A Neoponera villosa (Fabricius, 1804) Worker Pupa with too Many Legs (Hymenoptera: Formicidae).

Several somatic and sexual anomalies such as gynandromorphism and other morphological malformations have been described in ants, but cases of supernumerary legs in natural populations are rare, with only six cases reported to date. Moreover, few cases of abnormalities have been reported for the Ponerinae subfamily, with only three cases of genetic chimeras and five teratological cases worldwide. We report here a new case of teratology in this subfamily, with a seven-legged worker pupa found in a Neoponera villosa colony nesting in an epiphytic tank bromeliad. This is the second case for Mexico of a morphological anomaly in a ponerine ant, but the first report of a teratological case in the subfamily for this country.

Hydrocarbons in Formicidae: influence of chemical footprints on ant behavioral strategies.

When an insect walks, it leaves chemical cues that derive from the arolium, a tarsal structure. These cues may contain important information about other species that occur in their community and can then mediate interactions of competition, predation, and information about resources with ants from their own colony. The compounds of these cues are released into the substrate in the form of chemical footprints. There are still few species studied, and little is known about the behavior of ants regarding these signals and how they use them in their interactions. Therefore, the aim of this study was to assess the behavioral strategy of different ant species when confronted with chemical footprints left by other ants, as well as identify their compounds and their relationship with the cuticular hydrocarbon profile. The experiments were performed using a Y-maze, where in one of the arms, there were chemical footprints of their own species or of other species, and the other Y arm was footprint-free. The chemical compounds of footprints and cuticle were analyzed by gas chromatography-mass spectrometry. The results show that foragers of all species detect and respond to the presence of chemical cues in the form of footprints left by other ants. Foragers of all species followed footprints of individuals of the same species both nestmates and non-nestmates; however, Neoponera villosa avoided the footprints of Cephalotes borgmeieri, and C. borgmeieri avoided the footprints of the other two species. The chemical compositions of the cuticle and footprints are related to each other and are specific to each species.

Two new ant species of the genus Leptogenys (Hymenoptera, Formicidae) from Hainan, China, with a key to the known Chinese species.

Two new species of ponerine ants from Hainan Province, China, Leptogenyshainanensissp. nov. and L.zhouisp. nov., are delineated and depicted based on the worker caste. Leptogenyshainanensissp. nov. belongs to the L.leleji species group, with mandibles elongate, slender and curved, lacking a distinct masticatory margin. On the other hand, L.zhouisp. nov. belongs to the L.crassicornis species group, distinguished by its square head, smooth body, mandibles with a dentate masticatory margin, and short antennae. A key to workers for the known species of Leptogenys in China are provided and a map is provided for the newly described species.

Habitat and Host Species Drive the Structure of Bacterial Communities of Two Neotropical Trap-Jaw Odontomachus Ants : Habitat and Host Species Drive the Structure of Bacterial Communities of Two Neotropical Trap-Jaw Odontomachus Ants.

Ants have long been known for their associations with other taxa, including macroscopic fungi and symbiotic bacteria. Recently, many ant species have had the composition and function of their bacterial communities investigated. Due to its behavioral and ecological diversity, the subfamily Ponerinae deserves more attention regarding its associated microbiota. Here, we used the V4 region of the 16S rRNA gene to characterize the bacterial communities of Odontomachus chelifer (ground-nesting) and Odontomachus hastatus (arboreal), two ponerine trap-jaw species commonly found in the Brazilian savanna ("Cerrado") and Atlantic rainforest. We investigated habitat effects (O. chelifer in the Cerrado and the Atlantic rainforest) and species-specific effects (both species in the Atlantic rainforest) on the bacterial communities' structure (composition and abundance) in two different body parts: cuticle and gaster. Bacterial communities differed in all populations studied. Cuticular communities were more diverse, while gaster communities presented variants common to other ants, including Wolbachia and Candidatus Tokpelaia hoelldoblerii. Odontomachus chelifer populations presented different communities in both body parts, highlighting the influence of habitat type. In the Atlantic rainforest, the outcome depended on the body part targeted. Cuticular communities were similar between species, reinforcing the habitat effect on bacterial communities, which are mainly composed of environmentally acquired taxa. Gaster communities, however, differed between the two Odontomachus species, suggesting species-specific effects and selective filters. Unclassified Firmicutes and uncultured Rhizobiales variants are the main components accounting for the observed differences. Our study indicates that both host species and habitat act synergistically, but to different degrees, to shape the bacterial communities in these Odontomachus species.

Formerly considered rare, the ant species Cryptoponeochracea (Mayr, 1855) can be commonly detected using citizen-science tools.

Citizen science is a valuable tool for monitoring different species, especially in cases concerning truly rare and difficult-to-detect species where time-consuming field studies are limited and long-term research projects are uncertain. To better understand the distribution of the rarely collected Cryptoponeochracea (Mayr, 1855) (Hymenoptera, Formicidae) in Hungary, we obtained the occurrence data with photos uploaded by non-professionals to the page of the largest Hungarian Facebook group dealing with ants and a citizen-science website dealing with biological data collection. In this article, we expand the known distribution of C.ochracea to include 46 new records from Hungary and one from Serbia. With two historical records, this previously undersampled species has now been found 48 times in Hungary. Our results prove that social media platforms and other websites for citizen science projects offer new and useful opportunities for researchers to involve non-professionals in scientific work and, thus, obtain large amounts of valuable data, even for understudied arthropod species.

Review of the Leptogenys unistimulosa species group (Hymenoptera: Formicidae) with the description of a new Amazonian species

ABSTRACT Leptogenys elzasoares new species, is described from workers and a male collected near Manaus in the Brazilian Amazon. The worker is recognizable by the presence of 12 chaetae (stout setae) on the clypeal median lobe, the straight mandible, and its bicolored body; the head and mesosoma are black while the gaster is brightly ferruginous. For the first time, the males of L. bohlsi Emery, 1896, L. unistimulosa Roger, 1863, and L. parensis Lattke, 2011 are described. A new key to the males of the unistimulosa species group is provided, and the key to workers of Lattke (2011) is updated to include the new species. Finally, we also report new records of L. parensis from French Guiana, expanding the known distribution by over 780 km northwest.

Tandem running by foraging Pachycondyla striata workers in field conditions vary in response to food type, food distance, and environmental conditions.

Ants show collective and individual behavioral flexibility in their response to immediate context, choosing for example between different foraging strategies. In Pachycondyla striata, workers can forage solitarily or recruit and guide nestmates to larger food sources through tandem running. Although considered more ancestral and less efficient than pheromone trail-laying, this strategy is common especially in species with small colony size. What is not known is how the decision to recruit or follow varies according to the immediate context. That is, how fine adjustments in information transfer affect immediate foraging decisions at the colony level. Here, we studied individually marked workers and evaluated their foraging decisions when food items varied in nature (protein versus carbohydrate), size, and distance from the nest at different temperatures and humidity levels. Our results show that tandem run leaders and potential followers adjust their behavior according to a combination of external factors. While 84.2% of trips were solitary, most ants (81%) performed at least 1 tandem run. However, tandem runs were more frequent for nearby resources and at higher relative humidity. Interestingly, when food items were located far away, tandem runs were more successful when heading to protein sources (75%) compared with carbohydrate sources (42%). Our results suggest that the social information transfer between leaders and followers conveys more information than previously thought, and also relies on their experience and motivation.

Flexibility in the integration of environmental information by Dinoponera quadriceps Kempf during foraging

Abstract Foraging behavior requires animals' behavioral flexibility to exhibit efficient strategies that result in the successful search for food. The navigation of ants enables long distance trips back and forth from the nest, using orientation cues. We analyzed the flexibility of Dinoponera quadriceps workers in integrating information introduced into the environment. We studied workers from two colonies in an area of secondary Atlantic Forest, with the use of a physical obstacle placed in front of the entrance of the nest with no fixed angular position. There was no significant difference in the resolution time workers to bypass the obstacle, in the angles between trips when exiting and returning to the nest, or in the positioning angles when returning to the nest. However, we found an increase in positioning angles when leaving the nest to search food, from the second contact onwards. They overcame the new obstacle as they would any other natural one. The presence of the obstacle did not prevent workers from maintaining route fidelity to individual areas. The behavior of D. quadriceps workers indicates that they have the flexibility to incorporate new information in a familiar environment. They likely use multimodal cues, which prevent them from wandering outside the familiar area.

Microsatellites for the Neotropical Ant, Odontomachus chelifer (Hymenoptera: Formicidae).

Odontomachus chelifer (Latreille) (Ponerinae) is a ground-dwelling, predominantly carnivorous ant whose colonies may contain multiple egg-laying queens and are potentially susceptible to border effects in the Brazilian savanna known as Cerrado. The ecology and natural history of O. chelifer is well studied, but very little is known about the genetic diversity of O. chelifer colonies. In this study, we developed microsatellite markers for the study of genetic variation in O. chelifer. We created a microsatellite-enriched library that resulted in the development and characterization of 22 markers, of which 18 were found to be polymorphic in the population studied. The mean expected heterozygosity was 0.59, whereas the mean rarified allelic richness was determined as 4.27 alleles per locus. The polymorphism level detected was similar to genetic diversity estimates found in other poneromorph ant species. The microsatellites developed here are likely to be useful for the investigation of colony structure, functional polygyny, breeding system, and population genetics in O. chelifer. Moreover, the description of O. chelifer's genetic diversity is crucial for its conservation and maintenance of its ecological role in the Cerrado savanna.

Odontomachus davidsoni sp. nov. (Hymenoptera, Formicidae), a new conspicuous trap-jaw ant from Ecuador.

One of the largest species in its genus, Odontomachus davidsoni Hoenle, Lattke & Donoso, sp. nov. is described from workers and queens collected at lowland forests in the Chocó-Darién bioregion in coastal Ecuador. The workers are characterized by their uniform red coloration, their large size (16-18 mm body length), and their frontal head striation that reaches the occipital margin. DNA barcodes (COI) and high resolution 2D images of the type material are provided, as well as an updated key for the Neotropical species of Odontomachus. In addition, a three-dimensional digital model of the worker holotype and a paratype queen scanned with DISC3D based on photogrammetry is presented, for the first time in a species description. Findings of large and conspicuous new species are uncommon around the world and suggest that these Ecuadorian rainforests may conceal many more natural treasures that deserve conservation.

ResumenDescribimos una especie nueva, entre las más grandes conocidas del género Odontomachus. La nueva especie, Odontomachus davidsoni Hoenle, Lattke & Donoso, sp. nov., es descrita a partir de obreras y reinas recolectadas en bosques de tierras bajas en la bioregión Chocó-Darién de la costa del Ecuador. Las obreras se caracterizan por su coloración rojiza uniforme, su grande tamaño (largo del cuerpo 16­18 mm), y la estriación del frente cefálico que alcanza el margen occipital. Proveemos códigos de barras de DNA (COI) e imágenes 2D de alta resolución para el material tipo y así como una guía de identificación actualizada para las especies neotropicales del género Odontomachus. Por primera vez en una descripción de especies, se proveen imágenes 3D de un escáner fotogramétrico DISC3D. Los hallazgos de especies grandes y conspicuas son poco comunes alrededor del mundo y sugieren que estos bosques lluviosos ecuatorianos pueden contener muchos más tesoros naturales que merecen ser conservados.

Revealing male genital morphology in the giant ant genus Dinoponera with geometric morphometrics.

Genitalia include some of the most complex and morphologically diverse structures in insects, finding extensive use in taxonomy, but ant taxonomy is female biased and knowledge of the males is little explored, potentially depriving ant taxonomy of valuable information. We examine the male genital morphology of six species of Dinoponera and the variation among species and within species is described. We performed geometric morphometric analyses for the penisvalvae and lateropenite of the volsella. The results from the descriptions and statistical analyses show the genitalia offer valuable characters for species delimitation. What is presently known as Dinoponera australis can be differentiated into discrete populations, perhaps some representing cryptic species. The similarities between D. australis and D. snellingi suggest a close relation between them as well as between D. gigantea and D. quadriceps. We conclude that several genital characters, especially those of the penisvalvae, can be used to differentiate the species and might be useful to clarify the taxonomy of Dinoponera.

Nest Site Selection during Colony Relocation in Yucatan Peninsula Populations of the Ponerine Ants Neoponera villosa (Hymenoptera: Formicidae).

In the Yucatan Peninsula, the ponerine ant Neoponera villosa nests almost exclusively in tank bromeliads, Aechmea bracteata. In this study, we aimed to determine the factors influencing nest site selection during nest relocation which is regularly promoted by hurricanes in this area. Using ants with and without previous experience of Ae. bracteata, we tested their preference for refuges consisting of Ae. bracteata leaves over two other bromeliads, Ae. bromeliifolia and Ananas comosus. We further evaluated bromeliad-associated traits that could influence nest site selection (form and size). Workers with and without previous contact with Ae. bracteata significantly preferred this species over others, suggesting the existence of an innate attraction to this bromeliad. However, preference was not influenced by previous contact with Ae. bracteata. Workers easily discriminated between shelters of Ae. bracteata and A. comosus, but not those of the closely related Ae. bromeliifolia. In marked contrast, ants discriminated between similar sized Ae. bracteata and Ae. bromeliifolia plants, suggesting that chemical cues and plant structure play an important role. Size was also significant as they selected the largest plant when provided two dissimilar Ae. bracteata plants. Nest site selection by N. villosa workers seems to depend on innate preferences but familiarization with plant stimuli is not excluded.

Flower perianth: first observations on a novel diet item for the ponerine ant Odontomachus chelifer (Latreille)

Abstract Ants are known to feed on a variety of plant resources. Nevertheless, there are very few reports in the literature on ants using flower parts. Here, we describe how two Odontomachus chelifer (Latreille) ants teared and removed a part of an inner tepal of a Neomarica candida (Hassl.) (Iridaceae) flower at the restinga sandy forest in the Cardoso Island State Park, Brazil. To determine which part of the perianth attracted these ants, we performed two independent two-choice field assays: tepals (inner and outer tepals) were cut in two parts (basal and apical), with contrasting colors, which were offered to ants leaving a colony. Our results show that ants significantly preferred to remove or lick the basal part of the inner tepal. Based on the knowledge of N. candida's floral anatomy, we hypothesize that ants were attracted by the nectar produced by trichomatic nectaries at the basal part of the inner tepals. These tepal parts containing nectar are likely to be used as an alternative food resource amid the scarcity of arthropods usually preyed or scavenged by O. chelifer, since the restinga forest is known as an arthropod-poor habitat.

Characterization of Nest Architecture of an Indian Ant Diacamma indicum (Hymenoptera: Formicidae).

Nests are physical entities that give shelter to the inhabitants from natural adversities, predators and act as a platform for organization of tasks particularly in social insects. Social insect nests can range from simple structures consisting of a single entrance leading to a chamber to complex nests containing hundreds of connected shafts and chambers. This study characterizes nest architecture of a tropical ponerine ant Diacamma indicum (Hymenoptera: Formicidae), which has small colony sizes and is known to be a scavenger. We also examined if these nests vary seasonally. By examining the microhabitat in the vicinity of the nest, the nest entrance characteristics and casting 77 natural nests of D. indicum across a year, we found that this species occupies relatively simple nests consisting of a single entrance that leads to a single chamber. This chamber progressed to a secondary tunnel that terminated at a greater depth than the chamber. The nest volume was not correlated to the number of adult members in the colony. Even though the microhabitat around the nest and the entrance itself change across seasons, principle component analysis showed that the nest architecture remained similar. Only one parameter, the entrance tunnel showed significant difference and was longer during postmonsoon. Nests of colonies living in the immediate vicinity of human habitation were comparable to other nests. We conclude that D. indicum found in the Gangetic plains live in relatively simple nests that do not vary across seasons.

Taxonomic revision of the genus Ponera Latreille, 1804 (Hymenoptera: Formicidae) of Taiwan and Japan, with a key to East Asian species.

Ponera is a widespread genus of litter and soil ants. The highest diversity of the genus is found in Asia, with Taiwan and Japan being two of the most species-rich regions. Here, we systematically review the taxonomy of the 16 Taiwanese and Japanese Ponera species, two of which are new species from Taiwan: Ponera terayamai sp. n. and P. wui sp. n. A new key for Ponera species of East Asia is presented.

A new species and new record of the cryptobiotic ant genus Ponera Latreille, 1804 (Hymenoptera, Formicidae) from Hong Kong.

Despite its small size, Hong Kong hosts a surprising level of ant diversity. Through faunal studies on arthropods conducted in Hong Kong over recent years, a new record and species of the genus Ponera have been discovered, which are introduced here. Ponera guangxiensis Zhou, 2001 is reported for the first time from Hong Kong, and Ponera tudigong sp. nov. is here described as a new species, easily distinguishable from other Ponera species and unique within the genus for its four mandibular teeth.

Caught red-handed: behaviour of brood thieves in an Indian ant.

Theft of resources is ubiquitous in the animal kingdom. An evolutionary arms race between thieves and their victims is expected. Although several studies have documented inter- and intraspecific theft of resources in different taxa, studies that delve into the behaviour of thieves and the factors that influence their behaviour have not been undertaken. In the current study on the primitively eusocial ant Diacamma indicum, we caught brood thieves red-handed: we observed them in the act of stealing brood and examined their behaviour. Thieves were persistent in their attempts despite facing aggression in the victim colony. Experiencing aggression or failure to steal in the previous attempt negatively impacted a thief's drive to reattempt. To avoid the risks associated with theft, successful thieves exited from victim nests about three times faster than others who were procuring brood from unguarded nests. In a series of experiments examining factors that caused thieves to increase their exit speed, we found that indirect cues of a foreign colony's presence, such as odour or the presence of foreign ants, did not induce these changes in thieves. Thus, we conclude that these ant thieves only respond to the direct threat posed by aggressive foreign ants. In this comprehensive study using behavioural experiments, we reveal the simple rules of engagement between victims and brood thieves.

A new species of the ant genus Leptogenys Roger, 1861 (Hymenoptera: Formicidae) from India.

BACKGROUND: There are no well defined Leptogenys species groups based on the worker morphology from the Oriental region Arimoto (2017). Leptogenys chinensis forms a complex species group with closely related species having little morphological changes Wilson (1958), Sarnat and Economo (2012). From the Oriental region, there are currently 9 species belonging to the L. chinensis group. The group is diagnosed by having edentate masticatory margin of the mandible, smooth body surface, elongate antennae and metallic green cuticle. The species included are: L. assamensis; L. chinensis; L. confucii; L. kraepelini; L. laeviterga; L. pangui; L. peuqueti; L. stenocheilos and L. sunzii. NEW INFORMATION: Leptogenys bhartii sp. n., a new ponerine ant species from Western Himalayas, India, is described and illustrated based on the worker caste. The new species belongs to the Leptogenys chinensis group and mostly resembles Leptogenys chinensis (Mayr, 1870). In the L. chinensis group, the original description of L. stenocheilos is insufficient as it lacks information about type material. As there is no further detailing of this species in the available literature, it is difficult to ascertain its valid status Xu and He (2015) and is therefore, considered a species inquirenda herewith. A revised key to the known species of chinensis-group in the Oriental Region is provided.

Novel thoracic glands in the ant Myopias hollandi.

Besides the common labial and metapleural glands, four novel exocrine glands are described in the thorax of both workers and queens of the ponerine ant Myopias hollandi. From anterior to posterior, these glands were designated as the propleural pit gland, the posterolateral pronotal gland, the anterolateral propodeal gland and the metasternal process gland. They all correspond with class-3 glands, that are made up of bicellular units that each comprise a secretory cell and a duct cell. In the propleural pit gland, the ducts are characterized by a gradually widening diameter, while in the three other glands the ducts show a portion which displays a balloon-like expansion, that on semithin sections stains very dark. For none of these novel glands the function is known as yet, although ultrastructural examination indicates that they produce a non-proteinaceous and therefore possibly pheromonal secretion.

A sibling species of Platythyrea clypeata Forel, 1911 in southeast Asia (Hymenoptera, Formicidae, Ponerinae).

A new species of the rarely collected ant genus Platythyrea Roger, 1863 closely related to Platythyrea clypeata Forel, 1911 is described and illustrated based on the worker caste under the name Platythyrea janyaisp. n. This species is distributed in southern Thailand and western Malaysia, while P. clypeata is distributed in Sri Lanka, Vietnam, Laos, and Thailand in the areas north of the Isthmus of Kra. Platythyrea clypeata is newly recorded from Thailand from dead wood on the forest floor. The type series of P. janyai was also collected from rotten wood on the forest floor.