Carebara lilith Fischer, Azorsa & Hita Garcia

Fischer, Georg, Azorsa, Frank, Garcia, Francisco Hita, Mikheyev, Alexander S. & Economo, Evan P., 2015, Two new phragmotic ant species from Africa: morphology and next-generation sequencing solve a caste association problem in the genus Carebara Westwood, ZooKeys 525, pp. 77-105 : 91-92

Taxon classification Animalia Hymenoptera Formicidae

Carebara lilith Fischer, Azorsa & Hita Garcia sp. n. Figs 1C, D, 5

Holotype.

(major worker), IVORY COAST, Grégbeu, 06.8°, -006.717°, 06.x.1980 (V. Mahnert & J.-L. Perret) (CASENT0709545), (MHNG). Paratypes: 2 minor workers (CASENT0709546, CASENT0709547), same data as holotype (MHNG).

Diagnosis.

Phragmotic worker: Anterolateral lobes of clypeus small, shorter than and ending well before anterior margin of lateral shield lobes, sculpture on cephalic shield simple, punctate and with cone-shaped, gland-like structures present. Major worker: unknown. Minor worker: Head weakly subquadrate to subrectangular (CI 90-93), hind femur short (FI 68-69), postpetiole slightly higher than long (LPpI 76-94) and on average about 1.35 times wider than petiole (PpWI 133-137).

Description of phragmotic major worker.

Measurements (n=1): HW 0.65, HL 0.75, SL 0.18, MDL 0.23, EL 0.01, WL 0.73, PNW 0.47, PTL 0.25, PPL -/-, PTH 0.17, PPH -/-, PTW 0.17, PPW -/-, PSL 0.06, MFL 0.36, MTL 0.29, CI 86, SI 28, MDI 35, EI 1, FI 56, PSLI 9.

Head in full-face view modified, phragmotic with a distinct, concave and oval cephalic shield with two forward-extending, semi-transparent anterolateral lobes, inside of cephalic shield in oblique frontolateral view deeply concave and with a sharply raised margin. Head shape in full-face view subrectangular, longer than wide (CI 86), posterior of cephalic shield with rounded posterolateral corners and small horns lateral of shallowly V-shaped posterior emargination. Mandibles reduced and compact (MDI 35). Anterior margin of clypeus straight, widely emarginate and with short anterior lobes lateral of mandibles, which are considerably shorter than and ending before anterior margin of anterolateral cephalic shield lobes. In profile, head anteriorly straight at the truncated cephalic shield margin, short antennal scrobe present ventrally, shielding scrobe and funiculus. Antennae ten-segmented, short, with reduced scape (SI 28), apical funicular segment about as long as the remaining segments combined. Eyes strongly reduced, consisting of one small ommatidium (EI 1), situated at the posterior end of scrobe.

In profile view, promesonotum high and convex, posteriorly roundly sloping towards a very short, partly fused scutellum, both together in dorsal view remotely resembling a diamond-shaped shield. Promesonotal suture absent or inconspicuous, posterior of scutellum a similar-sized, isolated, metanotum present. Propodeal dorsum in profile moderately short, weakly concave towards the short-triangular posterior teeth, posterior declivity almost vertical, with very narrow lamella, propodeal lobe well developed. Propodeal lobes weakly triangular. Propodeal spiracle circular, situated centrally at lateropropodeum.

Petiole in profile with long peduncle, ventrally weakly convex, posterior of small anterior, tooth-like subpetiolar process, the node weakly nodiform or very broadly wedge-shaped, dorsally rounded, anteriorly and posteriorly very weakly concave, in anterodorsal view very weakly convex, almost transverse. Holotype with postpetiole and gaster missing.

Mandibles, clypeus and most of the face finely shagreened, the interior of cephalic shield with many small, cone-shaped, gland-like structures present, posterior portion of clypeus with a short longitudinal carina. Sides of head, lateral to cephalic shield, with weakly reticulate-punctate sculpture, posterior of cephalic shield, towards posterior head margin, longitudinal, weakly reticulate, rugulae present, posterior head margin, between horns, weakly carinate. Ventral side of head smooth and shiny. Promesonotum, anepisternum, katepisternum, propodeal declivity and dorsum of petiole node mostly smooth and shiny; punctures present only at anterolateral promesonotum, at sides and dorsum of propodeum and remainder of petiole, lateropropodeum, below spiracle and near its base, with few longitudinal rugulae.

Lateral and posterior portions of head mostly with short and relatively stout, erect-suberect hairs, no hairs on cephalic shield visible. Mesosoma and petiole node dorsum with abundant, fine, relatively short and mostly decumbent pilosity, plus some longer, subdecumbent to suberect hairs on mesosoma and petiole. Scape and tibia pilosity short, appressed to decumbent. Color light reddish brown, antennae and legs lighter colored.

Description of minor workers.

Measurements (n=2): HW 0.29-0.30, HL 0.32-0.33, SL 0.21-0.22, MDL 0.18-0.19, EL 0.02, WL 0.32, PNW 0.19, PTL 0.10-0.13, PPL 0.06, PTH 0.09-0.10, PPH 0.06-0.08, PTW 0.07, PPW 0.09-0.10, PSL 0.04-0.05, MFL 0.20, MTL 0.16-0.17, CI 90-93, SI 73-73, MDI 62-63, EI 5, FI 68-69, PSLI 13-15, LPpI 76-94, DPpI 150-163, PpWI 133-137, PpLI 47-62, PpHI 71-81.

Head longer than wide (CI 90-93), in full–face view weakly subquadrate to subrectangular, with convex sides, posterior head margin straight or very weakly concave medially. Clypeus faintly bicarinate, anterior margin medially very weakly convex or almost transverse. Frontal carinae inconspicuous. Antennae with ten segments, scapes ending before posterior head margin (SI 72-73). Eyes present, consisting of one ommatidium and situated anterior of cephalic midline (EI 5).

In profile view, promesonotum convex, metanotal groove impressed. Propodeum in profile higher than long, weakly convex and declining towards short, acute, weakly triangular posterior teeth, posterior declivity oblique with a narrow lamella and well developed, triangular propodeal lobes. Propodeal spiracle circular, situated just below posterior teeth and very close to posterolateral border of propodeum.

In profile, petiole with moderately short peduncle, ventrally with convex bulge and acute anterior tooth, dorsal face of petiole node more or less convex to weakly wedge-shaped. Postpetiole about as long as high, distinctly lower than petiole (PpHI 71-81), convex dorsally, weakly convex ventrally. In dorsal view petiole node slightly wider than long, postpetiole on average 1.3 times wider than petiole (PpWI 133-137) with sides tapering anteriorly.

Mandibles and clypeus smooth and shiny. Face smooth and shiny, near antennal insertion with few weak, concentric rugulae. Promesonotum, postpetiole dorsum and gaster smooth and shiny, metapleuron, propodeum and petiole with large, partly effaced areolae, propodeal declivity largely smooth and shiny.

Whole body with abundant, relatively short, decumbent pilosity. Clypeus and mesosoma with few longer, suberect hairs present. Scapes and tibiae with short, decumbent pilosity. Color light brown with yellowish antennae and legs.

Distribution.

So far, this species is only known from the type locality, although it’s most likely present in unsorted and/or unidentified material in other collections with African ants, possibly collected without phragmotic workers.

Discussion.

No ecological or collection data exist for this species. Without the phragmotic major worker, Carebara lilith can easily be confused with similar Carebara species from the former genus Oligomyrmex , as for example Carebara thoracica , from which it can be distinguished by possessing ten instead of nine antennal segments. Phragmotic workers of Carebara lilith are differentiated from those of Carebara phragmotica and Carebara elmenteitae by the character combination given in the diagnosis. Morphological differences between minor workers of Carebara lilith and Carebara phragmotica are not very significant and may decrease even more with larger sample sizes. Especially for the former species, more material is needed for a better resolution of intra- and interspecific variability. Phragmotic workers may be necessary for definitive identifications, but it seems likely that the three species do not co-occur biogeographically.

Etymology.

This species is named after the Hebrew name Lilith, a female demon in Jewish mythology. The name is a noun in apposition and thus invariant.