Distribution of epigeic and hypogeic ants (Hymenoptera: Formicidae) in ombrophilous forests in the Brazilian Amazon

In the Amazon basin, ants are often associated with environmental or edaphic factors. However, these associations may vary between the epigeic and hypogeic strata. Here, we investigated differences in richness and composition of epigeic and hypogeic ant assemblages along an environmental gradient in the Brazilian Amazon. The four studied sites cover different topographic and soil characteristics. We sampled 25 plots of 250 m2 using 10 samples of epigeic pitfalls and 10 samples of hypogeic pitfalls installed at two depths (10 and 30 cm). The pitfalls remained in the fi eld for 48 hours. In the same plots, soil clay content and terrain altitude were also measured. We collected 219 species or morphospecies, of which 14 were exclusively hypogeics. We found higher local richness in the epigeic compared to hypogeic assemblages. We also found an interaction between clay content and strata for ant species composition. Overall, the species turnover was related to clay content, but the eff ect depended on the strata, with hypogeic fauna being more heterogeneous, compared with epigeic fauna. Despite the relationship between clay content and ant´s assemblage’s composition, we did not find strong environment predictors for both strata, which suggests that other factors may structure ant assemblages in these sites. This reinforces the need for studies to defi ne which environmental gradiente determines the distribution of Amazonian epigeic and hypogeic ants

Listening to Insect Agency: Reconsidering Relations Through Ecological Sound Art

Insects are vitally important to the survival of life on earth. Yet, in many western societies, humans have become quite averse to insects, and this is exacerbated by a narrative of fear, avoidance, and elimination. If we are to act on utilitarian evidence alone, insect decline caused by anthropogenic impacts makes it critically important to improve our relations with our insect kin. In this paper, we argue that listening to insects – and speculating as to how they listen – can move us towards relations based in curiosity, respect, and a recognition of their value. We present two works of ecological sound art that focus on cryptic insect sounds beyond the limits of human hearing ability: HVAC (2022) and Formiphony (2020). By foregrounding cryptic sound, we emphasize the vast unknown sound-worlds of insects in our shared environments. Through this expansion of our listening, we can recognize insect agency as expressed through decisions concerning their sonic relations. These works have been presented in performance, exhibits, lectures, radio, and albums, bringing a broad audience into conversation about our relations with insects

Occurrence of triatomines (Hemiptera: Reduviidae) in domestic and natural environments in novo remanso, itacoatiara, amazonas, Brazil

Introduction: The present study reports the presence of triatomines in natural, peridomestic, and intradomicile environments in Itacoatiara municipality, state of Amazonas, a non-endemic region for Chagas disease. Methods: Active search was performed inside tree trunks, and palm trees, residences, and peridomiciles localized near the forest area. Results: Twenty adults and ten triatomines nymphs were collected, fifteen of which were from natural forests, thirteen from intradomiciles, and two from peridomicile areas. Conclusions: The new records of adults and nymphs of triatomines in the intra-and peridomiciles suggest the adoption of prophylactic measures for vector surveillance in the study area. © 2019, Sociedade Brasileira de Medicina Tropical. All rights reserved

Distribuição de espécies de formigas ao longo de um gradiente topográfico em uma reserva florestal de terra firme na Amazônia Central

In Amazonia, topographical variations in soil and forest structure within "terra-firme" ecosystems are important factors correlated with terrestrial invertebrates' distribution. The objective of this work was to assess the effects of soil clay content and slope on ant species distribution over a 25 km2 grid covering the natural topographic continuum. Using three complementary sampling methods (sardine baits, pitfall traps and litter samples extracted in Winkler sacks), 300 subsamples of each method were taken in 30 plots distributed over a wet tropical forest in the Ducke Reserve (Manaus, AM, Brazil). An amount of 26,814 individuals from 11 subfamilies, 54 genera, 85 species and 152 morphospecies was recorded (Pheidole represented 37% of all morphospecies). The genus Eurhopalothrix was registered for the first time for the reserve. Species number was not correlated with slope or clay content, except for the species sampled from litter. However, the Principal Coordinate Analysis indicated that the main pattern of species composition from pitfall and litter samples was related to clay content. Almost half of the species were found only in valleys or only on plateaus, which suggests that most of them are habitat specialists. In Central Amazonia, soil texture is usually correlated with vegetation structure and moisture content, creating different microhabitats, which probably account for the observed differences in ant community structure.Na Amazônia, variações topográficas em ecossistemas de terra-firme são variáveis comuns que afetam a distribuição de invertebrados terrestres. O objetivo deste trabalho foi avaliar os efeitos do conteúdo de argila no solo e da inclinação do terreno na distribuição de espécies de formigas em uma área de 25 km2 que cobre a variação topográfica natural. Usando três métodos de coleta complementares (iscas de sardinha, armadilhas de fosso e amostras de serapilheira extraídas de sacos de Winkler), foram coletadas 300 subamostras de cada método em 30 parcelas distribuídas em uma floresta tropical úmida na Reserva Ducke (Manaus, AM). Foram registrados 26.814 indivíduos em 11 subfamílias, 54 gêneros, 85 espécies e 152 morfoespécies (Pheidole representou 37% das morfoespécies). O gênero Eurhopalothrix foi registrado pela primeira vez nesta reserva. O número de espécies não foi correlacionado com a inclinação do terreno ou o conteúdo de argila, exceto para espécies na serapilheira. No entanto, a Análise das Coordenadas Principais indicou que a composição de espécies das armadilhas e da serapilheira esteve correlacionada com o conteúdo de argila. Aproximadamente metade das espécies foi encontrada somente nos baixios ou nos platôs, sugerindo que a maioria é especialista do habitat. Na Amazônia Central, a textura do solo está geralmente correlacionada com a estrutura da vegetação e o teor de umidade, criando micro-habitats heterogêneos que provavelmente contribuíram para as diferenças observadas na estrutura da comunidade de formigas

Edge effects on ant diversity and functional composition in a forest fragment in the Central Amazon

The process of human-induced forest fragmentation increases the degree of isolation and causes biodiversity loss. Abrupt changes occur mainly near the edge of the fragment, where the average temperature is relatively higher and the humidity is lower. However, some natural environmental characteristics, such as higher air moisture in riparian areas, may buffer or minimize the edge effects. Here, we studied how the edge effect may affect ant species diversity and functional composition on valleys dissected by small streams (mesic areas). We categorized ant assemblages into the functional groups based on foraging, nesting habits, natural history information, and phylogeny. Ants were sampled using pitfalls and the Winkler extractor in ten riparian plots in a fragment of the Central Amazon. We individually fit the ant species richness, occurrence, and composition against two edge measures: forest edge distance and road-building distance. We recorded 99 species/morphospecies. Forest edge distance and road-building distance did not influence the occurrence and number of ant species per plot but were related to ant species composition. Moreover, there was not a clear pattern between functional groups distribution, except by leaf-cutters and generalist omnivorous species. Our results suggest a limited effect of forest edge distance and road-building distance on ant diversit

Listening to tropical forest soils

Acoustic monitoring has proven to be an effective tool for monitoring biotic soundscapes in the marine, terrestrial, and aquatic realms. Recently it has been suggested that it could also be an effective method for monitoring soil soundscapes, but has been used in very few studies, primarily in temperate and polar regions. We present the first study of soil soundscapes using passive acoustic monitoring in tropical forests, using a novel analytical pipeline allowing for the use of in-situ recording of soundscapes with minimal soil disturbance. We found significant differences in acoustic index values between burnt and unburnt forests and the first indications of a diel cycle in soil soundscapes. These promising results and methodological advances highlight the potential of passive acoustic monitoring for large-scale and long-term monitoring of soil biodiversity. We use the results to discuss research priorities, including relating soil biophony to community structure and ecosystem function, and the use of appropriate hardware and analytical techniques

Evolutionary history of the little fire ant Wasmannia auropunctata before global invasion: Inferring dispersal patterns, niche requirements and past and present distribution within its native range

The evolutionary history of invasive species within their native range may involve key processes that allow them to colonize new habitats. Therefore, phylogeographic studies of invasive species within their native ranges are useful to understand invasion biology in an evolutionary context. Here we integrated classical and Bayesian phylogeographic methods using mitochondrial and nuclear DNA markers with a palaeodistribution modelling approach, to infer the phylogeographic history of the invasive ant Wasmannia auropunctata across its native distribution in South America. We discuss our results in the context of the recent establishment of this mostly tropical species in the Mediterranean region. Our Bayesian phylogeographic analysis suggests that the common ancestor of the two main clades of W. auropunctata occurred in central Brazil during the Pliocene. Clade A would have differentiated northward and clade B southward, followed by a secondary contact beginning about 380 000 years ago in central South America. There were differences in the most suitable habitats among clades when considering three distinct climatic periods, suggesting that genetic differentiation was accompanied by changes in niche requirements, clade A being a tropical lineage and clade B a subtropical and temperate lineage. Only clade B reached more southern latitudes, with a colder climate than that of northern South America. This is concordant with the adaptation of this originally tropical ant species to temperate climates prior to its successful establishment in the Mediterranean region. This study highlights the usefulness of exploring the evolutionary history of invasive species within their native ranges to better understand biological invasions. © 2016 European Society for Evolutionary Biology

A test of the Geographic Mosaic Theory of Coevolution: investigating widespread species of Amazonian Protium (Burseraceae) trees, their chemical defenses, and their associated herbivore faunas

IntroductionPlants and their insect herbivores represent a large fraction of the species in Amazonian forests and are often directly implicated in the origin and maintenance of biodiversity at local and regional scales. How these interactions may change over geographic distance is unknown because very few studies have investigated the herbivore fauna and defense chemicals of any host plant species at multiple sites in tropical forests. One hypothesis, the Geographic Mosaic Theory of Coevolution, predicts that if herbivore assemblages turn over in different parts of a plant’s range, then plant defense chemicals should also change, reflecting local selection pressures.MethodsWe tested this theory by studying 12 species of Protium (Burseraceae) trees that occur in both Iquitos, Peru, and Manaus, Brazil, in rainforests separated by 1500 km. We surveyed all insects observed directly feeding on the plants in both locations for 48 weeks in Manaus and 64 weeks in Iquitos. We analyzed the secondary metabolites in the leaves of all species in both locations using GC/MS and HPLC.Results and DiscussionAlthough in both locations we found that Protium herbivores were dominated by insects from the orders Hemiptera, Coleoptera and Lepidoptera, we found almost complete turnover in the herbivore species composition in the two sites, and each host plant species had a different assemblage of herbivores in each location. Comparing the phylogenetic beta-diversity, we found low similarity in herbivore phylogenetic relatedness between host plant species in the two locations. However, the secondary metabolites found within a Protium species were similar across the two locations. We found no strong evidence that individuals from a host plant species in Iquitos or Manaus expressed locally-adapted defense chemicals, as individuals from geographic locations did not form clusters when looking at patterns of chemical similarity. These results are not consistent with the Geographic Mosaic Theory of Coevolution. The most intriguing pattern we found was a strong correlation between the diversity of herbivores per host plant species in both locations. We also found that plants with high chemical richness had lower numbers of herbivore species and numbers of total herbivores in both locations. We conclude that high chemical diversity is the most effective strategy for Protium trees to reduce insect herbivore attacks. We speculate that each secondary metabolite is effective at repelling only a few insect herbivores, and that different chemicals are likely effective in different parts of a plants’ geographic range. Future studies should investigate additional locations and additional natural enemies (i.e., fungal pathogens) to test the hypothesis that chemical diversity reduces attack from natural enemies and may explain the ecological and evolutionary success of rainforest trees over time and space

A global database of ant species abundances

What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51, 388 ant abundance and occurrence records of more than 2,693 species and 7,953 morphospecies from local assemblages collected at 4,212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type, and degree of disturbance. The aim of compiling this data set was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardized methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing data set