First survey of the ants (Hymenoptera, Formicidae) of Piauí: filling a major knowledge gap about ant diversity in Brazil

ARTICLE First survey of the ants (Hymenoptera, Formicidae) of Piauí: filling a major knowledge gap about ant diversity in Brazil Tainara Thais Jory¹² & Rodrigo Machado Feitosa¹³ ¹ Universidade Federal do Paraná (UFPR), Departamento de Zoologia (DZOO), Laboratório de Sistemática e Biologia de Formigas (LSBF). Curitiba, PR, Brasil. ² ORCID: http://orcid.org/0000-0003-4302-7396. E-mail: jorytainara@gmail.com ³ ORCID: http://orcid.org/0000-0001-9042-0129. E-mail: rsmfeitosa@gmail.com (correspondent author) Abstract. Piauí, a Brazilian Northeast state, has been considered one of the most important regions for the presence of new taxa in ants globally, especially considering the ecosystems’ diversity formed by the transition of the three biomes in the state, the Cerrado, Caatinga and the Atlantic Forest. Despite the recent increase in studies of ant diversity in the Neotropical region, Piauí still represents a major knowledge gap regarding its ant fauna. Therefore, this study aimed to increase the knowledge about the ant fauna of the state by generating a list of species with data obtained from the literature, online repositories and collection expeditions to the Serra da Capivara and Serra das Confusões National Parks. A total of 152 species in 52 genera and nine subfamilies were registered from 24 localities in Piauí. Fifty-eight out the 152 species recorded represent new records for the state, eight are new records for the Brazilian Northeast Region, and one consists of a new record for the country. Eleven species are here recognized as new for science. Considering the field expeditions carried out here, this work represents the first standardized study for the ant fauna of Piauí. The species list presented considerably exceeds the current number of species registered for the state so far. From the present 48 records, the number of species for Piauí raises to more than 150 with a tendency to increase with the accomplishment of future field endeavors and advances in the study of the local ants. Key-Words. Cerrado; Caatinga; Atlantic Forest; Taxonomy; Conservation. INTRODUCTION Ants are eusocial insects grouped into a single family (Formicidae), which in turn is classified into 17 subfamilies and 334 genera (Bolton, 2019). Ants occur in great diversity and abundance in most ecosystems (Choe, 2012). In view of this, ants are extremely important ecologically and are key participants in many ecosystem processes (Lamanceau & Blouin, 2018). In addition, these insects are also good indicators of environmental conservation status, since they are very sensitive to environmental stress (Silvestre et al., 2003; Ribas et al., 2012). In the Brazilian Northeast, anthropic action has led to a deterioration of natural areas and drastic changes in the relief and other characteristics of the soil surface. The state of Piauí, located in this region, has been suffering human disturbances since the 1960s, when tax incentives for agricultural projects were implemented (Lacombe, 1969; Aguiar & Monteiro, 2005). The key location of this state in a transition zone among three Brazilian biomes, the Cerrado, the Caatinga and the Atlantic Pap. Avulsos Zool., 2020; v.60: e20206014 http://doi.org/10.11606/1807-0205/2020.60.14 http://www.revistas.usp.br/paz http://www.scielo.br/paz Edited by: Helena Carolina Onody Received: 18/09/2019 Accepted: 30/01/2020 Published: 19/03/2020 Forest, makes it a priority for the study of diversity. Despite recent advances, which translate into a 33% reduction in deforestation of the state’s Cerrado areas, Piauí remains a leader in the deforestation of that biome (MMA, 2018). Also, since it is one of the last agricultural frontiers in the Cerrado, the southern region of the state is under intense threat (Machado et al., 2004). The ant fauna of Piauí has remained relatively unstudied compared to other Brazilian states (Camargo, 2011; Prado et al., 2019). One of the few studies involving the state’s ant fauna shows that deforestation and loss of diversity by monocultures are very high. In the same study, the anthropic impact on the balance of local ecosystems was highlighted, together with the need for accurate surveys of the local diversity in order to develop more efficient conservation policies, and to promote the documentation of species that are present there before they go locally extinct (Fontes & Almeida Filho, 2002). Considering the growing need for inventories to fill knowledge gaps about the diversity of places that need to be given conservation priorISSN On-Line: 1807-0205 ISSN Printed: 0031-1049 ISNI: 0000-0004-0384-1825 Pap. Avulsos Zool., 2020; v.60: e20206014 2/8 ity, regional species lists are an important tool (Castro et al., 2018; Demétrio et al., 2017; Vicente et al., 2018). The primary data generated by the inventory of animal and plant species are very important in decision-making regarding environmental conservation management. Similarly, as predominant and diverse organisms in any terrestrial environment, sampling the local ant fauna is essential. This is especially true when we consider the poorly explored regions of the state of Piauí, which are, on average, suffering more from deforestation than their surrounding areas and therefore deserve special attention regarding conservation and investment in scientific research. In fact, Brazil probably has a widely underestimated number of species and Piauí is where new genera are most likely to be found (Guénard et al., 2012). In this context, the objective of the present study is to increase the knowledge about the ant fauna of the state of Piauí by compiling records from literature, online repositories and field expeditions in two of the state’s main National Parks. MATERIAL AND METHODS Species records were gathered from a comprehensive independent literature review and consultation of the online repository Antmaps.org. Each species listed here is validated by at least one published reference or data source and the validity of names has been verified in the Antcat.org platform (Bolton, 2019). To confirm the occurrences (Table 1) and to prepare the map (Fig. 1), Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil the geographical coordinates, when not available in the respective reference, were georeferenced based on the Google Earth platform. Table 1. Collecting locations and municipalities with ant records for the state of Piauí, Brazil, according the specific reference list below. Locality Altos Bom Jesus Buriti dos Lopes Canto do Buriti Corrente Corrente 2 Estação Ecológica Uruçuí-Uma, Bom Jesus Floriano Floriano 2 Jacobina do Piauí Marvão Matias Olimpio Oeiras Oeiras 2 Parnaíba Piauí – uncertain locality Rio Uruçuí Preto Coordinates 05° 02′23″S 42°27′29″W 09°11′29″S 44°50′33″W 03°10′30″S 41°52′01″W 08°06′36″S 42°56′40″W 10°26′30″S 45°09′52″W 10°26′00″S 45°09′00″W 08°51′50″S 45°12′00″W 06°46′01″S 43°01′21″W 06°44′37″S 43°02′49″W 08°00′00″S 41°25′00″W 05°19′59″S 41°32′60″W 03°42′58″S 42°33′18″W 07°01′31″S 42°07′52″W 07°00′59″S 42°07′16″W 02°54′19″S 41°46′24″W — 07°19′00″S 44°37′00″W São Raimundo Nonato Serra da Capivara, Coronel José Dias Serra das Confusões, Caracol Sete Cidades Teresina Timon (Maranhão) Uruçuí 08°38′23″S 42°46′32″W 08°41′42″S 42°35′10″W 09°13′22″S 43°29′23″W 04°05′59″S 41°42′50″W 05°05′31″S 42°48′13″W 05°04′59″S 42°49′00″W 07°20′35″S 44°37′00″W Source 14 7 10 9; 17; 22 4; 9; 10; 17 1 10 10; 17 23 2 14 10 4; 9; 22 3 14 5; 6; 8; 16; 21 3; 10; 13; 15; 17; 19; 20 23 11 12 18 14 3 3 Figure 1. Areas with ant records in the state of Piauí, Brazil, based on literature review (black circles) and collecting expeditions of the present study to the Serra das Confusões (red circle) and Serra da Capivara (blue circle) National Parks. Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil In addition to the bibliographic survey, two collecting expeditions were made to the Serra da Capivara and Serra das Confusões National Parks. In both parks, ants were collected with three distinct techniques: manual capture, pitfall traps in the soil and vegetation, and Winkler leaf-litter extractors. Parque Nacional da Serra das Confusões is centered between the coordinates 09°13′22″S and 43°29′23″W and has an average elevation of approximately 700 m. It is located in a transitional area between Caatinga and Cerrado with a predominance of arboreal and shrubby vegetation cover with the presence of semi-deciduous forests in some areas, within the geographic domain of the Atlantic Forest (Gonçalves, 2003). Serra da Capivara National Park, on the other hand, is centered between the coordinates 08°41′42″S and 42°35′10″W and has an average elevation of approximately 500 m. It has a relief with plateaus and valleys with differences of up to 250 meters. In the high plateau areas, the phytophysiognomy of dense arboreal Caatinga predominates, while in the valleys where humidity is highest, the phytophysiognomy is arboreal Caatinga, with open understory (Barros, et al., 2012). The specimens were processed at the Laboratory of Ant Systematics and Biology of the Federal University of Paraná, Curitiba, Brazil. Identification to genus was accomplished with the help of the Guide for Ant Genera of Brazil (Baccaro et al., 2015) and for species we used the bibliographies recommended for each genus in this same Guide (Albuquerque & Brandão, 2004; Cuezzo, 2000; Gonçalves, 1961; Jesovnik & Schultz, 2017; Kempf, 1951, 1973; Kugler, 1994; LaPolla & Fisher, 2005; Longino, 2003; Ortiz-Sepulveda et al., 2019; Schmidt & Shattuck, 2014; Watkins, 1976). Vouchers were deposited in the Padre Jesus Santiago Moure Entomological Collection of the Universidade Federal do Paraná (DZUP), Curitiba, Brazil. RESULTS AND DISCUSSION A total of 152 ant species/morphospecies were recorded in the state of Piauí in 52 genera and nine subfamilies distributed in 24 locations (Table 1). A total of 96 species were namely identified (63%) and 56 remained as morphospecies due to the lack of taxonomic resolution for their genera. The most diverse subfamilies were Myrmicinae, with 94 species, and Formicinae, with 21 species, represented by 25 and five genera, respectively. Among the genera, Pheidole had the highest number of species, 25, followed by Solenopsis, with 16 species, and Camponotus with 13 species. Considering the ant genera listed, 31 represent new records for the state. Regarding the species, 58 are new records, all of which are collected in Parque Nacional da Serra da Capivara and Parque Nacional da Serra das Confusões. Eight species represent new records for the Northeast Region of the country: Camponotus mus Roger, 1863, Hylomyrma blandiens Kempf, 1961, Pheidole cardinalis Wilson, 2003, Pheidole fracticeps Wilson, 2003, Pheidole geraesensis Santschi, Pap. Avulsos Zool., 2020; v.60: e20206014 3/8 1929, Pheidole microps Wilson, 2003, Pheidole nubila Emery, 1906, and Strumigenys hindenburgi Forel, 1915. Additionally, there is a new record for Brazil, represented by the species Pheidole microps Wilson, 2003. The diversity pattern found among the recorded taxa was somewhat expected as the two subfamilies and the most diverse genera in this paper are extremely rich and widely distributed in the Neotropical region (Ward et al., 2015). Myrmicinae can be considered the most successful group among all subfamilies of Formicidae, comprising almost 50% of the diversity of Formicidae (Ward et al., 2015; Bolton, 2019). Their dominance can be explained by the broad feeding and reproductive strategies (Agosti et al., 2000; Hamidi et al., 2017). Thus, the results obtained for this subfamily are within the expectations of the literature, since approximately 62% of the species registered in the state of Piauí belong to this group. From the eight new ant species firstly recorded for the Northeast Region of Brazil, seven belong to megadiverse genera, including Pheidole, Camponotus, and Strumigenys. This highlights the importance of specific-level identification for an ant inventories, since these new records are both an artifact of the lack of expertise to identify these genera and the lack of data collection in Piauí state. In fact, different ant collections in Brazil probably hold unidentified specimens of Pheidole, Camponotus and similar genera that could be new records in species lists and surveys. Two exotic species, Monomorium pharaonis (Linnaeus, 1758) and Paratrechina longicornis (Latreille, 1802), were recorded. These species had already been recorded for neighboring states (AntMaps, 2019; Prado et al., 2019). Monomorium pharaonis is considered a species of medical importance in many parts of the world, including Brazil, specifically in hospitals, where it is a potential carrier of pathogens (Wetterer, 2010). Paratrechina longicornis is considered an urban and agricultural pest in most of the tropics and subtropics of the world for infesting buildings and facilitating the multiplication of populations of Hemiptera that feed on plant phloem (Wetterer, 2008). We recognize at least 11 new ant species (Table 2), of which one belongs to the genus Mycetophylax, one to Mycocepurus and nine to Pheidole. This demonstrates the great potential of this region to reveal taxonomic novelties, as predicted by Guénard et al. (2012), even though these authors referred to potential new genera. Regarding the relative contribution of each data source (literature and expeditions) to compose the final list of species in Piauí, literature contributed 25% of the registered species (38 species), while the collecting expeditions were responsible for 75% of the species (114 species), 71 collected in Serra da Capivara and 101 in Serra das Confusões. It is noteworthy that all 58 new species records for the state come from these collecting expeditions. From the species collected specifically in the expeditions, 79 were sampled with pitfall traps in the soil, 21 were manually collected, and 27 were exclusively found in leaf-litter samples submitted to the Winkler extractor. This highlights the importance of collecting expeditions Pap. Avulsos Zool., 2020; v.60: e20206014 4/8 Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil Table 2. Ant species recorded for the state of Piauí, Brazil. Numbers in the second column refer to the sources from which the occurrence information was obtained for each species, presented in the specific reference list below and in Table 1. Genera and species indicated with an asterisk (*) represent new records for the state of Piauí, two asterisks (**) represent new records for the Northeast Region of Brazil and three asterisks (***) represent new records for Brazil. Species indicated with a dagger (†) were recorded exclusively within the domain of the Atlantic Forest in the state, while all the other species were present only in savanna environments (Caatinga and/or Cerrado). Taxon Source Sampling methods for sources 11 and 12 Amblyoponinae Source Sampling methods for sources 11 and 12 Camponotus arboreus (Smith, 1858)* 11; 12 Hand collection Camponotus blandus (Smith, 1858)* 11; 12 Taxon Camponotus Mayr, 1861 Prionopelta Mayr, 1866* Prionopelta punctulata Mayr, 1866* 11; 12 Epigeic pitfall traps Dolichoderinae Camponotus cingulatus Mayr, 1862* 11 Epigeic pitfall traps Azteca Forel, 1878 Camponotus crassus Mayr, 1862* 11; 12 Epigeic pitfall traps 11; 12 Epigeic pitfall traps 12 Epigeic pitfall traps Azteca sp. 1 12 Hand collection Camponotus melanoticus Emery, 1894* Azteca sp. 2 11 Hand collection Camponotus mus Roger, 1863** Dorymyrmex Mayr, 1866 Camponotus renggeri Emery, 1894 Dorymyrmex goeldii Forel, 1904 9 Dorymyrmex sp. 1 aff. pyramicus 11; 12 Dorymyrmex sp. 2 Dorymyrmex sp. 3 Dorymyrmex sp. 4 Camponotus substitutus Forel, 1899* 11; 12 Hand collection Epigeic pitfall traps Camponotus vittatus Forel, 1904* 11; 12 Epigeic pitfall traps 11; 12 Epigeic pitfall traps Camponotus sp. 1 11; 12 Epigeic pitfall traps 12 Epigeic pitfall traps Camponotus sp. 2 11; 12 Epigeic pitfall traps 11 Epigeic pitfall traps Camponotus sp. 3 11 Epigeic pitfall traps Camponotus sp. 4 12 Hand collection 11; 12 Epigeic pitfall traps 12 Winkler extractor 12 Hand collection 11 Epigeic pitfall traps Forelius Emery, 1888 Forelius brasiliensis (Forel, 1908)* Forelius pusillus Santschi, 1922 8 Forelius sp. 1 11; 12 Nylanderia Emery, 1906* Nylanderia sp. 1† Epigeic pitfall traps Gracilidris Wild & Cuezzo, 2006 Gracilidris pombero Wild & Cuezzo, 2006 19; 22 Paratrechina Motschoulsky, 1863* Paratrechina longicornis (Latreille, 1802)* 18 Heteroponerinae Linepithema Mayr, 1866* Acanthoponera Mayr, 1862* Linepithema neotropicum Wild, 2007* 12 Epigeic pitfall traps Tapinoma Foerster, 1850* Acanthoponera mucronata (Roger, 1860)* Myrmicinae Tapinoma melanocephalum (Fabricius, 1793)* 12 Hand collection Tapinoma sp. 1 12 Epigeic pitfall traps Acromyrmex Mayr, 1865 Acromyrmex landolti (Forel, 1885) 14; 16 Dorylinae Acromyrmex rugosus (Smith, 1858) 11; 12; 14; 16 Acanthostichus Mayr, 1887* Apterostigma Mayr, 1865* Acanthostichus sp. 1 aff. brevicornis 11 Epigeic pitfall traps Eciton Latreille, 1804* Apterostigma gr. pilosum sp. 1† Epigeic pitfall traps 12 Atta Fabricius, 1804 Eciton dulcium Forel, 1912* 11 Epigeic pitfall traps Labidus Jurine, 1807* Labidus coecus (Latreille, 1802)* 12 Epigeic pitfall traps Neivamyrmex Borgmeier, 1940 Atta laevigata (Smith, 1858) 16 Atta sexdens (Linnaeus, 1758) 11; 16 Epigeic pitfall traps 11; 12; 7 Epigeic pitfall traps Blepharidatta Wheeler, 1915 Neivamyrmex diana (Forel, 1912)* 11 Epigeic pitfall traps Blepharidatta conops Kempf, 1967 Neivamyrmex minensis (Borgmeier, 1928)* 12 Epigeic pitfall traps Carebara Westwood, 1840* Neivamyrmex pertii (Shuckard, 1840) 16 Atta opaciceps Borgmeier, 1939 5; 16 Ectatomminae Ectatomma Smith, 1858 Carebara gr. lignata sp. 1† 12 Winkler extractor Carebara brevipilosa Fernández, 2004* 11 Epigeic pitfall traps Cephalotes Latreille, 1802 Ectatomma muticum Mayr, 1870 6; 11; 12; 19; 22 Epigeic pitfall traps Gnamptogenys Roger, 1863* Gnamptogenys striatula Mayr, 1884* Gnamptogenys sulcata (Smith, 1858)*† 11; 12 Epigeic pitfall traps 12 Hand collection Formicinae Acropyga Roger, 1862* Cephalotes atratus (Linnaeus, 1758) 10 Cephalotes betoi De Andrade, 1999 10; 19; 11, 12; 22 Hand collection 10; 12; 19; 22 Hand collection Cephalotes clypeatus (Fabricius, 1804) Cephalotes cordatus (Smith, 1853) 10 Cephalotes fiebrigi (Forel, 1906) 10 Cephalotes minutus (Fabricius, 1804) Acropyga goeldii Forel, 1893*† 12 Winkler extractor Brachymyrmex Mayr, 1868* Cephalotes pavonii (Latreille, 1809)* Cephalotes persimilis De Andrade, 1999 Brachymyrmex coactus Mayr, 1887*† Brachymyrmex patagonicus Mayr, 1868* 12 Winkler extractor Cephalotes pinelii (Guérin-Méneville, 1844) 11; 12 Epigeic pitfall traps Cephalotes pusillus (Klug, 1824) 10; 19; 22 11; 12 Epigeic pitfall traps 10; 12; 19; 22 Hand collection 10 10; 11; 12; 19; 22 Epigeic pitfall traps Brachymyrmex pictus Mayr, 1887* 12 Winkler extractor Crematogaster Lund, 1831* Brachymyrmex sp. 1 aff. fiebrigi 12 Epigeic pitfall traps Crematogaster crinosa Mayr, 1862* 11; 12 Hand collection Brachymyrmex sp. 2 11 Epigeic pitfall traps Crematogaster pygmaea Forel, 1904* 11; 12 Epigeic pitfall traps † Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil Taxon Crematogaster sp. 1 aff. obscurata Pap. Avulsos Zool., 2020; v.60: e20206014 5/8 Source Sampling methods for sources 11 and 12 12 Epigeic pitfall traps Cyphomyrmex Mayr, 1862 Source Sampling methods for sources 11 and 12 Rogeria curvipubens Emery, 1894*† 12 Winkler extractor Rogeria foreli Emery, 1894*† 12 Winkler extractor 11; 12 Epigeic pitfall traps Sericomyrmex mayri Forel, 1912† 3; 12; 15 Winkler extractor Sericomyrmex scrobifer Forel, 1911 3; 15 Taxon Cyphomyrmex rimosus (Spinola, 1851)* 11; 12 Epigeic pitfall traps Rogeria lirata Kugler, 1994* Cyphomyrmex transversus Emery, 1894 11; 12; 19; 22 Epigeic pitfall traps, Winkler extractor Sericomyrmex Mayr, 1865 12 Winkler extractor 11 Epigeic pitfall traps Cyphomyrmex sp. 1† Hylomyrma Forel, 1912* Hylomyrma blandiens Kempf, 1961** Solenopsis Westwood, 1840 Kalathomyrmex Klingenberg & Brandão, 2009 Kalathomyrmex emeryi (Forel, 1907) 12; 17; 19; 22 Hand collection Monomorium Mayr, 1855* Monomorium pharaonis (Linnaeus, 1758)* 12 Hand collection Mycetarotes Emery, 1913* Mycetarotes parallelus (Emery, 1906)*† 12 Hand collection Mycetomoellerius Solomon et al., 2019* Mycetomoellerius sp. 1† 12 Hand collection Mycetophylax Emery, 1913* Mycetophylax sp. n. 12 Epigeic pitfall traps, Winkler extractor Mycocepurus Forel, 1893* Mycocepurus sp. n.† 12 Hand collection Myrmicocrypta Smith, 1860* Myrmicocrypta sp. 1 11 Epigeic pitfall traps Oxyepoecus Santschi, 1926 Oxyepoecus kempfi Albuquerque & Brandão, 2004 1; 22 Oxyepoecus sp. 1 aff. vezenyii 11; 12 Epigeic pitfall traps Pheidole exigua Mayr, 1884* 19; 22 Solenopsis tridens Forel, 1911* 11; 12 Epigeic pitfall traps Solenopsis sp. 1 11; 12 Epigeic pitfall traps Solenopsis sp. 2 11; 12 Epigeic pitfall traps Solenopsis sp. 3 11; 12 Epigeic pitfall traps Solenopsis sp. 4 11; 12 Epigeic pitfall traps Solenopsis sp. 5 11 Epigeic pitfall traps Solenopsis sp. 6 11 Epigeic pitfall traps Solenopsis sp. 7† 12 Winkler extractor Solenopsis sp. 8† 12 Winkler extractor Solenopsis sp. 9 11; 12 Hand collection Solenopsis sp. 10† 12 Winkler extractor Solenopsis sp. 11 11 Epigeic pitfall traps Solenopsis sp. 12 11 Epigeic pitfall traps Solenopsis sp. 13 11 Epigeic pitfall traps Strumigenys crassicornis Mayr, 1887*† 12 Winkler extractor Strumigenys eggersi Emery, 1890*† 12 Winkler extractor Strumigenys elongata Roger, 1863 4; 12 Winkler extractor 12 Winkler extractor 12 Winkler extractor Strumigenys infidelis Santschi, 1919 4 12 Winkler extractor Strumigenys lilloana (Brown, 1950) 3; 4; 19; 22 Pheidole Westwood, 1839* Pheidole cardinalis Wilson, 2003**† 19; 22; 23 Solenopsis saevissima (Smith, 1855) Strumigenys Smith, 1860 Paratrachymyrmex Solomon et al., 2019* Paratrachymyrmex bugnioni (Forel, 1912)*† Solenopsis geminata (Fabricius, 1804) Strumigenys hindenburgi Forel, 1915**† 11; 12 Epigeic pitfall traps Strumigenys louisianae Roger, 1863 2; 6 Pheidole fimbriata Roger, 1863*† 12 Hand collection Strumigenys sp. 1 aff. elongata 12 Winkler extractor Pheidole fracticeps Wilson, 2003** 11; 12 Epigeic pitfall traps Strumigenys sp. 2 aff. louisianae 12 Winkler extractor Pheidole geraesensis Santschi, 1929** 11; 12 Epigeic pitfall traps Wasmannia Forel 1893* Wasmannia auropunctata (Roger, 1863) 12 Epigeic pitfall traps, Winkler extractor Pheidole microps Wilson, 2003***† 12 Epigeic pitfall traps Pheidole nubila Emery, 1906** 11; 12 Epigeic pitfall traps Pheidole obscurithorax Naves, 1985* 11; 12 Epigeic pitfall traps Ponerinae Pheidole radoszkowskii Mayr, 1884* 12 Epigeic pitfall traps Anochetus Mayr, 1861* Pheidole subarmata Mayr, 1884*† 12 Winkler extractor Anochetus neglectus Emery, 1894*† Pheidole synarmata Wilson 2003* 12 Epigeic pitfall traps Centromyrmex Mayr, 1866 Pheidole valens Wilson, 2003* 11 Epigeic pitfall traps Centromyrmex brachycola (Roger, 1861) Pheidole cf. caribbaea 11 Epigeic pitfall traps Dinoponera Roger, 1861 Pheidole cf. vallifica 11 Epigeic pitfall traps Dinoponera quadriceps Kempf, 1971 Pheidole gr. aberrans sp. n. 12 Epigeic pitfall traps Hypoponera Santschi, 1938* Pheidole gr. diligens sp. n. 11; 12 Epigeic pitfall traps Pheidole sp. 1 aff. rufipilis† 12 Epigeic pitfall traps Pheidole sp. 2 aff. radoszkowskii 11; 12 Epigeic pitfall traps Neoponera Emery, 1901 Pheidole sp. n. 1 (aff. diligens) 11; 12 Epigeic pitfall traps Neoponera bactronica (Fernandes et al., 2014) Pheidole sp. n. 2 (aff. puttemansi) 11; 12 Epigeic pitfall traps Neoponera commutata (Roger, 1860) Pheidole sp. n. 3 (aff. triconstricta) 11 Epigeic pitfall traps Odontomachus Latreille, 1804* Pheidole sp. n. 4 11 Epigeic pitfall traps Odontomachus bauri Emery, 1892* Pheidole sp. n. 5 11; 12 Epigeic pitfall traps Pseudoponera Emery, 1900* Pheidole sp. n. 6 11 Epigeic pitfall traps Pseudoponera gilberti (Kempf, 1960)*† Pheidole sp. n. 7 12 Epigeic pitfall traps Pseudomyrmecinae Procryptocerus Emery, 1887 19; 22 6; 11; 12; 19; 22 Epigeic pitfall traps Hypoponera sp. 1† 12 Winkler extractor Hypoponera sp. 2† 12 Winkler extractor 13 6; 21 11; 12 Epigeic pitfall traps 12 Winkler extractor Pseudomyrmex gr. pallidus sp. 1 11 Hand collection Pseudomyrmex tenuis (Fabricius, 1804)*† 12 Hand collection Pseudomyrmex termitarius (Smith, 1855)* 11 Epigeic pitfall traps Pseudomyrmex Lund, 1831* Procryptocerus hylaeus Kempf, 1951 3; 20 Procryptocerus victoris Kempf, 1960 3 Rogeria Emery, 1894* 12 Pap. Avulsos Zool., 2020; v.60: e20206014 6/8 to increase our knowledge of the ant fauna in subsampled areas of the Neotropics, especially when involving multiple collecting techniques. Regarding the representativity of ants in the different biomes of Piauí, it is not possible to characterize species typical of Cerrado or Caatinga, since these species can be found in both ecosystems and have been classified as “savanna specialists” (Leal et al., 2017; Vasconcelos et al., 2017). As for the Atlantic Forest ants, they are represented in our dataset by the specimens obtained from leaf-litter samples exclusive of our collection efforts in Parque Nacional da Serra das Confusões (Table 2). The list of species presented here considerably increases the number of species previously recorded in the state. From 48 records (AntMaps, 2019), the number of ant species for Piauí went to 152. Nevertheless, these numbers are constantly changing as taxonomic works are published frequently and this process leads to the documentation of new species (Ward, 2007), as well as the establishment of local research groups and field trips. Thus, the list of species presented here is likely to grow with future collecting and advances in ant studies. ACKNOWLEDGMENTS We are deeply indebted to Gabriela P. Camacho and Mila F.O. Martins for the support during fieldwork. Thanks to Alexandre Casadei Ferreira, Aline Machado Oliveira, Natalia Ladino, Thiago S.R. da Silva, and Weslly Franco for identifying our species of Pheidole, Cephalotes, Prionopelta, Strumigenys, and Gnamptogenys, respectively. We thank Dr. Christian Rabeling for confirming the new species belonging to the genus Mycocepurus. We are also grateful to three anonymous reviewers for the valuable comments on a previous version of this work. This study was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq (grants 1302462/2016-3 and 128319/2017-8 to RMF and TJ, respectively), and the Partnerships for Enhanced Engagement in Research (PEER) Science Program (NAS/USAID – award number AID-OAA-A-11-00012 – project 3-188). REFERENCES Agosti, D.; Majer, J.D.; Alonso, L.E. & Schultz, T.R. 2000. Ants: Standard methods for measuring and monitoring biodiversity. Washington, D.C., Smithsonian Institution Press. 304p. Aguiar, T.J.A. & Monteiro, M.S.L. 2005. Modelo agrícola e desenvolvimento sustentável: a ocupação do cerrado piauiense. Ambiente & Sociedade, 8(2): 1-18. Albuquerque, N.L. & Brandão, C.R.F. 2004. A revision of Neotropical Solenopsidini ant genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 1. The Vezenyii species-group. Papéis Avulsos de Zoologia, 44: 55-80. Antmaps, 2019. Available at: http://antmaps.org. Access in: 11/09/2019. Baccaro, F.B.; Feitosa, R.M.; Fernandez, F.; Fernandes, I.O.; Izzo, T.J.; Souza, J.P. de & Solar, R. 2015. Guia para os gêneros de formigas do Brasil. Manaus, Editora INPA. 388p. Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil Barros, J.S.; Ferreira, R.V.; Guidon, N. & Pereira da Silva, A.J.C.L. 2012. Geoparque Serra da Capivara – PI: Proposta. In: Schobbenhaus, C.; Silva, C.R. (Org.). Geoparques do Brasil. Brasilia, Serviço Geológico Brasileiro, CPRM. p. 493-542. Bolton, B. 2019. An online catalog of the ants of the world. Available at: http:// antcat.org. Access in: 06/09/2019. Camargo, K.S. 2011. Composição e diversidade de “Poneromorfas” (Hymenoptera, Formicidae) em duas fitofisionomias de cerrado e padrões de distribuição de “Poneromorfas”, Pseudomyrmecinae e Cephalotini (Myrmicinae) para o Brasil. (Tese de doutorado em ecologia). Universidade de Brasília, Brasília, D.F. 80p. Castro, D.; Fernández, F.; Meneses, A.D.; Tocora, M.C.; Sanchez, S. & PeñaVenegas, C.P. 2018. A preliminary checklist of soil ants (Hymenoptera: Formicidae) of Colombian Amazon. Biodiversity Data Journal, 6: e29278. Choe, J. 2012. Secret Lives of Ants. Baltimore, Johns Hopkins University Press. 184p. ilus. Cuezzo, F. 2000. Revisión del género Forelius (Hymenoptera: Formicidae: Dolichoderinae). Sociobiology, 35: 197-275. Demétrio, M.F.; Silvestre, R.; Souza, P.R. & Aoki, C. 2017. Inventário da fauna de formigas (Hymenoptera, formicidae) no Mato Grosso do Sul, Brasil. Iheringia, série zoologia, 107: 1-12. Fontes, L.S. & Almeida Filho, A.J. 2002. Espécies de formigas cortadeiras do estado do Piauí, Brasil. Revista de Agricultura, Piracicaba, 77(2): 305-310. Gonçalves, C.R. 1961. O gênero Acromyrmex no Brasil (Hym. Formicidae). Studia Entomologica, 4: 113-180. Gonçalves, M.R. 2003. Plano de Manejo do Parque Nacional da Serra das Confusões – PI. Brasília, IBAMA. 230p. Guénard, B.; Weiser, M.D. & Dunn, R.R. 2012. Global models of ant diversity suggest regions where new discoveries are most likely are under disproportionate deforestation threat. Proceedings of the National Academy of Science of the United States of America, 109(19): 7368-7373. Hamidi, R.; Biseau, J.C.; Bourguignon, T.; Segundo, G.B.M.; Fontenelle, M.T.M.B. & Quinet, Y. 2017. Dispersal strategies in the highly polygynous ant Crematogaster (Orthocrema) pygmaea Forel (Formicidae: Myrmicinae). Plos One, 12(6): e0178813. Jesovnik, A. & Schultz, T.R. 2017. Revision of the fungus-farming ant genus Sericomyrmex Mayr (Hymenoptera, Formicidae, Myrmicinae). ZooKeys, 670: 1-109. Kempf, W.W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Revista de Entomologia, 22: 1-244. Kempf, W.W. 1973. A revision of the Neotropical myrmicine ant genus Hylomyrma Forel (Hymenoptera: Formicidae). Studia Entomologica, 16: 225-260. Kugler, C. 1994. A revision of the ant genus Rogeria with description of the sting apparatus (Hymenoptera: Formicidae). Journal of Hymenoptera Research, 3: 17-87. Lacombe, A.L.M. 1969. Algumas considerações sobre os incentivos fiscais. Revista de Administração de Empresas, 9(4): 107-117. Lemanceau, P. & Blouin, M. 2018. Soil as a key component of the critical zone 6: Ecology. London, Wiley, ISTE. 196p. LaPolla, J.S. & Fisher, B.L. 2005. A remarkable new species of Acropyga (Hymenoptera: Formicidae) from Gabon, with a key to the Afrotropical species. Proceedings of the California Academy of Sciences, 56(4): 601-605. Leal, I.; Ribeiro-Neto, J.D.; Arnan, X.; Oliveira A.F.M.; Arcoverde, G.B.; Feitosa, R.M.; Andersen, A.N. 2017. Ants of the Caatinga: diversity, biogeography, and functional responses to anthropogenic disturbance and climate change. In: Silva, J.M.C.; Leal, I.R.; Tabarelli, M. (Org.). Caatinga: the largest tropical dry forest region in south america. Berlim, Springer. p. 65-95. Longino, J.T. 2003. The Crematogaster (Hymenoptera, Formicidae, Myrmicinae) of Costa Rica. Zootaxa, 151: 1-150. Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil Machado, R.B.; Ramos Neto, M.B.; Pereira, P.G.P.; Caldas, E.F.; Gonçalves, D.A.; Santos, N.S.; Tabor, K. & Steininger, M. 2004. Estimativa de perda da área do Cerrado brasileiro. Relatório técnico. Brasília, DF., Conservação Internacional. 71p. Ministério do Meio Ambiente (MMA). 2018. Desmatamento no Cerrado em 2018. Available at: https://www.mma.gov.br/component/k2/ item/15309-desmatamento-no-bioma-cerrado-em-2018.html. Access in: 19/08/2019. Ortiz-Sepulveda, C.M.; Bocxlaer, B.V.; Meneses, A.D. & Fernández, F. 2019. Molecular and morphological recognition of species boundaries an the neglected ant genus Brachymyrmex (Hymenoptera: Formicidae): Toward a taxonomic revision. Organisms Diversity & Evolution, 19: 447-542. Prado, L.P.; Feitosa, R.M.; Triana, S.P.; Gutiérrez, J.A.; Rousseau, G.X., Silva, R.A.; Siqueira, G.M.; Santos, C.L.; Silva, F.V.; Silva, T.S.R.; Casadei-Ferreira, A.; Silva, R.R. & Andrade-Silva, J. 2019. An overview of the ant fauna (Hymenoptera: Formicidae) of the state of Maranhão, Brazil. Papéis Avulsos de Zoologia, 59: e20195938. Ribas, C.R.; Campos, R.B.F.; Schimidt, F.A. & Solar, R.C.C. 2012. Ants as Indicators in Brazil: A review with suggestions to improve the use of ants in environmental monitoring programs. Psyche, 2012: 1-23. Schmidt, C.A. & Shattuck, S.O. 2014. The higher classification of the ant subfamily Ponerinae (Hymenoptera: Formicidae), with a review of Ponerinae ecology and behavior. Zootaxa, 3817(1): 1-242. Silvestre, R.; Brandão, C.R.F. & Silva, R.R. 2003. Grupos funcionales de hormigas: el caso de los gremios del Cerrado, Brasil. In: Fernández, F. Pap. Avulsos Zool., 2020; v.60: e20206014 7/8 Introducción a las hormigas de la región neotropical. Bogotá, Instituto de Investigación de Recursos Biológicos Alexander von Humboldt. p. 101-136. Vasconcelos, H.L.; Maravalhas, J.B.; Feitosa, R.M.; Pacheco, R.; Neves, K.C.; Andersen, A.N. 2017. Neotropical savanna ants show a reversed latitudinal gradient of species richness, with climatic drivers reflecting the forest origin of the fauna. Journal of Biogeography, 45(1):248-258. Vicente, R.E.; Ferreira, A.C.; Santos, R.C.L. & Prado, L.P. 2018. Ants (Hymenoptera: Formicidae) from an Amazonian fragmented landscape, Juara, Mato Grosso, Brazil, with new records of ant species. Papéis Avulsos de Zoologia, 58: e20185840. DOI Ward, P.S. 2007. Phylogeny, classification, and species-level taxonomy of ants (Hymenoptera: Formicidae). Zootaxa, 1668: 549-563. Ward, P.S.; Brady, S.G.; Fisher, B.L. & Schultz, T.R. 2015. The evolution of Myrmicinae ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae). Systematic Entomology, 40: 61-81. Watkins, J.F. 1976. The identification and distribution of New World army ants (Dorylinae: Formicidae). Waco, Texas, Baylor University Press. 102p. Wetterer, J.K. 2008. Worldwide spread of the longhorn crazy ant, Paratrechina longicornis (Hymenoptera: Formicidae). Myrmecological News, 11: 137-149. Wetterer, J.K. 2010. Worldwide spread of the pharaoh ant, Monomorium pharaonis (Hymenoptera: Formicidae). Myrmecological News, 13: 115-129. Pap. Avulsos Zool., 2020; v.60: e20206014 8/8 Jory, T.T. & Feitosa, R.M.: Ants of Piauí, Brazil REFERENCES AND SOURCES FOR THE LOCALITIES AND SPECIES RECORDS IN TABLES 1 AND 2. (1) Albuquerque N.L. & Brandão, C.R.F. 2004. A revision of the Neotropical Solenopsidini ant genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 1. The Vezenyii species-group. Papéis Avulsos de Zoologia, 44(4): 55-80. (2) Almeida Filho A.J. 1984. Notas sobre Strumigenys louisianae (Hymenoptera, Formicidae) e sua ocorrência no Nordeste do Brasil. Quid Teresina, 5: 133-139. (3) AntWeb, 2019. Available at: http://www.antweb.org. Access in: 18/07/2019. (4) Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute, Universidade de Wisconsin, Madison, United States. 1028p. (5) Borgmeier T. 1953. Vorarbeiten zu einer Revision der Neotropischen Wanderameisen. Studia Entomologica, 2: 1-51. (6) Brandão, C.R.F. 1991. Adendos ao catálogo abreviado das formigas da região neotropical (Hymenoptera: Formicidae). Revista Brasileira de Entomologia, 35(2): 319-412. (7) Brandão C.R.F.; Feitosa, R.M. & Diniz, J.L.M. 2015. Taxonomic revision of the Neotropical Myrmicinae ant genus Blepharidatta Wheeler. Zootaxa, 4012(1): 33-56. (8) Cuezzo F. 2000. Revisión del género Forelius (Hymenoptera: Formicidae: Dolichoderinae). Sociobiology, 35(2): 197-275. (9) Cuezzo F. & Guerrero, R.J. 2011. The ant genus Dorymyrmex Mayr (Hymenoptera: Formicidae: Dolichoderinae) in Colombia. Psyche, 2011: 1-24. (10) De Andrade, M.L. & Baroni Urbani, C. 1999. Diversity and Adaptation in the ant genus Cephalotes, past and present. Stuttgarter Beitrage zur Naturkunde Serie B, 271: 1-893. (11) DZUP – Coleção Entomológica Padre Jesus Santiago Moure, Universidade Federal do Paraná, Brasil. Expedição ao Parque Nacional da Serra da Capivara. (12) DZUP – Coleção Entomológica Padre Jesus Santiago Moure, Universidade Federal do Paraná, Brasil. Expedição ao Parque Nacional da Serra das Confusões. (13) Fernandes I.O.; de Oliveira, M.L. & Delabie J.H.C. 2014. Description of two new species in the Neotropical Pachycondyla foetida complex (Hymenoptera: Formicidae: Ponerinae) and taxonomic notes on the genus. Myrmecological News, 19: 133-163. (14) Gonçalves C.R. 1961. O gênero Acromyrmex no Brasil (Hymenoptera: Formicidae). Studia Entomologica, 4: 113-180. (15) Jesovnik A. & Schultz T.R. 2017. Revision of the fungus-farming ant genus Sericomyrmex Mayr (Hymenoptera, Formicidae, Myrmicinae). ZooKeys, 670: 1-109. (16) Kempf, W.W. 1972. Catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Studia Entomologica, 15: 1-4. (17) Klingenberg C. & Brandão, C.R.F. 2009. Revision of the fungus-growing ant genera Mycetophylax Emery and Paramycetophylax Kusnezov rev. stat., and description of Kalathomyrmex n. gen. (Formicidae: Myrmicinae: Attini). Zootaxa, 2052: 1-31. (18) Koch, E.B.A.; Correia, J.P.S.O.; Menezes, R.S.T.; Silvestrini, R.A.; Delabie, J.H.C. & Vasconcelos, H.L. 2018. New Records and Potential Distribution of the Ant Gracilidris pombero Wild & Cuezzo (Hymenoptera: Formicidae). Sociobiology, 65(3): 375-382. (19) Leal, I.R.; Ribeiro-Neto, J.D.; Arnan, X.; Oliveira, F.M.P.; Arcoverde, G.B.; Feitosa, R.M. & Andersen, A.N. 2017. Ants of the Caatinga: diversity, biogeography, and functional responses to anthropogenic disturbance and climate change. In: Cardoso da Silva J.M.; Leal, I.R. & Tabarelli, M., Caatinga. Springer, Cham, 65-96. (20) Longino, J.T. & Snelling, R.R. 2002. A taxonomic revision of the Procryptocerus (Hymenoptera: Formicidae) of Central America. Contributions in Science, 495: 1-30. (21) MacKay, W.P. & MacKay, E.E. 2010. The systematics and biology of the New World ants of the genus Pachycondyla (Hymenoptera: Formicidae). Edwin Mellen Press Lewiston, NY. 642p. (22) Ulysséa, M.A. & Brandão C.R.F. 2013. Ant species (Hymenoptera, Formicidae) from the seasonally dry tropical forest of northeastern Brazil: a compilation from field surveys in Bahia and literature records. Revista Brasileira de Entomologia, 57(2): 217-224. (23) Wauters N.; Dekoninck, W. & Fournier, D. 2018. Introduction history and genetic diversity of the invasive ant Solenopsis geminata in the Galapagos Islands. Biological Invasions, 20: 3207-3226. Published with the nancial support of the "Programa de Apoio às Publicações Cientí cas Periódicas da USP"