In Hawaii H. opaciceps is found in lowland and montane ecosystems (Reimer, 1994). It most often occurs in areas between 600–1200 m, but was collected as high as 2700 m and as low as 150 m. The Hawaiian populations form small colonies of less than 50 workers in the soil and under rocks, and is one of the few species that has been able to penetrate wet undisturbed rainforest. It is reported there to be a relatively innocuous species that has an insignificant effect on the native fauna.
In Costa Rica (Jack Longino) This is a tramp species, typically found in open and highly disturbed areas. I have only collected it once in Costa Rica, but this probably reflects my collecting bias for mature forest habitats. It could be relatively common in open areas.
My one observation was from a weathered but still largely bare lava flow on the slopes of Volcan Arenal, near the Arenal Observatory Lodge. I flipped about 100 stones in an area about 50m from the forest edge. The exposed stones were 10-50cm across, embedded in a sandy soil. The rocks were covered with a thin coating of lichens; otherwise the surface was bare. The only ants I found were nests of opaciceps, but they were relatively frequent, under about 10 of the rocks.
Stefan Cover collected two nests in Monteverde. They were along the road to Penas Blancas, 1/4 mile below the Ventana in the Monteverde Cloud Forest Reserve. They were shallow nests in clay soil at the roadside. One nest series contained a yellow ergatoid male with 13 antennal segments.
In the New World it ranges this species ranges from as far north as Boulder, Colorado, in the United States to as far south as Uruguay, South America, and throughout the islands of the West Indies (Smith, 1936). It is presumably native much of this range, including South America (Wild, 2007). In the Old World, its distribution is patchier, but is particularly widespread across the Pacific Islands. The exact native range of H. opaciceps is unclear, however. Ward (Ward, 2005), for example, lists the species as possibly introduced to California, but might be native to nearby regions. The ant is considered by some to be native to Florida (Deyrup, 2003; Deyrup et al., 1988)and Louisiana (Dash & Hooper-Bùi, 2008), but introduced to Mississippi (MacGown et al., 2009). The Antweb record (LACM ENT 142427) from a hothouse in Washington State is more definitively representative of an introduction. The Afrotropical and West Palaearctic taxa previously considered to be subspecies of H. opaciceps have all been revised as synonyms of other Hypoponera species (Bolton & Fisher, 2011).
Native range. New World: Southern United States to southern South America and the Caribbean. Introduced range. Pacific Islands including: Hawaii, Fiji, French Polynesia, Marquesas, New Caledonia, Philippines, Samoa, Taiwan.
Fiji: Gau, Koro, Taveuni, Viti Levu. Hawaii: all the main islands.
Among workers of introduced and commonly intercepted ants in the United States Diagnosis among workers of introduced and commonly intercepted ants in the United States. Antenna 12-segmented. Antennal scapes exceed posterior head margin. Eyes small (equal to or less than 5 facets); situated distinctly below midline of head. Frontal lobes relatively narrow. Clypeus with anterior margin flat to convex, but never forming a distinct triangle that projects anteriorly beyond the base of the mandibles. Mandibles triangular; with more than 7 teeth and denticles. Metanotum does not form a prominent convexity bordered by distinct suture lines. Hind coxae lacking dorsal spine. Hind tibia with pectinate spur, but without simple spur. Tarsal claws lacking subapical tooth. Waist 1-segmented. Petiole narrowly attached to gaster; conspicuous posterior face. Gaster armed with sting. Distinct constriction between abdominal segments 3+4. Abdominal segment 4 lacking deep longitudinal furrows.
Hypoponera opaciceps, as it is currently defined, can be a highly variable species with respect to sculpture, length of antennal scapes and size (Kempf, 1962; Smith, 1936)Among introduced and commonly intercepted ants of the United States, H. opaciceps is most likely to be confused with H. punctatissima and H. ragusai, but can be separated from them by the antennal scapes which reach and slightly exceed the posterior margin of the head (vs. fail to reach), the uniformly punctate sculpture across the entire head and body, and the more rectangular petiole with parallel anterior and posterior faces (vs. more faces that converge towards each other apically).
In Costa Rica (Jack Longino). Worker: head densely punctate and opaque; in lateral view petiole thick and subrectangular, with the anterior and posterior faces parallel.
Hypoponera opaciceps is a small reddish-brown to blackish species with very small eyes, a densely punctate and opaque sculpture, antennal scapes that barely exceed the posterior head margin, and a nearly rectangular petiole with parallel anterior and posterior faces and a flat to weakly convex dorsal face. Hypoponera opaciceps is mostly limited to forested habitat where it nests opportunistically and forages in and around rotting logs, soil and leaf litter. The species is almost entirely blind, and is not often encountered foraging out in the open, nor is it known to recruit to food baits. The species is widely introduced across the globe (Wilson & Taylor, 1967). Interestingly, H. opaciceps produces ergatoid males. Despite being widely distributed and associated with disturbance, H. opaciceps is not considered to be a significant pest species. Hypoponera opaciceps was redescribed by Smith (1936) and Kempf (1962).
Extant: 4 valid subspecies
Ponera opaciceps Mayr, 1887 PDF: 536 (w.q.) BRAZIL. Neotropic. AntCat AntWiki HOLTaxonomic history
Smith, 1929c PDF: 545 (m.); Wheeler & Wheeler, 1964b PDF: 453 (l.).Combination in Hypoponera: Taylor, 1967a PDF: 11.Senior synonym of Hypoponera perkinsi (and its junior synonym Hypoponera andrei): Wilson & Taylor, 1967b PDF: 28.Senior synonym of Hypoponera opaciceps postangustata: Wild, 2007b PDF: 54.See also: Smith, 1936d PDF: 428; Wheeler, 1937c PDF: 59; Kempf, 1962b PDF: 7.
Hypoponera opaciceps is a species of ant in the family Formicidae.[1][2][3][4][5]
These seven subspecies belong to the species Hypoponera opaciceps:
Data sources: i = ITIS,[1] c = Catalogue of Life,[2] g = GBIF,[3] b = Bugguide.net[4]
