Anochetus miserabilis

Workers of A. miserabilis were collected associated with Acromyrmex hispidus Santschi (Formicidae: Myrmicinae: Attini) in Chacoan region of Paraguay and Argentina.

Identification
Anochetus miserabilis is easy to distinguish from the three species cited for Argentina (Anochetus neglectus, A. altisquamis and A. diegensis), due to its longer head (CI: 88.00). In addition, A. diegensis differs from the new species in presenting erect hairs on the mesosoma and mandibles with a single preapical tooth close to the apical teeth.

If we passed A. miserabilis through the key of Brown (1978), we arrived at couplet 5, the emarginatus group, nevertheless it does not fit any of those species. A. miserabilis is placed within this group (Brown 1978) which includes neotropical species of large size and slender mesosoma; with mandibles serially dentate; petiolar node short or long, bicuspidate or bidentate. The emarginatus group was distributed in northern South America and the Antilles previous to this study. With the inclusion of Anochetus miserablis in the emarginatus group, the range of this group is extended to the south, towards Argentina and Paraguay.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Paraguay.

Biology
Workers of A. miserabilis were collected associated with Acromyrmex hispidus Santschi (Formicidae: Myrmicinae: Attini) in Chacoan region of Paraguay and Argentina. The Gran Chaco covers over 1.000.000 square kilometers (386.000 square miles) of Argentina, Bolivia, Brasil and Paraguay. Argentina holds 60 percent of this region with a variety of habitats that includes humid and dry forests, wetlands, gallery forest and savannahs. Workers of A. miserabilis were frequently found walking around refuse dumps of A. hispidus. These refuse dumps are located about 50 centimeters from the mound of the attine nest and communicate with it through underground paths, also used by Anochetus miserabilis. Workers of both species were totally indifferent to each other. Generally, refuse dumps constitute a significant source of organic matter that serve as food for many insects which, in turn, could be used as a prey by Anochetus miserabilis. The workers of A. miserabilis were seen hunting cricket nymphs and termites, both in the foraging trails of the attines and in the refuse dump itself. Most observed nests of this leaf cutter species, which is very abundant in the Chaco, presented Anochetus associated with them. On one ocassion, when breaking an upper part of a mound of Acromyrmex hispidus, workers and winged queens of A. miserabilis were found but no brood. No nest of A. miserablis was found nearby.

Queen
Male: unknown.

Nomenclature

 *  miserabilis. Anochetus miserabilis González-Campero & Elizalde, 2008: 98, figs. 1, 2 (w.q.) ARGENTINA.

Worker
Head, mesosoma and gaster reddish; legs lighter. Head: In a full-face subrectangular; finely striated longitudinally, parallel rugae running mesad trough at eye level, posteriorly divergent, not reaching occipital corners; lateral cephalic margin slightly concave and widened at eye level; occipital margin concave; occipital angle rounded and smooth; medial furrow well-marked not reaching vertex; nuchal carina rounded and continuous; eye located laterally on anterior half of head; mid ocellus present and well-developed (except in the samples from Paraguay); scape smooth and shining, projecting beyond posterior head margin more than 1/8 its length; length of: flagellomers 1-4 and 6-10 twice its width, flagellomere 5 three times its width and flagelomere 11 is 4 o 5 times its width; mandible linear, without basal angle; inner mandibular margin with 3 long sensorial hairs (length > 0.75 mm), 12 preapical denticles and 3 apical teeth of which the central tooth is always shortest.

MESOSOMA: metanotal suture deeply concave in profile; metanotal area with longitudinal grooves in dorsal view; pronotum and propodeum finely punctate with no erect hairs; mesonotum transversally striated; posterior dorsal angle of propodeum well-marked without tooth or spine; mesopleuron with weak sculpture in upper half, smooth and shining in lower half; metapleural lobe well-defined slightly projecting over metacoxa; propodeal declivity straight in lateral view; in posterior view with weak transverse striation, propodeal spiracle elongated, its length twice its width; coxae and tibiae smooth and shining; pro and metatibia with 2 apical spurs, the outer one being simple with half length of the inner one’s; inner spur pectinated; mesotibia with two small and simple apical spurs of about 0.05 mm; procoxa with 5 (3-8 in paratypes) scattered erect hairs of > 0.1 mm; meso and metacoxas with 3 (2-5 in paratypes) erect hairs of > 0.1 mm. PETIOLE: with node higher than propodeum, apex bicuspid (Figure 1B), anterior face forming angle of 45º with main axis of the petiole, posterior face convex; anterior and posterior faces smooth and shining; subpetiolar process projects as well developed lobe anteriorly.

GASTER: Tergite I smooth and shining, without hairs, posteriorly following terga each smooth with 4 or more scattered erect hairs of more than 0.15 mm. Every sternite with 4 or more scattered erect hairs longer than 0.15 mm.

Queen
2 queens. HL: 1.92 (1.92); HW: 1.72 (1.75); ML: 1.25 (1.20); SL: 1.90 (1.90); EL: 0.40 (0.42).

Similar to worker in color of head, legs and body. HEAD: in dorsal view with fine longitudinal striation; in lateral view smooth and shining; 3 ocelli present, antennae with 12 segments; length of all flagellomeres approximately 2.5 times their width; well-developed compound eyes located on the anterior half.

MESOSOMA: pronotum rugose, mesonotum longitudinally striate, mesopleuron with weak sculpture in dorsal half, smooth and shining on ventral half; propodeum rough; smooth and shining coxa; procoxa with 5 scattered erect hairs of more than 0.1 mm; meso and metacoxa with 3 erect hairs of more than 0.1 mm; pro and metatibia with 2 apical spurs, outer one simple, its length half the width of inner one which is pectinated; mesotibia with 2 simple apical spurs; anterior wing with Radial, Medial and CuA closed; medial and cubital veins do not reach the wing margin; r-m3 and cu-a veins, incomplete leaving Cu1 and Cu2 cells open.

PETIOLE: similar to worker.

GASTER: tergite I smooth with no hairs; tergite II, slightly striate with no hairs; from terguite III posterad, smooth with 6 or more scattered erect hairs of more than 0.15 mm. Every sternite with 4 or more scattered erect hairs of more than 0.15 mm Male: unknown.

Etymology
miserabilis is derived from the Latin word “miserable” and it refers to the behavior of this species of visiting the refuse dump of the ant Acromyrmex hispidus.