Solenopsis merengue sp. nov.

Type material.

Holotype. Worker, specimen identifier MNHNSD FOS 18.130 [MNHNSD] (Fig. 5 A – E); Dominican Republic, deposited in the Museo Nacional de Historia Natural “ Prof. Eugenio de Jesús Marcano ”, Santo Domingo, Dominican Republic (Fig. 5). Preserved within a 5 mm by 3 mm section of yellow amber with internal bubbles. No synclusions.

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.

Diagnosis.

Worker. With characters of the Solenopsis genus, plus the following unique combination of characters: Head sub-quadrate, slightly longer than wide, posterior margin of head straight; scape about 2 / 3 of head length; anterior margin of clypeus with poorly-developed lateral teeth, with teeth height lower than a fifth of the distance separating the teeth; masticatory margin of the mandibles with 3 large, coarse teeth and a basal fourth, smaller. Propodeum in dorsal view with subparallel lateral margins; in lateral view dorsal and declivitous margins subequal, propodeal propodeum unarmed; mediodorsal position of spiracle on propodeum. Petiolar peduncle shorter than the length of the petiolar node, petiolar node rounded dorsally; in dorsal view petiole broader than long; petiole and postpetiole nodulous, postpetiole wider than petiole; in lateral view postpetiole lower than petiole and broader than long in dorsal view; subpetiolar process with a ventral tooth; subpostpetiolar process thick and shovel-like, creating a concave cavity. Body setae medium and sub-erect, with pairs of longer setae on dorsum of propodeum, petiole, and postpetiole segments.

Description.

Worker.

Head. In full-face view, head sub-quadrate, slightly longer than wide, posterior margin straight; eyes small, with 6–7 ommatidia, located slightly in front of the mid-length of the head; frontal carinae restricted to the small frontal lobes; frontal lobes present and rather developed, concealing most of the antennal sockets; antenna 10 - segmented; antennal scape bent in its basal part, not surpassing the occipital margin, about 2 / 3 of head length and more than four times pedicel length; median portion of clypeus slightly concave, narrowly inserted between the frontal lobe, clypeus longitudinally bicarinate, consisting of two symmetrical and sub-rectilineal carinae, each one terminating in a poorly developed tip in the anterior clypeal margin, projected forward; clypeal lateral teeth poorly developed, their height lower than a fifth of the distance that separates teeth tips; extralateral teeth absent; anterior margin of clypeus in W-shaped (its extremity defined by the lateral teeth), concave margin between the teeth; clypeus with an unpaired long seta at the midpoint of the anterior margin; mandibles with 3 conspicuous teeth and a fourth tooth defining the basal angle; the apical tooth being the longest. Subbasal and subapical teeth spaced apart.

Mesosoma. In profile, outline of pronotum convex; metanotal groove deep laterally and dorsally; propodeum in dorsal view with lateral margins subparallel; in profile, dorsal face slightly convex, about as long as declivitous face, meeting declivitous face at rounded angle, declivitous face slightly convex; propodeal spiracle large, circular, centered on upper half of propodeum (mediodorsal position).

Metasoma. In lateral view, petiolar peduncle shorter than the length of the petiolar node, subpetiolar process forming conspicuous anterior facing tooth; petiolar node rounded dorsally; in dorsal view broader than long, in lateral view anterior face convex, dorsal face strongly convex, posterior face convex. Postpetiole rounded dorsally, as wide as petiole and only slightly lower than petiole in lateral view; subpostpetiolar process with conspicuous coupled anterior facing lobes, ventrally lobes meet at strongly concave sternite. Gaster lanceolate; sting out, very elongate, its extremity ended by a beveled or at least a tapered edge.

Sculpturing, setation and coloration. Head (mandibles and antennae included), mesosoma (legs included), metasoma with suberect setae of medium-size, which seem to be especially more abundant on the head and the gaster; anterior margin of pronotum, dorsum of petiole and postpetiole with a pair of long setae; mandibles, antennae and legs covered by numerous short suberect setae. Sculpturing appears uniformly smooth.

Holotype measurements (in mm) and indices.

TL 1.32; HL 0.37; HW 0.30; PH 0.15; PW 0.19; PPH 0.12; PPL 0.10; PPW 0.12; PTH 0.14; PTL 0.15; PTW 0.12; SL 0.22; WL 0.39; ATIVL 0.31; CI 81; SI 73; DMI 49; LMI 38; LPeI 107; DPeI 80; LPpI 83; DPpI 120; PPI 100; PTI 93.

Etymology.

The species was named by students of the Universidad Autónoma de Santo Domingo (Santo Domingo, Dominican Republic). The naming refers to words from Dominican Republic. The specific epithet refers to the “ Merengue ” music and dance originating from the Dominican Republic. It is treated as a name apposition.

Comments.

Among Dominican amber Solenopsis, S. merengue sp. nov. is most similar to S. pilonaria sp. nov., although it differs from it notably in having longer scape relative to head length, no extralateral clypeal teeth, four mandibular teeth, and a propodeum spiracle centered on upper half of propodeum and not deported toward the posterior margin. It differs from S. viralata sp. nov., and S. picapica sp. nov. in having a straight posterior margin of head, different antennal configuration, less developed lateral clypeal teeth, different subpetiolar process configuration, and different pilosity configuration. The teeth of the mandible resemble S. lamellata sp. nov., but S. merengue sp. nov. lacks the propodeal lamella, the head is rectangular and the propodeum tapers posteriorly. It is the only species having a scape longer than 2 / 3 of head length

Solenopsis merengue sp. nov. shares affinities with the brevicornis species complex, based on: funicular segments broader than long, eyes fewer than 12 ommatidia, bicarinate clypeus with concave median anterior margin of clypeus, head somewhat quadrate to slightly elongate, postpetiole about as wide as petiole, to slightly wider in dorsal view, and fine punctures on dorsum of head. Among the brevicornis species complex, the species mostly resembles S. brevicornis. However, it also differs from it by a longer scape, the presence of a ventral tooth on the petiolar peduncle, and a different shape of propodeum. The combination of antennal configuration, large and coarse teeth (except the basal one) and the greater height of the petiole relative to the postpetiole separates this species from other Solenopsis and most or all Formicidae.