Strumigenys longimala

Known from the Ecuadorian type material, collected from leaf litter.

Identification
Baroni Urbani & De Andrade (2007) - A member of the Strumigenys trudifera-group. Differing from the only other member of the group, Strumigenys trudifera, in the worker and gyne by the smaller values of SI ≤ 104.5 instead of 108.0, by the propodeal spines shorter, and by the flagellate hairs on the gaster sparser; in the worker only by the smaller values of MI (≤ 103) instead of ≥ 110; and in the gyne only by MI 91.6 instead of 102.8.

S. longimala is obviously the sister species of trudifera (Brazil, Colombia and Venezuela) with which it shares all most remarkable traits. Both species constitute the trudifera-group characterized by the very long mandibles and by the scape with 2 hairs curved towards the base. S. longimala and trudifera can be easily separated from all other species of the genus by the values of SI, MI (see diagnosis) and by the number of flagellate hairs on the first gastral tergite. The worker and gyne of longimala have 16 and 22 flagellate hairs respectively on the first gastral tergite while those of trudifera have 20 and 26.

Distribution based on Regional Taxon Lists
Neotropical Region: Ecuador.

Nomenclature

 *  longimala. Strumigenys longimala De Andrade, in Baroni Urbani & De Andrade, 2007: 147, fig. 51 (w.q.) ECUADOR.

Worker
TL 2.78-2.94; HL 0.64-0.66; HW 0.44-0.46; SL 0.46-0.48; ML 0.65-0.68; EL 0.05-0.06; WL 0.62-0.64; CI 68.7-69.7; SI 104.3-104.5; MI 101.5-103.0.

Head strongly converging anteriorly and with round vertexal angles. Frontal lobes slightly expanded and convex. Anterior half of the dorsal margin of the antennal scrobes broad and ending in a subround denticle over the eyes. Antennal fossae ventrally with a broad carina visible in full-face view, straight and medially denticulate, covering the lower margin of the scrobes and ending close to the upper border of the eye. Eyes with 3 ommatidia in the longest row, placed over the ventral margin of the antennal scrobes, and partially visible in dorsal view. With the head in profile the scrobes are distinct, almost reaching the vertexal angles, with ventral margin and posterior half of the dorsal margin superficially marked. Lateral clypeal margins gently convex and anteriorly concave in the middle. Postbuccal groove impressed. Scapes subcylindric, slightly more than 2/3 of the head length and surpassing the eyes posteriorly. Antennae with six segments. Apical funicular joint as long as the rest of the funiculus. Mandibles very long, about as long as the head length. Apical fork of the mandibles with two teeth and without intercalary denticles. Preapical dentition consisting of one long, spiniform tooth only.

Mesosoma in profile convex anteriorly and slightly raised posteriorly before the propodeal spines. Propodeal spines long but shorter than the basal face of the propodeum; declivous propodeal face with a thin lamella.

Petiole with a long pedicel and with convex node. Ventral surface of the petiole with a thin lamina. Petiolar node with marked posterior margin and with a small spongiform process on the posterior lateral third. Postpetiole convex in profile, with marked anterior and posterior faces; lateral faces surrounded by broad spongiform process. Ventral surface of the postpetiole with very broad spongiform process.

Gaster oval and with costulae on its anterior third. Base of the first gastral tergite and sternite with spongiform pad broader on the sternite.

Sculpture. Head, mesosoma, petiole and postpetiole reticulate-punctuate. Gaster and area between meso- and metapleurae smooth.

Pilosity. Head and mesosoma with sub decumbent or decumbent, narrow spatulate hairs, rarer on the mesosoma. Apicoscrobal hair long and flagellate. Cephalic dorsum with two pairs of standing hairs. Leading edge of the scape with 2 long hairs that curve toward the base of the scape. Pronotal humeral hair long and flagellate. Mesonotum with 1 pair of erect, flagellate hairs. Petiole, postpetiole, first and second gastral tergites with flagellate hairs. Posterior half of the first gastral sternite and remaining sternites with sparse, erect pointed hairs.

Colour. Dark brown.

Queen
TL 3.26; HL 0.72; HW 0.52; SL 0.50; ML 0.66; EL 0.10; WL 0.76; CI 72.2; 51 96.1; MI 92.9.

Similar to the worker but differing in the following details. Eyes large. Ocelli present. Mesosoma robust and weakly convex in profile. Parapsidal furrows impressed. Sides of the scutellum with a thin lamella converging posteriorly to form an obtuse angle. Basal face of the propodeum declivous posteriorly. Propodeal spines large and continuing to the declivous face as a lamella.

Ventral surface of the petiole with a broader lamina.

Sculpture. Head and mesosoma with irregular rugosities, more regular and denser on the mesosoma.

Pilosity. Similar to the worker but the mesonotum with 3 pairs of flagellate hairs. Pre-scutellum and scutellum with a flagellate hair on each side.

Type Material
Holotype worker from Ecuador labelled: Yasuni Scientific Station, Provo Orellana, 00° 40' 760" S, 76" 23' 032" W, 230 m, leaf-litter, 28.VIII.2004, M. L. de Andrade & C. Baroni Urbani . Paratypes: 2 worker and 1 dealate gyne same data and collection as the holotype (PUCE, 1 paratype worker ).

Etymology
From the Latin longus (= long) and mala (= mandible), referred to the length of the mandibles, among the longest of the genus.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C., and M. L. De Andrade. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species (Hymenoptera, Formicidae). . Annali del Museo Civico di Storia Naturale "Giacomo Doria" 99: 1-191.
 * Silva T. S. R., and R. M. Feitosa. 2019. Using controlled vocabularies in anatomical terminology: A case study with Strumigenys (Hymenoptera: Formicidae). Arthropod Structure and Development 52: 1-26.