Diversity of the Ground Inhabiting Ant Fauna at Department of Atomic Energy Campus, Kalpakkam (Tamil Nadu)
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Halt6rc., \bl.l, No.'l, 2009 Diversity of the ground inhabiting ant fauna at Department of Atomic Energy campus, Kalpakkam (Tamil Nadu) T. Ramesh2, K. Jahir Hussainl, M. Selvanayagam2and K. K. Satpathyr,* " 1. Environmental and tndustiat Safe$ Section, Safety Group, tndira Gandhi Centre for Atomic Resea rch, Kal pakka m-603 1 02 (Tam il N adu) 2.Loyola lnstitute of Frontier Energy (LIFE), Loyola College, Chennai-600 034. (#e-mail: [email protected]. in) Abstract Ant sampllng was carrled out ln different locatlons of the Department of Atomic Energy (DAE) Campus at Kalpakkam durlng dry season (March - June 2008). Plt-fall traps and hand-plcklng methods were used to collect ants from 20 different sampllng sltes. A total of 3l specles, 15 genera, and 5 subfamllles of ants wore collected. The Myrmicinao were the most common, wlth 7 genera and 16 specles, fgllowed by the Formlclnae (4 genera and 8 specles), the Ponerinae (2 genera and 2 species), the Pseudomyrmeclnae (l genus and 4 specles) and the Dollchoderlnae was rspresented by only I species. Interestlngly 86.6% of the genera, 83.8% of the species, and 92.1c/o of the Indlviduals collected belonged to three subfamllles (Myrmlcinae, Ponerlnae, and Formicinae). The five most species-rlch genera were Monomori um, Camponotus, Tetraponera, Crematogasfer and Tetramorlum. The taxonomic structure of the myrmecofauna sampled, resembles that of Western and Eastern Ghats and other tropicil regiong_in two ways: Firstly, many rare species and a few abundant speclos: Secondly, fhe domlnance of subfamllles such as Myrmlclnae, Ponerinae and Formlclnae. The species accumulatlon curve Indlcated that the llkellhood of getting mqre number of specles In DAE campus and this finding was supported by rarefactlon curve Keywords: Ant diversity, Ground-inhabiting ants, Pit-fall trap, DAE Campus, Kalpakkam. lntroduction The use of indicator tiaxa, i.e. taxa that these groups should permit predictions about are theoretically representative of othertaxa at he ohertaxa to be present (Pearson and Canoll a given site, has become important in studies 1998, Lawton ef ar.,1998, Lindenmayer, 1999 of biodiversity in light of the need for rapid, and Kerr ef a/., 2000).Traditionally, majority of reliable and cost€ffective assessments that can studies used vascular plants and vertebrates be used in conservation and monitoring as indicator taxa (Agosti and Alonso, 2000). programs (Oliverand Beattie, 1993and Kenef However, recently the importance and a/., 2000). Determining the levelof diversity of appropriateness of using invertebrate groups Oivrrslty otthe ground Inhabldng antfauna at dapartnont ofAtomlc Energy campus, Kalpakkam (Tamll Nadul have been recognized (Pearson, 1994, Oliver antfauna of DAE Campus at Kalpakkam, Tamil and Beattie, 1996a and 1996b). Ants in Nadu. This exercise assumes greater particular are an excellent choice for use as an significance considering the fact that DAE indicatortaxon (Longino and Cohnrell, 1997 and campus is going to be a nuclear complex soon. AgostiandAlonso, 2000) due to their high local Thus, it in imperative to take stock of present diversity, numericaland biomass dominance in biod iversig status for futu re im pact assessment ilmost every tenestrial habitat. Moreover, their studies. important functions in ecosystems, organization in communities that are sensible Materials and Methods to variations in the environment, relativelygood Study area base of taxonomic knowledge, and ease of The DAE-campus at Kalpakkam sampling (Ganolland Janzen, 1973, Holldobler encompasses seashore and a vast plain area and Wilson, 1990, Bestelmeyer et ai.,2OOO, of the Bay of Bengal. The coastal system forms Brown, 2000 and SchulE and McGtynn 2OQ0) the complex natural site where intense are also responsible for their choice as indicator interactions occur among land, sea and species. Ground-inhabiting ants are particularly atmosphere.The unique interaction throws promising group as they represent a large portion biological consortia peculiar to this system. lt of the myrmecofauna. The ant fauna of India spreads through the biologically diverse and remains relatively unexplored (Rastogi ef a/., productive habitat for native flora and fauna and 1997). Barring a few isolated studies, very litile aesthetically blended with introduced information is available on ants in India, vegetation. All the study sites were located especially bio-ecology and their usefulness as inside the DAE campus. Totally 20 bioindicators of environmental health. representative sampling sites comprising of Site-specific reports are essential because diflerent landscapes viz., undisturbed scrub biodiversity profile varies regionally. Studies on Jungle, nearwater bodies, riparian woods, sandy ant faunal divdrsity in Tamil Nadu still remains area, casurina monoculture, area with meagre rudimentary. Hence, an attempt was made to native vegetation and building area (Fig.1) were study the diversity pattern of ground inhabiting selected for the study. Fig.l: Map showing study area and sampling locations 3 Halteres, \rol.'1, No.l, 2009 quantitative Methodology cover overall species spectrum, method was not preformed because Ant sampling was carried out in different collection leaf litterwas not available at many locations in locations of the DAE Campus during dry season of the campus. No attempt was (March June 2008). Pit-fall traps and hand- sandy area - abundance by these picking methods were used to collect ants in made to estimate methods. Data collected through pit-fall was different sampling sites. Pit-fall trapping method quantify abundance. Collected ant permits foraging workers to be captured and taken to were identified primarily based provides information on the species present in species samples Bolton (1995) and Fauna of British India, sampling area. The trap consisted of a one- on the were sent liter plastic jar with an opening of 7cm in Bingham (1903). Some specimens diameter and was placed at ground level. Six to specialist to confirm their identity. pit-fall traps were installed in a more or less straight transect line with each trap Results approximately 10mtrs apart. Each jar carried Taxonomic structure of the fauna 25 ml of 0.05% methyl parathion. The traps A total of 31 sPecies, 15 genera, and 5 were set up between 15.00 and 17.00 hrs and subfamilies of ants were collected. The were collected on the next day evening. Ants Myrmicinae were the most common, with 7 trapped in the jars were preserved in labelled genera and 16 species, followed by the containers of 70% alcohol. In addition totrapping Formicinae (4 genera and 8 species), the meth6d described above, an intensive all-out- Ponerinae (2 genera and 2 species), the search to physically collect representative of Pseudomyrmicinae (1 genus, 4 species) and as many species of ants as possible was made the Dolichoderinae was represented by only one in each sampling unit. In hand-picking species. Interestingly 86.6% of the genera, collection, two observers walked randomly 83.8% of the species, and 92'4o/o of the around each transects (site viz) and to thE- individuals collected belonged to three extent possible, the effort involved in this subfamilies (Myrmicinae, Ponerinae, with process was kept same. Ants associated Formicinae) (Table-1 ). leaf litter were also collected qualitatively to Table-l: Total number and percentage of species, genera, and individuals collected per subfamily' Subfamily Genera Species lndividuals o/ No. /o No. Vo No. % Formicinae 4 26.67 8 25.81 2t4.00 77.88 "t6 Myrmicinae 7 46.67 51.61 658.00 54.97 Ponerinae 2 13.33 2 6.45 234.00 19.55 15.00 1,.25 Pseudomyrmecinae 1 6.67 4 12.90 Dolichoderinae 1 6.67 1 3.23 76.00 6.35 Total(5) 15 100 31 100 1.197 100 Kalpakkam (Tar$l Nsdul Divorslty of tho ground Inhabldng ant tauna at depaltment ofAtomlc Enorgy camPu3' longipes, The five most species-rich genera were Pachycondyta sulcata, Plagiolepis Monomorium (5 sp.), Camponotus (4 sp.)' Monomorium scabriceps, Monomorium Oecophylla Tetraponera (4 sp.), Crematogaster(3 sp') and floricola, Paratrechina longicomis, destructor, Tetramorium (3 sp.). Outof 15 genera recorded smaragdina, Monomorium Monomorium these five genera collectively contribute 70'28o/o Camponotus compressus, Tetraponera of total species encou ntered (Table-2). Twenty tatinode, Pheidole latinoda, Tetraponera one species could be identified to the species rufonigra, Meranoplus bicolor, level'. Diacamma rugosum, Camponotus n ig ra, Tetramoriu m walsh i. variegates, So/enopsrs invicta, Crematogaster subnuda, TaPinoma melanocePhalum, Pafterns in sPecies richness numberof antspeciesfound in each Myrmicaria bru n nea, Camponotus sericeus, The Table-2: Specles richness of genera. Subfamily Genera Species No. Yo Camponotous 4 12.90 Formicinbe Oecophylla I 3.23 Parctrechina 2 6.45 Plagiolepis 1 3.23 Crcmatogast€r 3 9.68 Meranoplus 1 3.23 Monomoriun 5 16.13 Myrmicinae Myrmicaia t 3.23 Pheidole 2 6.45 So/enopsts L 3.23 9.68 Tetramorium 3 Diacamma 1. 3.23 Ponerinae hdtywrdyla 1 3.23 Dolichoderinae Taphoma 1 3.23 Pseudomyrmecinae TefuWen 4 72.90 1,00 Tohl 31 Haltoro3, Vol.1, No.t, 2009 sampling unit varied from six to ten in most 8- OG samples, with an average of eight (Fig.2). In 99 35 30 the first sampling unit itself, 13 species were b-8 (r) 25 encountered. To know the accumulation paftem ta and area vs. species relationship, species 20 =q l5 accumulation curve was plotted. The graph (Fig. VO ,=d l0 . 3), indicated increase in record of new species t:, o with the increase EE in sampling attempts. More 6r=.- than 60% of the species were recorded at gh 510t5 sampling effort and even at 9h sampling aftempt Ehobd-F) graph the showed increasing trend which clearly l---'l | +Slfilos)l indicated the possibility of gefting more species. Michaelis-Menten type model describes Fig.3: Species accumulatlon curve. well about the accumulation of species records as the numberof sampling attempt increases. 50 This model has clearlydemonstrated 45 that, with E40 increase in sampling attempts the likelihood Irt of !30 adding new species is most likely.