New Records of Ants ( Hymenoptera : Formicidae ) from Sri Lanka , Including Four Tramp Species

Sri Lanka is one of the 25 biodiversity hotspots in the world (Myers, 2000). It is relatively a large island (66,000 km2); a shallow continental shelf as India; been able to maintain a largely distinct fauna from that of the Indian mainland (Bossuyt, 2004). The country has the highest biodiversity density in Asia with 27% of the 3,210 flowering plants and 22% of the mammals being endemic to Sri Lanka (Mittermeier et al., 2000; Gunawardene et al., 2007). These distinct elements are established not only because of regional isolation as an Island but also because of the establishment of finest local endemic niches. Patterns of such local endemism at the finest scale, at which they may occur, should form basis for all future conservation programs. Ant diversity and distribution greatly influence faunal community dynamics; understanding such patterns is prerequisite for all conservational programs (Lach et al., 2010). Ant fauna of Sri Lanka is highly diverse with high IndoMalayan affinity and a high degree of endemism. The Sri Lankan ants include 11 of the 17 known extant subfamilies Abstract Five ant species are reported for the first time from Sri Lanka: Ooceraea alii (Bharti & Akbar, 2013); O. biroi (Forel, 1907); Prionopelta kraepelini Forel, 1905; Strumigenys emmae (Emery, 1890) and S. mem branifera Emery, 1869. Among the newly reported species, four species (O. biroi, S. mem­ branifera, S. emmae and P. kraepelini) are known for their invasive and tramping nature, spreading via human commerce and have attained broad cosmopolitan distribution. Impact of these ants on regional fauna is not known and needs immediate attention. A brief diagnosis, distribution, and illustrations are provided for each species. Sociobiology An international journal on social insects

New Records of Ants (Hymenoptera: Formicidae) from Sri Lanka, Including Four Tramp Species Introduction Sri Lanka is one of the 25 biodiversity hotspots in the world (Myers, 2000).It is relatively a large island (66,000 km 2 ); a shallow continental shelf as India; been able to maintain a largely distinct fauna from that of the Indian mainland (Bossuyt, 2004).The country has the highest biodiversity density in Asia with 27% of the 3,210 flowering plants and 22% of the mammals being endemic to Sri Lanka (Mittermeier et al., 2000;Gunawardene et al., 2007).These distinct elements are established not only because of regional isolation as an Island but also because of the establishment of finest local endemic niches.Patterns of such local endemism at the finest scale, at which they may occur, should form basis for all future conservation programs.
with 355 valid ant species in 78 genera (AntWeb, 2018a;Dias et al., in press).The region is home to many endemic ant species; more than 30 % of the regional ants are endemic including relict Sri Lankan ant Aneuretus simoni Emery, sole extant representative of the subfamily Aneuretinae and several genera and species, which are only reported from Sri Lanka.
In Sri Lanka, the documentation and cataloguing of ants has been fragmentary, with few earlier studies being largely focused on systematic accounts and mere species enumeration.However, recognizing the importance of ants as major ecosystem players, several significant initiatives for cataloguing this important group of insects have been taken in the recent past (Dias, 2006(Dias, , 2014;;Dias & Chaminda, 2000;Gunawardene et al., 2008).The regional centre for ant research attached to the Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka is pioneering these efforts.The centre intends to establish and maintain an ant repository for the ants of Sri Lanka and is currently encouraging young ant researchers with practical experience to explore many unknown ant species in the region.These findings of the present paper form part of the surveys conducted by the centre in recent years.

RESEARCH ARTICLE -ANTS
We report here five newly recorded species, Ooceraea alii, O. biroi, Prionopelta kraepelini, Strumigenys emmae and S. mem branifera from Sri Lanka.A brief diagnosis of each newly reported species including notes on distribution is provided along with illustrations.

Material and Methods
Specimens used in this study were collected by handsearching, soil sifting and Winkler's leaf litter extractor, and are preserved in the ant repository ZEMK.The morphology was examined under an Optika SZM-LED2 stereo-microscope.For digital images, ProgRes0 CapturePro v.2.8.0.evolution digital camera was used on the same microscope with Combine ZP-Montage software.Later, images were cleaned with Adobe Photoshop CS6.All measurements were recorded in millimeters to three significant figures and are presented to two significant figures due to measurement error and/ or variation in specimen orientation.Morphological definitions for measurements are followed as per generic standards and mainly include: HL Head length, length of head capsule from anterior clypeal margin to mid-point of posterior head margin in full-face view.HW Head width, maximum width of head, excluding eyes, in full-face view.SL Scape length, maximum length of scape, excluding the basal neck and condyle.ML Mesosomal length in profile, from the anteriormost border of the pronotum, excluding the pronotal cervix to the posterior basal angle of the metapleuron.PL Petiole length, maximum length of petiole from anterior process to posteriormost point of tergite, where it articulates with helcium.PW Petiole width, maximum width of petiole in dorsal view.TL Total outstretched length of a specimen, from mandibular apex to gastral apex.CI Cephalic index, HW / HL × 100.SI Scape index, SL / HW × 100.PI Petiole index, PW / PL × 100.Diagnosis: Indomalayan species with 9 segmented antennae; head width less than 0.40 mm; sculpture predominantly foveate; anterolateral shoulders of the first gastral segments as seen from above broadly rounded and gradually widening caudad (Bharti & Akbar, 2013a).
Remarks: The doryline cryptic ant was collected in soil and leaf litter samples from a coconut plantation.
Remarks: The species is native to the Asian mainland and has become invasive on tropical and subtropical islands throughout the world (Borowiec, 2016).Also called as clonal raider ant; a queenless clonal ant exhibiting the lytokous parthenogenesis means of reproduction.The specimens were collected while they were foraging near a coconut tree leaf litter.
Diagnosis: Mandibles short and narrow, closing tightly against the clypeus and armed with only 3-teeth, of which the median tooth is the smallest (although sometimes with a few very small denticles as well) that are grouped together near the tip.Dorsal pronotal sculpturing finely punctate which contrast markedly with widely spaced foveae on mesonotum and propodeum, the foveae on the propodeum varying in density across its width (weakest medially, stronger laterally); head width less than 0.48 mm; petiole relatively narrow, PW less than 0.21 (Shattuck, 2008).
Diagnosis: The species can be easily distinguished from other members of the genus by the characteristic form of the mandibles, intermediate worker size (1.9-2.1 mm), strongly marginate pronotum, absence of standing hairs.The species is close to S. disjuncta Bolton, 2000 but with mesopleuron and metapleuron smooth and shiny, petiole with a deep spongiform curtain, first gastral tergite with sparse minute appressed pubescence.
Remarks: This myrmicine ant was collected from a disturbed home garden of Watinapaha, Gampaha District during training course on field sampling and identification of ants, February 23-25 th , 2018, organized by University of Kelaniya.The specimens were found beneath a 2 year old coconut log.

Discussion
Biological invasion by ants is one of the leading threats to biodiversity, agriculture and the economy (Clavero & Berthou, 2005;Antweb, 2018b).Mass extinctions by these invaders to the native mesofauna (largely undescribed) may be rampant, but simply going on undocumented and unappreciated (Calcaterra & Cabrera, 2016;Santos, 2016).Invasive predatory ants can be particularly efficient at exterminating local arthropod species (Wetterer, 2012).Out of the five newly reported species from Sri Lanka, four are predatory in nature and may act as "keystone species" with a disproportionate impact on the make up of the community.Studies should focus on impact of these ants on regional fauna and test with similar studies carried across the globe.

1-
Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka 2 -Department of Zoology, Government Degree College, Shopian, Jammu and Kashmir, India 3 -Division of Entomology, Central Institute of Temperate Horticulture, Rangreth, Srinagar, Jammu and Kashmir, India