Myrmecological News 16 157-167 Vienna, January 2012 New trap-jaw ant species of Anochetus MAYR, 1861 (Hymenoptera: Formicidae) from the Philippine Islands, a key and notes on other species Herbert ZETTEL Abstract At present eleven species of Anochetus MAYR, 1861 are known from the Philippines, including four species described as new here: Anochetus werneri sp.n. (from the island of Mindanao), A. leyticus sp.n. and A. pangantihoni sp.n. (both from the island of Leyte) belong to Brown's A. risii FOREL, 1900 species group. Anochetus schoedli sp.n. (from northern Luzon) belongs to Brown's A. longifossatus MAYR, 1897 species group. Anochetus ruginotus STITZ, 1925 sp.rev. is a valid species and not a synonym of A. graeffei MAYR, 1870. An identification key to the workers of Philippine Anochetus species is added. Key words: Ponerinae, Anochetus, new species, description, taxonomy, key, Philippines, trap-jaw ants. Myrmecol. News 16: 157-167 ISSN 1994-4136 (print), ISSN 1997-3500 (online) Received 24 October 2011; revision received 17 November 2011; accepted 21 November 2011 Subject Editor: Helge Schlüns Herbert Zettel, Natural History Museum Vienna, Entomological Department, Burgring 7, 1010 Vienna, Austria. E-mail: [email protected] Introduction Here I present descriptions of four new Philippine species from one or a few well-known localities, additional unde- of the ponerine ant genus Anochetus MAYR, 1861. The scribed species must be expected. Especially Winkler ex- study follows previous works on Philippine "trap-jaw ants" traction could provide numerous samples of Anochetus and of the genera Odontomachus LATREILLE, 1804 (SORGER & other small and cryptic ants of the leaf litter, which are not ZETTEL 2011) and Myrmoteras FOREL, 1893 (ZETTEL & readily sampled by other techniques (BESTELMAYER & al. SORGER 2011). Since the revision by BROWN (1978) no 2000, IVANOV & al. 2010). Yet, I include a preliminary further species of Anochetus was described from the entire key to facilitate the identification of the recorded species. Oriental Region (BOLTON 2011). Descriptions of two spe- Material and methods cies from the transition zone between the Palaearctic and Oriental Regions (TERAYAMA 1989, WANG 1993) were All specimens were dry mounted on card squares or tri- considered in this study. angles. Examination of specimens was carried out with a Regarding the Philippine fauna, BROWN (1978) reported Nikon SMZ 1500 and a Leica Wild M10 stereomicroscope on six species of Anochetus: (1) Anochetus brevis BROWN, and measurements were taken at magnifications of 50× 1978, only known from the type series collected on Mt. Apo, and 80×. Line drawings (Figs. 1 - 7) were done by help of Mindanao; (2) A. graeffei MAYR, 1870, a polymorphic and a camera lucida. Stacked digital images (Figs. 8 - 29) were widely distributed species occurring from India to Polyne- taken with a Leica DFC490 camera attached to a Leica sia with the junior synonym A. ruginotus STITZ, 1925 de- MZ16 binocular microscope and processed with the help scribed from Luzon (but see below); (3) A. incultus BROWN, of Leica Application Suite. They were then stacked with 1978, only known from the type series from Mt. Makiling, ZereneStacker 64-bit and processed with Adobe Photoshop Luzon; (4) A. isolatus MANN, 1919, a chiefly Melanesian 7.0. species with records from Luzon and Negros; (5) A. modi- Acronyms of repositories: Specimens will be deposit- cus BROWN, 1978 with type locality Moaratoa Island off- ed in the following collections: shore Borneo and possibly conspecific specimens from Java CZW Coll. H. & S.V. Zettel, Vienna, Austria and Negros; (6) A. princeps EMERY, 1884, distributed from FMNH Field Museum of Natural History, Chicago, Illi- Myanmar to Sulawesi, with a record from Luzon. Describ- nois, USA ing four species new to science and revocating A. rugi- MNKB Museum für Naturkunde, Berlin, Germany notus from synonymy, this paper raises the number of Phil- NHMW Natural History Museum, Vienna, Austria ippine species to eleven (see Box 1). However, I do not UPLB University of the Philippines, Los Baños, Philip- have enough data for conducting a comprehensive study in pines the "Ants of the Philippine Islands"-series (e.g., SORGER & USC University of San Carlos (Entomological Collec- ZETTEL 2011). Considering that most species are only known tion), Cebu City, Philippines Measurements and indices: CI Cephalic index. HW / HL × 100. HL Head length. Maximum length of head in full-face view, excluding mandibles, measured from anterior- most point of gena to posterior-most point of head vertex, parallel to midline. HW Head width. Maximum width of head (at ocular pro- minences) in full-face view (eyes not reaching out- line of head). MdI Mandible index. MdL / HL × 100. MdL Mandible length. Maximum length of mandible in frontal view of head measured from base of shaft to apex (excluding condyles). MsL Mesosoma length. Maximum length of mesosoma, measured in lateral view, diagonal from cervical shield to posterolateral propodeal edge. PnW Pronotum width. Maximum width of pronotum in dorsal view. PtH Petiole height. Maximum height of petiole, meas- ured in lateral view as a straight line from bottom edge of petiole, perpendicular to petiolar apex (see SORGER & ZETTEL 2011: fig. 2). PtL Petiole length. Measured in lateral view along antero- dorsal outline of petiole from small antero-apical tooth to apex (see SORGER & ZETTEL 2011: fig. 2). Figs. 1 - 7: Apex of mandible, seen approximately from di- PtW Petiole width. Maximum width of petiole in dorsal rection of body axis when mandibles closed: (1) Anochetus view. princeps; (2) A. schoedli sp.n.; (3) A. graeffei (specimen SI Scape index. SL / HW × 100. from Luzon, Mt. Banahaw); (4) A. ruginotus (specimen SL Scape length. Maximum length of antennal scape from Mindanao, Songkoy Spring); (5) A. werneri sp.n.; (6) in dorsal view excluding basal constriction. A. pangantihoni sp.n.; (7) A. leyticus sp.n.; dat = dorsal TL Total length. Length of entire ant measured in dorsal apical tooth; dsh = dentition of shaft (distal part); ict = in- view with head stretched out, from anterior margin tercalary tooth; vat = ventral apical tooth. of mandible to apex of abdomen. Measurements are taken from holotypes (in A. graeffei: lectotype) and from paratype workers of new species with 5 Emargination of vertex shallow (Fig. 24). Me- smallest and largest HW. All measurements are in milli- sosoma stout (Fig. 26), PW / HW > 0.57 (0.58 metres. Terms for head structures and mandibular dentition in lectotype, 0.61 - 0.65 in Philippine speci- follow BROWN (1976, 1978) (see also Figs. 1 and 8). mens). First gaster tergite coarsely punctured, in Philippine specimens with some additional Key to species (workers) striation (Fig. 28). .................................. A. graeffei 1 Intercalary tooth on mandibular apex well de- – Emargination of vertex deep (Fig. 25). Meso- veloped and situated between base and mid- soma slender (Fig. 27), PW / HW 0.50 - 0.53 length of ventral apical tooth (Figs. 1 - 4). .......... 2 (0.53 in holotype). First gaster tergite finely – Intercalary tooth on mandibular apex absent or punctured (Fig. 29). ................ A. ruginotus sp.rev. small and situated at apical third of ventral api- 6 Pronotal disc sculptured (e.g., Figs. 10, 22). ........ 7 cal tooth (Figs. 5 - 7). ........................................... 6 – Pronotal disc smooth and shiny (e.g., Fig. 14). ...... 9 2 TL > 8 mm. Shaft of mandible bread-knife- 7 TL 9.4 mm. Node of petiole very broad in lat- shaped, with a single sharp, dentate medial edge eral aspect (Fig. 21). Intercalary tooth on man- (Fig. 1). ................................................ A. princeps dible distinct (Fig. 5). ................... A. werneri sp.n. – TL < 7 mm. Shafts of mandibles forceps-shaped, – TL < 6 mm. Node of petiole slender in lateral each with a narrow medial plane between two aspect (Fig. 9). Intercalary tooth on mandible more or less distinct, often finely serrate edges minute or absent (e.g., Fig. 7). ............................. 8 (Figs. 2 - 4). ......................................................... 3 8 TL 4.4 - 5.2 mm. Striation on head confined to 3 Pronotal disc smooth and shiny (e.g., Fig. 18). frons between frontal carinae. Pronotum with Eye glabrous (Fig. 16). .......................................... 4 longitudinal, but irregular striation. ....... A. incultus – Pronotal disc strongly sculptured (Figs. 26, 27). – TL 5.5 - 5.7 mm. Striation on head extended Eye beset with minute setae (Figs. 24, 25). .......... 5 onto vertex (Fig. 8). Pronotum with dense, regu- 4 Head smooth. Eyes of normal size. TL > 6 mm. lar, longitudinal striation (Fig. 10). .. A. leyticus sp.n. ............................................................. A. isolatus 9 Eyes minute, length 0.13 - 0.14 mm. Mandibles – Head sculpture reaching nuchal carina. Eyes mi- short, length < 0.70 mm. Longitudinal striae on nute (Fig. 16). TL 3.7 - 3.8 mm. ... A. schoedli sp.n. frons obsolete. .......................................... A. brevis 158 Box 1: List of species recorded from Philippine islands Colour: Medium brown; centre of head dorsum, meso- (* = endemic species). soma, and tergites 2 - 3 slightly infuscated; mandibles, an- tennae, tarsi, and apex of abdomen pale brown. *A. brevis BROWN, 1978 Mindanao Structures: Head (Fig. 8) with moderately developed ocular and temporal prominences and deeply emarginated *A. graeffei MAYR, 1870 Luzon, Masbate, Negros, Palawan vertex; frontal striation extended posteriorly onto vertex, *A. incultus BROWN, 1978 Luzon almost reaching nuchal carina. Eye medium-sized, glab- *A. isolatus MANN, 1919 Luzon, Negros rous. Mandible moderately long, stout, medial plane termi- *A. leyticus sp.n. Leyte nating in a large tooth, ventral edge of plane weakly ser- *A. modicus BROWN, 1978 Negros rate; intercalary tooth absent (Fig. 7). Antenna (Fig. 8) long *A. pangantihoni sp.n. Leyte and slender; scape strongly curved, distal part narrowed; flagellum slender, antennomere 3 slightly shorter than an- *A. princeps EMERY, 1884 Luzon tennomeres 2 and 4, following antennomeres steadily in- *A. ruginotus STITZ, 1925 Luzon, Mindanao creasing in length. *A. schoedli sp.n.