Leptanillavoldemort sp. nov., a gracile new species of the hypogaeic ant genus Leptanilla (Hymenoptera, Formicidae) from the Pilbara, with a key to Australian Leptanilla.

The genus Leptanilla Emery, 1870 of the family Formicidae, subfamily Leptanillinae, comprises miniscule, pale, blind ants that are rarely collected and poorly understood due to their hypogaeic (i.e. underground) lifestyles. Here we describe a new Leptanilla species from two workers collected via subterranean scraping in the arid Pilbara region of Western Australia. Leptanillavoldemortsp. nov. is the second leptanilline species documented in Australia after the elusive Leptanillaswani Wheeler, 1932. Workers of L.voldemortsp. nov. display a remarkably gracile morphology characterised by elongated legs, antennae, and mandibles, and they are easily differentiated from other Leptanilla species. We also provide new measurements for L.swani from two workers found proximally to the type locality of L.voldemortsp. nov. A key to the worker caste of Leptanilla species of the Australian continent is presented.

A new subterranean species and an updated checklist of Strumigenys (Hymenoptera, Formicidae) from Macao SAR, China, with a key to species of the Greater Bay Area.

In the past few decades, sampling of leaf litter with Winkler extractors revealed how abundant and ubiquitous ants from the genus Strumigenys are. It is now known that this genus has the third greatest number of species within the Formicidae family. However, very few subterranean species are known, which may be due to the current under-sampling of the soil stratum. Here, a holistic sampling approach, including the use of subterranean traps, was employed in Macao SAR, China. Subterranean traps allowed the collection of a new cryptic ant species: Strumigenys subterranea Brassard, Leong & Guénard, sp. nov. Moreover, extensive sampling of the leaf litter in secondary forests provided four new species records for the genus. The list of Macanese Strumigenys is here updated, elevating the known diversity in Macao to nine species. Furthermore, to facilitate further research on ants of the Guangdong-Hong Kong-Macao Greater Bay Area, a key to the 29 Strumigenys species known from the region is provided. Lastly, recommendations for sampling methods to assess ant biodiversity underground are discussed. In conclusion, this study highlights the importance of using extensive sampling methods, and suggests that relatively small patches of secondary forests within cities can hold a surprisingly high diversity as well as some undescribed species.

Accessing the subterranean ant fauna (Hymenoptera: Formicidae) in native and modified subtropical landscapes in the Neotropics / Avaliação da mirmecofauna subterrânea (Hymenoptera: Formicidae) em paisagens nativas e modificadas na região subtropical do Neotrópico

Abstract: Several studies have characterized and delimited subterranean ant assemblages. Soil extraction, one of the methods employed to access this fauna, employs the removal of monoliths. One of the most widely used methods for the extraction of soil sampling is called TSBF (developed by the Tropical Soil Biology and Fertility Programme). This method provides relevant data about the species associated with the soil. In the present study we characterized assemblages of subterranean ants using the TSBF method in different subtropical areas of the Neotropics. We considered two sampling designs in different localities. The first design resulted in 315 TSBF samples obtained from layers at distinct depths. The second design resulted in 270 TSBF samples and 270 epigaeic pitfall trap samples. This material was used to delimit the species that occur exclusively in the subterranean stratum (TSBF) and that are not found on the soil surface. A total of 281 species were recorded. Of these, 57 can be considered subterranean, based on their occurrence in subterranean strata. We also verified that the highest occurrence of ants was in the first 10 cm of soil depth. Due to the importance of using methods that efficiently extract the subterranean ant fauna in studies, we suggest the TSBF method should be used to sample ants or to associate this method with epigaeic pitfall traps to delimit strictly subterranean assemblages in specific community stratification studies.

Resumo: Vários estudos têm caracterizado e delimitado assembleias de formigas subterrâneas. A extração de solo, um dos métodos utilizados para amostragem dessa fala, implica na remoção de monólitos. Um dos métodos mais utilizados na extração de monólitos é chamado TSBF (desenvolvido pelo Programa Tropical Soil Biology and Fertility). Esse método fornece dados extremamente relevantes sobre as espécies associadas ao solo. No presente estudo, nós caracterizamos as assembleias de formigas subterrâneas usando o método TSBF em diferentes áreas subtropicais do Neotrópico. Utilizamos dois delineamentos amostrais distintos. O primeiro delineamento resultou em 315 amostras de TSBF obtidas a partir da estratificação do solo. O segundo resultou em 270 amostras de TSBF mais 270 provenientes de armadilhas pitfall epigeicas. Esse material foi utilizado para delimitar espécies que ocorrem exclusivamente no estrato subterrâneo (TSBF) e não são encontradas na superfície do solo. Registramos um total de 281 espécies. Destas, 57 podem ser consideradas subterrâneas (baseado na ocorrência no respectivo estrato). Também verificamos que a maior ocorrência de formigas se deu nos primeiros 10 cm de profundidade. Devido à importância do uso de métodos que coletem eficientemente formigas subterrâneas, sugerimos o uso do método TSBF em estudos de estratificação de comunidades ou sua associação a armadilhas do tipo pitfall epigeica para delimitar assembleias estritamente subterrâneas.

Leptanilla hypodracos sp. n., a new species of the cryptic ant genus Leptanilla (Hymenoptera, Formicidae) from Singapore, with new distribution data and an updated key to Oriental Leptanilla species.

A new species of the cryptic and rarely collected ant genus Leptanilla is described. Leptanilla hypodracos sp. n. is the first Leptanilla recorded from Singapore in over a century since Leptanilla havilandi Forel, 1901 and represents the fourth species of Leptanilla known from the Malay Peninsula. An updated key to the Leptanilla of the Oriental region is presented. Taxonomic comparisons between Leptanilla hypodracos sp. n. and four morphologically similar species are provided with particular attention given to Leptanilla clypeata Yamane & Ito, 2001, for which new measurements and indices are presented. The first report is presented for the Leptanillinae subfamily from the southeastern part of China with a worker of the genus Leptanilla collected in Hong Kong. Finally, the potential of subterranean bait to collect Leptanilla species is discussed.

Fauna de formigas (Hymenoptera: Formicidae) atraídas a armadilhas subterrâneas em áreas de Mata Atlântica / Ant fauna (Hymenoptera: Formicidae) attracted to underground traps in Atlantic Forest

Este estudo teve como objetivo avaliar a composição da fauna de formigas que forrageia abaixo da superfície do solo de áreas de Floresta Atlântica em estágio avançado de regeneração. Foram estudadas duas áreas similares em relação às características abióticas do solo, sendo uma localizada na Serra do Mar e a outra na Serra do Itapeti, ambas no Estado de São Paulo, Brasil. Em cada área foram distribuídos, a cada dois meses, 20 conjuntos de três armadilhas subterrâneas, contendo iscas atrativas, em buracos de 30 cm de profundidade, e equidistantes 20 m um do outro. As armadilhas permaneceram no campo por 24 horas. Foram registradas no total sete subfamílias, 16 gêneros e 42 morfoespécies/espécies. Três destas espécies, Acanthostichus quadratus, Labidus coecus e L. mars, podem ser consideradas criptobióticas. A riqueza observada não difere em relação aos meses de coleta e, independentemente da época do ano, as comunidades são similares. Houve registro de uma espécie nova pertencente ao gênero Megalomyrmex, além de táxons normalmente pouco coletados, como Acanthostichus. Os resultados demonstram a importância de estudos sobre a fauna que forrageia abaixo da superfície do solo para a taxonomia, dado seu potencial para revelar novas espécies ou pouco representadas em coleções.

This study aimed at evaluating the composition of ant fauna that forage below the soil surface of the Atlantic Forest areas in advanced stage of regeneration. Two similar areas regarding the soil's abiotic characteristics were studied; one in the Serra do Mar and the other in the Serra do Itapeti formations, state of São Paulo, Brazil. Twenty sets of three subterranean traps containing attractive baits were distributed every two months in each area, placed in 30 cm deep holes 20 m equidistant from each other. The traps remained in field for 24 hours. A total of seven subfamilies, 16 genera and 42 morphospecies/species were recorded. Three of these species, Acanthostichus quadratus, Labidus coecus and L. mars can be considered cryptobiotic. The observed richness does not differ through the sampling months and communities are similar regardless of season. There was a record of a new species of the genus Megalomyrmex, and some taxa usually not collected as Acanthostichus. The results demonstrate the importance of studies on the fauna that forages below the soil surface to the taxonomy, given the potential to reveal new and rarely sampled species.

Rediscovery of the putatively extinct ant species Simopelta minima (Brandão) (Hymenoptera, Formicidae), with a discussion on rarity and conservation status of ant species / Redescoberta da espécie supostamente extinta de formigas, Simopelta minima (Brandão) (Hymenoptera, Formicidae), com uma discussão sobre raridade e estado de conservação de espécies de formigas

Simopelta minima (Brandão, 1989) was originally described based on four workers collected in soil samples from a small cocoa plantation in Ilhéus, state of Bahia, northeastern Brazil. In the subsequent years after the description, this cocoa plantation was eliminated and the species was then considered extinct by the Brazilian environmental institutions. The recent rediscovery of S. minima workers in subterranean pitfall trap samples from Viçosa, state of Minas Gerais, southeastern Brazil, over 1.000 km distant from type locality, suggests that the rarity and vulnerability status of some ant species may be explained by insufficient sampling of adequate microhabitats, in time and space.

Simopelta minima (Brandão, 1989) foi originalmente descrita com base em quatro operárias coletadas em amostras de solo provenientes de uma pequena plantação de cacau localizada em Ilhéus, Estado da Bahia, nordeste do Brasil. Nos anos seguintes à descrição, esta pequena plantação de cacau foi eliminada e a espécie passou a ser considerada extinta pelas instituições ambientais brasileiras. Recentemente foram coletadas operárias de Simopelta minima em amostras de armadilhas subterrâneas do tipo "pitfall", em Viçosa, Estado de Minas Gerais, sudeste do Brasil, a mais de 1.000 km de distância da localidade tipo. Esta redescoberta sugere que o status de raridade e/ou vulnerabilidade atribuído a algumas espécies de formigas pode ser explicado pela amostragem insuficiente de microhabitats adequados, no tempo e no espaço.