Systematic Entomology (1991) 16, 1-13
New myrmicine ant genera from the Oriental Region (Hymenoptera: Formicidae)
BARRY B 0 LTO N Department of Entomology, The Natural History Museum, London
Abstract. Four new myrmicine ant genera are described from the Oriental Region. Vombisidris gen.n. (twelve species) is predominantly an arboreal genus that ranges from India to Queensland, with the majority of species in Malaysia and Indonesia. Rotastruma gen.n. (two species) is known from China, Singapore, and East Malaysia and is also arboreal. Tetheamyrma gen.n. is monotypic and known only from a single leaf litter sample from East Malaysia. The three species of Kartidris gen.n. are terrestrial and have been found in mountainous areas in southern China. Thailand and India.
Introduction It belongs to the Stenamma- Rogeria-group of genera and is particularly interesting as it re- The four new genera described here belong to presents the third evolutionary lineage to de- the ant subfamily Myrmicinae and come from velop spongiform tissue on the waist segments the Oriental region, an area with an enormous and gaster. Other myrmicines with such tissue and little understood diversity of myrmicine include the unrelated tribe Dacetini (see e.g. ants. Two of the genera, Vombisidris and Brown, 1962; Bolton, 1983; and their included Rotastruma, are mostly or entirely subarboreal references), and the isolated and peculiar genus to arboreal. Tree-fogging, a specialized sam- Dacetinops (Taylor, 1985). pling technique whose value has only recently Finally Kartidris, a member of the Pheidole- become fully appreciated, is to a large extent Messor-Aphaenogaster-group of genera, is responsible for our knowledge of Vombisidris. known from three species collected in moun- Like most other arboreal ant genera the bio- tainous areas of southern China, India and logies of Vombisidris and Rotastruma remain Thailand; one species from each of these unknown, but their numbers always appear to countries. Members of this genus are terrestrial be low. Whether this is because they find it hard but their biologies remain uninvestigated. to compete with other arboreal genera, or have As a general rule I do not favour the publi- very specialized lifeways, is also unknown. cation of isolated descriptions of new taxa, that The twelve species of Vombisidris range from is, taxa described out of the context of some eastern India to Queensland, Australia, with broader study. The general rule must be broken most occurring in Malaysia and Indonesia. here, reluctantly, as these genus-level names Rotastruma is currently known from southern need to be made available for inclusion in other China, Singapore, and Sarawak in East studies and in the new general catalogue of ants Malaysia. These two genera are referred to the which is currently in preparation. tribe Leptothoracini, a large and diverse group Standard measurements and abbreviations of with a predominantly holarctic distribution. museum titles are as defined in Bolton (1983). Tetheamyrma was recovered from a single leaf-litter sample taken in Sabah, East Malaysia. Vombisidris gen.n. (Figs 1 - 11) Correspondence: Mr B. Bolton, Department of Entomology, The Natural History Museum, Diagnosis of worker. Monomorphic terrestrial Cromwell Road, London SW7 SBD. to arboreal myrmicine ants with the following 2 Barry Bolton combination of characters. variable. Pilosity present, moderately dense, 1. Palp formula 5, 3. the individual hairs usually short and often 2. Mandible short-triangular, the masticatory blunted. Scapes with long outstanding (erect to margin with 5 teeth, uniquely arranged. The suberect) hairs at least on the leading edge. large apical tooth is followed by two smaller Female. As worker but with ocelli and full teeth (third smaller than second), then a long complement of flight sclerites; winged when diastema and two small basal teeth. Length of virgin. Females known only in bilongrudi, diastema is at least equal to length of margin renateae, and australis, see Taylor (1989). occupied by the apical group of three teeth Male. Unknown. (Figs 2, 11). 3. Anterior clypeal margin lacking an isolated Type-species: Vombisidris philax sp.n. median seta; instead with a pair of setae that straddle the midpoint. Notes 4. Median portion of clypeus broad pos- teriorly, broadly inserted between the frontal Character 2, the form of dentition, is lobes. autapomorphic and unique in the Myrmicinae. 5. Frontal lobes narrow, each lobe distinctly This character alone will instantly diagnose narrower than the portion of the clypeus which Vombisidris and separate it from all other is inserted between them. genera in the subfamily. The genus belongs in 6. Torulus concealed by frontal lobes in full- tribe Leptothoracini, as that taxon is currently face view, not freely projecting. understood. Leptothoracini is, however, a very 7. Frontal carinae and antenna1 scrobes nebulous tribe whose constituents and real limits absent. are not clearly known, and is in need of analysis 8. Eyes of moderate size, at or slightly in on a world-wide basis. front of the midlength of the sides of the head. 9. Antennae 12-segmented, with a strongly defined 3-segmented apical club. Key to workers 10. Sides of head usually with a strong sinuate subocular groove (Figs 1, 3-6, 8-10); groove 1 Subocular groove incomplete or absent; at most incomplete in two species (Fig. 7) (see second the groove running from the mandibular insertion lug of key couplet 1). to the anteroventral margin of the eye, nevcr 11. Alitrunk elongate and low in profile; continued bcyond the eye to the lateroccipital promesonoturn not domed-convex; propodeum margin (Fig. 7) ...... 2 bispinose. - Subocular groove complete; the groove running 12. Propodeal spiracle high on side, at about from the mandibular insertion to the antero- midlength of sclerite, distinctly separated from ventral margin of the eye, then passing through a the small metapleural gland bulla. shallow angle and continuing along the side to the 13. Metapleural lobes present, small and lateroccipital margin (Figs 1,3-6,s-10) . . . . . 3 rounded. 2 Subocular groove present from mandibular inser- 14. Metasternal process absent. tion to eye. Mesonotum without teeth. Dorsum 15. Tibia1 spurs absent from middle and hind of head without a rugoreticulum. Propodeal legs. dorsum strongly sloping downward posteriorly so 16. Petiole pedunculate, the spiracle located that the spines appear attached very low (Fig. 7). Petiolar spiracle closer to base of peduncle than from very close to the alitrunk articulation to to node. SI<90. Legs short; length of hind tibia just behind the midlength of the peduncle. less than length of petiole and petiole and >SL; hind femur length >HL. (Papua - With alitrunk in profile the metanotal groove New Guinea) ...... bilongrudi entirely lacking or at most forming an inconspicuous shallow depression in the dorsal 3 Legs relatively long; maximum length of hind outline (Figs 5,6) ...... 10 femur >HW. Antennal scapes relatively long, SI 81-93; if SIi85 then the metanotal groove in 8 Spaces between basigastral costulae finely and profile is completely absent. Petiolar spiracle densely sculptured so that an opaque transverse located at or behind the midlength of the pedunclc arc is present on the first gastral tergite (Figs1,3,4) ...... 4 immediately behind the postpetiole. Eyes relatively small, 0.22 X HW (Fig. 11). Hairs on - Legs relatively short; maximum length of hind first gastral tergite short thick and abruptly femur - First gastral tergite glassy smooth or at most with - Propodeal dorsum convex to sloping but not very faint superficial reticular patterning. Basi- abruptly downcurved; the spines set high. gastral costulae extremely short, restricted to area Propodeal spiracle below level of spine (Figs 5, immediately behind postpetiole and much shorter 6) ...... 11 than the postpetiolar dorsum. Dorsum of 11 Longest hairs on dorsal alitrunk short stout and mesonotum with sides angulate in dorsal view but truncated apically. SI 69. Maximum diameter of without vertical teeth (Fig. 3) ...... 6 eye 0.27 x HW. Entirely yellow species. 6 Propodeal declivity reticulate-punctate. Head and Alitrunk in dorsal view with sides of mesonotum alitrunk yellow, gaster brown. (Australia: broadly but shallowly triangular and prominent. Queensland) ...... renateae Anterior face of petiole node meeting dorsum in a blunt angle (Fig. 5). (East Malaysia: - Propodeal declivity with 3-4 fine transverse Sarawak) ...... harpeza rugulae between the spines and the petiolar foramen. Entirely yellow, the gaster paler - Longest hairs on dorsal alitrunk elongate, fine than the head and alitrunk. (Indonesia: and tapering apically. SI 76. Maximum diameter Sulawesi) ...... nahet of eye 0.23 X HW. Head and alitrunk brown, gaster lighter brown. Alitrunk in dorsal view with 7 With alitrunk in profile the metanotal groove sides of mesonoturn extremely shallowly convex, forming a very conspicuous broad deep inden- not prominent. Anterior face of petiole node tation in the dorsal outline (Figs 8- 10) ...... 8 4 Barry Bolton Figs 1-11. Vombisidris species, workers, 1, body profile of regina; 2, head of reginu; 3-10, body profiles of 3, nahet; 4, philax; 5, harpeza; 6, occidua; 7, acherdos; 8, dryas; 9, lochme; 10, xylochos; 11, head of xylochos. New myrmicine ant genera from the Oriental Region 5 mceting dorsum through a broad smooth curvc CI 85, SL 0.74, SI 87, PW 0.64, AL 1.18. (Fig. 6), (India) . . . . , ...... occidua Maximum diameter of eye 0.24 (0.28 x HW). As holotype but slightly lighter in shade. Holotype worker, PAPUA NEW GUINEA: Species-groups of Vombisidris 6 km NE Kundiawa, 5.59S, 144.56E3,19.vi.1980, 2000 m, no.4498, on low vegetation, montane V. bilongrudi-group. Subocular groove incom- forest (P. S. Ward) (BMNH). plete or absent. Includes bilongrudi, acherdos. Paratype, one worker with same data as V.philax-group. Subocular groove complete. holotype (MCZ). Legs and antennae relatively long (key couplet 3). Propodeal spines long and downcurved. Metanotal groove vestigial to absent. Includes Vombisidris bilongrudi (Taylor) c0mb.n. phifax, nahet, renateae, regina. V.dryas-group. Subocular groove complete. Leptothorax bilongrudi Taylor, 1989: 605, Legs and antennae relatively short (key couplet Figs 1-3. Holotype worker and para- 3). Propodeal spines short to long but not usually type workers and females, PAPUA NEW downcurved. Metanotal groove broad and GUINEA: West Sepik Prov., Victor Em- strongly impressed in profile, trench-like. manuel Range, 5.07S, 141.38E, near Tele- lncludes dryas, lochme, xylochos. fomin, 1550 m, 17- 19.viii. 1984, no. 305 (R.J. V. austrafis-group. Subocular groove Kuhuut). [Paratype worker in BMNH complete. Legs and antennae relatively short. examined.] Metanotal groove vestigial to absent. A convenience-group to hold species not fitting any of the above groups. Includes australis, philax-group harpeza, occidua. Vombisidris nahet sp.n. (Fig. 3) bilongrudi-group HoLotype worker. TL 4.1, HL 0.82, HW 0.68, CI 83, SL 0.62, SI 91, PW 0.55, AL 1.02. Vombisidris acherdos sp.n. (Fig. 7) Maximum diameter of eye 0.19 (0.28 x HW) and with 10 ommatidia in the longest row. Holotype worker. TL 4.2, HL 1.00, HW 0.87, Cephalic dorsum with a rugoreticulum every- CI 87, SL 0.74, SI 85, PW 0.64, AL 1.18. where. Subocular groove complete. Sides of Maximum diameter of eye 0.23 (0.26 X HW) head weakly convergent behind eyes. Alitrunk and with 14 ommatidia in the longest row. long and low, reticulate-rugose everywhere. Mandibles unsculptured. Sculpture of head Sides of mesonotum obtusely angular in dorsal capsule feeble, consisting of scattered short view. Propodeal spines very long and strongly longitudinal rugulae dorsally; no rugoreticulum. arched along their length. Metanotal groove Weak ground-sculpture present above the eye absent. Peduncle of petiole long, the spiracle but head capsule otherwise mostly smooth. approximately at the midlength. Petiole and Subocular groove incomplete, running only postpetiole reticulate-rugulose. First gastral from base of mandible to anterior angle of tergite glassy smooth except for a band of eye. Dorsal alitrunk evenly convex in profile, short basigastral costulae immediately behind the propodeum sloping steeply so that the the postpetiole. All dorsal surfaces of body with spines appear to be set low down. Mesonotum dense standing pilosity. Colour yellow, the unarmed. Metanotal groove absent. Dorsal gaster paler than the head and alitrunk. alitrunk with fine superficial sculpture only. Paratype worker. TL 3.8, HL 0.80, HW 0.66, Petiole shape as in Fig. 7. Base of first gastral CI 83, SL 0.60, SI 91, PW 0.53, AL 0.98. tergite unsculptured. Pilosity sparse and fine Maximum diameter of eye 0.19 (0.29 x HW). everywhere, the hairs acute; only one pair as holotype. present on the sloping portion of the propodeal Holotype worker, INDONESIA: Sulawesi dorsum. Colour uniform dark brown. Utara, G. Mogogonipa, m, 26.iv- Paratype worker. TL 4.4, HL 1.00, HW 0.85, 22.v.1985 (J. Martin) (BMNH). 6 Barry Bolton Paratype, one worker, INDONESIA: rugulose everywhere. Sides of head weakly Sulawesi Utara, Dumoga Bone NP, 16- convergent behind eyes. Anterior clypeal 20.iii.1985 (J. Martin) (MCZ). margin with a distinct median indentation. Sub- Both specimens were collected from ocular groove complete. Alitrunk reticulate- vegetation. rugose everywhere. Propodeal spines long and sharp, elevated but only shallowly curved along their length. Metanotal groove vestigial to absent. Propodeal declivity finely rugulose and Vombisidris philax sp.n. (Fig. 4) superficially punctulate. Mesonotum unarmed, the sides not angular nor prominent in dorsal Holotype worker. TL 3.6, HL 0.82, HW 0.72, view. Petiole and postpetiole reticulate- CI 88, SL 0.64, S1 89, PW 0.54, AL 1.00. rugulose, the petiolar spiracle approximately at Maximum diameter of eye 0.17 (0.24 X HW) the midlength of the short peduncle. Gaster and with 11 ommatidia in the longest row. unsculptured, smooth and shining. All dorsal Cephalic dorsum with a fine dense rugo- surfaces of body with numerous hairs. Colour reticulum everywhere. Subocular groove com- uniformly blackish brown to black. plete. Sides of head weakly convergent behind Paratype worker~s.TL 4.8-5.6, HL 1.04- eyes. Alitrunk long and low, reticulate-rugulose 1.16, HW0.88-0.96, CI 83-87, SLO.80-0.86, everywhere. Lateral edge of mesonoturn with a S1 87-93, PW 0.64-0.72, AL 1.30-1.42. small vertical triangular tooth on each side. Maximum diameter of eye 0.20-0.24 (0.21- Propodeal spines very long and strongly arched 0.24 X HW) (10 measured). As holotype. along their length. Propodeal declivity with fine Holotype worker, EAST MALAYSIA: transverse rugulae. Metanotal groove absent. Sabah, Mt Kinabalu, 1550- 1650 m, 23.v. lY87, Petiolar spiracle slightly behind midlength of no. 38 (Burckhardt & Lobl) (MHN). peduncle. Petiole and postpetiole reticulate- Paratypes, 2 workers with same data but rugulose. Basal two-thirds of first gastral tergite 28.iv.lY87, 1540 m, no. 7c; 1 worker with same densely sculptured, with long coarse basigastral data but 23.iv.1987, 1550 m, no. Ib; 3 workers costulae, longitudinal rugulae and densely with same data but 20.iv.1987, 1500 m, no. 9b; sculptured spaces between the rugular sculp- 1 worker with same data but 21.iv.1987, 1550- ture. All dorsal surfaces of body with dense fine 1650 m, no. 2b; 1 worker with same data but pilosity. Colour uniformly yellow. 30.iv.1987, 1500 m, no. 9c; 2 workers with same Paratype workers. TL 3.4-3.6, HL 0.78- data but 27.v.1987, no. 36; 3 workers with same 0.80, HW 0.68-0.72, C1 87-90, SL0.60-0.64, data but Pinosuk Plateau, 14- 17.iii.1964, 5225 S1 88-90, PW 0.50-0.54, AL 0.96-1.02. ft (S. Kueh) (MHN; BMNH; MCZ). Maximum diameter of eye 0.16-0.17 (0.23- This conspicuous black species appears to be 0.24 X HW) (3 measured). As holotype. the only one in the genus which is predominantly Holotype worker, INDONESIA: Sulawesi or entirely terrestrial in foraging habits. All the Utara, Dumoga Bone NP, fog 5, BMNH plot 1987 samples recorded above were collected by C, 400 11.ii.1985 (N. Stork) (BMNH). rn, Winkler Bag technique. Paratypes, 3 workers with same data as holo- type (BMNH; MCZ). Specimens were obtained by fogging a forest tree with pyrethrum. Vombisidris renateae (Taylor1 corn b. n. Leptothorax renateae Taylor, 1989: 609, Figs Vombisidris regina sp.n. (Figs 1, 2) 4-7. Holotype worker and paratype worker, AUSTRALIA: Queensland, 11 km ENE of Holotype worker. TL 5.0, HL 1.09, HW 0.'94, Mt Tozer (12.438, 143.18E), 11-16.vii.1986, CI 86, SL 0.84, SI 89, PW 0.86, AL 1.34. ANIC no. 1064, rainforest litter (7'. Weir). Maximum diameter of eye 0.21 (0.22 X HW). Other paratype workers and females, see Eyes in full-face view short but strongly promi- Taylor, same reference. [Paratype worker nent, dome-like, Cephalic dorsum reticulate- examined, BMNH.] New rnyrrnicine ant genera from the Oriental Region 7 dry as-group Vombisidrisxylochos sp.n. (Figs 10, 11) Vombisidris dryas sp.n. (Fig. 8) Holotype worker. TL 3.4, HL 0.78, HW 0.74, CI 95, SL 0.52, SI 70, PW 0.56, AL 0.98. Holotype worker. TL 3.8, HL 0.84, HW 0.72, Maximum diameter of eye 0.16 (0.22 X HW) CI 86, SL 0.58, SI 81, PW 0.56, AL 1.02. and with 10 ommatidia in the longest row. Maximum diameter of eye 0.21 (0.29 X HW) Cephalic dorsum densely reticulate-rugose and with 9-10 ommatidia in the longest row. everywhere. Subocular groove complete. Sides Mandibles finely shagreenate. Subocular groove of head divergent behind the eyes. Metanotal complete. Cephalic dorsum finely reticulate- groove broad in dorsal view, deeply impressed rugose. Sides of head approximately parallel in profile; outline of propodeal dorsum distinctly behind eyes. Metanotal groove very broad in humped behind metanotal groove. Alitrunk dorsal view, markedly impressed in profile. reticulate-rugose. Sides of mesonotum distinctly Alitrunk reticulate-rugose, sides of mesonotum angular in dorsal view. Propodeal spines long. angular in dorsal view. Propodeal spines Petiole and postpetiole reticulate-rugose, shallowly curved. Petiole and postpetiole with a Spiracle of petiole very close to articulation fine rugoreticulum. Spiracle of petiole very close with alitrunk. Basigastral costulae short, spaces to articulation with alitrunk. Gaster unsculp- between them finely sculptured and opaque; tured except for extremely short basigastral remainder of gaster unsculptured. Hairs present costulae. All dorsal surfaces of head and body on all dorsal surfaces, short thick and truncated with stout bluntly pointed pilosity. Colour apically. Colour uniformly yellow. uniformly yellow. Holotype worker, BRUNEI: Bukit Sulang, Holotype worker, EAST MALAYSIA: nr Lamunin, fogging, 2O.viii-l0.ix. 1982, Sarawak, 4th Division, G. Mulu NP, Gn. Mulu BM1982-388, no. T17/1 (N. Stork) (BMNH). trail to camp 3, x.1977, RGS Expd, on tree (D. Species obtained by pyrethrum fogging of Hollis) (BMNH). forest tree. Collected by hand from tree trunk. australis-group Vombisidrislochme sp.n. (Fig. 9) Vombisidris australis (Wheeler) c0mb.n. Holotype worker. TL 3.5, HL 0.78, HW 0.70, CI 90, SL 0.50, SI 71, PW 0.54, AL 0.98. Leptothorax australis Wheeler, 1934: 60. Syn- Maximum diameter of eye 0.19 (0.27 X HW) type workers, AUSTRALIA: Queensland, and with 9-10 ommatidia in the longest row. Cairns District (A. M. Lea) (MCZ). [Not Cephalic dorsum finely reticulate-rugose. Sub- seen.] ocular groove complete. Sides of head divergent Leptothorax australis Wheeler; Taylor, 1989: behind eyes. Metanotal groove broad in dorsal 607. [Redescription of worker and description view, markedly impressed in profile. Alitrunk of female.] reticulate-rugose. In dorsal view sides of mesonotum angular, the angles accentuated by a thin cuticular crest on each side. Petiole and Vombisidris harpeza sp.n. (Fig. 5) postpetiole reticulate-rugose. Spiracle of petiole very close to articulation with alitrunk. Gaster Holotype worker. TL 3.5, HL 0.80, HW 0.75, with very short basigastral costulae, the first CI 94, SL 0.52, SI 69, PW 0.56, AL 1.00. tergite finely superficially reticulate everywhere. Maximum diameter of eye 0.20 (0.27 X HW) All dorsal surfaces with relatively short blunt and with 9 ommatidia in the longest row. pilosity. Colour uniformly yellow. Cephalic dorsum finely reticulate-rugulose Holotype worker, INDONESIA: Sulawesi everywhere. Subocular groove complete. Sides Utara, Dumoga Bone NP, fog 5,400 m, BMNH of head behind eyes approximately parallel. plot C, 11.ii.1985 (N. Stork) (BMNH). Alitrunk reticulate-rugulose, sides of meso- Collected by pyrethrum fogging of a forest notum broadly angular in dorsal view. tree. Metanotai groove almost obliterated, visible in 8 Barry Bolton dorsal view as a shallow but quite broad im- which straddle the midpoint. pression, only vestigially impressed in profile. 4. Median portion of clypeus broad pos- Petiole and postpetiole reticulate-rugulose. teriorly, broadly inserted between the frontal Petiole spiracle close to articulation with ali- lobes. trunk. Very short basigastral costulae present. 5. Frontal lobes narrow, each lobe distinctly First gastral tergite with vestigial traces of faint narrower than the portion of the clypeus that is superficial reticular patterning. Hairs on all inserted between them. dorsal surfaces short stout and truncated api- 6. Torulus not freely projecting. cally. Colour uniformly yellow. 7. Frontal carinae very weakly present; Holotype worker, EAST MALAYSIA: antenna1 scrobes represented only by extremely Sarawak, 4th Division, G. Mulu NP, RGS shallowly depressed areas running above the Expd., Long Pala, 20.ix.1977, lowland rain- eyes. forest on tree trunk (B. Bolton) (BMNH). 8. Eyes large, situated at or just behind the The single worker was hand-collected, midlength of the sides. walking on the bark of a large forest tree. 9. Antennae 12-segmented, the 3 apical segments forming a strongly defined club. 10. Alitrunk low in profile and with a shal- Vombisidris occidua sp.n. (Fig. 6) lowly evenly convex dorsum; promesonotum not domed-convex; metanotal groove absent; Holotype worker. TL 4.0, HL 0.90, HW 0.79, propodeum bispinose; sides of alitrunk margin- CI 88, SL 0.60, SI 76, PW 0.58, AL 1.12. ate, especially on mesonotum and propodeum. Maximum diameter of eye 0.18 (0.23 X HW) 11. Propodeal spiracle set low on the side at and with 11 ommatidia in the longest row. about the midlength of the sclerite, very close Cephalic dorsum finely reticulate-rugulose to the dorsalmost point of the metapleural gland everywhere. Subocular groove complete. Sides bulla. of head behind eyes feebly convergent pos- 12. Metapleural lobes present, small and teriorly. Alitrunk reticulate-rugulose, sides of rounded. mesonotum shallowly convex in dorsal view, 13. Metasternal process absent; cuticle be- not angular. Metanotal groove absent. Petiole tween anterior halves of metacoxal cavities and postpetiole finely reticulate-rugulose, depressed. petiole spiracle in front of midlength of ped- 14. Tibia1 spurs absent from middle and hind uncle. Basigastral costulae vestigial. First gastral legs. tergite with extremely faint scratch-like super- 15. Petiole nodiform, with a short anterior ficial patterning on an otherwise smooth surface. peduncle; petiolar spiracle located at about the Hairs on all dorsal surfaces elongate fine and midlength of the peduncle. acute apically. Head and alitrunk dark brown, 16. Postpetiolar sternite reduced, small in gaster lighter brown, legs yellow. profile. Holotype worker, INDIA: 25 km W. of 17. Sting functional, strong and simple. Mudigere, 3.xi.1979 (J. Noyes) (BMNH). 18. Cuticle thick and armoured. Pilosity pre- The single specimen was swept from low sent on all dorsal surfaces of head and body. vegetation. Female. As worker but only very slightly larger in size. Ocelli present. Alitrunk with full complement of flight sclerites and certainly Rotasrruma gen.n. (Figs 12-15) winged when virgin. Male. Unknown. Diagnosis of worker. Monomorphic subar- boreal to arboreal myrmicine ants with the Type-species: Rotastruma recava sp.n. following combination of characters. 1. Palp formula 5, 3. 2. Mandible triangular, with 6 teeth which Notes decrease in size from apical to basal. 3. Clypeus with a median longitudinal carina; Rotastruma is a marginal leptothoracine anterior clypeal margin with a pair of hairs genus. It falls into an assemblage of small and New myrmicine ant genera from the Oriental Region 9 little-understood genera on the periphery of Maximum diameter of eye 0.24-0.26 (0.35- what is currently understood as tribe Lepto- 0.37 x HW) (10 measured). As holotype. thoracini. Rotastruma appears to have affinities Paratype females. TL 3.9-4.0, HL 0.80- with the genera Paratopula and Romblonella, 0.81, HW 0.69-0.70, CI 85-86, SL0.54-0.56, which form part of this marginal group. Little S1 78-81, PW 0.56-0.58, AL 1.08-1.12. more can be said of this enigmatic small genus Maximum diameter of eye 0.26-0.28 (0.37- until a detailed survey can be made to define 0.40 x HW) (4 measured). The females are with some accuracy where the limits of tribe small, only the same size as the workers or Leptothoracini really lie. slightly larger. Alate when virgin and with a complete complement of flight sclerites. Nests appear to be polygynous as both the Singapore Key to workers collections noted below contained more than one dealate female. 1 With head in full-face view the occipital margin Holotype worker, EAST MALAYSIA: conspicuously concave, the sides of the head Sarawak, 4th Division G. Mulu NP, 22.v.1978, convex (Fig. 14). (Singapore; East Malaysia: mixed dipterocarp forest, on tree (N. M. Sarawak) ...... recava Collins) (BMNH). - With head in full-face view the occipital margin Paratypes, 18 workers and 2 females, more or less transverse, the sides of the head SINGAPORE: Bukit Timah Forest, 15.iii.1973 approximately straight (Fig. 15). (China: (D. H. Murphy); 2 workers and 2 females, Guangdong) ...... stenoceps Bukit Timah, 100 m, 8.iv.1989, no. 10254, ex dead twig, vine, rainforest (P. S. Ward) (BMNH; MCZ; MHN). Rofasffum8 r8cava spa. (Figs 12, 14) Holotype worker. TL 3.6, HL 0.80, HW 0.69, Rotastruma stenoceps sp.n. (Figs 13, 15) CI 86, SL 0.56, SI 81, PW 0.48, AL 0.94. Maximum diameter of eye 0.24 (0.35 X HW). Holotype worker. TL 3.7, HL 0.82, HW 0.68, Mandibles finely longitudinally striolate. CI 83, SL 0.56, SI 82, PW 0.48, AL 0.92. Central strip of dorsum of head with a number Maximum diameter of eye 0.22 (0.32 x HW). of longitudinal costulae which may run the Answering the description of recava but lacking length of the head or may be broken or inter- its concave occipital margin. Sides of head rupted. Occipital margin distinctly concave in behind eyes with projecting hairs in stenoceps full-face view, the sides of the head in front of but hairs absent in front of the occipital corners the large eyes convex. Median portion of clypeus in recava. Propodeal spines of stenoceps shorter with 3 longitudinal carinae. Dorsal alitrunk with and less downcurved than in recava, and its predominantly longitudinal sharp rugulae; propodeal spiracle closer to the apex of the cross-meshes present, especially on pronotum. metapleural gland bulla (compare Figs 12, 13). Sides of alitrunk marginate, margination Holotype worker, CHINA: Guangdong, Ding- sharpest on mesonotum and propodeum. Hu Mts, 60 km W. of Guangzhou, vi.1983 (2. Propodeal spines long, depressed and down- Boucek) (BMNH). curved along their length. Sides of alitrunk with weak longitudinal rugulae. Petiole and post- petiole rugulose to reticulate-rugulose dorsally. Tetheamyrma gen.n. (Figs 16, 17) First gastral tergite unsculptured except for sparse short basigastral costulae and feeble Diagnosis of worker. Monomorphic terres- superficial reticular patterning. Standing hairs trial (leaf litter) myrmicine ants with the follow- present on all dorsal surfaces, short fine and ing combination of characters. acutely pointed. Colour yellow, the first gastral 1. Palp formula 2, 2 (in situ count). tergite with a broad brown band. 2. Mandible triangular, with 6 teeth, the two Paratype workers. TL 3.6-4.0, HL 0.80- basal teeth poorly defined. 0.84, HW 0.66-0.70, CI 83-86, SL0.56-0.60, 3. Anterior clypeal margin lacking an isolated SI 81-86, PW 0.48-0.52, AL 0.94-1.02. median seta, instead with a pair of setae that 10 Barry Bolton straddle the midpoint. related to either of these and thus represents 4. Median portion of clypeus narrow pos- a third independent evolution of this feature, teriorly, narrowly inserted between the frontal whose function remains unknown. lobes. Tetheamyrma belongs in the Rogeria- 5. Median portion of clypeus narrowly bi- Stenamma-group of genera, based on the struc- carinate, the carinae arising between the frontal ture of the mandibles and clypeus, and the form lobes and diverging anteriorly. of the alitrunk. It is isolated among these, 6. Frontal lobes broad, each lobe considerably however, by its combination of 11-segmented broader than the portion of the clypeus that is antennae with a 2-segmented club, and the inserted between them. presence of spongiform material on the waist 7. Torulus concealed by frontal lobes in full- and gaster. face view. 8. Frontal carinae and antenna1 scrobes absent. Tetheamyrma subspongia spm. (Figs 16, 17) 9. Small eyes present, situated just in front of the midlength of the sides. Holotype worker. TL 2.3, HL 0.55, HW 0.51, 10. Antennae 11-segmented, with a strongly CI 92, SL 0.32, SI 63, PW 0.36, AL 0.66. defined 2-segmented apical club. Maximum diameter of eye 0.08 (0.16 X HW), 11. Alitrunk short and compact in profile; the eye with only about 10 ommatidia in total. promesonotum forming a single even convexity; Mandibles smooth. Head capsule everywhere metanotal groove impressed: propodeal dorsum extremely finely and densely sharply reticulate- steeply sloping posteriorly. rugose and with dense short soft curved pilosity. 12. Propodeum with a pair of short triangular Promesonoturn sculptured as head. Sloping spines which are connected to the narrow propodeal dorsum sculptured to level of spines rounded metapleural lobes by narrow infra- but declivity thereafter smooth and shining. dental lamellae. Petiole and postpetiole both much broader than 13. Propodeal spiracle conspicuous, low on long in dorsal view and more finely sculptured side and behind midlength of sclerite. than the promesonotum. Gaster smooth and 14. Tibia1 spurs absent from middle and hind shining between conspicuous pits from which legs. hairs arise. All dorsal surfaces of alitrunk, waist 15. Petiole with a short stout anterior ped- and gaster with dense soft curved pilosity except uncle and with a relatively large anteroventral for the propodeum behind its highest point, process; petiolar spiracle located at the node. which lacks hairs. Colour medium brown, the 16. Petiole ventrally (behind the process) and appendages lighter. postpetiole ventrally with a clump of loose Paratype worker. TL 2.2, HL 0.54, HW 0.49, spongiform material which appears to be com- CI 91, SL 0.30, SI 61, PW 0.35, AL 0.62. posed of densely interwoven or fused pilosity: Maximum diameter of eye 0.07 (0.14 X HW). base of first gastral sternite with a pad of similar As holotype. spongiform material. Holotype worker, EAST MALAYSIA: 17. Sting functional, simple. Sabah, Poring Hot Springs, Langanan River, 18. Cuticle thick and densely sculptured: 850 m, 14.v.87, no. 25a (Lob1 & Burckharclt) pilosity fine and dense everywhere. (MHN). Paratype, one worker with same data as holotype (BMNH). Female and male. Unknown. The two workers were recovered from a single Winkler Bag sample of forest leaf litter. Type-species: Tetheamyrma subspongia sp.n. Karfidris gen.n. (Figs 18-21) Notes Spongiform material on the waist segments Diagnosis of worker. Monomorphic terres- and base of the gaster ventrally was previously trial myrmicine ants with the following combi- known only in the tribe Dacetini and the non- nation of characters. dacetine genus Dacetinops. Tetheamyrma is not 1. Palp formula 4, 3. New myrmicine ant genera from the Oriental Region 11 Figs 12-21.12-15, Rotastruma species, workers: 12-13, body profile of 12, recava; 13, stenoceps; 14-15, head of 14, recava; 15, stenoceps; 16-17, Tetheamyrma subspongia, worker: 16, head; 17, body profilc; 18-21, Kartidris species, workers: 18, body profile of nyos; 19, head of nyos; 20-21, body profiles of 20, galos; 21, matertera. 12 Barry Bolton 2. Mandible triangular, usually with 5 sharp Notes teeth which decrease in size from apex to base; sometimes with a denticle following the third Kartidris belongs in the Pheidole- tooth, giving a total dental count of 6. Aphaenogaster- Messor-group of genera, 3. Anterior clypeal margin with a row of stout characterized by the high-domed pronotum, setae, lacking an isolated median seta. elongate sloping mesothorax, anteriorly situated 4. Median portion of clypeus broad and bi- petiolar spiracle, and propodeal spiracle located convex, posteriorly broadly inserted between high on the side and close to the midlength. The the frontal lobes. mandible of Kartidris is specialized by reduction 5. Frontal lobes relatively narrow, each lobe in the number of teeth and the median portion narrower than the portion of the clypeus which of the clypeus is markedly biconvex. is inserted between them. 6. Torulus projecting beyond margin of frontal lobe, visible in full-face view. Key to workers 7. Frontal carinae and antenna1 scrobes absent. 1 Dorsum of head finely and densely reticulate- 8. Eyes of moderate size, positioned behind granular everywhere, the surface opaque. Dark the midlength of the sides of the head. brown slightly larger species, HW 0.85. (China: 9. Antennae lZsegmented, with a con- Hainan I.) ...... gabs spicuous 3-segmented apical club. - Dorsum of head at most with fine superficial 10. Occipital margin convex and vertex with reticulation. Yellow to brownish yellow slightly a broad depressed area between the eyes, smaller species, HW 0.73-0.84 ...... 2 depression conspicuous in profile. 2 Dorsal alitrunk densely hairy (Fig. 18). First 11. Alitrunk elongate, the pronotum forming gastral tergite with all hairs suberect. Outline of a raised dome in profile behind which the propodeum immediately behind metanotal groove mesonotum forms a long gradual slope to the raised but rounded, not forming a distinct peak. metanotal groove. (India) ...... nyos 12. Metanotal groove impressed; propodeum - Dorsal alitrunk sparsely hairy (Fig. 21). First unarmed and rounded. gastral tergite with many hairs decumbent or 13. Propodeal spiracle high on side, located subdecumbent. Outline of propodeum at or just in front of the midlength of the immediately behind metanotal groove forming a sclerite . distinct peak. (Thailand) ...... marerrera 14. Metapleural lobes vestigial to absent. 15. Metapleural gland bulla large but widely separated from the propodeal spiracle. Kadidris nyos sp.n. (Figs 18, 19) 16. Metasternal process vestigial to absent. 17. Tibia1 spurs absent from middle and hind Holotype worker. TL 4.4, HL 0.96, HW 0.83, legs or at least not distinguishable from the CI 86, SL 0.90, SI 108, PW 0.60, AL 1.24. surrounding pilosity. Maximum diameter of eye 0.21 (0.25 X HW) 18. Petiole pedunculate, the spiracle located and with 10-11 ommatidia in the longest row. at or just in front of the midlength of the Mandibles finely longitudinally rugulose. Entire peduncle. cephalic dorsum with only vestigial sculpture, 19. Postpetiolar sternite large and a very feeble superficial reticulation visible. conspicuous. Median portion of clypeus conspicuously bi- 20. Sting reduced and desclerotized, excertile convex, without longitudinal carinae. Eyes with but subspatulate apically. abundant anteriorly curved short hairs arising 21. Cuticle thick and strong, sculpture weak. between the facets. Dorsal alitrunk virtually Pilosity abundant; eyes with projecting sh’ort smooth except for the propodeum, which shows hairs. weak reticulation. Dorsal outline of propodeum rounded immediately behind the metanotal Female and male. Unknown. groove. Sides of pronotum shining, almost un- sculptured. Mesopleuron densely sculptured, Type-species: Kartidris nyos sp.n. reticulate-punctate with some fine longitudinal New myrmicine ant genera from the Oriental Region 13 rugulae. Sides of propodeum and metapleuron Kartidris marettera sp.n. (Fig. 21) with sculpture intermediate in density between Holotype worker. TL 3.8, HL 0.86, HW 0.75, pronotum and mesopleuron. First gastral tergite CI 87, SL 0.80, SI 107, PW 0.54, AL 1.10. with fine superficial shagreening between hair- Maximum diameter of eye 0.19 (0.25 x HW). pits, almost smooth. Pilosity dense on all dorsal Answering to description given for nyos but surfaces, the hairs erect to suberect everywhere. contrasting as follows. Scapes and tibiae with numerous suberect to (i) Eyes with only sparse minute curved subdecumbent short hairs. Colour light hairs arising between the facets. yellowish brown. (ii) Dorsal outline propodeum rising to a Paratype workers. TL 4.2-4.6, HL 0.92- of distinct peak immediately behind the metanotal 0.98, HW 0.78-0.84, CI 85-88, S 0.86-0.92, groove. S1 108-111, PW 0.59-0.62, AL 1.22-1.34. Maximum diameter eye 0.20-0.22 (0.25- (iii) Pilosity sparse on all dorsal surfaces of (compare Figs 18, 21), many or most hairs 0.27 x HW) (4 measured). As holotype. on the first gastral tergite subdecumbent to Holotype worker, INDIA: Meghalaya, Khasi decumbent. Hills, Shillong, 10.v.1975 (R. Mathew) Paratype workers. TL 3.8-4.0, HL 0.84- (BMNH). 0.90, HW 0.73-0.78, CI 87-89, SL0.80-0.86, Paratypes, workers with same data as holo- 5 SI 107-111, PW 0.52-0.55, AL 1.00-1.15. type (BMNH; MCZ). Maximum diameter of eye 0.18-0.20 (0.25- 0.26 x HW) (10 measured). As holotype. Holotype worker, THAILAND: Nong Hoi, Kartidris galos sp.n. (Fig. 20) 2.viii.1975 (D.Jackson) (BMNH). Paratypes, 29 workers with same data as Holotype worker. TL 4.4, HL 0.97, HW 0.85, holotype (BMNH; MCZ; MHN). CI 88, SL 0.90, SI 106, PW 0.60, AL 1.28. Maximum diameter of eye 0.22 (0.26 x HW). Answering the description given for nyos but References contrasting as follows. Bolton, B. (1983) The Afrotropical dacetinc ants. (i) Cephalic dorsum everywhere finely and Bulletin of the British Museum (Natural History) densely reticulate-granular, the surface opaque. (Entomology), 46, 267-416. (ii) Pronotal dorsum with superficial reticular Brown, W.L., Jr (1962) The Neotropical species of patterning, less strongly sculptured than head the ant genus Sfrumigenys Fr. Smith: synopsis and or propodeal dorsum. key to species. Psyche, 69, 238-267. (iii) Sides of pronotum glossy but super- Taylor, R.W. (1985) In: Taxonomy, Phylogeny, and ficially reticulate; mesopleuron and side of Zoogeography of Beetles and Ants (ed. by G. E. propodeum with sculpture of almost equal Ball), pp. 41-67. Junk, Dordrecht. intensity . Taylor, R.W. (1989) Australian ants of the genus Leptothorax Mayr. Memoirs of the Queensland (iv) First gastral tergite with fine superficial Museum, 27, 605-610. reticulation between hair-pits. Wheeler, W.M. (1934) An Australian ant of the (v) Colour uniform dark brown. genus Leptofhorax Mayr. Psyche, 41, 60-62. Holotype worker, CHINA: Hainan I., Tien Fong Mts, v.1983 (Z. Boucek) (BMNH). Accepted 16 July 1990