Solenopsis picapica sp. nov.

Type material.

Holotype. Worker, specimen identifier MNHNSD FOS 18.129 # 1 [MNHNSD] (Fig. 7); Dominican Republic, deposited in the Museo Nacional de Historia Natural “ Prof. Eugenio de Jesús Marcano ”, Santo Domingo, Dominican Republic (Fig. 7). Preserved within a 20 mm by 15 mm piece of yellow amber with internal bubbles. Synclusions include a small termite and an Azteca ant worker.

Horizon and locality.

Early Miocene, Burdigalian (ca. 16 Ma; Iturralde-Vinent and MacPhee 1996); in amber from the Northern mines of the Santiago Province, Dominican Republic.

Paratypes.

3 workers, specimen identifiers MNHNSD FOS 18.129 # 2 (Fig. 6 D), MNHNSD FOS 18.129 # 3, and MNHNSD FOS 18.129 # 4 (3 workers) [MNHNSD]; Dominican Republic.

Additional material examined.

Worker, specimen identifier AMNH -DR-10-169 [AMNH] (Fig. 6 E), Dominican Republic.

Diagnosis.

Worker. With characters of the Solenopsis genus, plus the following unique combination of characters: Head sub-quadrate, with posterior margin shallowly concave; scape about 2 / 3 of head length, longer than four times length of pedicel (a 2); anterior margin of clypeus with well-developed lateral teeth, lateral teeth higher than a fifth of the distance that separates them; mandible with 3 conspicuous teeth and a basal fourth. Propodeum in lateral view with subequal dorsal and declivitous margins and unarmed, and posterodorsal propodeal spiracle. Petiolar peduncle longer than length of the petiolar node, petiolar node angular dorsally; petiole in dorsal view longer than wide and longer than high in profile; postpetiole wider than long in dorsal view and broader than petiole; subpetiolar process without ventral tooth and subpostpetiolar configuration, consisting of laterally produced tubercules and a long centrally projected lip. Body with suberect setae, particularly abundant on dorsum of gaster.

Description.

Worker.

Head. In full-face view, head sub-quadrate, slightly longer than wide, posterior margin shallowly concave; compound eyes small, containing 5–6 ommatidia, oval and weakly bulging, inserted in the latero-dorsal margin, located slightly in front of the mid-length of the head; frontal carinae restricted to the small rounded frontal lobes; frontal lobes present and rather developed, concealing most of the antennal sockets; antenna 10 - segmented; antennal scape about 2 / 3 of head length and longer than four times pedicel length; median portion of clypeus raised and rather narrowly inserted between the frontal lobe; clypeus longitudinally bicarinate, consisting of two symmetrical and subrectilinear carinae, into frons in v shape, each one terminating in a prominent tooth in the anterior clypeal margin (clypeal lateral teeth), concave margin between the two lateral teeth, extralateral teeth absent; mandibles with three conspicuous teeth and a fourth one defining the basal angle; the apical tooth being the longest.

Mesosoma. In profile, outline of pronotum convex; metanotal groove deep laterally and dorsally; propodeum in dorsal view with subparallel lateral sides, regular carina on each side of the dorsum, from the metanotal groove to the posterior margin; in profile, dorsal and declivitous margins subequal, propodeum unarmed; propodeal spiracle located on the upper half of propodeum, excentered toward the posterior margin (posterodorsal position).

Metasoma. In lateral view, petiolar peduncle longer than length of the petiolar node, subpetiolar process reduced, sometimes forming a translucent lamella; petiolar node angular dorsally; in dorsal view, petiole longer than wide and longer than high, in profile, anterior face concave, dorsum flat, posterior face coarsely convex. Postpetiole nodulous, broader than long in dorsal view, wider than petiole, and lower than petiole in lateral view, subpostpetiolar process produced as sharp downward facing lip, flanked by two bulbs. Gaster lanceolate.

Sculpturing, setation and coloration. Body smooth. Head (mandibles and antennae included), mesosoma (legs included), metasoma with suberect setae; mandibles, antennae and legs covered by numerous short suberect setae.

Holotype measurements (in mm) and indices.

TL 1.46; EL 0.038; HL 0.42; HW 0.33; PH 0.23; PW 0.22; PPH 0.14; PPL 0.13; PPW 0.12; PTH 0.18; PTL 0.17; PTW 0.11; SL 0.33; WL 0.55; ATIVL. 30; CI 89; SI 100; OI 10; DMI 46; LMI 42; LPeI 81; DPeI 85; LPpI 136; DPpI 120; PPI 109; PTI 123.

Etymology.

The specific epithet is a name in apposition referring to the Dominican “ Locrio de pica pica ”, a typical Dominican recipe similar to paella, but made with canned sardines.

Comments.

Among Dominican amber Solenopsis, S. picapica sp. nov. is most similar to S. viralata sp. nov., although it differs from it in having longer scape relative to head length but shorter pedicel relative to following antennomeres, dorsal margin of propodeum not visibly shorter than declivitous margin, and a propodeum spiracle deported toward the posterior margin. It differs from S. pilonaria sp. nov., and S. merengue sp. nov. in having a shallowly concave posterior margin of head, different antennal configuration, more prominent clypeal teeth, different subpetiolar process configuration, and no pairs of longer setae on propodeum, petiole, and postpetiole dorsum. S. picapica sp. nov. is the only species with S. lamellata sp. nov. to have an antenna pedicel much shorter than antennomeres 3–7 combined; it is the only species with a petiole not higher than long.

Solenopsis picapica sp. nov. shares affinities with the molesta species complex, based on: funicular segments broader than long, eyes small but distinct of fewer than 12 ommatidia, bicarinate clypeus with concave median anterior margin of clypeus, head somewhat quadrate to slightly elongate, postpetiole slightly wider than petiole in dorsal view, and fine punctures on dorsum of head. Within the molesta species complex, the body size (ca. 2.0 mm), fine punctures, developed clypeal teeth, oval-shaped eyes, and rounded propodeum, suggests affinities with the molesta subgroup. Similarities are also displayed with the pygmaea species complex and more particularly with the species S. goeldii Forel, 1912 mainly for sharing a relatively short peduncle, without a ventral tooth, and with ventrally convex margin. Yet, it differs from these species by the head without abundant coarse punctures, nor abundant pilosity, with larger eyes containing 5–6 ommatidia, as opposed to 1–3. The new species differs from all previously described species by the following combination of characters: smooth mesopleuron, spiracle on posterior part of propodeum, absence of petiolar peduncle ventral tooth, and the subpostpetiolar configuration, consisting of laterally produced tubercules and a long centrally projected lip.