Solenopsis geminata (Fabricius)

Type location Central America (Atta geminata Fabricius, 1804: 423, queen; Roger, 1862c: 289, worker & male); junior synonym innota (Santschi, 1915c: 257, illustrated, all forms) from Gabon; (see Bolton, 1995). Well known as one of the viciously stinging "fire-ants" .

There are numerous junior synonyms from the Americas - clypeatus, mandibularis, paleata, cephalotes, glaber, laboriosus, polita, drewseni, coloradensis, linecumii, saxicola, innota, nigra, mellea, laevissima, rufa (and its junior synonym diabolus), eduardi (and its junior synonym perversa), medusa (and its junior synonym bahiaensis) and galapageia - for full listing see Trager (1991, link below). One subspecies, micans, also was listed by Bolton (1995: 387).

Roger's (1862c) description is at .

A comprehensive illustrated description was provided by Creighton (1930: 163), this is at .

A comprehensive illustrated description was provided by Trager (1991: 163), this is at , and .

I note, however, that Trager's synonymic list drew together the prior works of Creighton (1930) and Ettershank (1966: 136). There are some errors in Trager's list. For instance, the Galapagos Islands form S. geminata var. galapageia Wheeler (1922: 272) was listed as a variety of geminata by Ettershank (1966) and not a synonym as cited by Trager. The synonymy of S. geminata var innota Santschi (1915c: 257), from Gabon, Liberia and Congo, was attributed to Ettershank by Trager but, in fact, Ettershank did not list innota at all. Ironically, the two latter forms appear to be the only non-American material examined by Trager. Trager noted the African population as resembling the black form found in Georgia, Florida and the Antilles but innota was given as reddish-yellow or brownish, with some browner areas by Santschi (see my fuller treatment below).

The example right was edited from the Japanese Ant Color Image Database, from where the following description appears - Workers polymorphic, total body length ranging 3 to 5 mm. Body reddish brown, head brown. In major workers: head almost square, posterodorsal margin distinctly convex in frontal view; mandibles robust, each with a strongly convex outer margin and 4 blunt teeth on the masticatory margin; mandibular teeth obscure in some individuals; clypeus with a pair of longitudinal carinae; eyes rather small, each with more than 20 facets; anterior ocelli often present; antennal scapes reaching nearly to posterior border of head; antennal club longer than the 3rd to 9th antennal segments combined; legs, mesosoma and gaster with numerous erect hairs. In minor workers: head almost square in frontal view; mandibles 4-toothed; antennal scapes reaching posterior margin of head; clypeus with a pair of longitudinal carinae; posterolateral corners of propodeum carinate, the carinae reaching the dorsal surface of the propodeum; subpetiolar process absent.

African forms

Emery (1915c) noted that Solenopsis geminata F and pylades Forel (then regarded as a race of geminata but now a junior synonym of S. xyloni McCook, type location USA) had recently been imported to Africa from America. He gave no details of any sort. Santschi (1910c: 359) recorded it from Brazzaville, Congo, received from Prof. Galli Valerio, without any details. Wheeler (1922) listed findings from Liberia (Monrovia by Delafosse), and in the Congo areas - Congo, Samkita (F. Faure), Brazzaville (Valerio), Zaïre, Goma (Valerio). None were among the Congo Expedition findings (Wheeler, 1922: 163). Trager (1991) states: "The African population is less well known, but is found in tropical West Africa. It resembles the black form found in Georgia, Florida and the Antilles". Possibly he referred to the specimens recorded by Santschi (1939f: 162) as Solenopsis geminata Fabricius v. nigra Forel, from Guinea, Iles de Los, Ile Kassa and Il Corail, one worker each. Forel's (1908b: 45) description of Solenopsis geminata F. v. nigra n. var., from the Atlantic coast of Costa Rica, is at . This form is black with coarser sculpturation.

In Nigeria it is an introduced neotropical species apparently common in the Warri Delta, where it was known as "okubrass" (Bolton, 1973a). Specimens collected by A. Youdeowei were used for my drawing.

Nigeria specimen (Taylor, 1980a: 43). MINOR - TL 2.43 mm, HL 0.65, HW 0.51, SL 0.50, PW 0.36
Colour yellow-brown, gaster slightly darker; shiny and polished. Unsculptured except for faint rugoreticulation on the lateral mesonotum and propodeum. Eyes moderately large. Very small obtuse denticles at the lateral junction of dorsal and posterior faces of the propodeum.

The photomontages are of specimens collected in Cameroun - south-western tropical coastal forest area between Edéa and Campo (McKey Wolbachia project) - Cameroon 04, 24 March 2001, and Cameroon 49, 15 April 2001, from location Ebojé, on soil and surface in the village; Cameroon 94 and Cameroon 98, from location Kribi, 15 April both on soil and surface at sardine oil bait; and Cameroon 95 from location Kribi, 15 April 2001, in herbaceous vegetation in the garden of the Catholic Mission.

These all seem to generally match the type form if one allows for the variations noted by Trager, 1991). The largest specimen, however, is much smaller than the majors illustrated by Ettershank and Trager (shown above), with HW only 66% of the North American form; Crighton gives the type form major as TL 6 mm. Unlike the type form, in full face view the Cameroon 04 major does not broaden at the anterior margin but narrows slightly with smoothly rounded anterior corners.

The Cameroon 04 specimen is almost exactly the same size and form as the type specimen of S. geminata galapageia Wheeler. Creighton (1930: 65) noted on galapageia - "Aside from its smaller size there is little to distinguish the worker .. from that of the typical geminata", of the queen he noted the - "summit of the petiole, when seen from behind, shows a very distinct obtuse median notch" In almost all other queens of geminata that he examined the summit of the petiole node is entire and slightly convex. The camroon 04 major clearly has a notched petiole apex. Both majors in Cameroon 04 and galapageia have quite sharp clypeal teeth. Although not fully visible in the Antweb photographs (below), it seems that the majors have a smoothly rounded profile to the propodeum and the declivity is vertical with obvious concavity. The minima morphs of Cameroon 04 and galapageia also are near identical (seem below).

The question that has to be posed, reiterating Trager (1991) is whether the "western South American population of Colombia and Peru ... apparently the source of source of the rather small S. geminata typical of the Galapagos Islands" AND, from these Cameroon specimens, one of the African forms, might be a distinct species.

Trager (1991) states: "The African population is less well known, but is found in tropical West Africa. It resembles the black form found in Georgia, Florida and the Antilles". There is no evidence from the literature and certainly not from the Cameroon specimens of the African specimens being of a "black form".

A fuller photomontage of the Cameroon 04 major and photomontages of the minor morphs can be seen on the linked page Cameroon 04 - African type morphs.

Very high quality images of specimens from the Galapagos Islands - S. geminata galapageia Wheeler 1919: 272. These and other specimens can be seen on the Antweb site at http://www.antweb.org/getComparison.do?rank=species&genus=solenopsis&name=geminata&project=&project=

S. geminata Cameroon 04 - African type minima

S. geminata galapageia minima

S. geminata galapageia queen

Solenopsis geminata innota Santschi

Solenopsis geminata F. var. innota n. var., Santschi1915c: 257, illustrated all forms) from Gabon, Liberia and Congo. The synonymy of S. geminata var innota Santschi (1915c: 257), from Gabon, Liberia and Congo. The synonymy with the type S. geminata was given by Bolton, 1995: 388, as Wheeler, 1922; 877; but Wheeler simply listed innota as a variety and, as common with his 1922 catalogue, there is no evidence Wheeler examined the specimens. Trager had attributed the synonymy to Ettershank (1966: 136). In fact Ettershank did not list innota at all. Santschi's original text is on .

My translation is
SOLDIER - TL 2-4.3 mm; head as long as wide (1.1 X 1.2 mm), more in largest specimens, but smaller than the type. Clypeus quadridentate, outer teeth very small, inserted in the base of the inner teeth. Petiole node slightly more slender than the type, not as slim as subspecies pylades. Colour yellow red or brownish; femora, antennae and base of gaster rust yellow; rest of gaster, mid or posterior quarter of head and mandibles more or less brown. Pilosity and sculpture as type, sides of thorax more finely punctate.
MINOR - as the type, outer teeth of clypeus hardly visible; mandibles striated, with 4 teeth and yellowish.
QUEEN - TL 7.5 mm; posterior quarter of head, alitrunk (except the base of the sides), femora and gaster (other than a triangular basal area and the borders) dark brown; rest rust or yellow rust. Wings hyaline, otherwise as soldier.
MALE - TL 6.3 mm; brown black; lateral sutures and dorsal alitrunk, mandibles, femora and antennae, variably dark yellow.
Specimens from Gabon, Samkita, by F. Faure, 1914. Others seen from Liberia, Monrovia, by Delafosse; and Congo, Ngoma, by Galle-Valerio. Probably a variety imported from America, where it is widespread. It appears to develop rapidly in Africa and Faure wrote how they are a great nuisance in (Gabon) plantations.

The photomontage right and the queen below are specimens from Cameroun - south-western tropical coastal forest area between Edéa and Campo (McKey Wolbachia project) - Cameroon 49, 15 April 2001, from location Ebojé, on soil and surface in the village.

A fuller photomontage of the Cameroon 49 major and photomontages of the minor morphs can be seen on the linked page Solenopsis geminata innota morphs.

Although Trager (1991) noted that he had seen the Santschi specimens, he made no comment apart from listing the form as a synonym of the type species. The specimens shown here, especially the major, which in any case has the greatest use for diagnosis, appear to be quite distinct from the several other samples collected in Cameroun.

Major - the major has a much more rounded profile to the head; in full face view the specimen is squarer and has a near straight occipital margin. The anterior clypeal margin (as noted by Santschi) has a somewhat reduced but sharp main pair of teeth and much smaller lateral teeth. The mandible is densely rugose with several pronounced teeth. The median longitudinal groove on the front of the head is reduced forward of the occiput to no more than a slightly darker area. The scapes are noticeably longer almost attaining the occiput. The alitrunk profile is flatter with a lower drop into the metanotal groove which itself is scarcely impressed. The head has a much denser covering of what is longer and finer pilosity; the erect hairs all over the body being longer and finer than on the type forms. The colouration is distinctive, notably the pale anterior to the gaster.

Queen - This matches the Santschi description - TL 7.5 mm; posterior quarter of head, alitrunk (except the base of the sides), femora and gaster (other than a triangular basal area and the borders) dark brown; rest rust or yellow rust; wings hyaline, otherwise as soldier. In comparison with the type form (Trager's drawing above) and the queen of S. geminata galapageia shown above, it has a squarer head with relatively larger eyes and somewhat longer scapes. The frontal groove on the head is reduced to a fine line. Both the petiole and post-petiole in dorsal view are relatively wider than the type and the petiole has a sharp apex. The propodeum from above has a distinctive near rectangular shape.