Apterostigma ierense, Neal A. Weber, University of North Dakota, 1936

Neal A. Weber, University of North Dakota, 1936, The biology of the fungus-growing ants. Part. I. New forms. 1, Revista de Entomologia 7, pp. 378-409 : 387-388

Apterostigma ierense , sp. nov. (Fig. 4)

Worker: Length 2.4-2.7 mm. - Head, excluding mandibles, 1.6 times as long as wide between the eyes. Neck short but distinct. Occipital margin impressed by broad groove, with parallel sides, which is a continuation of frontal area; occipital corners more angular than in many species of the genus. Sides of head sub-parallel, clypeal margin broadly convex. Frontal lobes semi-circular, slightly reflexed. Eyes convex, 1/5 in diameter the length of head without mandibles. Antennal scapes moderately stout, slightly bent distally, surpassing occipital margin by a distance equal to their distal diameter. Joints 2-9 of funiculus much broader than long; terminal joint longer than joints 5-9 taken together.

Thorax in profile as illustrated (Fig. 4). Anterior margin of pronotum extended as two lobes. Mesonotum with a pair of median carinae of irregular height, produced posteriorly on declivity as a pair of lobes. Basal surface of epinotum with a pair of high, acute carinae. Dorsal surface of petiole nearly flat, with slightly raised and angular sides. Petiole 1/2 as wide as postpetiole. Postpetiole from above much broader behind, with rounded sides and dorso-medial impression. Gaster feebly marginate.

Opaque, coarsely punctate. - Pilosity abundant, of gray appressed hairs and finer, sparser pubescence. - Dark, red-brown, appendages paler.

Female (dealate): Length 2.9 mm. - Resembling the worker with the usual sexual differences. The scutellum is bituberculate behind. Declivous surface of epinotum is carinate on each side. Petiole and postpetiole are impressed on dorsal surface and the gaster is distinctly marginate.

Male: Length 2.6-3.1 mm. -' Head, with mandibles but excluding eyes, roughly triangular with angularly convex occipital margin; neck distinct, cylindrical. Occipital corners obtusely angulate. Anterior clypeal margin extended in an obtuse angle. Mandibles triangular, with edentate straight cutting- margin. Frontal lobes large, auriculate, almost vertical. Eyes hemispherical, occupying slightly more than 1/2 of sides. Antennal scapes stout, nearly straight, exceeding occipital angles by a distance less than their narrowest diameter. All but first joint of funiculus distinctly longer than broad, terminal joint as long as next two joints taken together.

Pronotum extended as a bi-lobed structure as in worker. Mesonotum with a pair of longitudinal carinae. Scutellum produced posteriorly as a pair of converging tubercles. Epinotum with low tubercles. Pedicel, in profile, evenly rounded; petiole appreciably longer than postpetiole but distinctly lower. Gaster very feebly marginate. Legs long and slender. Wings infuscated with margins of veins and an antero-distal blotch brown.

Opaque, coarsely and sparsely punctate. - Pilosity abundant, of appressed gray hairs and finer and sparser pubescence. - Red-brown but paler than in worker.

Described from a colony consisting of males and workers taken by myself May 28, 1936, near the Maracas Waterfall of the Maracas Valley, Northern Range (Type colony), a single worker taken July 12, 1935, in the foothills north of Tunapuna, and a dealate female with three workers taken July 24, 1935 in the latter locality, Trinidad, B. W. I. The fungus garden of the colony with males was 20 mm. in diameter, cellular, and without an enveloping mesh of mycelia. The nest was under leaf mold in a steep-sided heavily forested ravine. The colony with female had a fungus garden of ordinary appearance consisting of small pellets and slivers of woody plants under debris of the forest floor.

This species resembles mayri , which I have taken in neighboring valleys, in size but differs in strongly carinate thorax, coarse punctation, and somewhat paler color.

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