Messor instabilis

Distribution based on Regional Taxon Lists
Oriental Region: India, Pakistan. Palaearctic Region: Israel.

Nomenclature

 * . Atta instabilis Smith, F. 1858b: 163 (w.m.) INDIA (no state data, “Northern India”).
 * Type-material: syntype workers, syntype males (numbers not stated).
 * Type-locality: India: northern India (no collector’s name).
 * Type-depository: BMNH.
 * Bingham, 1903: 279 (s.q.).
 * Combination in Messor: Bingham, 1903: 278.
 * As unavailable (infrasubspecific) name: Emery, 1921f: 71.
 * Junior synonym of barbarus: Tiwari, 1999: 38 (error).
 * Subspecies of capitatus: Emery, in Dalla Torre, 1893: 101.
 * Subspecies of barbarus: Forel, 1903a: 694; Bingham, 1903: 278; Forel, 1906b: 86; Emery, 1922c: 94; Emery, 1924a: 8; Wheeler, W.M. 1926: 3; Karavaiev, 1926b: 100; Karavaiev, 1927a: 287; Chapman & Capco, 1951: 137.
 * Status as species: Mayr, 1863: 396; Smith, F. 1871a: 333; Santschi, 1923f: 325; Santschi, 1927c: 247 (in key); Wheeler, W.M. 1927g: 103; Santschi, 1931a: 4; Santschi, 1936c: 200; Menozzi, 1939a: 297; Eidmann, 1942: 246; Cagniant, 1964: 87; Pisarski, 1967: 383; Pisarski, 1970: 306; Bolton, 1995b: 254; Vonshak, et al. 2009: 42; Borowiec, L. 2014: 107; Bharti, Guénard, et al. 2016: 38; Rasheed, et al. 2019: 432.
 * Senior synonym of punctata: Bingham, 1903: 279; Pisarski, 1967: 383; Pisarski, 1970: 306; Bolton, 1995b: 254.
 * Distribution: Afghanistan, India, Israel, Pakistan.
 * punctata. Aphaenogaster barbara var. punctata Forel, 1886d: 248 (w.) INDIA (Jammu & Kashmir).
 * Type-material: holotype (?) worker.
 * [Note: no indication of number of specimens is given.]
 * Type-locality: India: Kashmir (no collector’s name).
 * Type-depository: MHNG.
 * As unavailable (infrasubspecific) name: Emery, 1891b: 12.
 * Subspecies of capitatus: Dalla Torre, 1893: 101.
 * Subspecies of barbarus: Forel, 1894b: 89; Forel, 1903a: 694; Wheeler, W.M. 1922a: 803.
 * Junior synonym of barbarus: Tiwari, 1999: 38 (error).
 * Junior synonym of instabilis: Bingham, 1903: 279; Pisarski, 1967: 383; Pisarski, 1970: 306; Bolton, 1995b: 256.

Description
Worker

Bodlah et al, (2019): Head square, as broad as long, opaque, a little striated, ocelli absent. Antennae shorter, scape little longer than top of head, flagellum gradually thicker toward apex. Eyes somewhat broader in width than length, placed above the middle of head. Clypeus finely carinate. Mandibles long, striated longitudinally, denticulate at inner margin. Mesosoma transversally striated. Pronotum broader than meso and metanotum, mesonotum compressed laterally, metanotum without spines or teeth. Petiole and post petiole equal in width. Gaster smooth and oval. Coloration: Head and mesosoma dark shining red; gaster black. Scape of antennae and tarsi pale.

Measurements (mm) of Worker: Head length 1.6 mm; Head width 1.6 mm; Scape length 1.3 mm; Eye length 0.36 mm; Eye width 0.38 mm; Mesosoma length: 2.2 mm; Pronotum width 1 mm; Petiole length 0.2 mm; Petiole height: 0.33 mm; Petiole width 0.4 mm; Post petiole length 0.2 mm; Post petiole width 0.4 mm; Post petiole height: 0.5 mm; Gaster length: 1.60 mm; Body length 8.5 mm; Cephalic index: 100; Scape index 1: 81.25; Scape index 2: 81.25; Petiole index: 60.60; Post petiole index: 40

Bingham (1903):

Major: Dark- shining red, the abdomen in some specimens black, the scape of the antennae and the tarsi pale. Head in some specimens finely longitudinally striate, in the majority smooth, with a few obsolete striae and scattered punctures; thorax above coarsely transversely, the sides obliquely striate; legs, pedicel and abdomen highly polished, smooth and shining; the legs with a few widely scattered punctures, nodes of the pedicel with some half obsolete transverse striae above. pilosity almost entirely wanting, reduced to a very few erect soft, not obtuse hairs on the underside of the head and abdomen and on the thorax above. Mandibles finely longitudinally striate. Metanotal spines or teeth entirely wanting. For the rest the characters of the genus.

Minor: Resembles the major, but is of course smaller; the head invariably smooth, highly polished and shining, with no trace of striae and fewer punctures than in the major. ; the sculpture of the thorax much more feeble; metanotum unarmed as in the major.

Length: 4 - 9 mm

Queen

Bingham (1903): Closely resembles the major worker, but is larger and darker, almost black, the head anteriorly subopaque, longitudinally striate, the posterior portion with the thorax and abdomen sparsely punctured, polished and shining; the metanotum and nodes of pedicel transversely striate; wings hyaline.

Length: 11 - 12.5 mm

Male

Bingham (1903): Resembles the $, but is smaller, with a considerably smaller head and proportionately larger and broader wings. Pilosity and sculpture more dense than in the queen; mandibles with a distinct dentate masticatory margin; antenna; long, the scape half the length of the flagellum; neuration of the wings as in the queen.

Length: 7.5 - 8 mm

References based on Global Ant Biodiversity Informatics

 * Bharti H., Y. P. Sharma, M. Bharti, and M. Pfeiffer. 2013. Ant species richness, endemicity and functional groups, along an elevational gradient in the Himalayas. Asian Myrmecology 5: 79-101.
 * Bharti H., Y. P. Sharma, and A. Kaur. 2009. Seasonal patterns of ants (Hymenoptera: Formicidae) in Punjab Shivalik. Halteres 1(1): 36-47.
 * Bodlah I., M. T. Rasheed, X. Huang, A. Gull-E-Fareen, J. A. Siddiqui, and M. A. Bodlah. 2019. First records of two species of genus Messor Forel, 1890 (Formicidae: Myrmicinae) along with trophic associations with aphids from Pothwar Region, Pakistan. The J. Anim. Plant Sci. 29(4): 7 pages.
 * Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
 * Cagniant, H. 1964. "Étude de quelques fourmis marocaines. Statistique provisoire des Formicidae du Maroc." Bulletin de la Société d' Histoire naturelle de l' Afrique du Nord 53 (1964): 83-118.
 * Forel A. 1903. Les Formicides de l'Empire des Indes et de Ceylan. Part X. J. Bombay Nat. Hist. Soc. 14: 679-715.
 * Menozzi C. 1939. Formiche dell'Himalaya e del Karakorum raccolte dalla Spedizione italiana comandata da S. A. R. il Duca di Spoleto (1929). Atti della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano. 78: 285-345.
 * Pajni H. R., and R. K. Suri. 1978. First report on the Formicid fauna (Hymenoptera) of Chandigarh. Res. Bull. (Science) Punjab University 29: 5-12.
 * Raci N., C. Sravanthy, C. Sammaiah, and M. Thirupahaiah. 2015. Biodiversity of ants (Insecta-Hymenoptera) in agroecosystem and grass land in Jammikunta, Karimnagar District, Telangana, India. Journal ofEnvironment 4(1): 11-16.
 * Rasheed M. T., I. Bodlah, A. G. Fareen, A. A. Wachkoo, X. Huang, and S. A. Akbar. 2019. A checklist of ants (Hymenoptera: Formicidae) in Pakistan. Sociobiology 66(3): 426-439.
 * Vonshak M., and A. Ionescu-Hirsch. 2009. A checklist of the ants of Israel (Hymenoptera: Formicidae). Israel Journal of Entomology 39: 33-55.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004