Monomorium petiolatum is a cryptic forager in rainforest ground litter (Heterick 2001).
Heterick (2001) - A member of the kilianii group. This species has a remarkably long petiolar peduncle, and this feature, combined with the glossy, shining cuticle, gives the ant the appearance of a glasswork creation when viewed under a microscope. The long peduncle also distinguishes it from other members of the kilianii-group, except for Monomorium shattucki (which, however, has a conspicuous petiolar node).
Keys including this Species
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
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The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- petiolatum. Monomorium petiolatum Heterick, 2001: 388, figs. 29, 80 (w.) AUSTRALIA.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Holotype. HML 2.02; HL 0.62; HW 0.51; Cel 81; SL 0.57; SI 114; PW 0.37. Others. HML 2.04-2.29; HL 0.59-0.65; HW 0.50-0.57; CeI 80-88; SL 0.56-0.59; SI 104-111; PW 0.30-0.40 (13 measured).
As for the worker of Monomorium kiliani, but with the following apomorphies.
Head. Head square or rectangular; vertex convex. (Viewed laterally) compound eyes set at midline of head capsule. Anteromedial clypeal margin straight or slightly emarginate, median clypeal carinae not produced as teeth or denticles. Posteromedial clypeal margin level with posterior surface of antennal fossae. Anterior tentorial pits equidistant between mandibular insertions and antennal fossae. Palp formula 2,2. Maximum number of mandibular teeth and denticles: four; mandibles (viewed from front) triangular and smooth, with piliferous punctures.
Alitrunk. Promesonotal setulae appressed. Mesonotal suture absent. Metanotal groove present as feebly impressed furrow between promesonotum and propodeum. Dorsal propodeal face gently convex, or sloping posteriad with wedge-shaped flattening or shallow depression that is widest between propodeal angles. Propodeal setulae absent.
Petiole and postpetiole. Petiolar spiracle lateral and positioned in pedicel well anteriad of petiolar node. Petiolar node conical, dorsally rounded. Ratio of greatest node breadth (viewed from front) to greatest node width (viewed in profile) near 1:1. Height ratio of petiole to postpetiole near 1:1 to near 4:3; height-length ratio of postpetiole near 3:4 to near 1:2.
Gaster. Pilosity of first gastral tergite consisting entirely of well-spaced erect and suberect setae.
General characters. Colour shining orange: head gaster, and legs often lighter in colour. Worker caste monomorphic.
Holotype. Worker, Queensland, Mt Tyson 2 km SW Tully l7°55'S, 145°54'E, 7.v.1983, D. K. Yeates, QM berlesate no. 588, rainforest, 650m, sieved litter (Australian National Insect Collection). Paratypes. Queensland: 3x3 workers, Table Mtn., Cape Tribulation 16°09'S, 145°26'E, 24.iv.1983, G. B. Monteith & D. Cook, QM berlesate no. 542, rainforest, 320m, sieved litter, ANIC ants vial no. 40.211 (ANIC, The Natural History Museum, Museum of Comparative Zoology); 3x2 workers, same collection data as preceding paratypes, QM berlesate no. 540 (ANIC, BMNH, MCZ); 3 workers, Queensland, banks of Daintree R., 8.viii.1975, B. B. Lowery, RF., in rotten wood, Chelaner (ANIC).
- Holotype, worker, Mt. Tyson, 2km W Tully, Queensland, Australia, Yeates,D.K., ANIC32-015679, Australian National Insect Collection.
- Paratype, 3 workers, banks of Daintree R., Queensland, Australia, Australian National Insect Collection.
- Paratype, 5 workers, Table Mtn., Cape Tribulation, Queensland, Australia, Australian National Insect Collection.
- Paratype, 5 workers, Table Mtn., Cape Tribulation, Queensland, Australia, The Natural History Museum.
- Paratype, 5 workers, Table Mtn., Cape Tribulation, Queensland, Australia, Museum of Comparative Zoology.
Latin: “little stalk” (referring to the petiolar peduncle).
- Heterick, B. E. 2001. Revision of the Australian ants of the genus Monomorium (Hymenoptera: Formicidae). Invertebrate Taxonomy. 15:353-459. PDF (page 388, figs. 29, 80 worker described)