Urban Ant Ecology

2018

Roeder, K. A., D. V. Roeder, and M. Kaspari. 2018. The role of temperature in competition and persistence of an invaded ant assemblage. Ecological Entomology. 43:774-781. doi:10.1111/een.12663

Abstract 1. To achieve numerical dominance, an ectotherm consumer requires a sizeable abiotic window in which it can forage. Here we explore how one abiotic factor, temperature, provides opportunity and regulates the impact of the invasive red imported fire ant, Solenopsis invicta, on an urban ant assemblage. 2.We first quantified S. invicta’s ability to outcompete native species by contrasting its foraging biomass to that of its potential competitors. In doing so, we found that S. invicta deployed more ant biomass at baits than the estimated whole colony biomass of three of the four co-occurring native species. It did so across c. 75% of the hours in a summer day, those hours below its thermal maximum of 49 ∘C. Higher thermal maxima allowed two native species to avoid encountering workers of S. invicta. 3. Exclosure experiments revealed that a third species, Dorymyrmex flavus, more similar in body size and thermal tolerance to S. invicta, was competitively suppressed by the invasive. Carbon and nitrogen stable isotope analysis suggests that D. flavus’ persistence is likely due to dietary differences. 4. Although thermal and dietary traits help predict how species coexist in this invaded assemblage, one key to S. invicta’s success is likely to be its ability to forage in all but 6 h of a summer’s day.

2017

Leong, C-H., Shiao, S-F. and B. Guénard. 2017. Ants in the city, a preliminary checklist of Formicidae (Hymenoptera) in Macau, one of the most heavily urbanized regions of the world. Asian Myrmecology 9:e009014 doi:10.20362/am.009014

Abstract Macau is a small territory in South East China and one of the most densely populated regions in the world. Previous studies on insect groups have shown that a relatively diverse, yet specific, fauna could still survive in this region. However, to this point, studies on the myrmecofauna of Macau are scarce and to date no species checklist exists. Here, we present the first checklist of Macanese ant species by combining results from recent ant surveys using hand-collections and Winkler extractors with published records. During the surveys, 82 species and morphospecies belonging to 37 genera and 8 subfamilies have been collected, with 37 species representing new records for Macau, including an interesting new record of an undescribed Leptanilla species, the second record of the Leptanillinae subfamily for South East China. To date, Macanese ants comprise 105 species/morphospecies and 8 subspecies, after the removal of dubious records present in the literature (though some misidentifications may remain). While still likely incomplete, these results represent the most comprehensive list of ants for Macau, and a baseline for future research on ant diversity in heavily urbanized environments and for understanding the potential consequences of urbanization on native and non-native diversity in Asia.

2015

Lange, D., A. A. Vilela, G. Erdogmus, A. B. Barbosa, S. C. Costa, and V. Stefani. 2015. Temporal dynamic of foraging of epigeic ants in an urban forest fragment. Bioscience Journal. 31:1501-1511.

Abstract The present study aimed to investigate the foraging dynamic of an ant community in an urban semideciduous mesophitic forest. A total of 4,297 individuals, distributed in 23 species, seven genera and four subfamilies were sampled in January, April, July and October of 2010. Four ant species guilds were found: leaf cutters, soil-dominant omnivores, soil and vegetation opportunists and large-sized epigaeic predators. There were no significant differences in total of species richness and abundance of individuals in samples among the months evaluated. However, there was a clear substitution (turnover) of species over the months. Nine species were sampled exclusively in the rainy period and five species were present only during the dry period. Thus, the species turnover over the months support the hypothesis that ant communities present a temporal dynamics in their foraging activities even in an urban forest fragment. In general, the abundance of ants foraging on soil was greatest during the months with greater rainfall. However, two species belonging to the guild of opportunistic ants from soil and vegetation doubled the number of foraging individuals in period during the months with less precipitation. These findings support that ant communities, independent of isolation and environment (urban or natural), have temporal dynamics that arise from factors relating to the biology and behavior of the group.

Ossola, A., M. A. Nash, F. J. Christie, A. K. Hahs, and S. J. Livesley. 2015. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants. PeerJ. 3. doi:10.7717/peerj.1356

Abstract Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size.

Talaga, S., J. H. C. Delabie, O. Dezerald, A. Salas-Lopez, F. Petitclerca, C. Leroy, B. Heraultd, R. Cereghino, and A. Dejean. 2015. A bromeliad species reveals invasive ant presence in urban areas of French Guiana. Ecological Indicators. 58:1-7. doi:10.1016/j.ecolind.2015.05.027

This study in French Guiana investigated the species of ants found in Aechmea aquilega (a bromeliad) in urban trees. The incidence of invasive ants were higher in baited trees with bromeliads trees without bromeliads and at baits on the ground.

Abstract Tank bromeliads, frequently associated with ants, are considered ‘biodiversity amplifiers’ for both aquatic and terrestrial organisms, and thus have a high ecological value. The focal species of this study, Aechmeaaquilega, sheltered the colonies of 12 ant species in a Guianese rural habitat where Odontomachus haematodus, associated with 60% of these plants, was the most frequent. Unexpectedly, the ant species richness was higher in a compared urban habitat with 21 species, but two synanthropic and four invasive ants were noted among them. Consequently, we conducted baiting surveys (on the ground, on trees and on trees bearing A. aquilega) as well as complementary surveys using different sampling modes in urban areas to test if A. aquilega is a surrogate revealing the presence of certain invasive ants. During the bait-ing survey, we recorded four Neotropical and eight introduced invasive ants out of a total of 69 species. Of these 12 invasive species, five were noted by baiting A. aquilega (including two only noted in this way). A bootstrap simulation permitted us to conclude that A. aquilega significantly concentrates certain species of invasive ants. This was confirmed by complementary surveys, where we did not record further species. We conclude that baiting on trees bearing large epiphytes in human-modified, Neotropical areas is a relevant complement to the early detection of invasive ants.

2014

Philpott, S., J. Cotton, P. Bichier, R. Friedrich, L. Moorhead, S. Uno, and M. Valdez. 2014. Local and landscape drivers of arthropod abundance, richness, and trophic composition in urban habitats. Urban Ecosystems. 17:513-532. doi:10.1007/s11252-013-0333-0

Abstract Urban green spaces, such as forest fragments, vacant lots, and community gardens, are increasingly highlighted as biodiversity refuges and are of growing interest to conservation. At the same time, the burgeoning urban garden movement partially seeks to ameliorate problems of food security. Arthropods link these two issues (conservation and food security) given their abundance, diversity, and role as providers of ecosystem services like pollination and pest control. Many previous studies of urban arthropods focused on a single taxon (e.g. order or family), and examined either local habitat drivers or effects of landscape characteristics. In contrast, we examined both local and landscape drivers of community patterns, and examined differences in abundance, richness, and trophic structure of arthropod communities in urban forest fragments, vacant lots, and community gardens. We sampled ground-foraging arthropods, collected data on 24 local habitat features (e.g., vegetation, ground cover, concrete), and examined land-cover types within 2 km of 12 study sites in Toledo, Ohio. We found that abundance and richness of urban arthropods differed by habitat type and that richness of ants and spiders, in particular, varied among lots, gardens, and forests. Several local and landscape factors correlated with changes in abundance, richness, and trophic composition of arthropods, and different factors were important for specific arthropod groups. Overwhelmingly, local factors were the predominant (80 % of interactions) driver of arthropods in this urban environment. These results indicate that park managers and gardeners alike may be able to manage forests and gardens to promote biodiversity of desired organisms and potentially improve ecosystem services within the urban landscape.

2010

Pecarevic, M., J. Danoff-Burg, and R. R. Dunn. 2010. Biodiversity on Broadway - Enigmatic diversity of the societies of ants (Formicidae) on the streets of New York City. PLoS ONE. 5(10): e13222:8 p. doi:10.1371/journal.pone.0013222

Abstract Each year, a larger proportion of the Earth’s surface is urbanized, and a larger proportion of the people on Earth lives in those urban areas. The everyday nature, however, that humans encounter in cities remains poorly understood. Here, we consider perhaps the most urban green habitat, street medians. We sampled ants from forty-four medians along three boulevards in New York City and examined how median properties affect the abundance and species richness of native and introduced ants found on them. Ant species richness varied among streets and increased with area but was independent of the other median attributes measured. Ant assemblages were highly nested, with three numerically dominant species present at all medians and additional species present at a subset of medians. The most common ant species were the introduced Pavement ant (Tetramorium caespitum) and the native Thief ant (Solenopsis molesta) and Cornfield ant (Lasius neoniger). The common introduced species on the medians responded differently to natural and disturbed elements of medians. Tetramorium caespitum was most abundant in small medians, with the greatest edge/area ratio, particularly if those medians had few trees, whereas Nylanderia flavipes was most abundant in the largest medians, particularly if they had more trees. Many of the species encountered in Manhattan were similar to those found in other large North American cities, such that a relatively small subset of ant species probably represent most of the encounters humans have with ants in North America.

2005

Iwata, K., K. Eguchi, and S. Yamane. 2005. A Case Study on Urban Ant Fauna of Southern Kyusyu, Japan, with Notes on a New Monitoring Protocol (Insecta, Hymenoptera, Formicidae). Journal of Asia-Pacific Entomology. 8:263-272. doi:10.1016/S1226-8615(08)60244-7

Abstract Ant fauna of a green buffer belt adjacent to an industrial zone in Kagoshima City, southern Kyushu, Japan was elucidated using a standardized protocol. A total of 39 species belonging to 24 genera in five subfamilies were recorded from this park. Most speciose genera are Camponotus and Tetramorium having four species. The number of species per genus is 1.56 on average. Pheidole nodus, Monomorium chinense, Solenopsis japonica, Tetramorium bicarinatum and Technomyrmex albipes were most frequently encountered. Excepting Pheidole nodus they are open-land and/or forest-edge inhabitants. Furthermore, Tetramorium bicarinatum and Technomyrmex albipes are tramp species. Thus, ant fauna there strongly reflects environmental conditions derived from urbanization/industrialization. Based on the present results, we propose here a new protocol monitoring ants in urban/industrial zones consisting of baiting and time unit sampling.