Strumigenys solifontis

Chien and Lin (2015) analyzed the chemical constituents of the venom of five Taiwanese Strumigenys species: Strumigenys chuchihensis, Strumigenys formosensis, Strumigenys liukueiensis, Strumigenys minutula and Strumigenys solifontis for a chemotaxonomy study. The venom was collected from extruded stings and was thought likely to contain a mixture of poison (venom) and Dufour gland secretions. GC/MS profiles showed that three of the five species were clearly differentiated by the chemical composition of their sting secretions. Two remaining two species, S. chuchihensis and S. liukueiensis, showed chemical signatures that were not significantly different from one another.

Identification
Bolton (2000) - There are four species known in the smythiesii-complex in which the specialised humeral hair is stiff and simple, moderately long, straight or at most only evenly shallowly curved; definitely not flagellate: Strumigenys hispida, Strumigenys jepsoni, Strumigenys liukueiensis, solifontis. Of these liukueiensis is easily distinguished as it is much more densely hairy than the other three. Its upper scrobe margin has freely projecting straight hairs anterior to the apicoscrobal hair, the dorsal alitrunk has more than four pairs of erect hairs and the hind basitarsus has at least 5 stiffly erect hairs on its dorsal (outer) surface. The other three species lack freely projecting straight hairs anterior to the apicoscrobal hair, the dorsal alitrunk has at most four pairs of erect hairs and the hind basitarsus has only 1-2 erect hairs, that are fine and flagellate, on its dorsal (outer) surface.

The Fijian jepsoni lacks laterally projecting hairs on the cephalic dorsolateral margin posterior to the apicoscrobal hair. The propodeal dorsum and petiole node dorsally are smooth and shining and the dorsal surface of the petiolar peduncle has a narrow cuticular carina on each side. In profile the carina arises anterior to the spiracle, extends to the node and ascends its anterior face. In dorsal view the carinae are straight to near the base of the node where they are concave and have a pinched-in appearence. In both hispida and solifontis 2-4 conspicuous laterally projecting hairs occur on the dorsolateral margin of the occipital lobe, posterior to the apicoscrobal hair. The propodeal dorsum and petiole node dorsally are reticulate-punctate and the dorsal surface of the petiolar peduncle lacks the cuticular carinae as seen in jepsoni.

S. hispida (CI 72-73, SI 85-86) has a broader head and shorter scapes than solifontis (CI 66-69, SI 98-100). S. hispida also has the transverse row of hairs near the base of the first gastral tergite flagellate. Posterior to this the tergite is hairless except for a transverse row at the apex of the sclerite. In solifontis hairs in the transverse row near the base of the first gastral tergite are stiff and simple, and other hairs arise from the sclerite between this row and the apical transverse row. Finally, in hispida the lamella on the propodeal declivity, in absolute profile, is about equally broad throughout and has its posterior (free) margin nearly straight, at most only extremely feebly convex. In solifontis the lamella in absolute profile becomes broader basally and its posterior (free) margin is markedly convex in at least its lower half.

Distribution based on Regional Taxon Lists
Oriental Region: Taiwan. Palaearctic Region: Japan.

Nomenclature

 *  solifontis. Strumigenys (Strumigenys) solifontis Brown, 1949d: 18 (w.q.) JAPAN. See also: Bolton, 2000: 813.

Worker
Bolton (2000) - TL 2.9-3.0, HL 0.74-0.77, HW 0.49-0.53, CI 66-69, ML 0.36-0.40, MI 49-52, SL 0.49-0.52, SI 98-100, PW 0.28-0.29, AL 0.76-0.80 (2 measured).

Characters of smythiesii-complex. Apicoscrobal hair stiff; anterior to this there are no freely projecting hairs but posteriorly there are 2-3 similar stiff hairs on the dorsolateral margin of the occipital lobe. In profile cephalic dorsum with a transverse row of erect hairs at the occipital margin; anterior to this with inclined ground-pilosity but without a pair of erect hairs near highest point of vertex. Pronotal humeral hair stiff and simple, straight or slightly curved. Pronotal dorsum with 1 pair and mesonotum with 3 pairs of erect simple hairs. Entire dorsal alitrunk finely and densely punctate to reticulate-punctate except for anterior half of propodeal dorsum which is usually smooth; sculpture may be somewhat effaced posteromedially on pronotum. Lamella on propodeal declivity becoming broader basally, its posterior (free) margin distinctly convex in the lower half. With petiole in profile the lateral spongiform lobe terminates at about the midlength of the node, not reaching the anterior face of the node. Dorsum of petiole node finely and densely punctate to reticulate-punctate; disc of postpetiole smooth. Erect hairs on first gastral tergite not restricted to a transverse row near base and another near apex. Basigastral costulae distinct on first gastral tergite.

Type Material
Bolton (2000) - Holotype worker, paratype worker and queen, JAPAN: Shikoku, nr Saruta, in cave (J. Ishikawa); paratype worker, U. S. A.: Washington, Seattle, Plant Quarantine, in cargo from Japan [examined].