Undecomposed Twigs in the Leaf Litter As Nest-Building Resources

Hindawi Publishing Corporation Psyche Volume 2012, Article ID 896473, 8 pages doi:10.1155/2012/896473

Research Article Undecomposed Twigs in the Leaf Litter as Nest-Building Resources for Ants (Hymenoptera: Formicidae) in Areas of the Atlantic Forest in the Southeastern Region of Brazil

Tae Tanaami Fernandes,1 Rogerio´ Rosa da Silva,2 Debora´ Rodrigues de Souza,1 Natalia´ Araujo,´ 1 and Maria Santina de Castro Morini1

1 Laboratorio´ de Mirmecologia, Universidade de Mogi das Cruzes, 08701-970 Mogi das Cruzes, SP, Brazil 2 Museu de Zoologia da Universidade de Sao˜ Paulo, Avenida Nazar´e 481, Ipiranga, 04263-000 Sao˜ Paulo, SP, Brazil

Correspondence should be addressed to Maria Santina de Castro Morini, [email protected]

Received 12 June 2012; Revised 15 September 2012; Accepted 17 September 2012

Academic Editor: Diana E. Wheeler

Copyright © 2012 Tae Tanaami Fernandes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

In tropical forests, the leaf-litter stratum exhibits one of the greatest abundances of ant species. This diversity is associated with the variety of available locations for nest building. Ant nests can be found in various microhabitats, including tree trunks and fallen twigs in different stages of decomposition. In this study, we aimed to investigate undecomposed twigs as nest-building resources in the leaf litter of dense ombrophilous forest areas in the southeastern region of Brazil. Demographic data concerning the ant colonies, the physical characteristics of the nests, and the population and structural of the forest were observed. Collections were performed manually over four months in closed canopy locations that did not have trails or flooded areas. A total of 294 nests were collected, and 34 ant species were recorded. Pheidole, Camponotus,andHypoponera were the richest genera observed; these genera were also among the most populous and exhibited the greatest abundance of nests. We found no association between population size and nest diameter. Only tree cover influenced the nest abundance and species richness. Our data indicate that undecomposed twigs may be part of the life cycle of many species and are important for maintaining ant diversity in the leaf litter.

1. Introduction rich in terms of taxonomy, morphology, and function [13– 15], and its high diversity [5, 14, 16] has been associated with Ants represent only 2% of the described insect fauna; how- vegetation structure and the biotic and abiotic characteristics ever, they constitute more than 50% of the animal biomass of the habitat [17, 18]. of tropical forests, savannas, ﬁelds, and other important In the leaf litter, ants have access to food resources, habitats [1, 2]. The majority of ant species inhabit the locations for nest building, and a favorable microclimate soil and/or leaf litter [3]. In tropical forests, approximately [17, 19–23]. The variation in nest-building locations among 50% of the ant fauna may be associated with the leaf litter species is a prerequisite for the maintenance of leaf-litter [4], but the factors that structure these communities are ant species diversity [24]. Despite a reasonable amount of poorly understood [5, 6], especially for communities that ecological knowledge, the biology of the majority of leaf- live in the leaf litter of the Brazilian Atlantic Rainforest. One litter species is still largely unknown [25]. fundamental goal of ecology is to understand the structure Litter-nesting ants are a particularly useful group for and maintenance of diverse tropical assemblages [7]. community-level comparisons because litter can be exhaus- Studies of the diversity of leaf-litter ants are relatively tively searched to provide accurate data on nest density and abundant [8, 9], and several studies have been conducted species richness, regardless of weather [6]. Ant nests in the in the Atlantic Rainforest sites selected for the present study leaf litter are located among interstices, in the interior of (see [10–12]). The ant fauna that inhabits the leaf litter is fruits, between leaves, or in branches and trunks at various 2 Psyche

Table 1: Locations of sampling sites in southeastern Sao˜ Paulo state, Brazil.

Municipality Sampling sites (acronym) Geographical coordinates Altitude (m) Size∗ (ha) Ribeirao˜ do Campo Dam (RC) S 23◦3810;W45◦4957 780 200 Ponte Nova Dam (PN) S 23◦3419;W45◦4410 783 200 Salesopolis´ Reserva do Incra (RI) S 23◦3639;W45◦4947 750 130 Estaçao˜ Biologica´ de Boraceia´ (EBB) S 23◦3156;W45◦5047 780 96 Museum of Energy Dam (ME) S 23◦3347;W45◦5010 790 100 Municipal Natural Park Francisco Affonso de Mello (PNMFAM) S 23◦3122;W46◦1116 810 350 Itapeti Ecological Station (EEI) S 23◦3033;W46◦1414 820 89 Mogi das Cruzes Legal Reserve (RL) S 23◦3035;W46◦1422 830 104 Agro-Environmental Nucleus (NA) S 23◦2947;W46◦1227 810 20 Fazenda Santo Alberto (SA) S 23◦2621;W46◦0950 690 130 ∗ Approximate size of the sampling areas. stages of decomposition [26]. Among the resources provided All of the undecomposed twigs with lengths of 10 to by the leaf litter, twigs/trunks are essential for ant nests to 30 cm and containing ants were manually collected and occur [27]. individually placed in plastic bags for later identification. Small ants and those with little dispersal ability, such This twig size was selected because smaller twigs were as species of Myrmicinae and the tribe Dacetini or species generally decomposing in the sampling areas. Furthermore, of Ponerinae, can be found by breaking pieces of branches the selected size was the approximate size of most of the and twigs that have fallen in the leaf litter or by looking ant-colonized twigs [27]. Only the twigs that were found on in rotten trunks [28]. However, fallen trunks are colonized the surface were collected because they are the most recent by few species [29]; twigs are important for the nesting of resources in the leaf litter. a higher number of species, especially twigs in stages of The number of twigs with nests was recorded (=the decomposition [27]. This preference may be related to the density of the nests), and the ants were identified to the ants’ access to the inside, as digging is easier [27], or to genus level using identification keys. The species were moisture, which is the limiting factor for leaf-litter ants [5]. identified by comparison with the examples deposited in In the present study, we investigated in detail the ant the reference collection of the Zoological Museum of the species that use twigs that are still undecomposed, a subset University of Sao˜ Paulo (Museu Zoologia da Universidade of twigs that is less exploited by ants [27]. Furthermore, de Sao˜ Paulo) (MZSP). The taxonomic scheme proposed by to investigate the determinants of community organization, [33] was used. Vouchers are deposited in the collection of we collected measurements related to twig characteristics, the Myrmecology Laboratory of the University of Mogi das colony structure (workers, alates, and immature ants), can- Cruzes (Universidade de Mogi das Cruzes) and the MZSP. opy cover, and litter depth.

2. Methods 2.2. Characterization of the Nests, Demographic Data, Canopy Cover, and Litter Depth. Using a digital pachymeter, the total 2.1. Study Area and Sampling. Thecolonieswerecollected diameter of the twigs that contained colonies was measured; in 10 dense ombrophilous forest fragments [30]located fivemeasurementswereconductedoneachtwig.Thecounts in the Upper Tieteˆ Hydrographic Basin in the state of of immature ants (eggs, larvae, and pupae) and workers were Sao˜ Paulo, Brazil (Table 1). The sampling expeditions were performed using a manual counter. only conducted once during the experimental period. The The canopy cover was recorded at the center and at the samples were collected between September and December vertices of each of the 16 m2 plots using a Nikon D80 digital of 2010 (approximately one sampling per week), spanning camera with a fish-eye objective. The Gap Light Analyzer the region’s rainy season [31]. Each sampling expedition was (GLA) application version 2.0 was used to analyze the images conducted one day after rain in locations without trails, [34]. without flooded areas and under a closed canopy. The The litter depth was measured using calipers at the vegetation of the collection areas was similar and composed corners and in the center of each 1 m2 parcel. These small oftreesthatwere2to20minheightwithtrunksthathad parcelswererandomlymarkedwithineach16m2 parcel. The a diameter at chest height that was equal to or greater than average of five values was used to define the stratum depth. 20 cm. Six 16 m2 parcels were delimited in each area along a linear transect. The plots were separated by 50 m to ensure 2.3. Data Analysis. Comparisons among the collection sites the independence of the samples [16, 32]. were made using the number of occurrences of the species The sampling effort for each plot was constant (collection (presence and absence data). The ant richness was compared time = 30 minutes, and number of collectors = 3perplot). using accumulation curves based on the number of species Psyche 3

40 Estimated richness 35

30 Observed richness

20 Species richness 15

0 3.37 30.3 50.5 70.7 90.9 10.1 16.83 23.57 43.77 77.43 84.17 151.5 131.3 171.7 191.9 37.03 57.23 63.97 97.63 111.1 144.77 158.23 104.37 117.83 124.57 138.03 164.97 178.43 185.17 198.63 Occurrence Figure 1: Accumulation and estimated species richness curves in undecomposed twigs in the leaf litter of dense ombrophilous forest. that occurred. The expected number of species was deter- of nests. Pheidole was the richest genus in terms of species mined using the Chao2 richness estimator, which is based followed by Camponotus.SpeciesofPheidole, Solenopsis, on incidence and uses the number of “uniques” (species Myrmelachista, Camponotus and Linepithema represented found in only one sample) and “duplicates” (species found the greatest numbers of nests and were also the most in only two samples) [35]. The curves were obtained using populous species; the number of workers ranged from 165 the EstimateS program version 8.2 [35]. to 458 and of immature ants from 108 to 1,317 among these We used Spearman correlations to analyze the relation- species (Table 2). ship between the total number of immature ants and workers The nest abundance ranged from 3.16 (±2.85) to 7 and the twig diameter, excluding rare species (those with (±2.44) among the dense ombrophilous rainforest frag- anumberofrecords<10 nests) [27]. The relationships ments, and species richness ranged from 2.33 (±1.79) to between species richness and tree cover and leaf-litter depth 4.66 (±2.16). The tree cover spanned 8.02 (±1.89) to 18.33 were identified using scatter plots and Pearson correlations. (±1.89) %, and leaf litter depth ranged from 2.99 (±0.76) to The same analyses were performed for nest abundance. All 12.82 (±5.5) cm (Figure 2). Canopy cover influenced the nest of the analyses were preceded by the Lilliefors test to verify abundance (r = 0.3949; P<0.05; Figure 3(a)) and species data normality. The BIOESTAT 5.0 software [36]wasused richness (r = 0.2806; P<0.05; Figure 3(b)). The leaf-litter for both of the tests with a 5% significance level. depth was not related to the nest abundance (r =−0.0519; P>0.05) or species richness in twigs (r =−0.0099; P> 3. Results 0.05). The twig diameter ranged from 10.77 (±4.48) to 39.61 In 960 m2 of leaf litter, there was a total of 294 nests (±3.66) mm, and these twigs were occupied by Camponotus (0.31 nests/m2), seven subfamilies, 15 genera, and 34 species. sp.9 and Hypoponera sp.10, respectively (Table 2). We did The species density was 0.03 species/m2. A total of 264 not detect a relationship between the twig diameter and the nests (89%) were immature. Eleven species (32%) occupied size of the colonies (workers, immature ants and workers + ≥10 twigs, especially Pheidole sp.13, with 56 recorded nests immature ants) (P>0.05), except for Pheidole sp.13, for (Table 2). Each twig was inhabited exclusively by one species which there was a relationship between the size of the worker (we did not observe the cooccurrence of species in individual population and the twig diameter (r = 0.3283; P<0.05). twigs). The richness curve did not stabilize, but the estimated We recorded 17 species with queens, 12 with alates and 8 curve of the number of species reached a stable level with queens and alates. We found that more than one queen (Figure 1). coexisted in the same twig for five species: L. neotropicum Myrmicinae was the richest subfamily both in terms of Wild (one nest with five queens), Brachymyrmex incisus the number of nests (56%) and the number of species (41%). Forel (one nest with two queens), Crematogaster sp.1 (one Ectatomminae was the least rich subfamily, with only one nest with three queens), Pheidole sp.13 (one nest with two species (Gnamptogenys striatula Mayr) being observed, but queens), and Pheidole sp.43(onenestwithtwoqueensand it was among the subfamilies with the greatest abundance one with three queens) (Table 3). 4 Psyche SD) ± SD) Variation Average ( ± 264 = posed twigs in the leaf litter of dense ombrophilous forest. Number of nests with immature ants SD) Variation Average ( ± Number of workers Number of immature ants Twig diameter (mm) Variation Average ( 294 Total nests with immature ants ∗ = 33 1–121 61.66 (60.01) 2–21 13 (9.84)7 3 3–31 2 14.42 (9.01) 1–28 11.33 (14.57) 16.19–24.63 19.12 (4.77) 14–42 7 28 (19.79) 7.53–21.36 13.48 (7.11) 1–31 11.42 (11.47) 5.67–21.23 14.18 (5.75) 1 2 — 1 2 — 12.13 — 2 4–18 11 (9.89) 2 9–38 23.5 (20.50) 14.38–22.74 18.56 (5.91) 2 5–31 18 (18.38) 135 1 4–18 1–97 10.33 (7.09) 26.80 1 (40.11) 9.2–35.53 22.36 (18.61) 3 5 7–58 3–100 31.33 52.40 (25.57) (34.65) 8.84–23.64 8.92–23.80 14.60 13.89 (7.92) (5.89) 1 26 — 1 134 — 9.19 — 9 4–65 32.88 (25.55) 7 27–110 61 (31.13) 8.82–32.77 15.38 (7.66) 18 3–165 74.94 (45.83)1814 15 13–458 10–166 100.16 (124.53) 47.21 (45.92) 2–1317 144.94 (332.51) 10.58–59.84 16 24.23 (13.01) 13 13–537 129.68 (156.62) 34–172 5.14–25.98 68.76 (35.52) 13.72 (7.50) 6.23–17.76 12.53 (4.04) 16 5–47 19.37 (11.44) 12 1–43 16.25 (13.97) 9.76–46.19 20.53 (11.42) 18 4–196 34.5 (47.91) 18 4–108 29.66 (28.18) 5.54–18.79 10.62 (4.19) 2: The colony and nest structure of species reported in undecom ) 4 13–68 32 (24.77) 3 23–41 33.33 (9.29) 9.41–21.68 14.77 (5.11) ) 2 64–97 80.5 (23.33) 2 42–82 62 (28.28) 15.85–33.55 24.7 (12.51) Table 10 workers + immature ants. Arthocrema ≤ sp.1sp.2 6 2 11–40 9–12 24 (12.89) 10.5 (2.12) 6 2 20–54 3–21 32.83 (11.51) 10.46–16.30 12 (12.72) 13.79 (2.88) 12.32–15.36 13.84 (2.14) gr. Myrmaphaenus Tanaemyrmex sp.1 1 13 — 1 23 — 26.29 — ( ( sp.8sp.9sp.10 2 2 18 10–28 9–34 4–66 19 (12.72) 27.88 21.5 (19.92) (17.67) 2 18 2 3–125 5–36 14–128 44.94 (32.38) 20.5 (21.92) 71 (80.61) 7.85–17.18 16.12–23.36 7.6–13.94 13.60 (2.54) 19.74 (5.11) 10.77 (4.48) sp.4sp.7sp.8sp.10 1 4 2 2 13 7–31 10–46 6–23 23.5 (11.21) 28 (25.45) — 14.5 (12.02) 4 1 2 — 6–75 4–117 10 29.75 (32.06) — 60.5 (79.90) 10.15–20.69 15.56 37.02–42.21 (4.96) — 39.61 (3.66) — 12.1–35.53 24.12 (16.13) 19.88 — . Diplorhoptrum 34 Total nests gr sp.5 4 42–185 102 (65.82) 4 17–66 37.75 (23.44) 5.58–23.21 11.41 (8.30) = sp.6sp.7sp.9sp.13sp.14sp.43 13 11 3 56 15 3–288 26 4–103 50–113 65 2–234 (73.03) 43.45 (36.62) 2–87 89 64.94 4–211 (34.07) (54.27) 32.46 (22.82) 53 (45.10) 13 8 51 3 14 22 1–78 1–113 1–167 38–389 44.37 29.53 (44.25) (19.05) 3–131 40.82 208.66 (40.45) (175.69) 8.78–33.89 4.18–26.83 2–268 20.66–38.44 28.21 (34.73) 8.82–59.73 14.99 14.75 (7.59) (6.35) 29.71 (8.89) 53.45 (59.87) 9.29–33.86 24.10 (12.74) 8.60–147.63 14.64 (6.74) 20.23 (26.83) 10 workers or ≥ Linepithema neotropicum Linepithema iniquum Brachymyrmex incisus Heteroponera mayri Solenopsis wasmannii Camponotus Camponotus Camponotus Camponotus Camponotus Myrmelachista catharinae Myrmelachista ruszkii Heteroponera dentinodis Gnamptogenys striatula Acanthognathus ocellatus Crematogaster Hypoponera Hypoponera Hypoponera Hypoponera Pachycondyla crenata Pseudomyrmex phyllophilus Pseudomyrmex pallidus Solenopsis Solenopsis Pheidole Pheidole Pheidole Pheidole Pheidole Procryptocerus Procryptocerus Mycetosoritis Pheidole Nest: Dolichoderinae Ectatomminae Formicinae Heteroponerinae Myrmicinae Ponerinae Pseudomyrmecinae Total species Subfamily/species Total nests ∗ Psyche 5

Table 3: Presence of queens and alates among the species reported in undecomposed twigs in the leaf litter of dense ombrophilous forests.

Queens Alates Species/morphospecies Nests with queens Queens/nest Nests with alates Total or variation Linepithema neotropicum 2 1–5 3 2–50 Brachymyrmex incisus 12—— Camponotus (Myrmaphaenus)1 1 — — Camponotus (Tanaemyrmex)— — 1 8 Camponotus sp.8 — — — — Camponotus sp.9 1 1 1 5 Camponotus sp.10 1 1 3 1–16 Myrmelachista catharinae ——3 1–13 Myrmelachista ruszkii ——1 18 Crematogaster sp.1 2 1–3 2 3–14 Mycetosoritis sp.1 1 1 — — Pheidole sp.6 8 1 1 2 Pheidole sp.7 5 1 2 3–14 Pheidole sp.9 1 1 — — Pheidole sp.13 23 1-2 2 2–4 Pheidole sp.14 10 1 — — Pheidole sp.43 16 1–3 — — Solenopsis wasmannii 11—— Solenopsis sp.2 8 1 1 3 Solenopsis sp.5 — — 2 1-2 Hypoponera sp.7 1 1 — — Pseudomyrmex pallidus 11——

4. Discussion leaf litter of tropical forests, approximately 1/3 of the species are polydomic [5]. Although the causes of polydomy are The results presented in this paper indicate that unde- uncertain [41], polydomy may be related to the occupation of composed twigs are an important nest-building resource new areas [45], increased foraging area [42, 47], or increased used by many leaf-litter ant species and by several arboreal food supply [41]; there may be yet another cause found for ant species, as reported in other studies [8, 10, 37, 38]. certain arboreal ant species, which have larger colonies, in Specifically in the case of arboreal ants, twigs in the leaf compensating for restricted space in twigs [27]. Polydomy litter may represent external nests, as already reported is also observed in polygynous species, such as C. pygmaea for Azteca [39, 40]andCrematogaster torosa Mayr [41]. Forel [49]andM. schumanni Emery [50, 51]. Polydomy may This microhabitat probably originated from trees near the be the case for 29% of the nests determined to have more site where colonies resided that fell, bringing the eggs, than one queen, especially for Pheidole. larvae, alates, and adults to the ground [38]. In silk-nesting Sampling of ant nests from twigs at different stages Camponotus, entire colonies frequently fall, especially during of decomposition resulted in abundance measurements the rainy season [42]. of 7.43 nests/m2 in tropical wet forest (Costa Rica) [16], In our study sites, many nests can be characterized as 0.22 nests/m2 in the central Amazonian rainforest (Brazil) temporary because only workers and immature ants were [27] and 0.88 nests/m2 in lowland rainforest (Ecuador) found. This result suggests the presence of satellite nests, [6]. Thus, the density of undecomposed twigs with nests as observed for C. brasiliensis Mayr [27]andPachycondyla recorded in areas of Atlantic Rainforest in southwestern villosa (Fabricius) [43]. The existence of satellite nests Brazil may be considered high because these twigs represent increases the chances of defending a given territory and only a portion of the twigs available in the leaf litter and are increases the survival of the colony itself, which is at the probably less attractive for ants due to low moisture [27]. greatest risk of predation when concentrated in one place Moisture is a limiting factor for ant recruitment in leaf litter, [42, 44–46]. When the nest is not centralized, the search and nest recolonization, and recovery in artificially disturbed for food can be completed by workers found in all of the parcels is slower, as observed by [5]. In contrast, the observed nest locations, thereby increasing the foraging capacity of the species density was relatively similar to that of the Amazon colony [42, 47] and reducing the distance to the food supply rainforest, with 0.02 species/m2 being recorded [27], and [48]. the density was similar to that observed in other studies Alternatively, we cannot exclude the polyatomic species [16, 29]. However, the observed species curve indicates that hypothesis without the presence of queens (see [41]). In the rare species were not fully sampled. 6 Psyche

12 25 10 8 20 6 15 4

Nest abundance Nest 2 10 0 RI SA RL RC PN NA EEI ME Canopy openness (%) Canopy

EBB 5

PNMFAM 0 (a) 0 2 4 6 8 10 12 Nest abundance 8 7 (a) 6 25 5 4 3 20 2 Species richness 1 15 0 RI SA RL RC PN NA EEI ME

EBB 10 Canopy openness (%) Canopy PNMFAM 5 (b) 0 25 0 246810 20 Species richness 15 (b) 10 5 Figure 3: Relationship between canopy cover and the nest abundance (a) and species richness (b) in undecomposed twigs in the

Canopy openness (%) Canopy 0 leaf litter in dense ombrophilous rainforest fragments. RI SA RL RC PN NA EEI ME EBB PNMFAM (c) and this relocation may be one of the factors regulating the 20 18 richness of species that use twigs as resources. 16 14 Another factor regulating species richness may be the 12 limited space within twigs. The structure of the ant colonies 10 8 found in the interiors of twigs and trunks in the leaf 6 4 litter is relatively simple, due to space limitations [44]. Litter depth (cm) Litter 2 However, independent of the twig’s dimensions, colonies of 0

RI L. neotropicum Wild, M. catharinae Mayr, M. ruszkii Forel, SA RL RC PN NA EEI ME EBB Pheidole spp., and Solenopsis spp. had many workers and immature ants. In dense ombrophilous rainforest, records of PNMFAM populous colonies of M. catharinae and M. ruszkii in fallen (d) twigs in the leaf litter seem common and are unrelated to the Figure 2: Average number of nests ± S.D. (a), species (b), canopy diameter of the twig where the colony is housed [38]. openness (c), and litter depth (d) of the sampled dense ombrophi- The presence of a more closed canopy has been associated lous forest fragments. with habitats richer in resources for ants [23, 44]. The relationship between the structural complexity of the canopy and the higher number of nests observed in our study also suggests that the canopy can be a determinant of the When using a 1 m2 sampling unit of dense ombrophilous community structure of the species that use twigs in the leaf rainforest, we found that the species richness in fallen twigs litter. Our results also show that leaf-litter depth is not one on the soil was much lower than that in the leaf litter [8, 15]. of these factors. Reference [6] did not find a relationship Many species that nest in twigs may be limited by high between tree cover and nest abundance or leaf-litter depth mortality during alate dispersion or during relocation of and suggested that predation, prey density, or plant diversity colonies from one twig to the next. Changing colonies is a may be responsible for the observed patterns. The ants that relatively constant factor because twigs are ephemeral [16], build nests in leaf litter do not show preferences for twigs of Psyche 7 specific plant species [5, 16], but a high species richness of [9]H.L.Vasconcelos,A.C.C.Macedo,andJ.M.S.Vilhena, twigs can favor ant species diversity [22]. “Influence of topography on the distribution of ground- Our results expand the current knowledge of ant species dwelling ants in an Amazonian forest,” Studies on Neotropical that use undecomposed twigs as a nest-building resource in Fauna and Environment, vol. 38, no. 2, pp. 115–124, 2003. dense ombrophilous forest and show that this habitat has an [10] R. Pacheco, R. R. Silva, M. S. C. Morini, and C. R. F. Brandao,˜ important role in the biology of certain species, especially “A comparison of the leaf-litter ant fauna in a secondary those species for which the entire colony development cycle atlantic forest with an adjacent pine plantation in southeastern Brazil,” Neotropical Entomology, vol. 38, no. 1, pp. 55–65, 2009. may occur within twigs. Furthermore, our findings suggest [11] S. S. Suguituru, R. S. Silva, D. R. Souza, C. B. Munhae, and that undecomposed twigs, despite containing a low density M. S. C. Morini, “Ant community richness and composition of species compared to the leaf litter, represent a resource across a gradient from Eucalyptus plantations to secondary for nest building and consequently are part of the set of Atlantic Forest,” Biota Neotropica, vol. 11, pp. 1–8, 2011. structural elements that maintain the diversity of the ants [12] M. S. C. Morini, R. S. Silva, S. S. Suguituru, R. Pacheco, and M. that forage in this layer of tropical forests. Our study also A. Nakano, “Formigas da serra do itapeti,” in Serra do Itapeti: confirms the dominance of the genus Pheidole [27]along Aspectos Historicos,´ Sociais e Natural´ısticos,M.S.C.Moriniand with Camponotus and Hypoponera in ant communities that V. F. O. Miranda, Eds., pp. 195–203, Orgs, Bauru, Brazil, 2012. use twigs as a resource in the leaf litter of dense ombrophilous [13] E. O. Wilson, “The arboreal ant fauna of Peruvian amazon rainforests. forests—a 1st assessment,” Biotropica, vol. 19, pp. 245–251, 1987. [14]D.Agosti,J.D.Majer,L.E.Alonso,andT.R.Schultz,“The Acknowledgments biodiversity challenge,” in Ants: Standard Methods for Meas- uring and Monitoring Biodiversity, D. Agosti, J. D. Majer, L. The authors thank the National Council for Scientific and E. Alonso, and T. R. Schultz, Eds., pp. 17–19, Smithsonian Technological Development (Conselho Nacional de Desen- Institution Press, Washington, DC, USA, 2000. volvimento Cient´ıfico e Tecnologico—CNPq)´ for the schol- [15] R. R. Silva and C. 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