Cerapachys (Syscia) ierensis, Weber, N. A., 1939

Weber, N. A., 1939, New ants of rare genera and a new genus of ponerine ants., Annals of the Entomological Society of America 32, pp. 91-104 : 94-95

Cerapachys (Syscia) ierensis , sp. nov.

Worker.-Length, 2.1-2.2 mm. Head, excluding mandibles, one-seventh longer than broad, rectangular with feebly convex sides rounding into evenly concave occipital margin and feebly convex anterior clypeal margin. Mandibles trigonal with acute apical tooth and finely denticulate cutting margin. Frontal lamina projecting as acute, feebly divergent teeth. Antennal scrobes bordered laterally by strong carinae. Eyes lacking. Antennae 9-jointed; scape strongly clavate, extending slightly more than half-ways to occipital margin; funicular joints 2-7 distinctly broader than long, terminal joint long-elliptical, longer than preceding three joints taken together. Thorax from above sub-rectangular, slightly over twice as long as broad, with convex pronotal margin and sides slightly impressed at meso-epinotal suture; in profile evenly and slightly convex. Epinotal declivity plane, feebly carinate on sides. Petiole from above trapezoidal with feebly convex sides converging anteriorly and convex posterior margin; in profile with rounded dorsum, higher anteriorly, and large ventral lobe produced anteriorly. Postpetiole from above trapezoidal with feebly convex sides converging anteriorly, a little longer than petiole and one-fourth wider; in profile with basal half produced anteriorly as a large lobe and with feebly convex dorsum.

Gaster from above ovate, 1st gastric segment comprising about nine-tenths of gaster. Legs short, with thickened femora and tibiae; basal tibial joint of prothoracic leg equal in length to distal four taken together. Sub-lucid; with dense and moderately coarse setigerous punctations. Moderately pilose, with fine reclinate to recumbent yellowish white hairs interspersed with much longer, sparser, and more upright hairs. Color uniformly yellowish brown.

Described from a series of workers taken in small tunnels in red clay in the same banana plot at St. Augustine, Trinidad, B. W. I., but in two different years, May 17, 1935, and May 20, 1936. The first year I found them in small tunnels just above the fungus gardens of a nest of Acromyrmex octospinosus Reich between four mature banana stalks. The ants were at first thought to be dorylines because they beat their antennae upon the ground before them as they crawled along in single file, precisely as do the army ants. This observation further substantiates the removal of this group of ants from the ponerines to a separate subfamily, the Cerapachyinae . They were not strongly negatively phototropic but "felt" their way cautiously in their tenuous tunnels. One worker was carrying beneath it with ease a larva, fully two-thirds its own length, whose long axis was parallel to that of the ant. When the two were put in alcohol the worker maintained its grip for many seconds. Another larva was resting in an L-shaped position but was soon carried off. A single worker was taken nearby August 3, 1935, among leaves at the base of a saman tree ( Pithecolobium saman ). When the banana plot was revisited in 1936 workers were found at the base of a mature banana clump in small tunnels from near the surface to a depth of at least 12 cm. Brood was found, not in a single brood chamber, but in small pockets off from the tunnels and of only slightly larger dimensions. Their doryline behaviour was again noted.

This species differs from cotypes of Syscia silvestrii Wheeler of Hawaii in the Museum of Comparative Zoology in slightly smaller size, shorter antennal scapes, more rounded postpetiole, seen from above, and in paler color. Judging from the description and drawing of Syscia seini Mann of Puerto Rico, ierensis differs in slightly larger size, longer head and antennal scapes, less impressed sides of thorax, proportionately broader and more convex postpetiole, seen from above, and in other ways. The three species are evidently closely related.

The poetic Indian name for Trinidad is Iere, land of the humming bird.