Simopone laevissima Arnold

Bolton, Barry & Fisher, Brian L., 2012, Taxonomy of the cerapachyine ant genera Simopone Forel, Vicinopone gen. n. and Tanipone gen. n. (Hymenoptera: Formicidae) 3283, Zootaxa 3283 (1), pp. 1-101 : 28-29

Simopone laevissima Arnold

Simopone laevissima Arnold, 1954: 291 , figs 1, 1a. Holotype worker, UGANDA: nr Kampala, Dedewe Forest , 4.v.1952, lake shore, on trunk of palm (G. Arnold) (SAMC) [examined].

WORKER. HL 1.24, HW 0.97, SL 0.34, EL 0.36, PW 0.78, AIIW 0.89, AIIL 0.94, AIIIW 0.94, AIIIL 0.81, WL 1.60, MFL 0.68, CI 78, SI 35, EL/HW 0.37, EP 1.90, AIIW/AIIL 0.95, AIIIW/AIIIL 1.16.

Clypeus relatively shallowly longitudinally convex, without a median carina; clypeo-labral junction anterior, not strongly reflexed below and behind the evenly convex anterior clypeal margin. Frontal lobes and carinae broad across, not elevated, continuously divergent from front to back, without a constriction at junction of lobe and carina; carinae extend back beyond the level of the anterior margins of the eyes. Eyes located well behind the cephalic midlength, EP> 1.00; in full-face view outer margins of eyes just interrupt the outlines of the sides. Sides of head shallowly convex behind the eyes, shallowly concave in front of them. Scape short (SI 35) but quite broad apically, SW/SL 0.50. Leading edge of scape with 1–2 short setae that are inclined toward the apex. Head in profile with a short, narrow, deep scrobe that extends from antennal socket to anterior margin of eye. Cephalic dorsum with two short setae on each frontal carina but only a single pair of long erect setae, located close to level of posterior margin of eye. Mandibles smooth with scattered small pits. Cephalic dorsum with scattered small punctures, here and there with a vague vestige of superficial, almost effaced, ground sculpture. Mesopleuron with a strong transverse sulcus that also extends across the entire width of the metapleuron, continuing the same line; mesopleural-metapleural sulcus also strongly developed. Mesopleural-mesonotal suture conspicuous in profile and also visible in dorsal view. Pronotum, mesonotum and propodeum each with 1–2 pairs of standing setae (may be some abrasion). In dorsal view both the promesonotal suture and the metanotal groove present but shallow; pronotum with a sharp anterior carina and acute humeri, the sides feebly convergent posteriorly; sides of mesonotum feebly concave. Pronotum relatively narrow with respect to AII, AIIW/PW 1.14. Dorsum of propodeum meets the declivity through a narrowly rounded angle, without a carina between the two surfaces. AII (petiole) with a strong anterior carina; in dorsal view the sides almost straight and markedly divergent posteriorly. Posterior corners of AII narrowly but bluntly rounded on each side of the broadly concave posterior margin, the corners not extended into laterally directed teeth. Anteroventral process of AII merely a small, insignificant tooth. AII longer than broad but AIII obviously broader than long, the latter with a shallowly convex anterior margin and sides that are almost straight and almost parallel. Uniquely among Afrotropical species AII is longer than AIII. Abdominal tergites, from AII to apex, with numerous standing long setae, the longest of which on AII and AIII are ca 0.60. Outline of pygidium in profile rounded downward near its base so that most of the outline is a very steep slope, almost vertical. Apex of pygidium obscured by glue but apparently without a strong pygidial fork. Mesosoma and abdominal tergites from AII to apex with small, scattered punctures on a smooth surface. Mesofemur and metafemur short, markedly incrassate medially in both dorsal and lateral views. Mesotibia and metatibia very slender basally, becoming much broader from about the midlength; metatibia in posterior view ca 0.06 near base, ca 0.17 at broadest. Shiny jet-black species, the appendages lighter.

Palp formula could not be assessed as the holotype, the only known specimen, is mounted flat on a card rectangle. S. laevissima is the only known member of the grandidieri group in the Afrotropical region, and as such is very easily distinguished from all other species by the characters of its species group and those in the key. In addition, the pronotal width of laevissima , with respect to AIIW, is the narrowest in the Afrotropical and Malagasy regions, with AIIW/PW 1.14. In all other Afrotropical species the combined range of AIIW/PW is 0.89–1.07, and for Malagasy species the combined range is 0.88–1.04.

Material examined. Uganda: Dedewe Forest, near Kampala (G. Arnold).