Discothyrea wakanda Hita Garcia & Lieberman, 2019

Hita-Garcia, Francisco, Lieberman, Ziv, Audisio, Tracy L., Liu, Cong & Economo, Evan P., 2019, Revision of the Highly Specialized Ant Genus Discothyrea (Hymenoptera: Formicidae) in the Afrotropics with X-Ray Microtomography and 3 D Cybertaxonomy, Insect Systematics and Diversity 5, pp. 1-84 : 78-79

Discothyrea wakanda Hita Garcia & Lieberman sp. n.

( Figs. 4T , 5 E–F, 6T, 7T, 8T, 9T, 10T, 11T, 12T, 13F, 14T,

58, 59; Supp. Video S20 [online only])

Type Material

HOLOTYPE, pinned worker, DEMOCRATIC REPUBLIC OF CONGO, North Kivu, Virunga National Park, Massif Ruwenzori, Lamya-Ruanoli , Muhira , [0.498, 29.884], 2600 m, bamboo, 9.I.1963 (R.P.M.J. Celis) ( MRAC: CASENT0790326 ) . PARATYPES, four pinned workers with same data as holotype ( MRAC: MRACFOR000117 , MRACFOR000118 , MRACFOR000119 , MRACFOR000120 ) .

Cybertype. Volumetric raw data (in DICOM format), 3D rotation video, still images of surface volume rendering, and 3D surface (in PLY format) of the physical holotype (CASENT0790326) in addition to stacked digital color images illustrating head in full-face view, profile and dorsal views of the body.The data are deposited at Dryad (Hita Garcia et al. 2019, http://doi.org/10.5061/dryad.3qm4183) and can be freely accessed as virtual representation of the type. In addition to the cybertype data at Dryad, we also provide a freely accessible 3D surface model of the holotype at Sketchfab (Model 20).

Nontype Material

DEMOCRATIC REPUBLIC OF CONGO: North Kivu, Virunga National Park, Massif Ruwenzori, Lamya-Ruanoli , [0.498, 29.883], 2500 m, bamboo, 9.I.1963 (R.P.M.J. Celis) ; North Kivu, Virunga National Park, Massif Ruwenzori, Lamya- Ruanoli , [0.497, 29.887], 2700 m, bamboo, 9.I.1963 (R.P.M.J. Celis) ; North Kivu, Virunga National Park, Massif Ruwenzori, Lamya-Ruanoli , Kaleberwa , [0.499, 29.88], 2300 m, montane forest, bamboo, 9.I.1963 (R.P.M.J. Celis) ; North Kivu, Virunga National Park, Massif Ruwenzori, Kalonge , Katsambu River , affl. dr. Butahu , [0.43936, 29.17389], 2200 m, 26.I.–19.II.1953 (P. Vanschuytbroeck; J. Kekenbosch) .

Diagnosis

The following character combination distinguishes D. wakanda from the remainder of the complex: large species (WL 0.59–0.65); in profile frontal lamella with prominent, elongate elliptical basal fenestra; propodeum denticulate, in dorsal view posterior propodeal margin strongly concave; standing pilosity present on mesosomal and abdominal terga; medial and lateral clypeus abruptly differentiated from posterolaterad antennal sockets, lateral clypeus very narrow and strongly concave between anterolateral corner of gena and antennal socket; sides of head slightly constricted laterally between eyes and anterolateral corner of gena, appearing concave in frontal view.

Worker Measurements and Indices (n = 15)

EL 0.03–0.04; HL 0.60–0.64; HW 0.50–0.52; SL 0.34–0.36; PH 0.33–0.36; PW 0.36–0.40; PrH 0.39–0.41; DML 0.37–0.41; WL 0.59–0.65; HFL 0.39–0.41; PeL 0.09–0.10; PeW 0.22–0.25; PeH 0.23–0.25; LT3 0.37–0.40; LT4 0.42–0.51; OI 4–7; CI 81–85; SI 55–58; LMI 51–57; DMI 59–62; DMI2 92–103; ASI 115–125; HFI 63–68; DPeI 240–267; LPeI 230–278.

Worker Description

Head longer than broad (CI 81–85), posterior head margin weakly emarginate medially; posterodorsal corners of head broadly rounded, sides of head subparallel from posterodorssal corner to eye, constricted laterally between eyes and anterolateral corner of gena, this region appearing concave in frontal view; eyes present, relatively large (OI 4–7), round, situated slightly more than one-third of way between corner of gena and posterior head margin; eyes just visible in frontal view; frontal lamella lobate in profile, with anterodorsal corner rounded; lamella with conspicuous, large, basal fenestra; medial clypeus weakly sinuate, with differentiated anteromedial lobe; posterolaterad antennal sockets, lateral clypeus strongly excavated, concave between antennal socket and anterolateral corner of head; entire anterior border of clypeus bearing relatively distinct, curved, suberect to erect white setae. Antenna with moderately long scape (SI 55–58); scape moderately incrassate, gently bent; pedicel subcylindrical, slightly broader than long; true antennomere count nine; apparent antennomere count 8–10, flagellomeres basad apical club highly compressed, taken together only about as long as apical club. Ventral head with very fine, sinuate postoccipital ridge without anteromedian carina; medial region of hypostoma broadly triangular, arms somewhat narrowed, similar in width across their length; palpal formula not examined. Mandible edentate except for small, curved prebasal denticle not strongly differentiated from rounded basal angle; ectal face with carina originating around distal point of prebasal denticle and becoming confluent with masticatory margin at around distal half of mandible length.

Mesosoma weakly to moderately convex, pronotum scarecly higher than propodeum; in dorsal view, mesoma robust and stocky (DMI 59–62; DMI2 92–103), somewhat narrowed posteriorly, pronotum wider than propodeum; pronotal humeri rounded; posterodorsal corners of propodeum dentate, teeth thick, opaque; declivitous face of propodeum concave in profile and oblique posterior view; propodeal spiracle relatively large, round, directed posterolaterally; propodeal lobes moderately well-developed, lobate.

Legs moderately long (HFI 63–68) and slender. Mesotibia without apicoventral spur.

Petiolar node not strongly attenuated dorsally, about 2.3–2.8 times higher than long (LPeI 230–278); in profile anterior face of node sloping posterodorsally, apex peaked, posterior face sloping posteroventrally; in dorsal view, petiole subrectangular, sides subparallel to weakly convex, about 2.4–2.7 times as broad as long (DPeI 240–267); in anterior view, petiolar outline pentagonal, edges fairly well-defined, dorsally rounded; in oblique anterior view, anterior face flat; subpetiolar process relatively long, lobate to rounded-triangular.

Abdominal segment 3 roughly campaniform, tergite slightly prolonged anteriorly past anterior sternal margin; sternite convex in profile; AS 3 with well-defined median ridge broadening posteriorly to a broad lobe; prora sharply carinulate, lunate with strongly defined anterolateral corners; AT4 around 1.2 times longer than AT3 (ASI 115–125); AT4 almost perfectly hemidemispherical; AS 4 with well-developed, broad anterior lip overlapping most of the width of AS 3, anterior margin straight to slightly curved in ventral view; successive abdominal segments short, telescopic, often concealed.

Sculpture on head densely foveolate to foveolate-reticulate, often becoming weakly sculptured just anterad occiput; mandibles, frontal lamella, clypeus, and ventral head surface roughly punctate to punctulate, postgenal bridge smoothest posteromedially; mesosoma dorsally and alterally foveolate-reticulate, fine rugulae present on lower areas of lateral mesosoma; declivitous face of propodeum horizontally rugulose, rugulae strongest ventrally; AT3 and AS 3 shallowly punctate to weakly foveolate, AS 4 becoming smooth for most of its ventromedial surface; AT4 very smooth with shallow scattered punctulae, a few more prominent punctae present posteriorly.

Setation on head fine, appressed, white pubescence, sometimes longer in posterior third of head; mesosomal, petiolar, and abdominal dorsa with fairly abundant standing pilosity, subdecumbent to erect, in addition to decumbent and appressed pubescence, usually longer on petiolar node than mesosoma and abdominal terga; appressed pubescence on lateral mesosoma fairly long but inconspicuous; on AT4 long and evenly disributed over entire tergite; AT4 usually with more fully erect setae than remainder of dorsal surfaces; scape and legs evenly distributed appressed to decumbent pubescence, scape usually with subdecumbent setae apically; ectal face of mandible with long, distinct, appressed to erect setae, curved to straight.

Color dull orange to testaceous orange, dorsal surfaces sometimes lightly infuscated.

Etymology

The specific epithet refers to the fictional nation of Wakanda from the Marvel comic universe. The new species is endemic to the Rwenzori Mountains in the Albertine Rift, the location of Wakanda in the Black Panther comics. Wakanda is a peaceful, prosperous country which was never colonized, where ancient cultural traditions coexist with conservation of natural resources and high-technology modernity. Discothyrea wakanda is named in honor of these ideals for Africa and the world. The species epithet is to be treated as an appositive noun.

Distribution and Biology

At present D. wakanda is known only from a few nearby highelevation localities in the Rwenzori Mountains of eastern Democratic Republic of Congo ( Fig. 4T ), mostly from montane forest in the bamboo zone above 2500 m. Considering the lack of ant collections in the Albertine Rift in general, it is likely that it might be more common and wider distributed. Nothing is known of its biology.

Comments

Discothyrea wakanda is similar to D. damato , D. dryad , and D. schulzei , with which it shares the conspicuous elliptical basal fenestra on the frontal lamella. Like the latter two species but unlike D. damato , there is standing pilosity present on the mesosomal and abdominal terga.The profile of the frontal lamella, having a rounded rather than acute apex is similar to D. schulzei , as is the stocky shape of the mesosoma, which is more elongate and, in dorsal view, posteriorly tapered in D. dryad . These three species notably differ in size, with D. wakanda representing the largest (WL 0.59–65). Discothyrea wakanda is unique among this group of possibly related species in several cephalic characters: the slight medial emargination of the posterior head margin, the compression of the sides of the head between the eye and the anterolateral corners of the head, the weakly sinuate anterior border of the clypeus, and the excavation of the lateral clypeus laterad the antennal sockets.

Variation

There is some variation in size (WL 0.59–0.65) and in the degree of attenuation of the petiolar node (DPeI 240–267; LPeI 230–278). Also, there is some notable variability in the development of the propodeal denticles, which are always present and prominent but may be larger and more laterally divergent in some individuals. The density of the cephalic pilosity also varies somewhat, being rather thicker in some individuals, but the general distribution and stature of setae is consistent.

Figures

Fig. 4. Maps showing the known distribution ranges of Afrotropical Discothyrea species.

Fig. 5. Still images from surface display volume renderings displaying the general morphology of both species complexes. Discothyrea oculata complex, D. mixta (CASENT0285473): (A) head in full-face view, (B) head in profile, (C) head in ventral view, (D) body in profile. Discothyrea traegaordhi complex, D. wakanda (CASENT0790326): (E) head in full-face view, (F) head in profile, (G) head in ventral view, (H) body in profile.