Carebara minuta

This species, with body length from 0.99 to 1.00 mm, may be the smallest in the Western Hemisphere.

Identification
Fernández (2004) - Very close to Carebara globularia with which it shares postpetiolar and clypeal configuration and frontal triangle. C. minuta  is smaller, the clypeal apron shorter and the head pilosity less dense. The specimens have the label “C. mayri”, but I can’t find any positive proof that both workers belong to this species, otherwise known only from males. Two males labeled as “C. mayri” in MZSP (and a few others without names) came from other sites in Brazil, but there is no local association between these workers and C. mayri males. As a result, C. minuta may actually be workers of mayri, or workers from any other Neotropical Carebara described solely on the basis of females or males. Only the collection of nest series with all castes will clarify the picture.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  minuta. Carebara minuta Fernández, 2004a: 217, fig. 14 (w) BRAZIL.

Worker
Holotype (Paratype): HW 0.23 (0.21); HL 0.30 (0.31); SL 0.16 (0.15); PW 0.15 (0.15); WL 0.27 (0.28); GL 0.25 (0.24); TL 0.99 (1.00); CI 75 (70); SI 69 (71).

Head slightly longer than wide. Posterior border concave, lateral sides faintly concave. Mandibles with 4 teeth. Median portion of clypeus slightly concave. In frontal oblique view, clypeal lateral carinae strongly narrowed posteriorly and between frontal lobes, then continued as frontal triangle. Scapes fail to reach the vertexal border in ½ of the head length. In side view, alitrunk slightly convex, interrupted by the deep metanotal groove. Propodeum with feeble angulation between dorsal and sloping faces. Propodeal spiracle relatively large, circular, high and very close to the propodeal margin. Bullae of metapleural gland relatively large in size. Propodeal lobes reduced to narrow lamellae that reach the propodeal dorsum. Petiole with short peduncle, evenly continuous with the dorsal rounded node; petiolar node midway along petiolar length. Subpetiolar process produced as strong spine directed forward, spine normally not visible in mounted specimens. Postpetiole dorsally concave, lower than petiole. In dorsal view petiole longer than wide, postpetiole subglobose, wider posteriorly and notably wider and longer than petiole. In dorsal view anterior margin of first tergum slightly concave. Body smooth and shining. Mandibles with several scattered punctures, head with scattered puncturations (except in the central longitudinal area), each punctum with a small hair. Anterior sides of head with very fine longitudinal striation. Sides of alitrunk (except pronotum), petiole, postpetiole and dorsum of petiolar peduncle with a faint to moderate reticulation. Short curved hairs (less than 0.017 mm) relatively abundant over body, especially on dorsum of head. Medium hairs (about 0.033 mm): Six to eight on promesonotum, two on propodeum, about four on petiole and four on postpetiole, several on gaster. Longer hairs (more than 0.040 mm): Four arising from anterior clypeal margin extending forward over most of mandible length. Two in each side of head, near the occipital border. Yellowish brown.

Type Material
Holotype worker. BRAZIL. Mato Grosso: Utiariti, Rio Papagaio, 10 nov 1966, K. Lenko & Pereira No. 4489, deposited in. Paratype, same data as type, MZSP.