Tapinoma rasenum

The type colony was located on a dead limb of a living tree of unknown species (3' hgt.) on the mountainside just over the edge of an embankment. The ants had established their colony under the bark of the dead limb apparently by using tunnels and chambers originally constructed by termites or carpenter ants. The colony was first discovered during March and workers were collected by pounding on the limb with a steel knife, which elicited an alarm reaction. Pieces of bark were removed from the limb and chambers containing winged males, larvae, and pupae, both worker and reproductive, were uncovered. Eleven large and 3 medium sized workers of Camponotus ustus were collected from the same chambers as T. rasenum workers when the nest was examined again on 27 May 1970. (Smith and Lavigne 1973)

Identification
Smith and Lavigne (1973) - The vestigial petiolar node, many toothed mandibles, and male genitalia place this species in the genus Tapinoma. Its large size, coloration, and long antennal scapes which surpass the posterior border of the head separate this species from Tapinoma melanocephalum and Tapinoma litorale, the only other known species of Tapinoma from Puerto Rico, and also from other Tapinoma species known to us.

There was little variation in the nest sample examined; the gaster of both the worker and male was pale gray to almost black.

Distribution based on Regional Taxon Lists
Neotropical Region: Greater Antilles, Puerto Rico.

Nomenclature

 *  rasenum. Tapinoma rasenum Smith, D.R. & Lavigne, 1973: 182, figs. 1-6 (w.m.) PUERTO RICO.

Worker
Holotype: Length, 3.1 mm; head width, 0.63 mm; head length, 0.65 mm; length of antennal scape, 0.65 mm; eye length, 0.1 mm. Head, thorax and legs pale yellow with head slightly darker; gaster light gray. Moderately shining with vestiture of moderately appressed white pubescence; without erect hairs except for row on posterior margin of each segment of gaster and row on anterior clypeal margin.

Antennal scape surpassing posterior margin of head by distance equal to length of first 2 funicular segments; antenna 12-segmented. Eye small, its length equal to 2/3 distance between mandibular insertion and eye: 9 facets in greatest diameter and 6 facets in shortest diameter. Clypeus broadly, circularly, and very shallowly emarginated on central 1/3 of anterior margin. Maxillary palpus long, 6-segmented. Each mandible with 4 large apical teeth and 10 to 12 smaller basal teeth. Thorax evenly curved in profile, interrupted only by shallow mesoepinotal depression. Petiole a slender stalk, without dorsal node. Anal slit ventroapical.

Male
Paratype: Length, 3.9 mm; head width, including eyes, 0.73 mm; head length, 0.6 mm; eye length, 0.31 mm; length of antennal scape, 0.6 mm; forewing length, 3.6 mm. Color pale yellow, head slightly darker; gaster pale gray; genitalia reddish brown; interocellar area black; dorsum of thorax with 2 submesal light gray longitudinal lines. Moderately shining with vestiture of moderately appressed whitish pubescence; erect hairs only on clypeus, apical sternite and genitalia.

Antenna 13-segmented; length of scape equal to first 4 1/2 funicular segments; all funicular segments longer than broad. Each mandible long, with 25 or more small teeth, all of similar size. Anterior border of clypeus without emargination. Eyes large, oval, greatly protruding from side of head in frontal view; ocelli large. No Mayrian furrows. Forewing with radial and cubital cell, no discoidal cell. Petiole low, stout, without dorsal node. Cerci short. Genitalia prominent; parameres separated, each large and rectangular; volsella with triangular lateral flap with many erect hairs and with 2 spinelike inner processes; penis valve pointed at apex, ventral margin with 15 long, curved spines. Ninth sternite densely clothed with hairs, with apical triangular projection at center.

Type Material
Holotype: Worker, Maricao Forest Reserve, Rte. 120 (K5, H2), Puerto Rico, 18 March 1970 ( R. J. Lavigne), Type No. 7217 4 in the United States National Museum. Paratypes: All from same nest sample as holotype, 310 workers, 54 males including male described above. In USNM, University of Wyoming, and University of Puerto Rico, San Juan.

Etymology
The species name is an arbitrary combination of letters and is to be treated as a noun.