Paratrechina longicornis

This ant has been transported to almost all the populated subtropical and tropical areas in the world.

Identification
Scapes without erect macrosetae; in lateral view propodeal dorsal face almost flat. . . . . Paratrechina longicornis

Scapes with erect macrosetae; in lateral view propodeal dorsal face convex. . . . . Paratrechina zanjensis

Key to Prenolepis Group Genera

Distribution based on Regional Taxon Lists
Afrotropical Region: Chad, Comoros, Democratic Republic of Congo, Eritrea, Guinea, Kenya, Malawi, Mali, Mauritania, Mozambique, Saint Helena, Senegal, Tanzania, Uganda, United Arab Emirates. Australasian Region: Australia, New Caledonia, Norfolk Island. Indo-Australian Region: Borneo, Cook Islands, Fiji, Guam, Hawaii, Indonesia, Kiribati, Krakatau Islands, Marshall Islands, Micronesia (Federated States of), New Guinea, Niue, Northern Mariana Islands, Palau, Philippines, Samoa, Solomon Islands, Timor-Leste, Tokelau, Tonga, Tuvalu, Vanuatu. Malagasy Region: Madagascar, Mauritius, Mayotte, Réunion, Seychelles. Nearctic Region: United States. Neotropical Region: Anguilla, Aruba, Bahamas, Barbados, Belize, Bermuda, Brazil, Cayman Islands, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, French Guiana, Galapagos Islands, Greater Antilles, Guatemala, Guyana, Haiti, Honduras, Lesser Antilles, Mexico, Netherlands Antilles, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, Saint Kitts and Nevis, Saint Lucia, Trinidad and Tobago, Turks and Caicos Islands, Venezuela. Oriental Region: Bangladesh, Cambodia, India, Nepal, Nicobar Island, Pakistan, Sri Lanka, Thailand, Vietnam. Palaearctic Region: Bahrain, Balearic Islands, Belgium, Canary Islands, China, Estonia, France, Iberian Peninsula, Iran, Israel, Japan, Libya, Malta, Spain, United Kingdom of Great Britain and Northern Ireland.

Male
Additional images can be found here.

Nomenclature

 *  longicornis. Formica longicornis Latreille, 1802c: 113 (w.) SENEGAL. Jerdon, 1851: 124 (q.); André, 1881b: 60 (m.); Hung, Imai & Kubota, 1972: 1024 (k.); Wheeler, G.C. & Wheeler, J. 1986d: 336 (l.); Fox, et al. 2007: 3 (l.). Combination in Prenolepis: Roger, 1863b: 10; in Pr. (Nylanderia): Emery, 1910a: 129; in Paratrechina: Wheeler, W.M. 1921e: 112. Senior synonym of currens: Emery, 1892b: 166; of gracilescens: Roger, 1863b: 10; of vagans: Dalla Torre, 1893: 179. Senior synonym of hagemanni: LaPolla, Brady & Shattuck, 2010a: 128. See also: Mayr, 1865: 50; Forel, 1891b: 81; Forel, 1894c: 406; Emery, 1910a: 129; Trager, 1984b: 153.
 * vagans. Formica vagans Jerdon, 1851: 124 (w.q.) INDIA. [Unresolved junior primary homonym of Formica vagans Olivier, 1792: 501.] Junior synonym of longicornis: Dalla Torre, 1893: 179; Forel, 1894c: 408.
 * gracilescens. Formica gracilescens Nylander, 1856a: xxviii (w.) FRANCE. [Also described as new by Nylander, 1856b: 73.] Junior synonym of longicornis: Roger, 1863b: 10.
 * currens. Paratrechina currens Motschoulsky, 1863: 14 (w.) SRI LANKA. Junior synonym of longicornis: Emery, 1892b: 166. Neotype designated: LaPolla, Brady & Shattuck, 2010b: 1.
 * hagemanni. Prenolepis longicornis var. hagemanni Forel, 1901h: 65 (w.) DEMOCRATIC REPUBLIC OF CONGO. Combination in Paratrechina: Emery, 1925b: 217. Junior synonym of longicornis: Wheeler, W.M. 1922a: 942. Revived from synonymy: Emery, 1925b: 217. Junior synonym of longicornis: LaPolla, Brady & Shattuck, 2010a: 128.

Worker
LaPolla et al. (2013) - Measurements in millimeters (n=4): TL: 2.1- 2.5; HW: 0.46-56; HL: 0.49-0.7; EL: 0.17-0.23; SL: 0.98-1.16; PW: 0.34-0.43; WL: 0.82-0.98; PrFL: 0.6-0.9; GL: 0.83-0.9. Indices: CI: 73-94; REL2: 38-42 ; SI: 182-226.

Overall coloration pale to very dark brown, often with a distinct blueish iridescent sheen, especially on the mesosoma and gaster. Mandibles, antennae and legs (especially the trochanters of all legs, which are a strongly contrasting very pale yellow-brown) much lighter in color; cuticle smooth and moderately shining with faint shagreenate sculpture, which is most obvious on head and gaster. Head narrow, distinctly longer than broad, with abundant pale (yellow-brown to almost white), erect macrosetae; anterior clypeal margin with a shallow medial indentation; scapes with a dense layer of very fine pubescence but lacking erect macrosetae; eyes large and convex, extending beyond head lateral margin in full frontal view; posterior head margin with rounded posterolateral corners; three distinct ocelli present. Mesosoma with scattered pale erect macrosetae (PSC = 3; MSC = 3-4); in profile pronotum and mesonotum almost flat dorsally, with a broadly angled junction; metanotal area relatively indistinct, medially about 1/5 the length of the mesonotum but longer laterally than medially; dorsum of propodeum almost flat to very shallowly domed, rounding evenly into the short declivitious face; anterolateral portion of dorsal face with some scattered pubescence. Gaster with abundant erect pale macrosetae.