Myrmecina modesta

This species occurs in small colonies beneath stones.

Identification
Myrmecina mandibularis Viehmeyer from New Guinea is very close to modesta, but has on the inner edge of the mandibles a broad widening, which Viehmeyer compares with that of Acropyga butteli Forel. In modesta the posterior corners of the blades are produced and rounded continuosuly with the inner border, resembling the structure of the mandible of Acropyga termitobia, rather than of butelli, as figured by Forel.

Type MCZ. 9,186.

Distribution
This taxon was described from Solomon Islands (Santa Cruz: Graciosa Bay (Type Locality)., Three Sisters: Malapaina. Ugi: Pawa. San Cristoval: Wainoni Bay, Wai-ai. Ysabel: Fulakora.

Biology
This species is found nesting in small colonies under stones.

Castes
Males and the worker caste have been described.

Description
Worker. Length 2.50 - 2.75 mm.

Head a little longer than broad, with slightly convex sides and shallowly concave occipital border. Clypeus broadly and transversely carinate at middle: bidentate at anterior border. Mandibles stout, their blades armed with six or seven small teeth and a large subapical tooth about as long as the terminal one. Antennal scapes extending to the occipital corners; first joint of funiculus three times as long as the very short second joint; joints three to eight transverse, but not strongly so; club as long as the rest of the funiculus, the terminal joint longer than the two others together. Prothorax three times as broad as epinotum; humeral and inferior corners angulate. Epinotal base sloping and separated from declivity by a transverse border; declivity convex; spines stout at base and acuminate at apex, as long as the declivity. Node, from avove,, quadrangular, anterior corners angulate; in profile longer than high, with a sloping anterior face equal in length to the straight dorsal surface. Postpetiolle broader than long and quadrangular.

Somewhat shining. Head with coarse striae, which are straight and parallel in front and somewhat irregular and oblique at sides. Clypeus and manidbles finely punctate and shining. Striae of thorax strong, longitudinal, and extending to epinotum where they become more feeble apically. Epinotal declivity smooth and shining. Petiole and postpetiole with widely separated costae, the spaces between smooth and shining. Legs sparsely punctate and shining. Gaster finely punctate and more shining than the other parts.

Head, body, mandibles, and legs with very abundantly and finely pilose. Black. Mandibles, antennae, and legs brownish red, in some specimens the lower part of femora darker than the rest. Pilosity gray.

Male. Length 2.75 mm. Head, excluding eyes, as broad as long, and broadly rounded behind. Cheeks very short. Clypeus transverse, with truncate anterior border. Antennal scapes as long as the first two funicular joints together; first funicular joint a little more than half as long as second; second joint twice as long as broad and a little longer than the third; joints three to eleven subequal, each a little less than twice as long as broad; terminal joint longer than the two preceeding joints together. Prothorax convex in front, flattened behind, with strong Mayrian furrows. Scutellum transverse and moderately convex. Epinotum with equal base and declivity, which are separated by an acute margin; spines stout and triangular. Petiole longer than in the worker, and the anterior surface proportionally shorter.

Shining. Head smooth except for a few fine striae inward from the eyes and between the ocelli, and minute punctures. Pro- and mesothorax very finely punctate and with sparse and coarse punctures apically. Scutellum almost smooth on disc, rugose laterally. Base of epinotum with six or seven strong longitudinal striae. Petiole and postpetiole sculptured as in worker. Gaster very shining.. Head, body, and appendages with abundant, long fuscous pile. Black; mandibles, antennae, and legs rufous, femora darker; genitalia white. Wings pilose, slightly infuscated, with brown veins and stigma.