Ant Diversity Studies 2018

The number of contemporary publications that focus on ant communities and ant biodiversity shows that these topics continue to be strong areas of interest. This page lists 2018 publications that focus on these topics.

Ant Diversity Studies 2017

A - L (by first author)

 * Achury, R. and A. V. Suarez. 2018. Richness and Composition of Ground-dwelling Ants in Tropical Rainforest and Surrounding Landscapes in the Colombian Inter-Andean Valley. Neotropical Entomology. 47:731-741. doi:10.1007/s13744-017-0565-4

Tropical rainforests are characterized by having high structural complexity, stratification, and species diversity. In Colombia, tropical rainforests are critically endangered with only 24% of their area remaining. Forest fragments are often valued based on the presence of vertebrate taxa despite that small habitat remnants may still harbor diverse invertebrate communities. We surveyed the ant fauna associated with rainforest fragments and their surrounding landscape elements (including mature forests, flooded forests, gallery forests, live fences, and pastures) in the Magdalena River watershed. Pitfall traps and litter samples were used to estimate ant richness and diversity, and to compare ant composition among landscape elements. We found 135 species from 42 genera, representing 16% of the species and 43% of the genera known for Colombia. Our surveys also uncovered 11 new ant records for the Colombian inter-Andean region and 2 new records for the country of Colombia: Mycocepurus curvispinosus (Mackay) and Rhopalothrix isthmica (Weber). The highest species richness was found in forest-covered sites, and richness and diversity was lower in the disturbed landscapes surrounding the forest patches. Species composition varied significantly between all habitat types, but was most similar between forest types suggesting that a loss of structural complexity has the greatest effect on ant communities. Across our study sites, ten species showed the greatest response to habitat type and could qualify as indicator taxa for this region. We conclude by discussing the value of conserving even small forests in this landscape due to their ability to retain high diversity of ants. -


 * Catarineu, C., G. G. Barbera, and J. L. Reyes-Lopez. 2018. Zoogeography of the Ants (Hymenoptera: Formicidae) of the Segura River Basin. Sociobiology. 65:383-396. doi:10.13102/sociobiology.v65i3.2822

The work submitted in this paper presents the first checklist of the ant species of the Segura River Basin based on a review of specific literature and biological material collected during field work conducted from 2012 to 2016. Our findings recorded 110 species that belong to 30 genera of ants and twenty-two of these species have been recorded for the first time in this area. The zoogeographical composition is dominated by the species of the Mediterranean zone (75.2%), followed by the mixed and deciduous forest zone (19.1%). The most important zoogeographic elements are: Iberian (20%), Holomediterranean (17.1%) and West-Mediterranean (13.3%). There are only six cosmopolitan species (5.71%). There is a greater proportion of species from the mixed and deciduous forest zone in the high-mid altitudes in the Segura River Basin, where the climate is cooler, and more humid. The Euro-Caucasian and Euro-West Siberian elements tend to be more associated to forest with a higher precipitation, whilst the South Palearctic elements seem to be more associated to ecosystems more similar to the forest-steppe zone with intermediate precipitation. The existence of these different zoogeographic origins in this area is probably linked with: the position between Africa and Europe; the complex geotectonic, paleogeographic, and paleoclimatic history during the last 7 My; the complex geomorphology; and the high climate and habitat diversity. Based on ant studies and other taxa, possible explanations of the zoogeographic origin of these ant chorotypes are proposed. -
 * Dambros, J., V. F. Vindica, J. H. C. Delabie, M. I. Marques, and L. D. Battirola. 2018. Canopy Ant Assemblage (Hymenoptera: Formicidae) in Two Vegetation Formations in the Northern Brazilian Pantanal. Sociobiology. 65:358-369. doi:10.13102/sociobiology.v65i3.1932

The landscape of the northern Pantanal region is a mosaic of fields and forests, distributed according to topography and hydrology of this floodplain, resulting in a particular pattern of vegetation distribution. Among the forest formations, mixed-species and monodominant landscape units can be found which are associated with floodable or non-floodable habitats. Our study tested the hypothesis that forest formations with greater tree richness and which are non-floodable (cordilheiras) maintain distinct richness and composition in canopy ant assemblages in relation to the seasonally floodable monodominant forests (cambarazais). Sampling was performed in 10 sample areas (five cambarazais and five cordilheiras) by means of canopy insecticide fogging during the dry and high water seasons of the Pantanal's hydrological cycle. The canopy ant assemblages revealed 105 species belonging to 30 genera and nine subfamilies. Myrmicinae (41 spp.), Formicinae (20 spp.) and Pseudomyrmecinae (17 spp.) predominated. Our results revealed that the composition of canopy ant assemblages varied between cambarazal and cordilheira forests, as well as between the dry and high water periods. Nevertheless, the richness was homogeneous between these forests and in the dry and high water periods. These results show the specificity of each forest, as well as its structure, in maintaining distinct compositions in ant assemblages in canopies in the Pantanal of Mato Grosso.

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 * Freedman, M. G., R. H. Miller, and H. S. Rogers. 2018. Landscape-level bird loss increases the prevalence of honeydew-producing insects and non-native ants. Oecologia. 188:1263-1272. doi:10.1007/s00442-018-4273-5

Bird exclusion experiments consistently show that birds exhibit strong top-down control of arthropods, including ants and the honeydew-producing insects (HPIs) that they tend. However, it remains unclear whether the results of these small-scale bird exclosure experiments can be extrapolated to larger spatial scales. In this study, we use a natural bird removal experiment to compare the prevalence of ants and HPIs between Guam, an island whose bird community has been extirpated since the 1980s due to the introduction of the brown tree snake, and two nearby islands (Rota and Saipan) that have more intact bird assemblages. Consistent with smaller-scale bird exclosure experiments, we show that (1) forest trees from Guam are significantly more likely to host HPIs than trees from Saipan and (2) ants are nearly four times as abundant on Guam than on both Saipan and Rota. The prevalence of HPIs varied slightly based on tree species identity, although these effects were not as strong as island-level effects associated with bird loss. Ant community composition differed between Guam and the other two islands. These results corroborate past observational studies showing increased spider densities on Guam and suggest that trophic changes associated with landscape-level bird extirpation may also involve alterations in the abundance of ants and HPIs. This study also provides a clear example of the strong indirect effects that invasive species can have on natural food webs.

M - Z (by first author)
The effect of environmental variability on species richness, community structure, and daytime activity of ants along a disturbance gradient was examined at El Cielo Biosphere Reserve, Tamaulipas, Mexico. The study site was delimited by LANDSAT satellite images. Ants were evaluated using pitfall traps from 0800 to 1800 every hour for four consecutive days in August 2016. In total, 1190 individuals of 20 species and seven subfamilies were obtained. Six species responded positively to the disturbed environment during the morning, with variation between assessment days. The daytime activity of ant species was variable during the day along the disturbance gradient. Solenopsis geminata was the species that showed the most activity during most of the day in the study. Abundance of species differed between most environments each hour. The total variation explained by the first two axes of the relationship analysis of species abundance and environmental attributes was 83% (Axis 1: Temperature and humidity = 64%, Axis 2: Rocks = 19%). S. geminata and Forelius pruinosus were the species that responded significantly to the variables evaluated. The results suggested that environmental variability along a disturbance gradient determines the establishment of the niche and the diurnal activity profile of each species throughout the day and between days. -
 * Rodriguez-de Leon, I. R., C. S. Venegas-Barrera, M. Vasquez-Bolanos, A. Correa-Sandoval, and J. V. Horta-Vega. 2018. Richness, Community Structure, and Diurnal Activity of Species of Ants along a Disturbance Gradient at El Cielo Biosphere Reserve, Tamaulipas, Mexico. Southwestern Entomologist. 43:919-938.


 * Salles, L. F. P., A. V. Christianini, and P. S. Oliveira. 2018. Dirt roads and fire breaks produce no edge effects on litter-dwelling arthropods in a tropical dry-forest: a case study. Journal of Insect Conservation. 22:647-657. doi:10.1007/s10841-018-0091-7

Edge effects threaten organisms and ecological processes in habitat remnants, but they have been poorly studied in non-humid forests such as cerradão, a tropical dry forest sometimes derived from fire-suppressed savanna in Brazil. The diverse ecosystem functions performed by arthropods may be disrupted by edge effects, and there is pressing need for more studies on this subject. We sampled fragments of cerradão facing either a road or fire breaks, assessing edge effects in: beta diversity and community composition of epigaeic (litter-dwelling) arthropod orders, ant species, and ant functional groups; ant species richness and diversity; leaf litter depth; and colony residence time of a predatory ground-dwelling ant, Odontomachus chelifer (Ponerinae). None of the variables measured differed between edge and interior of the sites sampled. Dry forests have high micro-climatic variations caused by discontinuities in the canopy cover and, as such, changes in abiotic variables in cerradão edges might not be as clear as those observed in tropical rainforests. Our study demonstrates that edge effects may not be so prevalent in cerradão facing roads or fire breaks, which possibly increases the chances of survival of a higher fraction of the original arthropod fauna compared to rainforest fragments.

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 * Santiago, G. S., R. B. F. Campos, and C. R. Ribas. 2018. How does landscape anthropization affect the myrmecofauna of urban forest fragments? Sociobiology. 65:441-448. doi:10.13102/sociobiology.v65i3.3042

We evaluate whether landscape variables surrounding urban remnant forest fragments influence ant diversity and its components in urban areas. The study was conducted in six riparian forest fragments in midwestern Minas Gerais State, Brazil, by sampling epigaeic and arboreal ants. Arboreal ants respond to fragment isolation with changes in alpha, beta and gamma diversities. Isolation likely hinders dispersion and re-colonization such that the more isolated a fragment is, the less likely that new species arrive there. On other hand, epigaeic diversity did not show any response to variables of the surroundings or fragments, probably because natural periodic floods constitute a more severe disturbance for these ants. In addition, throughout the process of urbanization, anthropogenic improvements, such as paving, that prevent the natural percolation of water, increase the flooding of riparian soil. Arboreal ant species composition responds to percentage of urban area, fragment area and distance from the urban center, while epigaeic ants respond only to fragment area and percentage of urban area. We believe that even with the loss of species diversity and anthropogenic influences on fragments within urban centers, these areas are still important for species conservation. We also suggest the development of environmental protection projects for riparian areas within urban centers, including investments in ecological corridors connecting fragments and public policies seeking to preserve these areas.

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 * Santos, L. A. O., A. Bischoff, and O. A. Fernandes. 2018. The effect of forest fragments on abundance, diversity and species composition of predatory ants in sugarcane fields. Basic and Applied Ecology. 33:58-65. doi:10.1016/j.baae.2018.08.009

Habitat loss and fragmentation have gradually caused loss of diversity and consequently the decline of ecological services. This study aimed to evaluate the effect of tropical forest fragments as natural habitats (river valley fragments and plateau fragments) on the community of predatory and omnivorous ants in nearby sugarcane fields. Twenty fields adjacent to these fragments were selected and evaluated one (dry season) and four months (rainy season) after harvest. In each field, ants were sampled in five linear plots (10 m inside the fragment, 0 m (field path between field and fragment), 5 m, 50 m and 100 m inside the crop fields). Each plot comprised ten sardine baits in a row parallel to the field edge. Species richness and frequency of ant species decreased with increasing distance from the forest fragments. Inside fields, species richness and frequency were higher during the period of vegetative growth (rainy season) than after harvest (dry season). Ant communities of sugarcane fields and forest fragments were more similar later in the season than directly after sugarcane harvest suggesting recolonization of the fields from the fragments. Several ant species were limited to forest fragments after harvest but occurred later in the season also in sugarcane fields confirming the potential contribution of fragments to the recolonization process and therefore to biological control of sugarcane-dominated pest insects.

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 * Walter, B., A. Graclik, P. Tryjanowski, and O. Wasielewski. 2018. Ants Response to Human-Induced Disturbance in a Rain Tropical Forest. Neotropical Entomology. 47:757-762. doi:10.1007/s13744-018-0624-5

A high rate of human-induced disturbance of tropical ecosystems results in enormous loss of biodiversity due to local extinctions. Yet, mechanisms at the population level that lead to the extinction are still poorly understood. Here we tested the hypothesis that human-induced disturbance results in smaller amount of nesting sites for wood-dwelling arthropods that leads to smaller population size and diminished reproduction, and therefore, may promote local extinctions. We completed censuses in less-disturbed and human-disturbed secondary rain forest plots in Puerto Rico. We measured population size and brood production in wood-nesting ants and examined whether these parameters differ between less-disturbed and more-disturbed habitats. In addition, we measured volume of wood parts of all inhabited and potential nesting sites to assess nest site availability. We found that more human-disturbed forests furnish smaller nest sites, resulting in diminished population size and lowered brood production. Our study shows that human-induced disturbance decreases volume of available nesting sites that leads to decreased population size and lowered reproduction. Thus, in addition to the well-documented loss of species richness in human-disturbed tropical habitats, we demonstrated the direct effect of the disturbance that may promote vulnerability of local populations.