camponotus yamaokai Terayama & Satoh, 1990. The right side of this specimen was characterized as a male and the left side as a minor worker, although some body parts did not show a clear division. The specimen had partially atrophied genitalia on the right side of the metasoma while the genital structures on the left side were absent. The individual engaged in frequent self‐grooming and received trophallaxis and allogrooming from the nestmates. This is the first report of the lateral ergatandromorph in the genus Camponotus, which has few documented cases of gynandromorphism. [ABSTRACT FROM AUTHOR]

Arboreal ant diversity is typically higher in tropical forests, particularly in the canopy, where they constitute approximately 90% of the total arthropod population in the crowns of tropical trees. Unfortunately, activities such as forest fragmentation, leading to isolated islands of remaining forest, can impact the species richness, diversity, and composition of arboreal ants. In this study, the responses of arboreal ants to experimental forest fragmentation were investigated across a range of fragment sizes (1 ha - 100 ha) and in salvage logged matrix habitat. The study recorded a total of 13,358 individuals belonging to 171 morphospecies Notably, Polyrhachis, Camponotus, and Crematogaster emerged as the most diverse genera. The ant composition exhibited significant variation with forest fragment size (ANOSIM: Global R = 0.0683; p = 0.0306). However, the species richness (Kruskal-Wallis test: x² = 1.242, df = 3, p = 0.743) and abundance (Kruskal-Wallis test: x² = 3.76, df = 3, p = 0.287) of arboreal ants did not exhibit significant differences across various forest fragment sizes. These alterations in the composition of arboreal ants within fragment areas may be attributed to differences between species in social behavior, nesting habits, movement patterns, and niche preferences. [ABSTRACT FROM AUTHOR]

The Brazilian cerrado is one of the world's biodiversity hotspots, comprising a mosaic of vegetation physiognomies. The cerrado presents a high ant diversity, and ant genetic variation can be subjected to the influence of landscape features. Here, we investigate how the composition and configuration of a cerrado reserve (4500 ha) in SE Brazil influence dispersal and gene flow (through measures of genetic distance) in two abundant carpenter ants, Camponotus renggeri and C. rufipes. Based on landscape genetics, we evaluated the degree of permeability of different land covers on the dispersal of ant queens, males and workers, employing a genetic optimization algorithm framework. We found little genetic structure in C. renggeri, regardless of caste. By contrast, we observed the formation of clear genetic clusters in C. rufipes, mainly for workers and queens. For workers of both species, we found that genetic distance was not influenced by geographic distance or landscape composition. For queens and males of C. renggeri, geographic distance was the most important factor explaining genetic distance. For C. rufipes queens and males, however, the best model considered the effect of landscape resistance to gene flow (i.e. the cost imposed by land use and cover types), with males dispersing through human-affected areas such as roads, and queens through forested cerrado areas. Our results showed that cerrado landscape can differentially affect ant dispersal, even for closely related species, reinforcing the importance of using different castes and sexes in landscape genetics of social insects. Our study also highlights that preservation of different vegetation physiognomies of cerrado is relevant for ant dispersal performance. [ABSTRACT FROM AUTHOR]

Purposive surveys were conducted at regular intervals in different districts of eastern dry zone of Karnataka (Zone 5) during the year 2021-22, to document the natural enemy fauna and the ant species associated with aphids. Out of 34 aphid species recorded, 16 species of aphids were preyed on by 14 species of predators belonging to Coccinellidae, Syrphidae, Hemerobiidae and Chamaemyiidae and seven species of aphids were found parasitized by eight species of parasitoids belonging to Braconidae. Predators belonging to Coccinellidae and Syrphidae were recorded more abundantly with six species in each family, preying on 12 and 10 aphid species, respectively. Among the aphid parasitoids, Aphidius spp. was the more abundant taxa. Eleven species of ants belonging to Formicinae, Myrmicinae and Dolichoderinae were found associated with 17 aphid species. Ants belonging to the genus Camponotus were found to be more abundant and associated with 10 species of aphids. A comprehensive list of predators, parasitoids and ants associated with different aphid species was put together during this study. [ABSTRACT FROM AUTHOR]

Parasitic fungi produce proteins that modulate virulence, alter host physiology, and trigger host responses. These proteins, classified as a type of "effector," often act via protein–protein interactions (PPIs). The fungal parasite Ophiocordyceps camponoti-floridani (zombie ant fungus) manipulates Camponotus floridanus (carpenter ant) behavior to promote transmission. The most striking aspect of this behavioral change is a summit disease phenotype where infected hosts ascend and attach to an elevated position. Plausibly, interspecific PPIs drive aspects of Ophiocordyceps infection and host manipulation. Machine learning PPI predictions offer high-throughput methods to produce mechanistic hypotheses on how this behavioral manipulation occurs. Using D-SCRIPT to predict host–parasite PPIs, we found ca. 6000 interactions involving 2083 host proteins and 129 parasite proteins, which are encoded by genes upregulated during manipulated behavior. We identified multiple overrepresentations of functional annotations among these proteins. The strongest signals in the host highlighted neuromodulatory G-protein coupled receptors and oxidation–reduction processes. We also detected Camponotus structural and gene-regulatory proteins. In the parasite, we found enrichment of Ophiocordyceps proteases and frequent involvement of novel small secreted proteins with unknown functions. From these results, we provide new hypotheses on potential parasite effectors and host targets underlying zombie ant behavioral manipulation. [ABSTRACT FROM AUTHOR]

Camponotus floridanus ants show altered behaviors followed by a fatal summiting phenotype when infected with manipulating Ophiocordyceps camponoti-floridani fungi. Host summiting as a strategy to increase transmission is also observed with parasite taxa beyond fungi, including aquatic and terrestrial helminths and baculoviruses. The drastic phenotypic changes can sometimes reflect significant molecular changes in gene expression and metabolite concentrations measured in manipulated hosts. Nevertheless, the underlying mechanisms still need to be fully characterized. To investigate the small molecules producing summiting behavior, we infected C. floridanus ants with O. camponoti-floridani and sampled their heads for LC–MS/MS when we observed the characteristic summiting phenotype. We link this metabolomic data with our previous genomic and transcriptomic data to propose mechanisms that underlie manipulated summiting behavior in "zombie ants." This "multiomic" evidence points toward the dysregulation of neurotransmitter levels and neuronal signaling. We propose that these processes are altered during infection and manipulation based on (1) differential expression of neurotransmitter synthesis and receptor genes, (2) altered abundance of metabolites and neurotransmitters (or their precursors) with known behavioral effects in ants and other insects, and (3) possible suppression of a connected immunity pathway. We additionally report signals for metabolic activity during manipulation related to primary metabolism, detoxification, and anti-stress protectants. Taken together, these findings suggest that host manipulation is likely a multi-faceted phenomenon, with key processes changing at multiple levels of molecular organization. [ABSTRACT FROM AUTHOR]

Social insects often share tasks among individuals. In this study, we analyzed the foraging activity of ants (Camponotus japonicus) and recorded the daily passage event counts of individual workers between a nest chamber and a foraging arena in five monodomous colonies. We proposed two hypotheses on the time series of foraging frequency by individual worker ants as follows: (i) for the time series of foraging frequency by individual worker ants, the foraging frequency on a certain day could be expressed by the product of the foraging frequency on the previous day and the exponential of a random number. (ii) The random numbers are correlated between some pairs of worker ants. The results for the five tested ant colonies showed that the probability of total daily passage counts (the sum of an individual's passage count) followed a log-normal distribution. The worker ants behaved differently in terms of active days and foraging frequency. However, for > 54% of the worker ants, the probability of the daily passage count was characterized by a log-normal distribution, and these worker ants performed > 72% of the tasks in each colony. Furthermore, for > 73% of the worker ants, the time development of the passage count was mathematically modeled; the logarithmic first difference between the passage counts on a certain day and those on the previous day was a random normal variable. These results support hypothesis (i). Additionally, the random numbers that were equivalent to the logarithmic first difference were correlated for some pairs of worker ants. These results support hypothesis (ii). [ABSTRACT FROM AUTHOR]

We report the first observations of Opheodrys vernalis (Smooth Greensnake) communal oviposition of 137 eggs within an active nest mound of Lasius interjectus (Citronella Ant) in a northern Illinois prairie. This is the first North American documentation of snake oviposition, and communal oviposition, within an active ant nest. The communal Smooth Greensnake nest is also the largest reported to date. We observed other instances of Smooth Greensnakes nesting in proximity to Citronella Ant nests beneath artificial cover objects, which may indicate a facultative inquiline relationship. Other documented North American associations between snakes and ants have been with Formica mound-building ants in which snakes used mounds as refugia or hibernacula. The only other North American observation of a reptile nesting within an active ant mound was with Anolis carolinensis (Green Anole) and Odontomachus brunneus ants in Florida (Kwapich 2021). Other accounts of inquiline oviposition by snakes within active ant nests have been from Central America, South America, and Africa, predominantly within the fungal-farming chambers of leaf-cutter ant genera Acromyrmex, Anochetus, Apterostigma, Atta, Camponotus, Platythyrea, and Strumigenys. [ABSTRACT FROM AUTHOR]

A new clown beetle species, Bacanius neoponerae, is described from Mexican nests of the arboreal ponerine ant Neoponera villosa found in the tank bromeliad Aechmea bracteata. Adult beetles were found in brood chambers or inner refuse piles, but also outside the ant nests, in decaying organic matter between the bromeliad leaves. No direct interactions between ants and microhisterid beetles could be observed. Several lines of evidence suggest a close relationship either with the ants, specific microhabitats within the ant nests or the bromeliads. Sample site elevation, colony size, monthly rainfall and collecting site were the main variables predicting the association. Almost half of the N. villosa colonies were associated with the microhisterids, and larger colonies favored their presence, especially during the driest months of the year. Two specimens were found in a nest of another ant species, Camponotus atriceps, also inhabiting A. bracteata. The new species is the seventh of the genus Bacanius reported from Mexico. This is the second time a species of this genus is associated with ants, and the fourth record of a histerid beetle cohabiting with ponerine ants. The small size of these beetles and their very protective body structure may facilitate their cohabitation with such aggressive hosts. [ABSTRACT FROM AUTHOR]

In Bariq Aseer Province, South Saudi Arabia, insect succession patterns on rabbit carcasses were examined from 17 June to 6 August 2020 and from 15 February to 6 March 2021. Fresh, bloated, decay, and dry stages of decomposition were all studied. Bloated and decay stages exhibited higher taxonomic diversity than fresh and dry stages. Eighteen species, three orders, and eight families were assembled and identified. Ten taxa were active in two seasons, while six species were recorded in the winter season only [Chrysomya marginalis (Wiedemann 1830), Scarabaeus acuticollis Motschulsky, 1849, Hister sp., Trichomyrmex destructor (Jerdon 1851), Monomorium sp, and Brachyponera sennaarensis (Mayr 1862)] and two species in the summer season [Camponotus aegyptiacus Emery 1915 and C. fellah Dalla Torre 1893]. A new species of beetle S. acuticollis was discovered that was not recorded in any region of Saudi Arabia. On the other hand, this study also reported on the ant species Monomorium bicolor and another species of beetle, Onthophagus variegatus (Fabricius 1798). But other members of the same genus had been recorded in Saudi Arabia in the past. Insect taxa associated with forensic investigations in the region of Bariq Aseer Province, South Saudi Arabia, were significant in determining the postmortem interval (PMI) during both seasons and different stages of decomposition. [ABSTRACT FROM AUTHOR]

Distinctive chemical signatures have the potential to serve as discriminatory cues for olfactory recognition mechanisms. Cuticular hydrocarbon (CHC) profiles are among the most prominent chemical signatures in insects that can be highly diverse even among closely related species and between populations with similar ecology. Particularly within the major insect order Hymenoptera, CHC profiles are characterized by high complexity and variation with the potential to evolve rapidly. In this study, we found two very distinct CHC chemotypes distinguishing sympatric colonies of the African carpenter ant Camponotus maculatus (Hymenoptera: Formicinae). These chemotypic differences were mainly detected on the surface profiles of eggs produced by either queens or isolated worker groups. In one chemotype, queen- and worker-laid eggs are very similar. This is largely contrasted by the other chemotype, where queen-laid eggs clearly differ from worker-laid eggs with several prominent queen-exclusive compounds. However, workers display a stable behavior of discriminating against and selectively disposing of worker-laid eggs i.e., worker policing, independent of egg chemotype. Furthermore, genetic barcoding of workers revealed a clear separation between colonies characterized by producing these two distinct egg chemotypes, which may indicate that these colonies belong to a cryptic species complex. Interestingly, worker policing behaviour appears to be evolutionarily conserved, despite the strikingly different egg surface profiles. [ABSTRACT FROM AUTHOR]

Social isolation negatively affects health, induces detrimental behaviors, and shortens lifespan in social species. Little is known about the mechanisms underpinning these effects because model species are typically short-lived and non-social. Using colonies of the carpenter ant Camponotus fellah, we show that social isolation induces hyperactivity, alters space-use, and reduces lifespan via changes in the expression of genes with key roles in oxidation-reduction and an associated accumulation of reactive oxygen species. These physiological effects are localized to the fat body and oenocytes, which perform liver-like functions in insects. We use pharmacological manipulations to demonstrate that the oxidation-reduction pathway causally underpins the detrimental effects of social isolation on behavior and lifespan. These findings have important implications for our understanding of how social isolation affects behavior and lifespan in general. The mechanisms behind the negative effects of social isolation on social species are unclear. Here, the authors examine colonies of carpenter ants, finding that behavioral, physiological, and lifespan changes may be caused by oxidative stress. [ABSTRACT FROM AUTHOR]

Simple Summary: Florida carpenter ants (Camponotus floridanus) live in colonies comprised of thousands of workers. The smallest workers, known as minors, engage in routine tasks such as nursing and foraging while the largest workers, known as majors, are thought to be soldiers specialized for defending the nest. How ant colonies allocate their workforce to address the dynamic and ever-changing needs of the colonies remains an open question in the field, but current evidence suggests that ant social behavior likely results from a combination of genetic/epigenetic, physiological, and systems-level processes. Here, we extend these studies by investigating the role of olfactory sensitivity in regulating ant behavior. Minor workers exhibited significant shifts in olfactory sensitivity and odor coding as they aged and switched tasks. The olfactory sensitivity of majors, however, remained relatively stable as they aged. From these studies, we also identified a single compound, 3-methylindole, which elicited significantly higher olfactory responses and aversive behavior in nurses compared to foragers, suggesting that this chemical may have a role in brood care. Overall, these studies support the hypothesis that changes in olfactory sensitivity play an important role in regulating social behavior in ants. Age-related changes in behavior and sensory perception have been observed in a wide variety of animal species. In ants and other eusocial insects, workers often progress through an ordered sequence of olfactory-driven behavioral tasks. Notably, these behaviors are plastic, and workers adapt and rapidly switch tasks in response to changing environmental conditions. In the Florida carpenter ant, smaller minors typically perform most of the work needed to maintain the colony, while the larger majors are specialized for nest defense and rarely engage in these routine tasks. Here, we investigate the effects of age and task group on olfactory responses to a series of odorant blends in minor and major worker castes. Consistent with their respective roles within the colony, we observed significant age-associated shifts in the olfactory responses of minors as they transitioned between behavioral states, whereas the responses of majors remained consistently low regardless of age. Furthermore, we have identified a unitary compound, 3-methylindole, which elicited significantly higher responses and behavioral aversion in minor nurses than in similarly aged foragers suggesting that this compound may play an important role in brood care. Taken together, our results suggest that age- and task-associated shifts in olfactory physiology may play a critical role in the social organization of ant colonies. [ABSTRACT FROM AUTHOR]

Coevolutionary relationships between parasites and their hosts can lead to the emergence of diverse phenotypes over time, as seen in Ophiocordyceps fungi that manipulate insect and arachnid behaviour to aid fungal spore transmission. The most conspicuous examples are found in ants of the Camponotini tribe, colloquially known as 'zombie ants'. While the behaviours induced during infection are well described, their molecular underpinnings remain unknown. Recent genomics and transcriptomics analyses of Ophiocordyceps camponoti-floridani have identified several highly upregulated biomolecules produced by the fungus during infection of Camponotus floridanus. Among them is an ergot alkaloid related to the mycotoxin aflatrem, known to cause 'staggers syndrome' in cows. Staggering, defined as unsteady movements side to side, is also observed in C. floridanus ants during late-stage infection. To test whether aflatrem-like compounds could be responsible, we injected healthy ants with aflatrem and recorded their behaviour for 30 min. Using both the automated object-tracking software MARGO and manual behavioural quantification, we found that aflatrem reduced ant activity and speed and increased staggering behaviours. To examine underlying transcriptomic changes, we performed RNA-seq on the heads of aflatrem-injected ants, keeping in step with previous transcriptomic work on Ophiocordyceps -manipulated ants. We identified 261 genes that were significantly dysregulated in the aflatrem-injected ants compared to sham-injected controls. When compared with RNA-seq data from Ophiocordyceps -manipulated ants, we found that both groups shared 113 differentially regulated genes. These included sensory neuron membrane protein genes, several odorant-binding protein genes and musculoskeletal genes such as titin and obscurin. Together, these results indicate that aflatrem-like compounds significantly affect neuromuscular and sensory function in C. floridanus. The conservation of staggers phenotype between C. floridanus and Bos taurus suggests that behaviour-manipulating strategies exhibited across the Tree of Life may be more similar in approach, if not widely different in application, than we realize. • Aflatrem causes staggered walking in zombie ants. • Aflatrem triggers the dysregulation of many neuromuscular and olfactory genes. • Microinjection of ants offers a way to test behaviour-modifying effectors. • The computational program MARGO can identify subtle behavioural changes in ants. • A new Venn diagram (kaleidoscope) can visualize multiple RNA-seq data sets. [ABSTRACT FROM AUTHOR]

[Objectives] To investigate the potential function of the mandibular gland of male Camponotus japonicus Mayr, which have the most developed mandibular glands among all castes of this species. [Methods] The morphology, surface ultrastructure and internal characteristics of secretory cells of the mandibular glands of male ants at different ages were observed using a light microscope (LM), a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Volatile mandibular gland secretions were extracted with n-hexane and analyzed using gas chromatography-mass spectrometry (GC-MS). [Results] (1) The mandibular glands of males consist of a cluster of secretory cells and a reservoir. Each cluster of secretory cells contains a secretory cell and a conducting cell. The total length of the mandibular gland, reservoir length and the diameter of secretory cells, were largest in the 1st month after eclosion. Secretory cells were initially moist, full and smooth, but became progressively less so as males aged. (2) The cytoplasm of secretory cells contains a lot of organelles, such as mitochondria, endoplasmic reticulum, Golgi apparatus, lipid droplets, other granular secretions and developed end apparatus. From the 1st to 4th month after eclosion, secretory cells have a low density of secretory granules, secretory vesicles gradually become more abundant and mitochondria surround the nucleus and microvilli. From the 8th to 9th month after eclosion, mitochondria become scattered among the nucleus, microvilli and secretory granules, the density of secretory granules increases, secretory vesicles disappear, and the cells began to disintegrate. (3) GC-MS analysis indicates that the least quantity of secretions was emitted during the 3rd month after eclosion and the most during the 9th month. A total of 23 volatile chemical components were identified, of which 2-hydroxy-6-methylbenzoate, Methyl anthranilate and (-)-Mellein were the most common in each period. The relative amounts of these three chemicals varied with age. [Conclusion] The secretory activity of the mandibular gland of male C. japonicus is highest in the initial stage of emergence, and gradually decreases with age. Determining the biological function of the chemicals secreted requires further investigation. [ABSTRACT FROM AUTHOR]

This study is on the ecology and population dynamics of the membracid Otinotus oneratus Walker on its host plant Tamarindus indica L. The daily activity of O. oneratus when analysed revealed that it was active during 11:00 and 16:00 hr, and on extremely warmer days. Adults preferred woody internodal parts, while the early nymphal stages fed on the axil of the leaves, and the later nymphs fed on the internodal parts along with the adults. The resting posture of the adults were found to be in position with its head directed upwards on its host plant. The mean number of nymphs resting in a posture facing towards and away from node was 79.7 and 17.1 respectively; with adults, for males and females it was 3.0 and 4.6 upwards facing, and for downwards it was 2.4 and 3.6, respectively. The individuals were sluggish, and when disturbed, moved in a spiral manner around the twig, and stopped after moving some distance. Mating occurred for 5 min, followed by a female preoviposition period of 3 days. Eggs were elongate and white and laid in 'V' shaped manner, arranged in two rows with 12-19 eggs in each row. Parental care was exhibited with the females guarding 71.4 to 83.3% of egg masses. The incubation period varied from 8-12 days. Hatching occurred during the morning hours, and the nymphs were slow moving, showing a strong myrmecophilous mutualism, regularly attended by the large black ant Camponotus compressus F. (56.5- 92.9%). Predation by Gonatocerus brevifuniculatus Subba Rao and Mirufens afrangiata Viggiani and Hayat of eggs wqas observed. O. oneratus nymphs mimicked the thorns of the host plant, but they were brightly coloured (in contrast to the twigs). The occurrence of nymphs and adults reached a peak in December and January. The present study also assessed the population dynamics in relation to weather factors. [ABSTRACT FROM AUTHOR]

The Argentine ant, Linepithema humile (Mayr) (Formicidae: Dolichoderini), has become one of the most invasive species in the world, causing economic and ecological imbalances due to its ability to dominate new environments. Although borated liquid baits are effective for its chemical control, as well as for other nectivorous ants, there are particularities in the response of each species. In feeding‐motivation controlled experiments, L. humile accepts boric acid more than borax (sodium borate); meanwhile, the opposite occurs with the carpenter ant, Camponotus mus (Roger) (Formicidae: Camponotini). To understand which aspects of the borax bait negatively affect its palatability for the Argentine ants, we analysed the individual feeding behaviour on sugar baits considering the number of boron‐equivalents offered, the sodium concentration and the alkaline pH and then compared their response to that of C. mus. We found that L. humile rejected borax baits more than the mixture of boric acid and sodium borate. However, they accepted the boric acid bait similar to the plain sugar solution (control). The addition of sodium (NaCl) to sugar solutions shortened feeding time in this species, but not in the carpenter ant. Finally, alkalinizing the bait with L‐arginine or potassium hydroxide (KOH) generated shorter intake times in L. humile, but not in C. mus. Our results showed that both the presence of sodium and a basic pH may discourage ingestion in the Argentine ant and also evidence the different responses towards the baits that can occur among ant species that share similar feeding habits. Understanding particular responses of the target Argentine ant is a key tool for more specific and efficient pest control strategies. [ABSTRACT FROM AUTHOR]