Ant Richness Research Articles

Scale-Dependent Spatial Ecology of Paleotropical Leaf Litter Ants (Hymenoptera: Formicidae)

The grain for which an observer conducts a study is an important determinant of its outcome. Studies of ants have considered spatial grains spanning from single meters to entire forest ecosystems and found patterns related to nutrient availability, leaf litter depth, disturbance, and forest composition. Here, we examine a Bornean leaf litter ant community at small (1–4 m) and large (50–250 m) spatial scales and consider the differences in community structure using structured 1 m2 quadrats sampled via leaf litter sifting and Berlese extraction. We found that small-scale patterns in ant abundance and richness did not spatially autocorrelate within a plot until >1.5 m. Leaf litter characteristics, forest stand characteristics and sampling season were homogenous among our sites, suggesting that macro-scale stand variables are not largely regulating the small spatial scale ant communities: These may be driven by microclimate, competition, niche space, nutrient available, microclimatic conditions, or other localized effects. Further experimental work is needed to elicit causal mechanisms.

Under the sun or stars: how a dune ant (Hymenoptera: Formicidae) community is shaped along the day and night

AbstractAtlantic Forest (AF) is a threatened megadiverse biome distributed from north to south along the ocean of South America and is considered a hotspot of biodiversity. Currently, over 3000 ant taxa are known to occur in AF ecosystems, and many more are expected but may never be acknowledged. The patterns and processes structuring AF ant communities are not well known, urging such studies. Temperature is a fundamental environmental condition that modulates ant species occurrences at different local and regional scales. Global warming may deeply impact species occurrence, dynamics and interactions, and efforts to amplify our understanding of AF biodiversity are urgent. Ants are widely distributed in the dunes, and many species are sensitive to local changes in temperature as some species are considered thermophilic. In open areas such as dunes, the temperature varies considerably over 24 h, with great changes mainly between day and night. In this study, we sought to answer whether the foredune ant community of the Restinga, one of the habitats of the AF, is structured by temperature from day and night. For this, we tested the following hypotheses: (i) temperature influences ant diversity; (ii) in warmer periods, there is a decrease in richness, with an increase in abundance; and (iii) ant species composition varies throughout the day and, consequently, at different temperatures. We arbitrarily drew a parallel transect to the ocean composed of 15 pitfall trap units spaced every 30 m. Traps were changed in five sampling periods: T1 (9:10–13:10 h), T2 (13:40–18:40 h), T3 (19:00–23:00 h), T4 (23:00–03:00 h) and T5 (03:00–07:00 h). In each period, we recorded the ambient temperature and relative humidity. We recovered 11 ant species on the foredunes. Our results showed that the richness and abundance of ants in the daytime period was higher than in the night‐time period, suggesting that temperature positively affected these two parameters of the studied community. The species composition also changed over the sampling periods. Considering that our aim was to describe the species diversity across 24 h of sampling, this ‘quick‐shot’ of the ant community allowed us to determine that temperature and humidity shape their occurrence and activity. These results indicate that there is an interplay between these factors that are correlated and play an important role in structuring ant communities in Restinga foredunes.

Does habitat type in no‐tillage agroecosystems influence ground‐dwelling macroarthropod community structure? A case study in KwaZulu‐Natal, South Africa

AbstractLoss of biodiversity in agroecosystems has negative implications for crop production and the functioning of the ecosystem. As such, agroecologists advocate minimum tillage practices in order to conserve biological diversity. To establish the influence of agricultural practices on biodiversity, we compared the species richness, abundance and composition of beetles, ants, spiders and small groups of ground dwelling arthropods in a veld and three agroecosystems (maize, sugarcane and multispecies pasture) under minimum tillage. Sampling was by pitfall trapping during the summer rainfall season in December 2019. Although ants were the most abundant (47%), followed by beetles (31%); beetles were the most speciose making up 40% of the morphospecies followed by spiders (31%). The veld had significantly greater relative proportion of species richness of spiders (54%) than the three agroecosystems, while significantly low relative proportion of species richness of ants was in the pasture (6%) compared to the veld (63%). Species richness and abundance of beetles were similar across habitat types. The four habitats supported different assemblages of ants, beetles and spiders. The differences in species composition among the habitats support the notion that agricultural practices with minimum soil disturbance enhance conservation of biological diversity, particularly, specialist species.

Identification of Ants (Hymenoptera: Formicidae) in Urban Manila, Philippines Through DNA Barcoding

Urbanization is a driving force behind habitat destruction and has a dramatic impact on ant richness and composition. This ecological and taxonomic study of urban ants generally focused on identifying species richness in different urban habitat types using DNA barcoding techniques. 17 species of ants collected from Manila, Philippines were sequenced and barcoded for a 600 – 700 range bp region of the mitochondrial cytochrome c oxidase subunit 1 gene (CO1). The AT content in the DNA of 16 ant species was estimated at 68.5%, which is following invertebrates. The distance within species was calculated using the Kimura 2-parameter (K2P) and it was 0.244, 0.168, and 0.331% for mean, minimum, and maximum, respectively. The phylogeny tree constructed using the N-J method also revealed two clusters. The first cluster consisted of three sub-clades representing four subfamilies: Myrmicinae, Ponerinae, while Pseudomyrmicinae, and Dolichoderinae are within the same sub-clade but with different sub-group. The second cluster is formed by the sub-clades of the Formicinae subfamily, which is not in contradiction with the cladistics analysis of morphological data for ants and is consistent with the traditional phylogeny. The results demonstrate that DNA barcoding is an additional tool for providing pertinent information for the systematist for quick and reliable identification of urban ants.

Rainfall as Correlate of Species Richness of Indian Ants (Hymenoptera: Formicidae)

Rainfall as Correlate of Species Richness of Indian Ants (Hymenoptera: Formicidae)

Response of ants, beetles and spiders to disturbance varies among taxa in a South African savannah biome

Savannahs are structurally complex ecosystems consisting of a diverse community of plants and animals such as arthropods. Arthropods are essential in many ecosystem processes that help maintain life on Earth. The anthropogenic conversion of natural landscapes into croplands, residential and industrial areas has a negative impact on surface-active arthropods that have limited dispersal abilities and narrow habitat preferences. This study investigated the effect of disturbance on assemblages of ants, beetles and spiders in the savannah vegetation in Mpumalanga province, South Africa. We compared species richness, abundance and composition of these three taxa between the pristine savannah and the savannah that is exposed to a variety of anthropogenic activities (disturbed savannah). Arthropods were collected using pitfall traps in 15 sites in pristine savannah and 15 sites in disturbed savannah. We found that disturbance affects species richness and abundance of these taxa differently. Disturbance did not affect species richness of spiders and abundance of beetles, while greater species richness of ants and beetles, as well as abundance of ants and spiders was in disturbed than in pristine savannah. Furthermore, the species compositions of all taxa were different between disturbed and pristine savannah. The disturbed savannah had twice more unique indicator species than the pristine savannah. Differences in assemblages of arthropods between pristine and disturbed habitats suggest that it may be important to consider habitats in and outside protected areas in the conservation of arthropods, particularly in areas with greater percentage of natural and semi-natural landscapes occurring outside protected areas.

Between two trees: Environmental effects of I. micheliana and A. latifolia on leaf litter ants in a coffee agroecosystem

AbstractShade trees provide important ecological services that support productivity in coffee agroforestry systems. Processes such as biological nitrogen fixation play a key role in this. Less is known, however, about potential indirect mechanisms by which nitrogen fixation supports coffee productivity. One potential route for this to occur is by providing ecological benefits to other above‐ and belowground organisms that enrich the overall function of agroecosystems. A useful lens with which to evaluate the ecological benefits to these communities under shade trees is to assess how ground‐dwelling ant communities respond to the quality of leaf litter from established nitrogen (N)‐fixing tree species. Here, we use two trees commonly planted in coffee agroecosystems: Inga micheliana, an N‐fixing species, and Alchornea latifolia, a non‐N‐fixing species. In this study, we set out to answer the following questions: (1) How does the leaf litter environment differ between I. micheliana and A. latifolia? (2) Do differences in environmental factors between I. micheliana and A. latifolia correlate with differences in ant abundance and species richness? and (3) Do differences in environmental factors between I. micheliana and A. latifolia correlate with differences in ant community composition? Twenty‐eight randomly selected sites (14 I. micheliana and 14 A. latifolia) were established within a 45‐ha plot in a shaded organic coffee farm in Chiapas, Mexico. Three 1‐m2 quadrats within a 5‐m radius from the base of the selected trees were established, and the leaf litter within the quadrats was removed and sieved. Ant specimens were extracted from leaf litter collected from quadrats using the mini‐Winkler method and identified to genus and species, or morphospecies, level. Results indicate that I. micheliana, the N‐fixing species, has a lower C:N ratio than A. latifolia. Differences in C:N ratios are correlated with ant abundance but not with ant species richness. Distance to edge (in meters) has significant effects on leaf litter ant abundance, richness, and species composition. Results suggest that there may be unaccounted feedbacks from N‐ and non‐N‐fixing vegetation to brown food webs enabling them to sustain similar ground‐dwelling ant communities.

New insights into the geographic patterns of functional role and taxonomic richness of ants from Mexico

One approach to prioritise conservation efforts is to identify hotspots that are either species-rich or that harbour a high proportion of narrow-ranged species with varying functional roles. Given this, we have developed full ant species distribution models as tools for identifying biodiversity and hotspot areas in Mexico. We predicted ant species richness and potential areas of endemism using the more complete data available from across America (i.e., including both North America and South America) and habitat/ecological specificity (functional diversity) in a species distribution model (SDM). In Mexico, the ecoregions more relevant for ant species richness and endemism are Mesoamerica, Petenes, Sierra Madre Oriental, Trans-Mexican Volcanic, and the Sierra Madre Occidental. While for hypogeic and arboreal ants the hotspots were localized in the tropic biomes, for epigeic and subterranean ants, hotpots were most prevalent in the tropics and desert. Moreover, the geographical patterns suggest that some hotspots for ants converge with those hotspots proposed for other invertebrates and vertebrates.Implications for insect conservationOur study highlights the importance of hotspots areas for biodiversity conservation, and provides data and maps for ant conservation programs.

Induced drought strongly affects richness and composition of ground-dwelling ants in the eastern Amazon.

Species loss in tropical regions is forecast to occur under environmental change scenarios of low precipitation. One of the main questions is how drought will affect invertebrates, a key group for ecosystem functioning. We use 1year of data from a long-term rainwater exclusion experiment in primary Amazonian rainforest to test whether induced water stress and covarying changes in soil moisture, soil respiration, and tree species richness, diversity, size, and total biomass affected species richness and composition (relative abundance) of ground-dwelling ants. Data on ant abundance and environmental variables were collected at two sites (control and experimental) in the Eastern Amazon. Since 2002, drought has been induced in the experimental plot by excluding 50% of normal rainfall. Ant species richness in the experiment plot was reduced and some generalist species responded positively. Ant species richness also increased in the experimental plot with increasing diversity of the plant species of the leaf litter. The relative abundance of ants differed between plots. The experimental plot was characterized by a higher frequency of generalist and other species that appeared to be favored by the reduction in rainfall. Between-plot comparisons suggested loss and changes in ant species composition in tropical forests were affected by increasing dryness. These changes could ultimately lead to cascading effects on ecosystem processes and the services they mediate.

Ant and plant diversity respond differently to seed‐based prairie restoration

Recovering biodiversity is a common goal of restoration, yet outcomes for animal communities are highly variable. A major reason for this variability may be that active restoration efforts typically target plant communities, with the assumption that animal communities will passively recover in turn. However, this assumption remains largely unvalidated experimentally making it unclear how plant‐focused restoration strategies influence animal communities. We evaluated how the diversity of seed mixes used to restore tallgrass prairies (a common plant‐focused technique) influenced the recovery of ant community diversity and composition. Our study took place within a large‐scale restoration experiment in southwest Michigan, where 12 former agricultural fields are being restored to tallgrass prairie by sowing seeds of prairie plant species native to our region. Half of each field was seeded with 12 prairie species and the other half with 72 prairie species. Sites restored with high diversity seed mixes increased plant species richness, but did not consistently influence ant richness or community composition. Instead, ant species richness and composition were related to an interaction between realized plant species richness (which was only partly structured by seeding treatments) and environmental structure. Specifically, ant richness increased more with higher realized plant richness when vegetation cover was lower and soil‐surface temperatures were higher. Our findings illustrate how plant and animal communities can respond differently to plant‐focused restoration efforts. Despite this, plant community restoration can structure animal community responses, in concert with environmental factors. Layering additional restoration strategies onto existing plant‐focused approaches may further benefit biodiversity across taxa.

Variation in the rates of biomass removal by soil macro-fauna in different land uses at Rashad, South Kordofan, Sudan

One of the main implications of reducing biodiversity is the loss or decline of ecosystem function. We have previously seen in the Rashad location that agricultural practices have a lower effect on ant biodiversity. However, how they affect the environmental services, they provide is unclear. The main objective of this study was to evaluate whether the conversion of native areas into agricultural systems affects the removal of biomass carried out by ants, an important ecosystem function linked to decomposition and predation. We sampled three transects from (the Rashad district). Each sampling plot consisted of a grid of 12 pitfall traps filled with sardine baits (simulating animal organisms) and bananas (as attractive vegetable resources). In addition, grass seeds (Sorghum bicolor) were applied in both natural (Campo, Kubos, and forest) and agricultural settings (soy monoculture, pastures, and organic agriculture). The Results showed that ant’s removal was highest in sardine with an average of 87.3g (σ ± 23.8), followed by banana (average of 70.5g, σ ± 31.5) and lowest in the seed (mean of 7.8g, σ ± 7.3) (highest p = 0.017). Only the soy monoculture regions showed the lowest levels of sardine removed, indicating an effect associated with the kind of land use. Because little biomass is eliminated in both natural and agricultural settings, no effect of the seeds bait has been observed. As for the banana bait, the data suggested a redundancy effect with another group of macro-fauna). Our results suggest that there is a redundancy effect with another group of macrofauna. However, macrofauna biomass (excluding ants) does not explain this biomass removal. In addition, it detected no impact of ant species composition on removed biomass. The reduction of sardine and banana biomass was correlated with ant richness, indicating that the effects on ecosystem function depend on the particularities of each evaluated role (such as resource type), the type of land use, and the ant richness in the study area.

The Effects of Pitfall Trap Spacing on Ant Richness (Hymenoptera: Formicidae), Abundance, and Composition in Dinder National Park, Sudan

Ants play an important role in Sudanese biodiversity and environmental impact assessments, Although baiting is easy and cheap to implement, several considerations, such as the spacing among bait, can affect the estimation of the abundance and richness of ants species. In this study, we evaluated the effects of bait spacing on abundance and the number of ant species. We also demonstrate which distance between baits showed the best relationship between costs and the number of ant species sampled. We sampled 30 transects of 100 m with bait spacing ranging (2.5; 3.3; 5; 6.7; 10 and 20 m), spread over 1 km² into three different type of ecosystems (Wooded grass land, Riverine ecosystem and Maya ecosystem), at DNP located in Sudan. The bait spacing did not affect the ant diversity estimative. Regardless bait spacing, the number of species collected every five baits was around 8, and the average abundance was approximately 50 individuals. However, the number of species per bait was higher in transects with a larger gap between baits. Transects with bait spans of 20 and 10 m captured 50% more species per bait than transects with baits 2.5 and 3.4 m apart. Our study suggest that the most efficient sampling design using only baits in the park would be, to place 450 baits every 10 m and 20 m.

Species and functional responses of ants to inter-row tillage and vegetation in organic Mediterranean vineyards

Ants are arthropods providing crucial ecosystem services such as soil structuring, nutrient cycling, seed dispersal and pest predation. Thus, their abundance and diversity need to be considered in approaches to improve sustainability of land use such as Mediterranean viticulture. In our study, we tested whether (1) inter-row vegetation and the absence of tillage increase the species richness and/or functional diversity of ants in vineyards and (2) ground cover vegetation drives ant species composition. We included 23 Mediterranean organic vineyards in our analyses and distinguished three types of inter-row management: all inter-rows tilled, half of the inter-rows tilled, and all inter-rows are untilled and covered by vegetation. The occurrence of ant species was analysed in six pitfall traps per vineyard. Around each trap, the floristic composition of inter-row vegetation was analysed in 2 × 2 m² plots. We found that inter-row tillage significantly affected ant species richness, being higher in partially than in fully tilled vineyards whereas untilled vineyards were not different from the other tillage types. Grass cover and the perennial/annual rate were positively correlated with ant species richness. Ant functional diversity and the frequency of most predatory ants were not correlated neither with plant functional groups nor with tillage type. In conclusion, ant communities benefit from inter-row vegetation and/or absence of soil disturbance but partial inter-row tillage of vineyards may be tolerated and even benefit several species. In particular, grasses and perennial plant species favour ants in our system and need to be considered in inter-row sowing.

Species Richness, Density, Activity, and Composition of Ground-dwelling Ants in the Humid Forest Zone of Southern Cameroon: Role of Vegetation Cover and Abiotic Factors.

The destruction of natural habitats is among the major factors responsible for the decrease in species diversity and distribution. This study focused on the effect of vegetation and its interaction with the season on ant species richness, density, activity, and composition in the three dominant habitats - forest, fallow, and mixed crop field - prevailing in southern Cameroon. Ants were sampled using two sampling techniques -pitfall trap and quadrat - in fallows, forest, and mixed crop fields from May 2007 to April 2008. Average ant species richness did not differ between fallow and forest, but the number of species in both habitats was higher compared with mixed-crop field. Species richness was also higher during the short dry season compared with other seasons. Species density was higher in mixed-crop field and in the long dry season. Species activity was similar in the three habitats, but it was higher during the long-wet season. Species richness, activity, and density were lower at low altitude. Vegetation and season affected the composition of ant species, but not the interaction between the two factors. The highest dissimilarity index was observed between mixed crop-field and forest while between seasons, it was between the short-wet and the long dry season. These results suggest that vegetation cover and abiotic factors interact to determine the distribution, density, activity, and composition of ant species. Identifying key drivers among environmental factors could help to understand the response of species to the variation of those factors in the context of climate change.

Ant Diversity Is Enhanced by Ecological Infrastructures in Agroecosystems: A Case Study in Irrigated Mediterranean Farmland

We aimed at assessing the role of ecological infrastructures (EI) in promoting ant biodiversity in floodplain Mediterranean agricultural crops. We examined and compared ant communities at the interface between EI (remnant vegetation patches) and adjoining agricultural matrix (maize, rice, others) in irrigated farmland. The study was conducted in 2019, in two agricultural landscapes in the valleys of the rivers Tagus and Sorraia, Central Portugal. We used the Akaike information criterion for model selection and to distinguish among a set of possible models describing the relationship between: the ant richness in the agricultural matrix and drivers associated with the surrounding landscape and crop type; the ant richness in EI and the habitat quality of EI patches, the characteristics of the surrounding landscape, and the presence of invasive ant species. We found that: EI patches supported a higher ant diversity and an overall specialized ant community, distinctive from the agricultural matrix; location but not vegetation physiognomy influenced ant diversity; ant richness within the agricultural matrix decreased with the distance to the EI, and that this relationship was influenced by the crop type; and that ant richness in the EI was associated with the absence of the invasive Argentine ant and the area of terrestrial EI in the surrounding landscape.

Ant diversity decreases during the dry season: A meta‐analysis of the effects of seasonality on ant richness and abundance

AbstractTropical studies traditionally describe insect diversity variation throughout the year. The temporally structured responses of insect assemblages to climate seasonality vary across ecosystems due to gradients of resource availability and limiting ecological factors. These idiosyncratic responses might be particularly true across the vast geographical range of the Brazilian territory, including various environments that harbor one of the most diverse ant faunas worldwide. This study addressed the relationship between ant diversity and climatic seasonality, performing a quantitative review of the published data on ant diversity collected in Brazil. We investigated the seasonality effect on ant abundance and richness described in the literature in 47 papers published between 2000 and 2018. These studies were developed mainly in the Atlantic Forest biome and collected ants with pitfall traps on the soil/litter stratum. We initially carried out a vote‐counting procedure by comparing the number of significant results describing seasonal differences in the ant assemblage. We found that most papers described a similar pattern of ant abundance, richness, and species composition between seasons. However, when we performed a meta‐analysis, we observed a clear pattern of higher ant abundance and richness in the wet/summer season compared with the dry/winter season. Our meta‐analysis reveals that the ant diversity decreases in the dry season, strongly in the Cerrado biome. Additionally, we point out differences in the sampling effort across biomes, indicating the need for further investments in studies focused on temporal diversity patterns, including seasonal effects, on the insect assemblage in biomes less investigated so far.Abstract in Portuguese is available with online material.

How do patch burnings affect ant communities and seed removal in a subtropical grassland?

Disturbances modify local abiotic properties, habitat structure and resource availability, shaping community assembly and ecological interactions. Open ecosystems have an evolutionary relationship with fire. We evaluated the effects of patch burnings on grassland ant communities and patterns of seed removal. We established 14 plots of 10 m2 in pairs in a disturbance-suppressed grassland in South Brazil. A random plot of each pair was burned, and another plot was the control. We accessed ant communities with pitfall-traps and sweeping net, and seed removal with seed traps in all plots prior the experimental fires, and then on three occasions following fires. We recorded 57 ant species belonging to 29 genera. Ant species composition did not significantly vary between treatments neither did ant body size. We detected significantly positive fire effects on ant richness after 1 month and 12 months, mediated by the increase in plant species richness in burned plots. Mean seed removal rates were increased in burned plots after 1 month. We showed that prescribed patch burnings in fire-prone grasslands promoted ant richness, and their foraging activity. Our study may serve as a basis for conservation decisions, showing the importance of maintenance of disturbances in grasslands.

Tradeoffs and synergies among ecosystem services, biodiversity conservation, and food production in coffee agroforestry

Concerns over the capacity of the world’s existing agricultural land to provide food for the global population under climate change and continued biodiversity loss have set the stage for a prevailing narrative of inherent tradeoffs with agricultural production. Coffee, a major export of tropical countries, offers a unique opportunity to examine how different management practices can lead to a variety of outcomes in food security, ecosystem services, and biodiversity conservation. Our study examined this intersection to identify tradeoffs and synergies using compiled data from Puerto Rico. At the island level, we analyzed data on coffee yield and planted area under shade or sun management. At the farm level, we analyzed management variables (percent shade cover, maximum canopy height, ground cover, and food crop richness), non-provisioning ecosystem services variables (total farm carbon storage, soil organic carbon storage, coffee plant carbon biomass, and hurricane resistance and resilience), and biodiversity variables (ant, bird, and lizard richness and abundance). At the island level, we found that planted area was the most significant predictor of total production, suggesting no obvious tradeoff between production and shade management in coffee farms. At the farm level, canopy cover of shade trees was negatively correlated with ground cover and positively correlated with food crop richness, suggesting a synergy between agroforestry and subsistence food production. We detected mostly synergies associated with ecosystem services, biodiversity conservation, and agroforestry management and no tradeoffs among ecosystem service and biodiversity parameters. Shade canopy cover significantly increased total carbon storage, coffee plant biomass, hurricane resistance, and bird species richness. Shade canopy height had a similar positive effect on total farm carbon storage while food crop richness had a positive effect on farm resilience following Hurricane Maria. Ground cover was positively associated with soil carbon storage and pest-controlling lizard abundance. Tradeoffs related to agroforestry management included an inverse relationship between ground cover and hurricane resistance and more dominance of an invasive ant species in farms with higher shade canopies. We discuss the implications of practicing agroforestry principles in this smallholder coffee system and highlight opportunities to contribute to more diversified food production systems that support biodiversity and ecosystem services.

Spatial variation in ant–tree bipartite networks is driven by a bottom‐up process

Spatial shifts in the organisation and pattern of ecological networks may be driven by species composition turnover, changes in species abundance and/or abiotic effects on species interactions. To test the above assumptions, we collected arboreal ants and recorded host tree species from five latitudinal sites in Xishuangbanna, China. We constructed bipartite networks and compared spatial variation in species composition, interactions and stability change. We also analysed the relationship between network structure metrics and network stability. Results showed that ant composition differed significantly among the five sites, primarily determined by weaver ants (Oecophylla smaragdina) and Crematogaster ant species. Dominant tree species included Ficus (32 individuals), Hevea (14 individuals), Castanopsis (11 individuals) and Pittosporopsis (8 individuals). Ant richness was positively correlated with tree richness, suggesting that host trees support ant diversity as a fundamental environment. The ant–tree bipartite networks showed low connectance, high specificity and low niche overlap. Links per species and network node were positively correlated with network stability, whereas connectance, nestedness, specificity and niche overlap were not. Ants and trees formed a nonspecific and sparse bipartite network, and the number of nodes and links per species promoted network stability. Because plant richness was positively related to ant richness, and because arboreal ants feed predominantly on extrafloral nectaries, seeds, insects and honeydew secreted from hemipteran insects, we believe the bottom-up process plays a central role in determining ant–tree interaction networks.

Effects of the pesticides chlorpyriphos, metsulfuron-methyl, and thiamethoxam on ant communities in wheat crop

Ants are important components of food webs in several ecosystems. In anthropic areas, they can be used as bioindicators of the environmental impacts caused by many factors or in the evaluation of the dynamics of the recovery of an area after a certain disturbance. In this context, ants can be used as bioindicators in studies on the evaluation of environmental disturbances caused by pesticide use. Thus, the present work investigated the environmental impacts caused by the application of the insecticides chlorpyriphos and thiamethoxam and the herbicide metsulfuron-methyl in the community of ants in wheat crop (Triticum aestivum L.). The data were collected by pitfall traps and Berlese funnels. A Principal Response Curve was used for a relative abundance analysis. In addition, diversity index and richness were calculated for ant communities. The presence of six families, 11 tribes, 15 genera, and 19 morphospecies of ants belonging to the guilds of fungivorous, omnivorous, and predaceous ants were observed in the soil of the wheat crop. The insecticides chlorpyriphos and thiamethoxam reduced the richness, diversity, and relative abundance of ants of all the guilds on the surface and inside the soil. The effect of the herbicide metsulfuron-methyl on the community of ants was lower than the impact of the insecticides on these insects.