Proceratium carri, Hita Garcia, Francisco, Hawkes, Peter G. & Alpert, Gary D., 2014

Hita Garcia, Francisco, Hawkes, Peter G. & Alpert, Gary D., 2014, Taxonomy of the ant genus Proceratium Roger (Hymenoptera, Formicidae) in the Afrotropical region with a revision of the P. arnoldi clade and description of four new species, ZooKeys 447, pp. 47-86 : 57-59

Taxon classification Animalia Hymenoptera Formicidae

Proceratium carri sp. n. Figs 3A, 3D, 11A, 11B, 11C, 12A, 12B, 12C, 13, 18

Type material.

Holotype, pinned worker, MOZAMBIQUE, Sofala, Gorongosa National Park, 4 km NW of Chitengo, 18°57'34.1"S, 34°20'30.7"E, 41 m, sandy forest on road #2, dry soil-leaf litter, collected three bags of dry soil, misc. ants, WP113, 28.IV.2013 (G.D. Alpert) (MCZ: MCZ-ENT00517081).

Non-type material.

MOZAMBIQUE: Tete, Moatize, Haul Road 6, 30 km, 15.97644S, 33.8557E, 336 m, closed undifferentiated woodland 13.IV.2014 (P. Hawkes & R. Mulaudzi) (AFRC: CASENT0250381), Tete, Moatize, Haul Road 6, 6 km, 15.78187 S, 33.81614 E, 303 m, closed undifferentiated woodland 14.IV.2014 (P. Hawkes & R. Mulaudzi) (AFRC: CASENT0250382).

Diagnosis.

Proceratium carri differs from the other Afrotropical members of the Proceratium arnoldi clade by the following character combination: eyes strongly reduced, consisting of a single ommatidium (OI 5); head clearly longer than broad (CI 85-86); maculae on vertexal angles of head absent; mesopleurae weakly to moderately inflated posteriorly; petiolar node high nodiform, anteroposteriorly compressed, with anterior face relatively straight; petiole in dorsal view between 1.1 to 1.2 times wider than long DPeI 111-119; ventral process of petiole lamelliform, subrectangular, lamella weakly pointed anteriorly and strongly pointed posteriorly; abdominal segment IV around 1.6 times longer than abdominal segment III (ASI 156-159); head, mesosoma and petiole with numerous long, fine, suberect to erect hairs on top of dense mat of much shorter decumbent to subdecumbent pubescence.

Worker measurements

(N=2). TL 2.96-3.07; EL 0.03; SL 0.48-0.51; HL 0.75-0.77; HLM 0.88-0.92; HW 0.63-0.66; WL 0.81-0.82; HFeL 0.55-0.59; HTiL 0.46-0.50; HBaL 0.34-0.35; PeL 0.26-0.29; PeW 0.31-0.32; DPeI 111-119; LT3 0.39-0.41; LS4 0.16-0.18; LT4 0.62-0.64; OI 5; CI 85-86; SI 64-66; IGR 0.25-0.29; ASI 156-159.

Worker description.

In full-face view head clearly longer than broad (CI 85-86), sides weakly convex, gently broadening posteriorly, vertex shallowly concave. Clypeus medially reduced, its anterior margin convex to slightly triangular, only slightly protruding anteriorly, not surrounding antennal sockets and not medially impressed, antennal socket with broad torulus. Frontal carinae relatively short and widely separated, not converging medially and strongly diverging posteriorly, partially covering antennal insertions; frontal carinae conspicuously raised on their anterior two thirds, much less posteriorly. Eyes small, consisting of a single ommatidium and located on mid line of head. Antennae 12-segmented, scapes short (SI 64-66), not reaching vertexal margin and noticeably thickening apically, first and last funicular segments longer than broad, remaining funicular segments noticeably broader than long. Mandibles elongate-triangular; masticatory margin of mandibles with five teeth/denticles, decreasing in size from larger apical tooth to basal denticles. Mesosoma weakly to moderately convex in profile and clearly shorter than maximum head length including mandibles. Lower mesopleurae with well impressed sutures, no other sutures developed on lateral or dorsal mesosoma; mesopleurae weakly to moderately inflated posteriorly; propodeum in profile armed with small, pointed teeth, propodeal lobes moderately developed, lamellate and blunt; declivitous face of propodeum between teeth and lobes noticeably concave; in posterodorsal view sides of propodeum separated from declivitous face by margin connecting propodeal lobes and propodeal teeth. Legs slender and elongate; all tibiae with pectinate spur; calcar of strigil without basal spine; pretarsal claws simple; arolia well developed. Petiolar node in profile high, blocky nodiform, anterior face of petiole relatively straight, anterior and posterior faces approximately parallel, dorsum of node flat to weakly convex; petiole in dorsal view between 1.1 to 1.2 times wider than long (DPeI 111-119), petiolar node in dorsal view clearly much broader than long and transverse; ventral process of petiole lamelliform, subrectangular, lamella weakly pointed anteriorly and strongly pointed posteriorly. In dorsal view abdominal segment III anteriorly broader than petiole; its sides diverging posteriorly; dorsum of abdominal tergum III with posteromedial, very faint, semitransparent, flat bulla below the integument; abdominal sternite III anteromedially with a marked subtriangular projection. Constriction between abdominal segment III and IV conspicuously impressed. Abdominal segment IV strongly recurved (IGR 0.25-0.29), conspicuously rounded on its curvature, especially posteriorly, abdominal tergum IV relatively long, around 1.6 times longer than abdominal segment III (ASI 156-159); moderately large, semitransparent and elongate bulla situated posteromedially on abdominal tergum IV; remaining abdominal tergites and sternites relatively inconspicuous and curved ventrally. Whole body covered with dense mat of relatively short, appressed to subdecumbent pubescence; antennal scapes and legs also with moderately abundant, much longer (several times longer than pubescence), subdecumbent to erect, long, fine, standing hairs; head, mesosoma, petiole and abdominal segments with same type of long, standing pilosity, but usually more scattered than on appendages. Mandibles longitudinally rugose; most of body irregularly foveolate and/or punctate, sculpture best developed on cephalic dorsum and abdominal tergum III, less so on sides of mesosoma and especially weak on most of relatively smooth and shining abdominal tergum IV, abdominal tergum IV posteroventrally (shortly before abdominal tergum V) with small irregularly rugose area; inflated, posterior part of mesopleura and declivitous face of propodeum also only very weakly sculptured and relatively smooth and shining. Body of uniformly yellow to light orange brown colour.

Etymology.

The name of the new species is a patronym dedicated to the American entrepreneur and philanthropist Gregg C. Carr. We want to honour his great accomplishments for the restoration of the Gorongosa National Park in Mozambique and his efforts in the conservation of African biodiversity.

Distribution and ecology.

Gorongosa National Park is geographically divided into two sections, a higher elevation section on Gorongosa Mountain (1863 m summit) with a montane rainforest and a separate lowland elevation (39 m) section within the southern end of the Great African Rift Valley of east Africa (Fig. 18). The holotype of Proceratium carri was collected at the lower elevation rift valley section within Gorongosa National Park in Sofala Province, Central Mozambique. The single specimen was collected from a dry sand forest with scattered, emergent trees including Baobab trees (Fig. 11). Several bags of sandy soil under a thin layer of leaves on the surface were collected and brought back to the lab to be hand sorted while ants were still alive. A single specimen covered in sand was collected (Fig. 13). Unfortunately, repeated trips to the same locality and microhabitat did not produce any additional specimens. The species is also known from the Tete region in northern Mozambique, where a single worker and a dealate queen were found at different localities (separated by 24 km) north of Moatize. In contrast to the holotype, both of these additional specimens were found under stones in rocky outcrops in open undifferentiated Zambezian woodland.

Taxonomic notes.

Proceratium carri displays a character combination that renders it easily identifiable within the Proceratium arnoldi clade. The most conspicuous difference is the lack of maculae on the vertexal margins of the head, which are present in all examined specimens of the other six species. Nonetheless, this character can be challenging to detect sometimes, especially under low magnifications or with the wrong lighting. An additional character unique to Proceratium carri is the relatively long abdominal segment IV, which is around 1.6 times longer than abdominal tergite III (ASI 156-159), whereas it is much shorter in the other four species, around 1.0 to 1.3 times longer (ASI 102-132). Furthermore, Proceratium carri has a comparatively thin head in full-face view (CI 85-86), which is shared by Proceratium arnoldi (CI 85-87), but strongly contrasts with the head shape of the other five species (CI 91-95).

Variation.

We cannot observe any significant intraspecific variation between the two known workers of this species. The only difference is that the specimen from Gorongosa is of darker colour than the one from Moatize.