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The males of the family Formicidae of the Malagasy region, including the islands of the southwest Indian Ocean (Madagascar, Mauritius, Reunion, Comoros, and Seychelles) are reviewed. A male-based synopsis of each subfamily and genera are provided. A richly illustrated male-based key to the eight subfamilies and 72 genera for which males are known are provided. The key is specific to the ant genera and species of the Malagasy region. Terminologies for morphology and wing cells are also reviewed. The keys are a product of three decades of collecting across the region. Despite efforts to collect males for all genera, males from five genera (Brachyponera, Chrysapace, Dicroaspis, Linepithema, Ochetellus) were included in the keys based on males from species collected outside the region, and males from one genus (Parvaponera) are unknown globally and not included in the key.

Abstract Novel methods for sampling and characterizing biodiversity hold great promise for re-evaluating patterns of life across the planet. The sampling of airborne spores with a cyclone sampler, and the sequencing of their DNA, have been suggested as an efficient and well-calibrated tool for surveying fungal diversity across various environments. Here we present data originating from the Global Spore Sampling Project, comprising 2,768 samples collected during two years at 47 outdoor locations across the world. Each sample represents fungal DNA extracted from 24 m3 of air. We applied a conservative bioinformatics pipeline that filtered out sequences that did not show strong evidence of representing a fungal species. The pipeline yielded 27,954 species-level operational taxonomic units (OTUs). Each OTU is accompanied by a probabilistic taxonomic classification, validated through comparison with expert evaluations. To examine the potential of the data for ecological analyses, we partitioned the variation in species distributions into spatial and seasonal components, showing a strong effect of the annual mean temperature on community composition.

The field cricket, Gryllus madagascarensis, is a sustainable and nutritious food resource that has the potential to mitigate global malnutrition. Feeds provided to this cricket can influence its growth parameters, nutritional content, and the cost of raising it for food. The current study aimed to evaluate the effects of feeds formulated from weeds, agro-byproducts, and chicken feed (control) on the growth parameters and nutritional content of G. madagascarensis. The formulated feeds included CFB (25.0% protein), CFC (24.5% protein), CFD (24.0% protein), CFE (23.5% protein), CFF (22.5% protein), CFG (21.5% protein), CFH (20.0% protein), CFI (14.5% protein), and CFJ (13.5% protein), and chicken feed (CFA) (28% protein) was used as the control. The formulation of the feeds was based on the acceptability and protein content of the 12 selected weeds and agro-byproducts. Proximate, mineral, and fatty acid analyses were conducted to determine the nutrient content of each feed, as well as the crickets raised on these feeds. The fastest development time was recorded with CFE and CFC. The highest survivorship (98%) was observed in CFG, CFE, and CFC. The highest body mass (1.15 g) and body length (26.80 mm) were observed in crickets fed CFG. By comparison, crickets fed control feed averaged a body mass of 0.81 g and a body length of 23.55 mm. The feed conversion ratio for G. madagascarensis fed CFG, CFE, and CFC was 1.71. Crickets raised on CFH and CFG had the lowest cost of feeding per kg live mass gain. Crickets fed on CFF had the highest quantity of protein (67%), followed by those fed CFG (65% protein); crickets with the lowest protein content (50%) were fed CFJ. Crickets fed on CFG had the highest mineral content. Linoleic acid, oleic acid, and palmitic acid were the major fatty acids. The findings indicate that formulated feeds from weeds and agro-byproducts have great potential to be used as an alternative feed source for crickets for two reasons: their capacity to positively influence the biology and nutrition of the cricket, and they can serve as an inexpensive replacement for chicken feed.

Morphometric analyses of male genitalia are routinely used to distinguish genera and species in beetles, butterflies, and flies, but are rarely used in ants, where most morphometric analyses focus on the external morphology of the worker caste. In this work, we performed linear morphometric analysis of the male genitalia to distinguish Monomorium and Syllophopsis in Madagascar. For 80 specimens, we measured 10 morphometric characters, especially on the paramere, volsella, and penisvalvae. Three datasets were made from linear measurements: mean (raw data), the ratios of characters (ratio data), and the Removal of Allometric Variance (RAV data). The following quantitative methods were applied to these datasets: hierarchical clustering (Ward’s method), unconstrained ordination methods including Principal Component Analysis (PCA), Non-Metric Multidimensional Scaling analyses (NMDS), Linear Discriminant Analysis (LDA), and Conditional Inference Trees (CITs). The results from statistical analysis show that the ratios proved to be the most effective approach for genus-level differentiation. However, the RAV method exhibited overlap between the genera. Meanwhile, the raw data facilitated more nuanced distinctions at the species level compared with the ratios and RAV approaches. The CITs revealed that the ratios of denticle length of the valviceps (SeL) to the paramere height (PaH) effectively distinguished between genera and identified key variables for species-level differentiation. Overall, this study shows that linear morphometric analysis of male genitalia is a useful data source for taxonomic delimitation.

The male of the myrmicine genus Erromyrma is described for the first time on the basis of two specimens of Erromyrma latinodis (Mayr, 1872) collected in northern Madagascar. We used COI barcoding to confirm the identification of the male specimens as conspecific with Erromyrma latinodis. We provide an illustrated male-based key to the four Myrmicinae tribes (Attini, Crematogastrini, Solenopsidini, Stenammini) and to the Solenopsidini genera (Adelomyrmex, Erromyrma, Solenopsis, Syllophopsis and Monomorium) for the Malagasy region.

The West-Palearctic region is a diversity hotspot for the ant genus Aphaenogaster. Species in this region are characterized by high morphological variation, which has led to their subdivisioninto different infrageneric groups. The very first classification in three subgenera, dated 1915, was gradually replaced by eight species-groups. To probe the evolutionary consistency of these species-groups, we sequenced 46 species from all eight species-groups and biogeographic sectors of the region, using one mitochondrial (COI) and six nuclear markers (EPICs), and interpreted the results by integrating qualitative morphology. Our results demonstrate the non-monophyly of all formerly recognized subgenera and species-groups, except for the crocea group. We use the phylogeny and morphological characters to propose a new classification of six monophyletic species-groups (crocea, gibbosa, graeca, pallida, sardoa, subterranea). The pallida, subterranea and sardoa (formerly testaceopilosa) groups attain monophyletic status by reassigning a few taxa. The gibbosa group is to be considered exclusively Western-Mediterranean until further assessments of similar Eastern species. The new graeca group is established by including former members of the splendida and subterranea groups, while the polyphyletic cecconii, obsidiana, and splendida groups are dismissed. Notably, the first is not part of the tropical Deromyrma clade as previously thought, while at least two independent clades which require further investigation are composed of species from both the cecconii and splendida groups, suggesting repeated morphological convergences based on similar ecological adaptations. Finally, A. cardenai is confirmed to be a significantly divergent lineage. In addition, three Aphaenogaster species are moved to different genera: Messor asmaae (Sharaf, 2018) comb. nov., Messor isekram (Bernard, 1977) comb. nov., and Pheidole sarae (Sharaf, 2018) comb. nov. Further studies should address the evolutionary relationships between the clades recovered in this study.

The Camponotus subgenus Myrmosaga subgen. rev. from the Malagasy region is revised based on analysis of both qualitative morphological characters and morphometric traits. The multivariate analysis used the Nest Centroid (NC)-clustering method to generate species hypotheses based on 19 continuous morphological traits of minor workers. The proposed species hypotheses were confirmed by cumulative Linear Discriminant Analysis (LDA). Morphometric ratios for the subsets of minor and major workers were used in species descriptions and redefinitions. The present study places the subgenus Myrmopytia syn. nov. in synonymy to Myrmosaga. It recognizes 38 species, of which 19 are newly described: C. aina sp. nov., C. aro sp. nov., C. asara sp. nov., C. atimo sp. nov., C. bemaheva sp. nov., C. bozaka sp. nov., C. daraina sp. nov., C. harenarum sp. nov., C. joany sp. nov., C. karsti sp. nov., C. kelimaso sp. nov., C. lokobe sp. nov., C. mahafaly sp. nov., C. niavo sp. nov., C. rotrae sp. nov., C. sambiranoensis sp. nov., C. tapia sp. nov., C. tendryi sp. nov., C. vano sp. nov. Eleven species are redescribed: C. aurosus Roger, C. cervicalis Roger, C. dufouri Forel, C. gibber Forel, C. hagensii Forel, C. hova Forel, C. hovahovoides Forel, C. immaculatus Forel, C. quadrimaculatus Forel, C. roeseli Forel, C. strangulatus Santschi. The following are raised to species and redescribed: C. becki Santschi stat. nov., C. boivini Forel stat. rev., C. cemeryi Özdikmen stat. rev., C. mixtellus Forel stat. nov., C. radamae Forel stat. nov. Camponotus maculatus st. fairmairei Santschi syn. nov., is synonymized under C. boivini. The following are synonymized under C. cervicalis: Camponotus cervicalis gaullei Santschi, syn. nov.; Camponotus perroti Forel, syn. nov.; Camponotus perroti aeschylus Forel, syn. nov.; Camponotus gerberti Donisthorpe, syn. nov. Camponotus dufouri imerinensis Forel, syn. nov. is a synonym of C. dufouri, Camponotus hova var. obscuratus Emery, syn. nov. is a synonym of C. hova, Camponotus quadrimaculatus opacata Emery, syn. nov. is a synonym of C. immaculatus, Camponotus maculatus st. legionarium Santschi, syn. nov. is a synonym of C. roeseli, Camponotus hova maculatoides Emery, syn. nov. is a synonym of C. strangulatus. The following are synonymized under C. quadrimaculatus: Camponotus kelleri Forel, syn. nov., Camponotus kelleri var. invalidus Forel, syn. nov., Camponotus quadrimaculatus sellaris Emery, syn. nov. As C. imitator Forel, C. liandia Rakotonirina & Fisher, and C. lubbocki Forel have been recently described and redescribed, only diagnoses and taxonomic discussions are provided. This revision also includes an illustrated species identification key, taxonomic discussions, images, and distribution maps for each species superimposed on the ecoregions of Madagascar.

Abstract Unprecedented technological advances in digitization and the steadily expanding open‐access digital repositories are yielding new opportunities to quickly and efficiently measure morphological traits without transportation and advanced/expensive microscope machinery. A prime example is the AntWeb.org database, which allows researchers from all over the world to study taxonomic, ecological, or evolutionary questions on the same ant specimens with ease. However, the reproducibility and reliability of morphometric data deduced from AntWeb compared to traditional microscope measurements has not yet been tested. Here, we compared 12 morphological traits of 46 Temnothorax ant specimens measured either directly by stereomicroscope on physical specimens or via the widely used open‐access software tpsDig utilizing AntWeb digital images. We employed a complex statistical framework to test several aspects of reproducibility and reliability between the methods. We estimated (i) the agreement between the measurement methods and (ii) the trait value dependence of the agreement, then (iii) compared the coefficients of variation produced by the different methods, and finally, (iv) tested for systematic bias between the methods in a mixed modeling‐based statistical framework. The stereomicroscope measurements were extremely precise. Our comparisons showed that agreement between the two methods was exceptionally high, without trait value dependence. Furthermore, the coefficients of variation did not differ between the methods. However, we found systematic bias in eight traits: apart from one trait where software measurements overestimated the microscopic measurements, the former underestimated the latter. Our results shed light on the fact that relying solely on the level of agreement between methods can be highly misleading. In our case, even though the software measurements predicted microscope measurements very well, replacing traditional microscope measurements with software measurements, and especially mixing data collected by the different methods, might result in erroneous conclusions. We provide guidance on the best way to utilize virtual specimens (2D z‐stacked images) as a source of morphometric data, emphasizing the method's limitations in certain fields and applications.

The subgenus Mayria of the genus Camponotus (Hymenoptera: Formicidae) is revised. The subgenus is endemic to Madagascar where it occupies a broad range of habitats, from deciduous and dry forest to rainforest. A taxonomic review is provided of this subgenus, integrating multiples lines of evidence including qualitative morphology and quantitative morphometry. Species hypotheses are formed by Nest Centroid clustering. In total, 36 species are treated, of which eleven are newly described: Camponotus andrianjaka sp. nov., Camponotus antsaraingy sp. nov., Camponotus chrislaini sp. nov., Camponotus claveri sp. nov., Camponotus ivadia sp. nov., Camponotus jjacquia sp. nov., Camponotus maintilany sp. nov., Camponotus norvigi sp. nov., Camponotus ihazofotsy sp. nov., Camponotus tsimelahy sp. nov., Camponotus zoro sp. nov. Five species are redescribed. Camponotus themistocles Forel stat. nov., is raised to species. In addition, the subgenus is redefined to include 39 species. Twenty-two previously described species are transferred to this subgenus and thirteen species previously placed in the subgenus are transferred out of the subgenus. Nine morphologically consistent species groups are delineated to facilitate species identification within the subgenus. This revision includes a classification, a key to species groups, and an updated key to species based on the minor worker caste.

This study describes the worker and queen castes of the Neotropical ponerine Corrieopone nouragues gen. nov., sp. nov., an ant from the tropical rainforest in French Guiana. Worker morphology of the taxon is compared with those of other Ponerinae and the similarities between them are discussed, refining the definition of character states for some diagnostic characters at the generic level, providing an identification key to the Neotropical genera, and making some adjustments to the taxonomic framework within the subfamily. Descriptions, diagnosis, character discussion, identification key, and glossary are illustrated with more than 300 images and line drawings. Open science is supported by providing access to measurement data for specimens of the new genus, a matrix of character states for all ponerine taxa evaluated in this study, and specimen data for all examined material. The new or revived combinations presented here are Pachycondyla procidua Emery, comb. rev., Neoponera curiosa (Mackay and Mackay), comb. nov., Leptogenys butteli (Forel), comb. nov., and Bothroponera escherichi (Forel), comb. nov. In addition, Leptogenys butteli is synonymized with Leptogenys myops (Emery), syn. nov.

Abstract Morphometric research is being applied to a growing number and variety of organisms. Discoveries achieved via morphometric approaches are often considered highly transferable, in contrast to the tacit and idiosyncratic interpretation of discrete character states. The reliability of morphometric workflows in insect systematics has never been a subject of focused research, but such studies are sorely needed. In this paper, we assess the reproducibility of morphometric studies of ants where the mode of data collection is a shared routine. We compared datasets generated by eleven independent gaugers, that is, collaborators, who measured 21 continuous morphometric traits on the same pool of individuals according to the same protocol. The gaugers possessed a wide range of morphometric skills, had varying expertise among insect groups, and differed in their facility with measuring equipment. We used intraclass correlation coefficients (ICC) to calculate repeatability and reproducibility values (i.e., intra‐ and intergauger agreements), and we performed a multivariate permutational multivariate analysis of variance (PERMANOVA) using the Morosita index of dissimilarity with 9,999 iterations. The calculated average measure of intraclass correlation coefficients of different gaugers ranged from R = 0.784 to R = 0.9897 and a significant correlation was found between the repeatability and the morphometric skills of gaugers (p = 0.016). There was no significant association with the magnification of the equipment in the case of these rather small ants. The intergauger agreement, that is the reproducibility, varied between R = 0.872 and R = 0.471 (mean R = 0.690), but all gaugers arrived at the same two‐species conclusion. A PERMANOVA test revealed no significant gauger effect on species identity (R2 = 0.69, p = 0.58). Our findings show that morphometric studies are reproducible when observers follow the standard protocol; hence, morphometric findings are widely transferable and will remain a valuable data source for alpha taxonomy.

The discovery in the Netherlands in a shipping container of the ant Monomorium sahlbergi Emery, 1898, a species similar to the invasive pharaoh ant M. pharaonis (Linnaeus, 1758), led to a quest to better define the distribution of this species, which was initially obscure due to uncertain specimen identifications. Here it is shown that M. sahlbergi, like M. pharaonis, is found worldwide, almost certainly as a result of introductions. Including quarantine interceptions, this species is recorded from seven global biogeographic regions, but its established outdoor distribution is currently limited to the tropics and subtropics. Monomorium dichroum Forel, 1902 is here presented as a junior synonym of M. sahlbergi syn. nov. based on morphometric and CO1 analyses.

The present study represents a taxonomic revision of the Pheidole sikorae species group from Madagascar. Forty-four members of this group are recognised and described, and an illustrated identification key to this group is also presented. One species is raised to species level: P. litigiosa Forel, 1892 stat. nov. Pheidole veteratrix angustinoda Forel, 1892 syn. nov. is proposed as a junior synonym of Pheidole veteratrix Forel, 1891. Worker castes are also described and lectotypes designated for P. litigiosa Forel, 1892, P. sikorae Forel, 1891, and P. veteratrix Forel, 1891. The following 41 new species are described: P. alina sp. nov., P. ambohimanga sp. nov., P. analavelona sp. nov., P. andohahela sp. nov., P. anomala sp. nov., P. anosyenne sp. nov., P. antranohofa sp. nov., P. beanka sp. nov., P. befotaka sp. nov., P. dasos sp. nov., P. flavominuta sp. nov., P. gracilis sp. nov., P. haboka sp. nov., P. havoana sp. nov., P. hazo sp. nov., P. itremo sp. nov., P. joffreville sp. nov., P. kely sp. nov., P. lavasoa sp. nov., P. mahamavo sp. nov., P. mainty sp. nov., P. mamiratra sp. nov., P. manantenina sp. nov., P. masoandro sp. nov., P. mavohavoana sp. nov., P. midongy sp. nov., P. mikros sp. nov., P. mivory sp. nov., P. nitidobruna sp. nov., P. parvula sp. nov., P. parvulogibba sp. nov., P. renirano sp. nov., P. sava sp. nov., P. sofia sp. nov., P. sparsa sp. nov., P. tampony sp. nov., P. trichotos sp. nov., P. tsaravoniana sp. nov., P. vadum sp. nov., P. volontany sp. nov., and P. vony sp. nov. At present, there are 109 valid species and subspecies of Pheidole known from Madagascar, but this number is expected to increase with upcoming taxonomic revisions of the species groups not revised in this study.

Background The Malagasy Region, one of the top megadiversity regions, hosts one of the highest numbers of endemic and threatened organisms on earth. One of the most spectacular examples of ant radiation on the island has occurred in the hyperdiverse genus Pheidole. To this date, there are 135 described Madagascan Pheidole divided into 16 species-groups, and 97% of Malagasy species are endemic to the island. This study is a taxonomic revision of the Pheidole megacephala group, one of only two species-groups comprising a combination of native, endemic taxa and widely distributed introduced species. Methods The diversity of the Malagasy members of the megacephala group was assessed via application of qualitative morphological and DNA sequence data. Qualitative, external morphological characteristics (e.g., head shape, gaster sculpture, body colouration) were evaluated in order to create a priori grouping hypotheses, and confirm and improve species delimitation. Mitochondrial DNA sequences from cytochrome oxidase I (COI) gene fragments were analyzed to test the putative species previously delimited by morphological analyses. Results We recognize three species belonging to the megacephala group: P. megacephala (Fabricius, 1793), P. megatron Fischer & Fisher, 2013 and P. spinosa Forel, 1891 stat. nov. Pheidole spinosa is redescribed and elevated to the species level. The following names are recognized as junior synonyms of P. spinosa: P. megacephala scabrior Forel, 1891 syn. nov., P. picata Forel, 1891 syn. nov., P. picata gietleni Forel, 1905 syn. nov., P. picata bernhardae Emery, 1915 syn. nov., and P. decepticon Fischer & Fisher, 2013 syn. nov. The results are supplemented with an identification key to species for major workers of the megacephala group, high-resolution images for major and minor workers, and comments on the distribution and biology of all Malagasy members of the group. Our study revealed that Pheidole megacephala, a species listed among the 100 worst invasive species worldwide, occurs in both natural and disturbed sites in the Malagasy region. The two remaining members of the megacephala group, most likely endemic to this region, are also present in anthropogenic habitats and often co-occur with P. megacephala. It appears that the Malagasy members of the group are generalists and dominant in anthropogenic habitats. Additionally, we documented the presence of supermajors in colonies of P. spinosa—a phenomenon previously not known for this group.

Global socioeconomic systems exacerbate disparities that leave a disturbing proportion of the human population malnourished, making conventional food sources such as animal livestock unsustainable at global scales. Edible insects have the potential to solve both malnourishment and the unsustainability of conventional livestock agriculture. The sustainability and accessibility of farmed, edible insects, however, depends on their feed source. Future expansion of farming rests on developing locally available and affordable insect feeds. This article presents a literature review of studies which evaluate the performance of edible crickets (Orthoptera) in response to alternative feed sources such as weeds and the byproducts of agricultural and food industries. For each insect species evaluated, we analyze measurements of feed and insect performance, feed composition, effects of diet on cricket growth and survivorship, as well as other sources of performance differences. The aim of this review is to assess the current state of alternative feed research for farmed crickets and to provide guidelines for future studies on alternative feeds.

Abstract Forests, and the vertebrate species within them, are irreplaceable sources of food and nutrition for millions of people living in areas of high biodiversity. Unfortunately, many of these forests are being cleared for agriculture, and many animals are threatened with extinction from unsustainable hunting. Forest clearing and the hunting of threatened species are untenable solutions to long‐term food insecurity and adequate nutrition, jeopardizing these species' survival, the healthy functioning of ecosystems, and the cultural identities of local people. Working with communities to develop culturally appropriate ways for people to obtain sustainable and legal sources of food from forests outside of protected areas is a key component of improving both conservation and food security. We tested the feasibility, suitability, and viability of farming an abundant and traditionally eaten forest insect, Zanna tenebrosa (locally known as sakondry), in rural communities whose food security relies heavily on the hunting of threatened vertebrates. We found that the insect is high in macro‐ and micronutrients, and can be cheaply, easily, and sustainably cultivated to sustainably diversify forest food systems without increasing habitat loss. Given the range of Z. tenebrosa, which covers a broad swath of central Africa, increasing production of this native insect may support multipronged agroecological approaches to promoting food security, adequate nutrition, and wildlife conservation.

The present study represents an introduction to the revision of Pheidole Westwood, 1839 from Madagascar. Sixteen species groups are established, of which eleven are revised below, and illustrated identification keys to species groups and species of groups revised in this monograph are presented. Two species are raised to species level: Pheidole petax Forel, 1895 stat. nov., and P. scabrata Forel, 1895 stat. nov. We also redescribe worker castes and designate lectotypes for P. annemariae Forel, 1918, P. nemoralis Forel, 1892, P. petax Forel, 1895, P. ensifera Forel, 1897, P. longispinosa Forel, 1891, and P. scabrata Forel, 1895. The following 46 new species are described: Pheidole aelloea sp. nov., P. ala sp. nov., P. andapa sp. nov., P. ankerana sp. nov., P. avaratra sp. nov., P. bemarahaensis sp. nov., P. bemarivoensis sp. nov., P. binara sp. nov., P. boribora sp. nov., P. brevipilosa sp. nov., P. curvistriata sp. nov., P. diakritos sp. nov., P. ehazoara sp. nov., P. ferruginea sp. nov., P. fisaka sp. nov., P. fitarata sp. nov., P. glabra sp. nov., P. goavana sp. nov., P. lamperos sp. nov., P. longipilosa sp. nov., P. lutea sp. nov., P. madinika sp. nov., P. mahaboensis sp. nov., P. maizina sp. nov., P. makaensis sp. nov., P. makirovana sp. nov., P. manantenensis sp. nov., P. mantadia sp. nov., P. marieannae sp. nov., P. masoala sp. nov., P. mavesatra sp. nov., P. miramila sp. nov., P. moramanaensis sp. nov., P. navoatrensis sp. nov., P. ocypodea sp. nov., P. parviocula sp. nov., P. podargea sp. nov., P. praegrandis sp. nov., P. ranohirensis sp. nov., P. rugocephala sp. nov., P. rugofitarata sp. nov., P. typhlos sp. nov., P. vatovavensis sp. nov., P. voasara sp. nov., P. vohemarensis sp. nov., and P. zavamanira sp. nov. At present, there are 69 valid species and subspecies of Pheidole known from Madagascar, but this number is expected to increase significantly with upcoming taxonomic revisions of the species groups not revised in this study.

Background Madagascar is famous for its extremely rich biodiversity; the island harbors predominantly endemic and threatened communities meriting special attention from biodiversity scientists. Continuing ongoing efforts to inventory the Malagasy ant fauna, we revise the species currently placed in the myrmicine genus Aphaenogaster Mayr. One species described from Madagascar, Aphaenogaster friederichsi Forel, is synonymized with the Palearctic A. subterranea Latreille syn. nov. This species is considered neither native to Madagascar nor established in the region. This revision focuses on the balance of species in the A. swammerdami group which are all endemic to Madagascar. Methods The diversity of the Malagasy Aphaenogaster fauna was assessed via application of multiple lines of evidence involving quantitative morphometric, qualitative morphological, and DNA sequence data. (1) Morphometric investigation was based on hypothesis-free Nest Centroid clustering (NC-clustering) combined with PArtitioning based on Recursive Thresholding (PART) to estimate the number of morphological clusters and determine the most probable boundaries between them. This protocol provides a repeatable and testable approach to find patterns in continuous morphometric data. Species boundaries and the reliability of morphological clusters recognized by these exploratory analyses were tested via confirmatory Linear Discriminant Analysis (LDA). (2) Qualitative, external morphological characteristics (e.g., shape, coloration patterns, setae number) were subjectively evaluated in order to create a priori grouping hypotheses, and confirm and improve species delimitation. (3) Species delimitation analyses based on mitochondrial DNA sequences from cytochrome oxidase I (COI) gene fragments were carried out to test the putative species previously delimited by morphological and morphometric analyses. Results Five species can be inferred based on the integrated evaluation of multiple lines of evidence; of these, three are new to science: Aphaenogaster bressleri sp. n., A. gonacantha (Emery, 1899), A. makay sp. n., A. sahafina sp. n., and A. swammerdami Forel, 1886. In addition, three new synonymies were found for A. swammerdami Forel, 1886 (A. swammerdami clara Santschi, 1915 syn. n., A. swammerdami curta Forel, 1891 syn. n. and A. swammerdami spinipes Santschi, 1911 syn. n.). Descriptions and redefinitions for each taxon and an identification key for their worker castes using qualitative traits and morphometric data are given. Geographic maps depicting species distributions and biological information regarding nesting habits for the species are also provided.

The genus Carebara is revised for the Malagasy region, and based on the examination of over 10,000 specimens, twenty-three species are recognized. Twenty one of these are described as new (C. bara sp. n., C. berivelo sp. n., C. betsi sp. n., C. creolei sp. n., C. demeter sp. n., C. dota sp. n., C. hainteny sp. n., C. hiragasy sp. n., C. jajoby sp. n., C. kabosy sp. n., C. lova sp. n., C. mahafaly sp. n., C. malagasy sp. n., C. omasi sp. n., C. placida sp. n., C. raberi sp. n., C. salegi sp. n., C. sampi sp. n., C. tana sp. n., C. tanana sp. n., C. vazimba sp. n.), and two are redescribed, C. grandidieri Forel (= C. voeltzkowi Forel n. syn.) and C. nosindambo Forel. A lectotype is designated for C. nosindambo. C. creolei sp. n. is known only from Mauritius and Seychelles, C. grandidieri Forel is distributed in Comoros, Madagascar and Mayotte, and the other twenty-one species are endemic to Madagascar. Most of the Carebara species recorded in this work are endemic to a specific habitat (ecoregion), but some of them (C. bara sp. n., C. grandidieri Forel, C. jajoby sp. n., C. kabosy sp. n., and C. nosindambo Forel) are widespread within Madagascar across all major habitats. The worker caste of Carebara can be differentiated from other genera in the Myrmicinae subfamily by the presence of the following combination of characters: antennae of eight to eleven segments, with a two-segmented club; anterior clypeal margin without central isolated seta (rarely present in some species or specimens), and usually with four distinct setae; mandibles with four to seven teeth (except in one species from Ghana - C. crigensis with three teeth); and palp formula 2,2 or 1,2. We report that almost all Carebara species found in the Malagasy region have intermediates (distinct forms) in the major worker subcaste, with the largest major workers showing remnants of queen flight sclerites and ocelli. The widespread presence of intermediates in the major worker subcaste expands the morphological boundaries of Carebara. We present an overview of the natural history of Carebara in the Malagasy region, an illustrated key for the identification of the known Malagasy species of Carebara, as well as high-resolution images and distribution maps. Unique identifiers are used for all specimens studied, including type material, and the raw data that forms the basis of this study are available on www.antweb.org (open access).

The ant genus Camponotus (Mayr, 1861) is one of the most abundant and species rich ant genera in the Malagasy zoogeographical region. Although this group is commonly encountered, its taxonomy is far from complete. Here, we clarify the taxonomy of the Malagasy-endemic Camponotus subgenus Myrmopytia (Emery, 1920). Species delimitation was based on traditional morphological characters and multivariate morphometric analyses, including exploratory Nest Centroid clustering and confirmatory cross-validated Linear Discriminant Analysis. Four species are recognized: Camponotus imitator (Forel, 1891), Camponotus jodina sp. n., Camponotus karaha sp. n., and Camponotus longicollis sp. n. All four species appear to mimic co-occurring Aphaenogaster species. A diagnosis of the subgenus Myrmopytia, species descriptions, an identification key based on minor and major subcastes of workers, and the known geographical distribution of each species are provided.

Mutualisms between ants and sap-sucking insects generally involve clear benefits for both partners: the ants provide protection in exchange for honeydew. However, a single ant genus associates with armoured scale insects (Diaspididae) that do not excrete honeydew. We studied three colonies of Melissotarsus emeryi ants from two localities in Mozambique. Vast numbers of the diaspidid Morganella conspicua occupied galleries dug by the ants under the bark of living trees. Unlike free-living M. conspicua and other diaspidids, M. conspicua living with ants are known to lack shields, likely because they gain protection against enemies and desiccation. Nevertheless, we documented the occurrence of rare individuals with shields inside ant galleries, indicating that their glands continue to secrete wax and proteins as building material. This is likely to constitute a significant portion of the ants’ diet, in addition to diaspidid exuviae and excretions from the Malpighian tubules. Indeed, Melissotarsus workers cannot walk outside the galleries due to modified middle legs, forcing them to obtain all nourishment within the tree. Melissotarsus founding queens, however, must locate a suitable host tree while flying, and acquire diaspidid crawlers. This mutualism involves ants that are highly specialised to chew through living wood, and diaspidids that can also live freely outside the bark. It is extremely widespread in Africa and Madagascar, recorded from 20 tree families, and harmful effects on plant hosts require rapid study.

We revise the species-level taxonomy of the Crematogaster (Crematogaster) degeeri-species-assemblage, a group of related ants occuring in Madagascar and the wider Malagasy region, and further provide an identification key to all species-groups of the genus Crematogaster in this region. Within the C. degeeri-assemblage, we recognize twelve species based upon morphological data from worker, queen and male ants, as well as genetic data from the barcode region of cytochrome oxidase I. Seven new species are described: Crematogaster alafara Blaimer sp. nov., C. bara Blaimer sp. nov., C. mafybe Blaimer sp. nov., C. maina Blaimer sp. nov., C. malahelo Blaimer sp. nov., C. masokely Blaimer sp. nov., C. ramamy Blaimer sp. nov. Crematogaster tricolor Gerstäcker, 1859 (stat. rev.) and C. dentata Dalla Torre, 1893 (stat. nov.) are raised to species level, and the following new synonymies are proposed: Crematogaster degeeri lunaris Santschi, 1928 as a synonym of C. degeeri Forel, 1886; Crematogaster sewelli improba Forel, 1907 and C. sewelli mauritiana Forel, 1907 as synonyms of C. dentata Dalla Torre, 1893, and C. pacifica Santschi, 1919 as a synonym of C. lobata Emery, 1895. Species descriptions, images, and distribution maps and identification keys based on worker ants, as well as on queen ants where available, are presented for all twelve species. In addition, we present a molecular gene tree for cytochrome oxidase I and summarize levels of sequence divergence within and between species of the C. degeeri-species-assemblage. Our findings are discussed in the light of previous work on Malagasy Crematogaster ants.

Background. Applying quantitative morphological approaches in systematics research is a promising way to discover cryptic biological diversity. Information obtained through twenty-first century science poses new challenges to taxonomy by offering the possibility of increased objectivity in independent and automated hypothesis formation. In recent years a number of promising new algorithmic approaches have been developed to recognize morphological diversity among insects based on multivariate morphometric analyses. These algorithms objectively delimit components in the data by automatically assigning objects into clusters. Method. In this paper, hypotheses on the diversity of the Malagasy Nesomyrmex angulatus group are formulated via a highly automated protocol involving a fusion of two algorithms, (1) Nest Centroid clustering (NC clustering) and (2) Partitioning Algorithm based on Recursive Thresholding (PART). Both algorithms assign samples into clusters, making the class assignment results of different algorithms readily inferable. The results were tested by confirmatory cross-validated Linear Discriminant Analysis (LOOCV-LDA). Results. Here we reveal the diversity of a unique and largely unexplored fragment of the Malagasy ant fauna using NC-PART-clustering on continuous morphological data, an approach that brings increased objectivity to taxonomy. We describe eight morphologically distinct species, including seven new species: Nesomyrmex angulatus (Mayr, 1862), N. bidentatus sp. n., N. clypeatus sp. n., N. devius sp. n., N. exiguus sp. n., N. fragilis sp. n., N. gracilis sp. n., and N. hirtellus sp. n.. An identification key for their worker castes using morphometric data is provided. Conclusions. Combining the dimensionality reduction feature of NC clustering with the assignment of samples into clusters by PART advances the automatization of morphometry-based alpha taxonomy.

The ant genus Strumigenys in the Arabian Peninsula is treated. Three species are recognized, S. arnoldi Forel, S. emmae (Emery) and S. membranifera Emery. The invasive species S. membranifera and the Afrotropical species S. arnoldi are recorded for the first time from Saudi Arabia and the Arabian Peninsula. A key to the Arabian species based on the worker caste is presented. Biological, ecological and distribution notes for each species are given. A regional distribution map for the three species is also presented.

The ant genus Cardiocondyla exhibits a fascinating diversity of its reproductive biology, with winged and wingless males, long-winged and short-winged queens, strict monogyny and facultative polygyny with or without queen fighting. Here we report on the previously unstudied Malagasy ant C. shuckardi. We describe the nesting habits, male morphology and colony structure of this species. Furthermore, based on the genotypes from three microsatellite loci we document a very high incidence of sib-mating.