Ant Diversity Research Articles

Nocturnal Velvet Ants (Hymenoptera: Mutillidae) of Joshua Tree National Park, Riverside County, California with the description of three new species

The diversity of nocturnal velvet ants at Joshua Tree National Park (JTNP) is investigated along with seasonal activity. The diversity of velvet ants found at JTNP is compared to the diversity of velvet ants found at the Algodones Sand Dunes, Philip L. Boyd Deep Canyon Desert Research Center, Ash Meadows National Wildlife Refuge and the Nevada Test Site. Diagnoses and a key are provided for the velvet ants of JTNP. Forty-one species in six genera, based on 10,202 specimens collected from a transect of 14 sampling sites transitioning from the Mojave to the Sonoran deserts, are found to inhabit areas in and around the park. Odontophotopsis dalyi, O. odontoloxia and Photomorphus schoenwerthi are described as new species. Odontophotopsis (Odontophotopsis) ambigua Mickel (1983) is a junior synonym of O. delodonta Viereck (1904), new synonym. The females of too few of the species are known, so only the males are treated. A key to all of the species and illustrations for those species not previously illustrated are provided for the males.

Variability of ant community composition in cork oak woodlands across the Mediterranean region: implications for forest management

Abstract: We evaluated the potential use of ants as a powerful tool for environmental monitoring, together with the applicability of the functional group approach as an alternative method for studying ant communities in cork oak woodlands. Variations in ant community composition, diversity and functional groups were studied in two cork oak forested sites across the Mediterranean region. Ants were sampled using pitfall traps placed along linear transects at 12 sites located in the main cork districts of Italy and Morocco (Gallura in Sardinia, and Maâmora, east of Rabat). A total of 13.501 specimens were collected, belonging to 38 species (five shared species). A distinct separation in the NMDS plots between Gallura and Maâmora ant assemblages was clearly visible. Ant species composition was widely different between the two districts and significant differences were detected within the Gallura district at the species level. Opportunist species were well represented in Gallura (about 27% of average Bray-Curtis similarity) as well as cryptic species (over 23%). In the Maâmora forest, generalized Myrmicinae, hot climate specialists and opportunists contributed equally to the average similarity (together about 53%). Multi-scale ant diversity showed that the true turnover was higher in Gallura than in Maâmora. These findings support the idea that the functional group approach, rather than species diversity per se, could be considered as a valuable tool to detect the response of the ant community to environmental changes in Mediterranean cork oak woodlands. Using ants as bioindicators could help not only in detecting early warning signs of habitat disturbance, but also in defining a useful management strategy to increase the resilience of agroforestry systems under future global change scenarios.

Diversity of ants and mites in the diet of the Brazilian frog Chiasmocleis leucosticta (Anura: Microhylidae)

Abstract We describe here the diet of the microhylid frog Chiasmocleis leucosticta based on the stomach contents of 72 individuals (47 males and 25 females) collected in pitfall traps at the Reserva Florestal de Morro Grande, state of São Paulo, southeastern Brazil. We identified 1,981 food items distributed in 13 prey categories of arthropods, mainly ants, mites and collembolans. Formicidae was the most abundant and frequent prey category, including 16 genera from seven subfamilies, and data on ant availability in the habitat suggest that C. leucosticta selects ants actively. The second main prey category was Acari, predominantly represented by mites of the suborder Oribatida. This is the first work identifying mites to the family level in the diet of a Microhylidae. There was no statistical difference between males and females regarding diet composition.

Higher Ant Diversity in Native Vegetation Than in Stands of the Invasive L., Along the Rio Grande Basin in Texas, USA

Our hypothesis was that there will be greater ant biodiversity in heterogeneous native vegetation compared with Arundo stands. Changes in ant biodiversity due to Arundo invasion may be one of the ecological changes in the landscape that facilitates the invasion of cattle fever ticks from Mexico where they are endemic. Ants collected in pitfall traps were identified and compared between native vegetation and stands of Arundo, Arundo donax L., monthly for a year at 10 locations. A total of 82 752 ants representing 28 genera and 76 species were collected. More ants were collected in the native vegetation which also had greater species richness and biological diversity than ants collected from Arundo stands. It is suggested that the greater heterogeneous nature of native vegetation provided greater and more predictable nourishment in the form of nectars and more abundant arthropod prey when compared with Arundo stands.

Ants Indicate Urbanization Pressure in Sacred Groves of Southwest India:A Pilot Study

Sacred groves may contain remnants of pristine and primary forests outside the state-owned protected area system. As they are small fragments and located in the neighbourhood of human settlements, towns, and cities, they are likely to be affected by urbanization. We studied the effect of urbanization on the ecosystem health of sacred groves of Kerala using litterdwelling ants as the indicator taxa. Ants were pitfalltrapped (10-12 traps/sacred grove) from three rural and two urban sacred groves, and identified to species. Overall, 1,119 ants of 32 species and 6 subfamilies (Aenictinae, Dolichoderinae, Ectatomminae, Formicinae, Myrmicinae and Ponerinae) were collected. This corresponds to 76.54% of the estimated species richness. Urbanization had little impact on the species diversity of ants. Abundance was remarkably high in urban sacred groves, mainly due to higher abundance of generalist and invasive species. The effect of urbanization was indicated by different ant assemblages. Rural sacred groves had nine species and three subfamilies exclusive to them as against the five exclusive species of urban sacred groves. Urban sacred groves were characterized by high abundance of Anoplolepis gracilipes , a globally important invasive species. Sacred groves were clustered based on the rural-urban gradient as hypothesized by the study.

Mortal combat between ants and caterpillars: an ominous threat to the endangered Schaus swallowtail butterfly (Heraclides aristodemus ponceanus) in the Florida Keys, USA

The federally endangered Schaus swallowtail butterfly (Heraclides aristodemus ponceanus) has reached critically low numbers. Exotic ants are a potential threat to H. a. ponceanus and other rare butterflies as they can attack immature stages. Ant surveys conducted in subtropical dry forests in Biscayne National Park documented ant species diversity and relative abundance. A caterpillar predator exclusion experiment using physical barriers in different combinations evaluated caterpillar survivorship of both early and late instar caterpillars exposed to different threats. Ant-caterpillar interactions were also documented by placing caterpillars on plants and observing physical interactions between caterpillars and ants. A total of 1418 ants comprising 25 ant species was captured and identified. In canopies of H. a. ponceanus host plants, 243 ants comprising 12 species were found. The four most common ants collected in the host plant canopies were Pseudomyrmex gracilis, Camponotus planatus, Cremastogaster ashmeadi, and Camponotus floridanus. The predator exclusion experiment revealed survivorship was significantly lower for early and late instar caterpillars without any physical barrier, as well as for early instars not protected by a mesh cage. Pseudomyrmex gracilis and C. floridanus were more aggressive towards caterpillars in comparison to other ant species; these two species ranked first and second in the “ant danger index” ranking predatory abilities of the four most common ant species. Pseudomyrmex gracilis is a common arboreal exotic ant in Biscayne National Park and presents a major threat to caterpillars during their earliest life stages.

Arthropod diversity and assemblage structure response to deforestation and desertification in the Sahel of western Senegal

Drylands are highly vulnerable to desertification and among the most endangered ecosystems. To understand how biodiversity responds to environmental degradation in these fragile ecosystems, we examined whether arthropod, beetle, spider and ant diversity and assemblage structure differed (1) between seasons, (2) among locations (3) between protected areas of tropical dry forest and adjacent communal lands suffering from desertification, as well as (4) how vegetation impacts assemblage structures. We established 12 plots spaced homogenously throughout each protected area and the adjacent communal land at three locations: Beersheba, Bandia and Ngazobil. Within each plot, we measured canopy closure, vegetation height, percent cover of bare ground, leaf litter, grasses and forbs and collected arthropods using pitfall traps during the 2014 dry (May) and rainy (September) seasons. We collected 123,705 arthropods representing 733 morphospecies, 10,849 beetles representing 216 morphospecies, 4969 spiders representing 91 morphospecies and 59,183 ants representing 45 morphospecies. Results showed greater arthropod and beetle diversities (P = 0.002–0.040) in the rainy season, no difference in diversity among locations for any taxonomic group and a difference (P ≤ 0.001) in diversity for all taxa between protected areas and communal lands. Assemblage structures of all taxa responded (P = 0.001) to vegetation characteristics, differed (P = 0.015–0.045) between seasons and, with a few exceptions, locations and fragments. Our results illustrate the importance of a multi-taxa approach in understanding biodiversity response to anthropogenic disturbances as well as the value of protected areas in preserving biodiversity of the Sahel.

Taxonomic Review and Natural History Notes of the Army Ant-Associated Beetle Genus Ecclisister Reichensperger (Coleoptera: Histeridae: Haeteriinae)

Abstract A great diversity of arthropods is symbiotically associated with army ant colonies. Despite the efforts of several generations of researchers to survey army ant symbiont diversity, many species still await scientific discovery. Moreover, the taxonomy of many army ant-associated groups remains unsettled. Here we re-assess the species status of two army ant-associated beetles of the family Histeridae (subfamily Haeteriinae): Ecclisister bickhardti Reichensperger, 1923 and Ecclisister bickhardti costaericae Reichensperger, 1935. We examined specimens fromCosta Rica, Panama, Ecuador, Peru, Guyana, and Brazil. Based on the analysis of external and genital morphological characters, we elevated the subspecies to species level. In addition to morphological characters, we provide 11 DNA barcodes for E. costaericae, new status, to facilitate future identifications. A survey of symbiont diversity of the six local army ant species of Eciton Latreille at La Selva Biological Station, Costa Rica, revealed a spe...

Taxonomic and functional ecology of montane ants

Why is biological diversity distributed in the way that it is? This question has been central to ecology and biogeography for centuries and is of great importance for pure and applied reasons. I use a functional trait view of ecology to complement standard sampling protocols to better understand the distribution and structure of ant (Hymenoptera: Formicidae) diversity across mountains. I use a long-term dataset of ant diversity and abundance, combined with a recently collected morphological trait dataset to examine how the alpha and beta diversity of ants responds to changes in temperature along an extensive elevational gradient in southern Africa. In addition, I link morphological thermoregulatory traits to each other and to the environment with a new database of ant elevational abundances from across the globe. Finally, I analyse how physiological thermal tolerances vary and constrain foraging patterns in montane ants. I find that temperature is a strong driver of both alpha and beta diversity patterns. In addition, morphological traits such as colour and body size are found to have a significant relationship to ambient temperatures. This relationship also implies that the relative abundances of different ant species change depending on their thermoregulatory traits (colour and body size) and the surrounding thermal environment. Furthermore, the critical thermal minimum (CTmin) of the ant species investigated and the lowest environmental temperatures are found to be key in constraining foraging activity patterns. The data presented here strengthen and link existing ideas about how thermoregulation can influence ecological communities and also suggests important ways in which diversity patterns may change in the future.

Mountain metacommunities: climate and spatial connectivity shape ant diversity in a complex landscape

Understanding what drives biodiversity patterns across scales is a central goal of ecology. Both environmental gradients and spatial landscape structure have been found to be important factors influencing species distributions and community composition, and partly reflect the balance of underlying deterministic and stochastic community processes. In some systems, environmental gradients and spatial connectivity are intertwined in that steep environmental gradients serve as boundaries on species movements and impose environment‐derived complex spatial structure to metacommunities. Mountainous landscapes are prime examples of this, and recent theory has linked principles of geomorphology, environmental gradients, and spatial structure to make predictions for resulting community patterns. In this context, we examine variation in taxonomic and phylogenetic ant diversity patterns along a geographic transect spanning > 5000 m in elevational range in the Hengduan mountains of southern China. We found that environmental gradients dominate variation in both alpha and beta diversity in this landscape, with alpha diversity strongly declining with elevation and beta diversity driven by elevational differences. However, within an elevational band spatial connectivity predicts beta diversity better than geographic distance. Our findings deviate from theoretical predictions in several ways, notably alpha diversity is monotonically declining and within‐band beta diversity is invariant with increasing elevation. The discrepancies between theory and observation may be explained by differences in the Hengduan landscape from idealized fluvial landscapes, such as a lack of a mid‐elevation peak in connectivity, as well as evolutionary limits on the source pool of species available to populate metacommunities at different elevations. The latter is supported by variation in phylogenetic community structure with elevation. Our results demonstrate the power of conceptual, statistical, and theoretical frameworks that integrate the roles of environment and spatial structure in metacommunities, but that additional work is needed to bridge the gap between abstract theory and real systems.

Temperature and ant assemblages: Biased values of community temperature index

The community temperature index (CTI) is increasingly used to identify the impacts of global warming on local biotic communities such as birds, butterflies, and plants. Temperature is one of the main determinants of global ant diversity and local ant assemblages. Therefore, the CTI can be used to identify the relationship between temperature and ant assemblages or to estimate the influence of global warming. This study aimed at finding the relationship between temperature and CTI values of ant assemblages. Ants were surveyed using baits and pitfall traps at six forest sites in South Korea, differing in mean annual temperature (MAT) from 7.4°C to 12°C. The national ant data was used to calculate the species temperature index (STI) of each species that was then used to estimate CTI. The CTI values were significantly positively correlated to MAT values, but the slopes of regression models were lower than one (0.43–0.62). The low slope might be partly caused by the bias of local occurrence data: Overestimation of STI of northern species and underestimation of southern species. The slope values varied according to data types (abundance-individuals, abundance-trap, and occurrence).

"Latitudinal Gradients in Species Diversity": Reflections on Pianka's 1966 Article and a Look Forward.

"Latitudinal Gradients in Species Diversity": Reflections on Pianka's 1966 Article and a Look Forward.

Serpentine soils affect heavy metal tolerance but not genetic diversity in a common Mediterranean ant

Natural habitats with serpentine soils are rich in heavy metal ions, which may significantly affect ecological communities. Exposure to metal pollutants results, for instance, in a reduction of population genetic diversity and a diffused higher tolerance towards heavy metals. In this study, we investigated whether chronic exposure to metals in serpentine soils affect accumulation patterns, tolerance towards metal pollutants, and genetic diversity in ants. In particular, we studied colonies of the common Mediterranean ant, Crematogaster scutellaris, along a contamination gradient consisting of two differently contaminated forests and a reference soil with no geogenic contamination. We first evaluated the metal content in both soil and ants’ body. Then, we tested for tolerance towards metal pollutants by evaluating the mortality of ants fed with nickel (Ni) solutions of increasing concentrations. Finally, differences in genetic diversity among ants from different areas were assessed using eight microsatellite loci. Interestingly, a higher tolerance to nickel solutions was found in ants sampled in sites with intermediate levels of heavy metals. This may occur, because ants inhabiting strongly contaminated areas tend to accumulate higher amounts of contaminants. Additional ingestion of toxicants beyond the saturation threshold would lead to death. There was no difference in the genetic diversity among ant colonies sampled in different sites. This was probably the result of queen mediated gene flow during nuptial flights across uncontaminated and contaminated areas of limited geographical extent.

Land cover diversity increases predator aggregation and consumption of prey.

A lower diversity of land cover types is purported to decrease arthropod diversity in agroecosystems and is dependent on patterns of land use and fragmentation. Ants, important providers of ecosystem services such as biological control, are susceptible to landscape-level changes. We determined the relationships between land cover diversity and fragmentation on the within-field spatial associations of ants to pests and resulting predation events by combining mapping and molecular tools. Increased land cover diversity and decreased fragmentation increased ant abundance, spatial association to pests and predation. Land cover diversity and fragmentation were more explanatory than land cover types. Even so, specific land cover types, such as deciduous forest, influenced ant and pest diversity more so than abundance. These results indicate that geospatial techniques and molecular gut content analysis can be combined to determine the role of land use in influencing predator-prey interactions and resulting predation events in agroecosystems.

Ant (Hymenoptera, Formicidae) diversity along a pollution gradient near the Middle Ural Copper Smelter, Russia.

Ants are considered to be suitable indicators of ecological change and are widely used in land management and environmental monitoring. However, responses of ant communities to industrial pollution are less known so far. We studied pollution-related variations of ant diversity and abundance near the Middle Ural Copper Smelter (Russia) in 2009 and 2013, with pitfall traps set up at 10 sites in Picea obovata and Abies sibirica forest. This study provided evidences for humped pollution-induced dynamics of ant diversity and abundance. Species richness and diversity peaked in the habitat intermediate between slightly damaged and fully destroyed forest ecosystems. The total abundance of ants peaked in the middle of the pollution gradient and was determined mainly by the dominant species Formica aquilonia. The abundance of other species increased towards the smelter, but was less important for total abundance than that of red wood ants. Community dominants changed with increase of exposure; F. aquilonia, a typical species of mature forests, was replaced by species of open habitats, Lasius niger and Myrmica ruginodis. Habitat variables and competition between species seem to affect local ant communities more strongly than pollution exposure. Stand basal area and cover of the field layer were the main determinants of ant diversity and abundance of individual species.

Evaluation of Malaise and Yellow Pan Trap Performance to Assess Velvet Ant (Hymenoptera: Mutillidae) Diversity in a Neotropical Savanna

Given the global biodiversity crisis, it is crucial to identify methods best suited for conducting inventories. We evaluated the relative merits of Malaise traps (MT) and ground-level yellow pan traps (YPT) to sample male velvet ants (Hymenoptera: Mutillidae) in a Neotropical savanna biodiversity hotspot. We compared richness, number of captures, evenness, composition, and body size of male velvet ants (Hymenoptera: Mutillidae) sampled with both methods in four sites at Parque Nacional da Chapada dos Veadeiros, central Brazil, during 19 d. We expected reduced diversity and smaller body size of velvet ants sampled with YPT, because they target visually oriented insects that are active closer to the ground, whereas MT represent a passive method that intercepts insects flying at different heights. Richness, total number of captures, and evenness of species and genera were significantly higher in MT. The body size of velvet ants captured with MT was significantly larger than those found in YPT. Generalized linear model and nonmetric multidimensional scaling analyses revealed a clear difference in the patterns of abundances and composition of velvet ants sampled with MT and YPT, especially for the genera Darditilla, Traumatomutilla, Lomachaeta, Pseudomethoca, Tallium, and Ephuta. YPT were effective at capturing few species that were rare in MT but, overall, MT were much more effective than YPT. We found similar patterns when using either species or genus for assessing samples obtained with MT or YPT, suggesting that ecological studies on Neotropical velvet ants may not require taxonomic resolution to the species level.

Ant assemblage (Hymenoptera: Formicidae) in three wind farms in the State of Paraná, Brazil.

The transformation of natural habitats into areas destined to agriculture or projects of energy production has generated a growing concern about the impact on biological diversity. Thus, this study evaluated the diversity of ants in agroecosystems in the area of direct influence of three wind farms in the municipality of Marmeleiro, State of Paraná and examined the association of occurrences with sampling periods. To this end, four samplings were conducted in 2013, one per season. Pitfalls, Malaise trap and Net sweep were used. The assemblages were characterized and compared using richness and number of occurrences of ants. Chao 2 estimates were calculated and a comparison (rarefaction analysis) of the assemblages was performed. The association of the species with the samples was evaluated by a Principal Component Analysis (PCA). Altogether, there were 1,576 occurrences of ants, totaling 55 species. The obtained estimate indicated that richness may be up to 35% higher. Our study adds important information about richness and occurrence of ants in a region poorly analyzed for this group. Most of all, it presents a survey of species occurring in agricultural ecosystems that may serve as a parameter for future evaluations when wind farms are installed.

Ant diversity in Brazilian tropical dry forests across multiple vegetation domains

Understanding the environmental drivers of biodiversity persistence and community organization in natural ecosystems is of great importance for planning the conservation of those ecosystems. This comprehension is even more important in severely threatened ecosystems. In this context, we analyzed ant communities in tropical dry forests (TDFs) in Brazil. These forests are embedded within other biomes, such as Cerrado and Caatinga. In this study, we asked whether (i) ant species richness and composition changes between TDFs within different vegetation domains; (ii) whether ant species richness and β-diversity increase north-to-south, possibly related to changes in tree richness and tree density; and (iii) species replacement contributes relatively more to β-diversity than does nestedness. We found that species composition is unique to each TDF within different biomes, and that species richness and β-diversity differ among the vegetation domains, being smaller in the Caatinga. We also found that replacement contributes most to β-diversity, although this contribution is lower in Caatinga than in Cerrado. We show that regional context is the main driver of species diversity, which is likely to be driven by both historical and ecological mechanisms. By analyzing large spatial scale variation in TDF environmental characteristics, we were able to evaluate how ant diversity changes along an environmental gradient. The high levels of species replacement and unique species composition of each region indicates that, to fully conserve TDFs, we need to have various conservation areas distributed across the entire range of vegetation domains in which these forests can be found. Thus, we demonstrate that a landscape-wise planning is urgent and necessary in order to preserve tropical dry forests.

Impact of the invasive ant Wasmannia auropunctata (Formicidae: Myrmicinae) on local ant diversity in southern Cameroon

AbstractThe little fire ant, Wasmannia auropunctata Roger, is one of the world's most destructive invasive ants. It has been present in Cameroon for more than four decades, but its impact on local ant diversity is not known. We studied impact of W. auropunctata in three disturbed habitats located in rural and urban areas. We monitored ant diversity in both invaded and noninvaded zones in each area using a combination of three sampling methods: bait, pitfall traps and visual catch in quadrat. We collected 28 species in urban area and 64 in rural area. In invaded zone, W. auropunctata made up 97.72% and 99.96% of all ant fauna and ant species richness decreased to 7 and 2 in urban and rural area, respectively. In accordance with others findings in introduced environments, the presence of W. auropunctata has severely reduced abundance and richness of local ant species in both urban and rural environments in Cameroon. Measures should therefore be put in place to prevent its introduction in natural environment as forest reserves and natural parks.

The surrounding landscape influences the diversity of leaf-litter ants in riparian cloud forest remnants.

Riparian vegetation is a distinctive and ecologically important element of landscapes worldwide. However, the relative influence of the surrounding landscape on the conservation of the biodiversity of riparian remnants in human-modified tropical landscapes is poorly understood. We studied the surrounding landscape to evaluate its influence on leaf-litter-ant alpha and beta diversity in riparian remnants in the tropical montane cloud forest region of central Veracruz, Mexico. Sampling was carried out in 12 sites with riparian vegetation during both rainy (2011) and dry (2012) seasons. Ten leaf-litter samples were collected along a 100-m transect per site and processed with Berlese-Tullgren funnels and Winkler sacks. Using remotely-sensed and ground-collected data, we characterized the landscape around each site according to nine land cover types and computed metrics of landscape composition and configuration. We collected a total of 8,684 ant individuals belonging to 53 species, 22 genera, 11 tribes, and 7 subfamilies. Species richness and the diversity of Shannon and Simpson increased significantly in remnants immersed in landscapes with a high percentage of riparian land cover and a low percentage of land covers with areas reforested with Pinus, cattle pastures, and human settlements and infrastructure. The composition of ant assemblages was a function of the percentage of riparian land cover in the landscape. This study found evidence that leaf-litter ants, a highly specialized guild of arthropods, are mainly impacted by landscape composition and the configuration of the focal remnant. Maintaining or improving the surrounding landscape quality of riparian vegetation remnants can stimulate the movement of biodiversity among forest and riparian remnants and foster the provision of ecosystem services by these ecosystems. Effective outcomes may be achieved by considering scientific knowledge during the early stages of riparian policy formulation, in addition to integrating riparian management strategies with broader environmental planning instruments.