Blepharidatta

A South American group of generalist predators that nest in the ground or in the leaf litter; nests are single, short (up to 20 cm) cylinders excavated in the ground or inside rolled leaves or rotting twigs, with one to 10 ergatoid gynes and up to 450 workers in the biggest colonies. Foragers patrol a roughly circular area around the single nest opening, where they collect live or dead arthropods to feed their larvae. (Brandao, Feitosa & Diniz, 2015.)

Identification
Brown (1953) - Closely related to the species of Wasmannia, differing chiefly in its more elongate head with produced posterior angles and in having a long, low petiolar node.

Kempf (1967) - The accepted relationship (Brown, 1953: 2-3) of Blepharidatta with Wasmannia is not contested by the male sex of the former, although it is quite distinct from the male of the latter (comparison made with males of Wasmannia auropunctata and unidentified males of other species) in the following characters: I. The relatively small size, not divergent from that of the worker; 2. The feebly developed, short, linear mandibles that do not meet when closed; 3. The elongate head which in general shape resembles that of the worker; 4. The antennae with funieular segment II distinctly shorter than scape, III and IV shortest of all, apical (XII) longer than X and XI combined; 5. The not unusually enlarged propodeal spiracle; 6. The presence of a closed discoidal cell in fore wing (cross-vein m-cu present); 7. The apically broadly rounded, spoon-shaped parameres of copulatory organ.

Distribution
Brandão et al. (2015) - B. brasiliensis and B. fernandezi are known, respectively, from the central and western Amazon basin, B. conops from different localities in the Brazilian savannas and caatingas, while B. delabiei is known from different localities in the Atlantic Forest, eastern Brazil.

Biology
See Blepharidatta conops.

Castes
Ergatoid queens of Blepharidatta conops have large disk shaped heads that can be used for phragmosis.

Worker Morphology
These characters are collated in the Worker Morphology table.

Nomenclature

 *  BLEPHARIDATTA [Myrmicinae: Blepharidattini]
 * Blepharidatta Wheeler, W.M. 1915e: 484. Type-species: Blepharidatta brasiliensis, by monotypy.
 * Blepharidatta provisional junior synonym of Ochetomyrmex: Brown, 1973b: 179.
 * Blepharidatta valid genus: Kempf, 1975c: 369; Wheeler, G.C. & Wheeler, J. 1991a: 132.

Worker
Small, monomorphic. Mandibles triangular, their apical margins with a few subequal teeth. Clypeus vertical, bicarinate. Frontal area large, frontal groove absent. Eyes moderately large and very convex. Ocelli lacking. Antennae 11-jointed, funiculus with a well-defined 2-jointed clava. Head rather large, with a deep scrobe on each side, extending its full length and bordered above by the frontal carinae which are large, expanded and horizontal, lobulate in front and extending to the posterior corners of the head. The inferior or lateral border of each scrobe is formed by a ridge as long as the frontal carina and running just above the eye. Thorax moderately long and slender, without promesonotal and mesoepinotal sutures; humeri and inferior angles of pronotum dentiform; epinotum armed with a pair of long spines; metasternal angles large, compressed and sharply angular above. Petiole long and slender, pedunculate, with a low, rounded node. Postpetiole small, subglobular. Gaster small, spherical, first segment very large, without ridges, grooves or tubercles; remaining segments very small. Sting vestigial. Legs rather slender; middle and hind tibiae without spurs; claws simple.

Head, thorax, pedicel, and appendages opaque, sculptured; gaster smooth. Upper surface of body beset with long, paired, very sparse, stiff, and blunt hairs.

Brandão et al. (2015) - Total length varying from 2 to 5 mm. Body yellowish to dark castaneous or ark reddish brown. Subopaque integument with more or less bright gaster. Body densely culptured. Margins of frontal carina with regularly arranged setiform hairs. Head in full-face view subrectangular, longer than broad, lateral margins slightly diverging caudad, posterior margin straight to slightly convex. Masticatory margin of mandible with apical tooth and 3–4 subapical teeth. Labrum bilobed. Anterior clypeal margin convex in frontal view. Frontal area triangular. Frontal lobe short anteriorly, not covering posterior margin of clypeus in frontal view. Compound eye large, located anterior to the longitudinal mid-length of head, bulging conspicuously from lateral margin in full-face view, sometimes conical, always set ventrally to antennal scrobe. Antennal scape apex almost reaching occipital corner when laid back inside scrobe; scrobe closed at vertex; regularly arranged setiform hairs present on scrobe dorsal margins. Antennal club 2-segmented, with apical segments distinctly longer than wide. Post occipital carina always reaching the latero-dorsal corner of head.

Pronotum with ventro-lateral angle always with projecting blunt tooth, sometimes bilobed and foliaceous. Anterior margin of katepisternum projects as triangular, sometimes translucid flange, in some species this structure is duplicated in twin lobes, one anterior to the other. Bulla of metapleural gland indistinct. Propodeum with pair of thin generally diverging spines, which can be extremely large. Petiole elongate, circa three times as long as wide, with an inconspicuous node. Gaster ellipsoidal with compressed sides.

Sting apparatus. Spiracular plate sub-quadrate or sub-rectangular; median connection with completely sclerotized margin; spiracle at middle of plate or closer to posterior margin. Dorsal cleft absent. Anterior apodeme narrow but slightly swollen antero-ventrally. Quadrate plate with ventral width approximately equal to dorsal width. Dorsal margin concave medially. Antero-dorsal corner with a well-developed projection. Posterior margin entire. Anal plate with sclerotized anal arch, perimeter well defined. Sensillar insertion at margin. Trichodea sensilla present. Posterior arm of oblong plate lacking ventral margin. Postincision developed. Gonostylus one-segmented. Terminal sensilla with dorso-terminal hair. Basiconic sensilla absent. Triangular plate short, its length less than twice its width. Lancets with a pair of valves and one barbule. Distal half well sclerotized and sharp, probably non-perforating. Dorsal aresta absent. Sting with sharp, well sclerotized shaft, probably perforating. Haemocoele development at sting shaft low or reduced. Sting bulb and valve chamber of size similar to sting shaft. Valve chamber with indistinct dorsum in relation to sting shaft base in profile. Internal apophysis present but not too long and probably does not extend significantly into valve chamber. Base of sting arch slightly curved. Basal ridge present but ill-developed, antero-lateral processes and articular processes present. Basal notches open. Campaniform sensilla of valve chamber present beyond basal half of sting shaft. Sting reduction index 31–41. Furcula dorsal arm present with variable length; dorsal arm subtriangular, with single apex; base of dorsal arm narrow in relation to sting bulb in ventral view. Articulation free, linked to sting base by lateral extremities only.

Queen
Brandão et al. (2015) - Ergatoid gynes. Head and body only slightly larger than conspecific worker, with more robust gaster; frons drastically different from conspecific worker, rendering the head phragmotic (as in Blepharidatta conops). Always wingless; wing buds never fully developed in B. conops, completely absent in Blepharidatta brasiliensis and in Blepharidatta delabiei.

Male
Kempf (1967) - Males from northeastern Minas Gerais State, Brazil, although not accompanied by workers or females, most certainly represent this hitherto unknown sex for the genus, and help in expanding the generic diagnosis:

Not significantly larger than the respective worker. Head elongate, subtrapezoidal, resembling that of worker. Mandibles feeble, sublinear, apically pointed but edentate, not meeting in front of clypeus when closed. Palpi 3, 2, the labial palpi geniculate. Median apron of clypeus, except the narrow anterior flat margin, bulging, convex in both directions. laterally submarginate. Frontal carinae more or less distinctly prolonged caudad to meet the occipital corner. Eyes huge, bulging. Ocelli relatively small, not protruding. Antennal scape as long as funicular segments I and II combined; funicular segments I, III and IV shorter than the remaining ones, segment XII (apical) longer than X and XI combined. Thorax short, compact; mesonotal scutum with distinct Mayrian furrows (notaulices) which converge caudad but do not meet, continuing parallel to each other and attain separately the posterior border of scutum; parapsidal sutures vestigial; propodeum unarmed, the basal face much shorter than the immarginate declivous face in side-view; inferior propodeal plates little protruding, entirely rounded. Wings: venation largely desclerotized, stigma of fore wing scarcely apparent; radial cell open (distal end of Rs not attaining the anterior margin of wing); discoidal cell very small, usually closed (m-cu present); hind wing with only 2-3 hamuli. Tarsomere I of hind legs longer than the respective tibia. Petiole elongate, pedunculate, clavate; postpetiole parallel-sided in dorsal view, lacking anterior and posterior subpostpetiolar processes. Genitalia (not dissected): apices of protruding parameres broadly rounded, spoon-shaped.

Brandão et al. (2015) - (unknown for Blepharidatta fernandezi). Total length varying from 2 to 5 mm. Body yellowish to dark castaneous or dark reddish brown. Subopaque integument with gaster brighter than rest of body. Body sculpture denser than in workers. Subrectangular head; falcate subtriangular mandibles with a single apical tooth; anterior border of clypeus convex, resulting in a small anterior denticle when clypeus is seen laterally, and median portion of clypeus inflated in lateral view; frontal carina relatively short and without lobe; frontal lobe obsolete, exposing basal condyle of antenna; antennal scrobes absent; antenna 13 segmented; compound eye ellipsoid, its longitudinal axis perpendicular to median transversal line in lateral view. Notauli well-marked; propodeal spiracle small and distant from declivitous margin; propodeal lobe vestigial. Legs more elongate than in conspecific females. Petiole pedunculate in lateral view.

Larva
Brandão et al. (2015) - (unknown for B. fernandezi). Profile attoid. Segmentation indistinct. No leg or wing vestiges observed under SEM. Integument mostly smooth, spinules minute and concentrated in ventrolateral body region, longitudinal smooth strip present along ventral region of body, and dorsum of posterior somites. Hairs sparse, randomly distributed, unbranched, smooth and slightly curved.

Cranium subcircular; frons, clypeus, and labrum projecting from cranium; relatively large antenna placed laterad of pronounced area at cranium mid-length with three sensillae, only slightly elevated from head surface; single faceted eye posterior to midlength of cranium. Mandible attoid, broad and short, apical portion abruptly attenuated; with one sharp pointed apical tooth and no subapical teeth. Labrum crescentic, very short and glabrous, with rounded anterior margin. Anterior clypeal margin broadly concave, posterior margin straight. Maxillae with rounded apex, palp shaped as short frustrum, galea relatively elongate and cylindrical paxilliform with three sensilla; labium feebly bilobed, with short rows of minute acute spinules.