Strumigenys deltisquama group

AntWiki: The Ants --- Online

Strumigenys deltisquama group Bolton (2000)

Species

Neotropical-Nearctic

Strumigenys deltisquama

Worker Diagnosis

Apical fork of mandible with one intercalary tooth. Mandible with two small spiniform preapical teeth, crowded close together and close to apicodorsal tooth. Mandible broad, its inner margin with a broad, straight-edged cuticular lamella that arises immediately posterior of the proximal preapical tooth and extends toward the base. MI 50-55.

Leading edge of scape with a row of broadly delta-shaped hairs that are at right-angles to the long axis of the shaft. Scape very short and broad, strongly dorsoventrally flattened and with a thin sharp leading edge. SI 44-46.

Scrobe behind level of eye short in profile, deep and with sharply defined posterior and ventral margins. Head in full-face view short and very broad, CI 95-98.

Preocular carina in profile short, strongly arched downward toward the anterior margin of the eye.

Ventrolateral margin of head with a short but deeply concave edge in front of eye.

Postbuccal groove obsolete.

Propodeum with teeth subtended by a narrow lamella on declivity; without a sharp tooth or spine at base of declivity.

Ventral surface of petiole with a cuticular carina but without spongiform tissue. Lateral lobes of petiole and postpetiole small, narrow, hardly more than a slight expansion or extension of the respective posterior collar. Ventral lobe of postpetiole present and spongiform, but small.

Pilosity. Pronotal humeral hair absent. Dorsal surfaces of head, scapes and promesonotum densely clothed with orbicular or squamate hairs. Apicoscrobal hair absent; cephalic dorsum and mesonotum without standing hairs. Waist segments and first gastral tergite with stout remiform to clavate standing hairs.

Sculpture. Dorsal surfaces of head, alitrunk and waist segments finely and densely reticulate-punctate. Mesopleuron and metapleuron more weakly sculptured, shagreenate, sometimes with quite smooth areas. First gastral tergite and sternite both entirely sculptured, the former more coarsely so than the latter.

Notes

The single species in this group is very different from any other in the Neotropical region. When Brown (1957a) first described deltisquama he associated it with Strumigenys cultrigera because both had a mandibular lamella proximal of the preapical teeth. Comparing the two I am convinced that the lamellae have arisen independently because cultrigera, apart from the lamella, is a perfectly normal member of the mandibularis group and complex, whilst deltisquama is uniquely aberrant in many characters.

References