The big data era in biology is underway, but the study of organismal form has been slow to capitalize on advances in imaging and computation. Imaging approaches can digitize whole organisms, but low throughput has limited the effort to document morphological diversity. Here, within the open science initiative 'Antscan', we applied high-throughput synchrotron X-ray microtomography to capture phenotypes across a diverse and ecologically dominant insect group: ants. At https://www.antscan.info, we provide 2,193 whole-body three-dimensional ant datasets from 212 genera and 792 species to broadly cover the ant phylogeny with a global scope, also pairing phenomic data with genome sequencing projects. Scans acquired with standardized parameters facilitate automated analysis, and free access to data can broaden the audience and incentivize methods development. Antscan presents a scalable approach to create libraries of diverse anatomies, heralding an era of studies on the evolution, structure and function of organismal phenotypes.

Abstract Lineage-specific genes are widespread and have been implicated as phenotypic innovation inducers 1 , but how they acquire complex developmental functions remains poorly understood. Ant queens and workers develop dramatically different organ sizes from identical genomes under juvenile hormone (JH) control 2 , yet the molecular effectors translating JH signalling into caste-specific organ growth remain unknown. Here we identify torch , a Hymenoptera-restricted gene, as the most consistently gyne-biased and JH-responsive gene across 68 ant species. Knockdown of torch in virgin queens of Monomorium pharaonis produces a worker-like, multi-organ growth-restricted phenotype. Mechanistically, torch harbours an E-box-like motif activated by the JH receptor Gce–Tai and acts as a GA-repeat-binding transcription factor that regulates Hippo signalling, the deeply conserved organ-size control pathway in animals. Expressing torch heterologously in mice and a growth-restricted Drosophila background shows that the gene retained its general growth-promoting activity across more than 700 million years of animal evolution in lineages that lack the gene, establishing that its function is mediated through conserved rather than ant-specific machinery. A lineage-specific gene can therefore acquire complex morphogenetic function by co-opting ancient organ-size circuitry, providing a general route by which novel genes can drive phenotypic innovation.

The ants of genus Syscia, are cryptic with an unequal distribution in Asia and the Americas; Currently, there are 34 species known in the New World, but only a mere 10 species are recognized in Asia. The New World species have been systematized, whereas Old World species are currently still at the stage of isolated species descriptions. Herewith a new species, namely Syscia chinensis sp. nov., is described and illustrated based on the worker caste. S. chinensis is the first species reported with 10-segmented antennae in this genus, and it is also one of the smallest minority species in this genus. These two characteristics readily distinguish the new species, and these morphological differences are supported by a phylogenetic analysis. A key based on the worker caste is provided for the known Asian species.

Camponotus and Colobopsis are two species-rich genera within the ant tribe Camponotini. Despite their non-sister phylogenetic relationship, pronounced morphological convergence has long complicated their taxonomic delineation. Here, we clarify the status of Colobopsis minus (Wang & Wu, 1994), comb. nov., a taxon historically misassigned to Camponotus, through an integrative approach combining COI phylogenetics, caste-specific morphometrics, and pupae type. We provide the first comprehensive description of all castes (minor and major workers, gynes, and males), alongside two taxonomic keys to Chinese Colobopsis species. Critical evidence for reclassification includes: (1) phragmotic major workers with Colobopsis-specific cephalic modifications; (2) naked pupae and (3) molecular phylogenetic analyses of COI barcode sequences, which robustly place C. minus within the Colobopsis clade. This study underscores the necessity of synthesizing phylogenetic data with detailed morphological analysis to disentangle complex taxonomic histories in hyperdiverse ant groups.

Ants originated over 150 million years ago through an irreversible transition to superorganismal colony life. Comparative analyses of 163 ant genomes, including newly generated whole-genome sequences of 145 ant species, reveal extensive genome rearrangements correlated with speciation rates. Meanwhile, conserved syntenic blocks are enriched with co-expressed genes involved in basal metabolism and caste differentiation. Gene families related to digestion, endocrine signaling, cuticular hydrocarbon synthesis, and chemoreception expanded in the ant ancestor, while many caste-associated genes underwent positive selection in the formicoid ancestor. Elaborations and reductions of queen-worker dimorphism and other social traits left convergent signatures of intensified or relaxed selection in conserved signaling and metabolic pathways, suggesting that a core gene set was used to diversify organizational complexity. Previously uncharacterized genetic regulators of caste development were confirmed by functional experiments. This study reconstructs the genetic underpinning of social traits and their integration within gene-regulatory networks shaping caste phenotypes.

Reproductive division of labor is one of the most prominent features of social insects. Yet, the neural mechanisms that govern this division and the associated behavioral differentiation among castes remain obscure. In this study, we systematically characterized the anatomical features of dopamine neurons in the brain of Monomorium pharaonis and compared the cell number and spatial distribution of these neurons across castes. We identified 17 anatomically distinct clusters of dopamine neurons in the ant brain, with cell numbers varying from ∼322 to ∼431 across castes. The major dopamine clusters are located in brain regions analogous to those in flies, with 2 clusters, PAL and PPL1 exhibiting significantly higher cell numbers in ants than in flies. Notably, 4 clusters, DAM, D1, DPL, and PPL2, showed remarkable variation in cell numbers across castes. Using single‐cell transcriptomics, we identified specific molecular markers for subdividing dopamine neurons. We validated the expression of multiple neuropeptide genes in specific dopamine clusters. In particular, we found that PPL2 cluster can be further divided into 2 subclusters, PPL2a and PPL2b, which are partially labeled by the peptide gene Nplp1 . PPL2b neurons, characterized by larger cell bodies, and present only in unmated queens and males, are absent in mature queens and workers. These neurons are located adjacent to Nlg2 ‐expressing lobular neurons, which are also absent in workers and may play a role in regulating mating behaviors. Our findings provide a foundation for further investigation into the neural mechanism underlying division of labor and caste‐specific behaviors in ant.

Throughout evolution, entomopathogenic (insect-pathogenic) fungi have played a pivotal role in regulating insect populations. However, little is known about ancient entomopathogenic fungi due to the scarcity of fossils displaying typical pathogenic structures on their presumed hosts. Here, we report two new fungi, Paleoophiocordyceps gerontoformicae sp. nov. and Paleoophiocordyceps ironomyiae sp. nov., from mid-Cretaceous Kachin amber (approx. 99 million years old). They share common traits with Ophiocordyceps and are associated with an ant pupa and a fly, respectively. These fossils are among the oldest fossil records of animal-pathogenic fungi. In addition, we performed a divergence time estimation analysis showing that Ophiocordyceps likely originated during the Early Cretaceous. We further compiled the hosts of extant Ophiocordyceps and inferred the evolution of host associations within the genus based on ancestral character state reconstruction. Our results suggest that Ophiocordyceps made a host jump from Coleoptera to Lepidoptera and Hymenoptera during the Cretaceous, and its subsequent speciation was probably related to the increase in diversity and abundance of its moth and ant hosts. Our results not only highlight the ecological significance of pathogenic fungi in Mesozoic terrestrial ecosystems, but also provide new insights into the coevolution between entomopathogenic fungi and host insects.

Camponotus japonicus is a widely distributed ant species in East and Southeast Asia and is an important natural enemy of agricultural and forestry pests. As a well-developed queen-right social insect species, a mature C. japonicus colony consists of thousands of individuals, including queens, gynes, males, and various forms of workers, each displaying different morphologies, physiologies, and behaviors related to their division of reproductive roles. Exocrine glands, as a vital part of social communication and organization, also reflect the functional specialization in each caste. In this study, we examined the function of one of the most important but less studied cephalic glands, the prepharyngeal gland (prePG), using transcriptome and metabolome data from four female castes and males of C. japonicus. We observed significant differences in gene expression patterns among various adult forms. As the core members of the colony, queen's exhibit enhanced immune defense functions, while gynes show stronger digestive capabilities. Minor and major workers, adapted to their more frequent extra-nest activities, secrete greater amounts of volatile components. Furthermore, we infer that the prePG may also play a role in larval fate determination. All these functions are available by releasing its secretions into the trophallactic fluid, thereby spreading across individuals within the colony. Based on the results of this study, future research could focus on regulating caste distribution and larval growth and development within C. japonicus colonies.

The Cretaceous is a key period for the evolution of ants. Zigrasimecia is a genus endemic to mid-Cretaceous Kachin amber. In previous studies, four species of the genus based on worker and/or queen castes have been reported and three wing types of gyne within the genus have been described. We report here a new species, Zigrasimecia zui sp. nov., based on a worker specimen, the morphological details of which are investigated and reconstructed by using Micro-CT and other techniques. Moreover, a new wing type is reported based on a gyne specimen. By comparison with the compound eyes and other structures of extant ants, we propose that species of Zigrasimecia had the capability for surface-dwelling or burrowing. This work augments the species diversity of Zigrasimecia, and provides direct evidence for the variety of ecological niches that may have been occupied by members of this genus.

The invasion of exotic ant species in China presents significant challenges to ecosystems, agriculture, and the economy. This paper provides an in-depth analysis of China's ongoing battle with exotic ants, examining the factors contributing to their introduction and establishment. It explores the responses implemented by the decision makers, including capacity building, establishment of research institutions, and legislative measures. Limitations and gaps in the current strategies are identified, highlighting the need for regional collaboration, increased awareness, and strengthened early detection and response systems. Furthermore, the paper emphasizes the importance of conducting research to understand various exotic ant species' ecological and economic impacts, facilitating the development of targeted and effective management approaches. By adopting a comprehensive and coordinated approach, China can mitigate the impacts of ant invasions and safeguard its biodiversity, agriculture, and economy. This analysis underscores the significance of collective efforts in addressing the ongoing battle with exotic ants and preserving the well-being of ecosystems, economies, and the society.

Phenotypic plasticity displayed by an animal in response to different environmental conditions is supposedly crucial for its survival and reproduction. The female adults of some ant lineages display phenotypic plasticity related to reproductive role. In pharaoh ant queens, insemination induces substantial physiological/behavioral changes and implicates remarkable gene regulatory network (GRN) shift in the brain. Here, we report a neuropeptide neuroparsin A (NPA) showing a conserved expression pattern associated with reproductive activity across ant species. Knock-down of NPA in unmated queen enhances ovary activity, whereas injection of NPA peptide in fertilized queen suppresses ovary activity. We found that NPA mainly affected the downstream gene JHBP in the ovary, which is positively regulated by NPA and suppression of which induces elevated ovary activity, and shadow which is negatively regulated by NPA. Furthermore, we show that NPA was also employed into the brain-ovary axis in regulating the worker reproductive changes in other distantly related species, such as Harpegnathos venator ants.

Despite the increasing focus on intangible cultural heritage tourism, there is a lack of research on the ecological protection behaviors of tourists in these contexts. With UNESCO’s continuous refinement of the World Heritage system, intangible cultural heritage has gradually become a focal point for tourism development and protection. While such tourism can promote the preservation and transmission of heritage, it also introduces ecological environmental issues that need to be addressed. Therefore, exploring the driving mechanisms of tourists’ ecological protection behavior holds significant practical value. Based on the Theory of Planned Behavior (TPB), this study constructs a driving model of tourists’ ecological protection behavior. It examines the influence of behavioral attitude, subjective norms, perceived behavioral control, and personal norms on tourists’ willingness to engage in ecological protection. By distributing questionnaires both offline and online, we analyzed data from 312 valid responses. The results indicate that all four factors have a significant positive impact on tourists’ willingness to engage in ecological protection behavior. Among these factors, personal norms and behavioral attitude have a relatively larger influence. The findings provide valuable references for intangible cultural heritage sites in China and regions with similar cultural and tourism dynamics.

The clonal raider ant, Ooceraea biroi, is a queenless species that reproduces asexually, and these traits make it an attractive model system for laboratory research. However, it is unclear where on the ant phylogeny these traits evolved, partly because few closely related species have been described and studied. Here, we describe a new raider ant species, Ooceraea hainingensissp. nov., from Zhejiang, China. This species is closely related to O. biroi but can be distinguished by the following features: 1) workers of O. hainingensissp. nov. have an obvious promesonotal suture and a metanotal groove, whereas these characters are ambiguous in O. biroi; and 2) the subpetiolar process of O. hainingensis is prominent and anteroventrally directed like a thumb with sublinear posteroventral margin, while in O. biroi, it is anteroventrally directed but slightly backward-bent. Molecular phylogenetic analyses confirm that O. hainingensis is genetically distinct from O. biroi. Importantly, unlike O. biroi, O. hainingensis has a queen caste with wings and well-developed eyes. This suggests that the loss of the queen caste and transition to asexual reproduction by workers is specific to O. biroi and occurred after that species diverged from closely related congeneric species.

A new Chinese ant species Carebara laeviceps sp. nov. is described based on the major and minor workers. This species is most similar to C. lusciosa (Wheeler, 1928) due to a spineless propodeum, the absence of horns, and a smooth head capsule. It is distinguished by the following features: (1) antenna 10-segmented; (2) katepisternum rugose-reticulate; (3) in major workers, lateral sides of head in full-face view parallel; (4) metanotal groove distinct, anterodorsal corner forming an acute tooth behind metanotal groove. Moreover, an updated key to Chinese Carebara species is presented based on major workers, with a checklist comprising a total of 36 Chinese Carebara species and subspecies. Morphological structures and scanning electron micrographs of the newly discovered species’ minor and major workers are provided.

Ants are traded as pets across the globe, but if introduced outside of their native ranges they could become invasive with dire environmental and economic consequences. We demonstrate how geotagged e-commerce information can be utilized for biosecurity risk assessment. We monitored online pet ant sales in China and found that 58,937 ant colonies from 209 species were sold by 206 sellers in 89 cities across the country in six months. More than a quarter of the traded species were not native to China. Trait-based analysis revealed that the most sought-after ants have higher invasive potential than less popular species. Climate-based distribution models suggest that 24.7 % of the non-native species could find suitable climatic conditions in the cities from which they were sold. If released, pet ants could interfere with urban ecosystems, rural agriculture, and spill over to threaten back-country habitats with high biodiversity. Based on our analysis we offer guidelines on wildlife trade policy and management: (1) we provide a list of potentially invasive ants sold in each Chinese city; (2) we identify the highest risk of a non-native ant introduction at the Greater Bay area of subtropical southern China; (3) we highlight the absence of within-country permitting requirements which resulted in invasive species being transported across Chinese provincial lines. Worldwide, similar wildlife trade records are only accessible to conservation practitioners cognizant of local languages and customs. We encourage grassroot web scraping of under-monitored, fast-developing economies to gather information crucial for guiding regional policy decisions.

The little fire ant Wasmannia auropunctata (Roger) is a major invasive species that seriously threatens the biodiversity of invaded areas. W. auropunctata was first reported in Chinese mainland in 2022 and its impact on native species is still unknown. To evaluate the impact of W. auropunctata invasion on the ant communities in southern China, a series of interspecific competition experiments were conducted in this study. The individual aggression index and group aggression experiments showed the advantage of W. auropunctata in competition with 5 resident ants under equal worker numbers. When encountering Anoplolepis gracilipes, Camponotus nicobarensis, Tetramorium bicarinatum, Polyrhachis dives, and Solenopsis invicta, W. auropunctata gradually gained a competitive advantage with an increase in its number of workers. In the group aggression experiments with equal worker numbers, there was a negative correlation between the body length and mortality rate of resident ants. The results of the foraging behavior experiments showed that W. auropunctata was able to dominate food resources under competition with Carebara diversa, which also displayed weak competition in the group aggression bioassay. In addition, the abilities to recruit workers and retrieve food were inhibited under competition with S. invicta and T. bicarinatum. The results of the nesting behavior experiments showed that in the 24-h bout of space resource competition, W. auropunctata was dominant over C. diversa, S. invicta, and T. bicarinatum. The results of this study show that W. auropunctata has certain advantages in competition for food and space resources over resident ants in southern China, and some resident ant species may be replaced in the future.

The iron maiden ant, which was first described as †Zigrasimecia Barden & Grimaldi, 2013, received its nickname for bearing a unique mandible and ferocious mouthparts covered by spiky, columnar-shaped denticles. Here, we describe a new species based on an alate female preserved in 99-Ma Kachin amber – †Zigrasimecia goldingot sp. nov. – which displays several diagnostic features shared with the known species of this genus. Such features include the peg-like mandibular setae, setae of the labrum, clypeal denticles, and an omega-shaped head capsule. Our findings suggest a high diversity among †Zigrasimeciinae and support the grouping of this subfamily. Our work adds to the biodiversity of †Zigrasimecia and †Zigrasimeciinae, and explores the morphological and functional aspects, as well as the early appearance of the unique mouthparts in this ancient ant group.

The paralysis behavior of some ponerine ants when foraging may be important for food storage and colony development. However, how workers invest in paralysis under different prey circumstances is often overlooked. Here, we report the prey-foraging behavior and paralysis behavior of Harpegnathos venator under different food supply conditions. Solitary hunting was the main foraging mode of H. venator, with occasional simple collective hunting. Nymphal cockroaches with high activity were the most attractive to H. venator. In the experiment, we found that the stings of H. venator completely paralyzed the cockroaches. The stinging time was significantly longer at a higher prey activity level and for larger cockroaches. In addition, there was no significant difference in the stinging time of H. venator for different prey densities. The results showed that the longer similar cockroaches were stung, the longer it took for them to revive and move. These results are helpful for further understanding the behavioral mechanism underlying the food storage of live prey by predatory insects.

For social insects such as ants, the internal organs are likely important in understanding their eusocial behavior and evolution. Such organs, however, are rarely preserved on fossils. In each of the few cases reporting exceptionally fossilized soft tissues in arthropods, the nervous, muscular and cardiovascular systems have been described individually, but never in combination. Here, we report a female specimen (gyne) of the extinct ant group-†Zigrasimecia-included in a Cretaceous amber piece from Kachin, Myanmar, with an almost complete system formed by various internal organs. These include the brain, the main exocrine system, part of the digestive tract, and several muscle clusters. This research expands our knowledge of internal anatomy in stem group ants. As the gyne bears a morphologically unique labrum, our specimen's internal and external features support the notion that the early ant may have special ecological habits during the Cretaceous period.