First survey of the Passalidae ( Coleoptera , Scarabaeoidea ) species from Reserva Ecológica de Guapiaçu ( REGUA ) , Cachoeiras de Macacu , RJ , Brazil

We present the details of a survey with species of passalid conducted in the Reserva Ecológica de Guapiaçu (Cachoeiras de Macacu, Rio de Janeiro State) together with illustrations for each species and an identification key. The study includes material collected between May 2010 and October 2013. We identified 11 species in three genera and two tribes (Passalini and Proculini). Passalini comprised two genera, Passalus with six species, and Spasalus with one species, representing 71.42% of all the species encountered. Proculini was represented by only one genus Veturius, with four species, representing 28.57% of the species surveyed. Nine species were recorded for the first time from Cachoeiras de Macacu municipality.


INTRODUCTION
The family Passalidae is included in the superfamily Scarabaeoidea and contains about 1,000 species in two tribes (Passalini and Proculini), of which at least 50% have been identified in America (Fonseca and Reyes-Castillo 2004;Boucher 2006;Mattos and Mermudes 2014).Passalidae is a morphologically homogeneous group.Species of this family live in decaying trunks and members of the colony show subsocial behavior, with complex acoustic communication between adults and larvae (Schuster 1983;Mattos and Mermudes 2014).Furthermore, these species play an important role as primary decomposers in tropical forests and can act as possible conservation bioindicators in priority areas (Schuster 1984;Schuster et al. 2000;Fonseca and Reyes-Castillo 2004).However, only few studies on the systematics of this family have been conducted in the Atlantic Forest biome, which could be because of the small number of researchers in Brazil (Santos-Silva 2000; Mattos and Mermudes 2013;Mattos and Mermudes 2014).
The Atlantic Forest biome has great endemic species richness and actually represents only 7.5% of the original area (Myers et al. 2000).Thus, studies that contribute to the knowledge of biodiversity in the Atlantic Forest biome are highly relevant for conservation and management strategies.This study presents an inventory of passalid diversity in the Atlantic Forest area within the Reserva Ecológica de Guapiaçu (REGUA), and to our knowledge, is the first study of coleopteran species in the reserve.Thus, we expand the knowledge of the diversity of Passalidae in one of the last remaining conserved areas of the Atlantic Forest in the municipality of Cachoeiras de Macacu.

Study site
Reserva Ecológica de Guapiaçu (REGUA) is a nongovernmental organization that protects about 6,000 ha of the Atlantic Forest, in the municipality of Cachoeiras de Macacu (22°25ʹ09.9ʺS, 042°46ʹ13ʺ W), Rio de Janeiro state, Brazil (Figure 1).The main objective of REGUA is to conserve the remaining forests in the Guapiaçu valley in southeastern Brazil, and more than 80% of the land is part of the Parque Estadual dos Três Picos (Pimentel and Olmos 2011).

Data collection
Field collecting was conducted between May 2010 and October 2013 in the REGUA, and from all marked trails in the conservation unit.We considered the samples collected into cold (April to September) and hot (October to March) periods, totaling ten samples.The insects were collected manually after inspection of decaying fallen logs by using knives and axes.A four-member group conducted twice-daily sampling, 4 h each in the morning and afternoon.A sample set

Passalus (Passalus) denticollis
Material examined.Brazil: Rio de Janeiro, Cachoeiras de Macacu, Reserva Ecológica de Guapiaçu, 1 specimen, 11.VII.2012, 60 m, Silveira col., I. Mattos det. 2012;Trilha Amarela, 3 specimens, 14.V.2011, 8 m, Mermudes et al. col., I. Mattos det. 2011;Trilha da Schincariol, 2 specimens, 14.V.2011, 47 m, Mermudes et al. col., I. Mattos det. 2011;Trilha da Cerca, 1 specimen, 20-23.V.2011, 35 m, Mermudes et al. col., I. Mattos det. 2011;Trilha Marrom, 1 specimen, 14.V.2011, 63 m, Mermudes et al. col., I. Mattos det.2011; Trilha São comprised three consecutive collection days, totaling 24 h per sample set.Illustrations were made using a Leica MZ7.5 stereomicroscope fitted with a drawing tube.The sampling effort was assessed by verifying the accumulation curve of the species constructed with the observed richness and number of specimens collected in the study area.Passalid richness was estimated by three nonparametric estimators: the estimated richness obtained by Chao I is a function of the ratio of the number of observed species represented by a single individual (singletons) and the number of observed species represented by two individuals (doubletons).The other estimator used was ICE, which is a coverage estimator that focuses on species found in ≤ 10 sampling units; and Jack I employed the number of species that occur only a single sample, as based on the incidence (Magurran 2004).The analyses were carried by EstimateS Win8.20, with (Colwell 2006).All specimens were deposited in the Collection José Alfredo Pinheiro Dutra of the Universidade Federal do Rio de Janeiro.

RESULTS
The passalids that we found mainly represent a subset of those known from the more extensively surveyed Atlantic Forest as reported by Fonseca and Reye-Castillo (2004) who listed the passalids from Brazil, and more recently Mattos and Mermudes (2014) who listed Brazilian passalids from a continental Island in Rio de Janeiro state (Ilha Grande).We found eleven species of passalids reported by these authors from other localities (Fonseca and Reye-Castillo 2004;Mattos and Mermudes 2014).
In this study, we report eleven passalids species in three genera which belonged to two Neotropical tribes of the Passalinae (Table 1).The species accumulation curves were based on the three different estimators Chao I, Jack I and ICE reached an asymptote when all species have been observed to 10 samples.These results represent more than 85% of the richness estimate and is significant with the sampling effort applied (Figure 2).Dalman, 1817, Figure 8 Passalus (Pertinax) convexus Dalman, 1817: 333;Luederwaldt, 1931: 114;Fonseca & Reyes-Castillo, 2004: 15 (cat.).

Figure 2 . 6 3
Figure 2. The accumulation curve of Passalidae species.Sobs: Total number of species observed in all samples.Singletons: single individual or case of rare species.Doubletons: two individuals or abundant species.See Supplemental Materials on-line.

Table 1 .
Number of Passalidae species from the Rio de Janeiro (RJ) state and Reserva Ecológica de Guapiaçu (REGUA).