Ropalidia daklak Bui, Mai & Nguyen, 2023

Bui, Hoa Thi Quynh, Mai, Thai Van & Nguyen, Lien Thi Phuong, 2023, A new species of the paper wasp genus Ropalidia Guerin-Meneville, plebeja group (Hymenoptera, Vespidae, Polistinae), from Vietnam, Journal of Hymenoptera Research 96, pp. 543-553 : 543

Ropalidia daklak Bui, Mai & Nguyen sp. nov.

Figs 1-11 , 12-19

Material examined.

Holotype (deposited in IEBR): Vietnam: • ♀; Dak Lak provvince, Krong Ana, Dray Sap ; 12°32'53.5"N, 107°58'27.9"E; 19 Jun. 2020; Bui TQH leg.; Nest#VN-TN-2020-R-01; QHoa-A11-12 . Paratype (deposited in IEBR): Vietnam: • 3 ♂♂, 8 ♀♀, same data as holotype .

Diagnosis.

This species can be distinguished from other species in the R. plebeja group by the following combination of characters: pronotal carina raised into thin lamella but somewhat weaker at dorsal part; vertex weakly sloping down to occipital carina behind posterior ocelli; epicnemial carina absent, border between punctured posterodorsal and unpunctured anteroventral areas of mesepisternum well-defined; disc of mesoscutellum flat, in lateral view mesoscutellum smoothly passing into mesoscutum; median concavity of propodeum deep and wide, with distinct lateral edges; TI with posterior lamella depressed, wide and flat; TII dorsally with lateral margins abruptly diverging in basal third, then almost parallel to near apical margin. In female, head in frontal view 1.2 times as wide as high; distance between posterior ocelli about 2.2 times as long as their diameter. In male, antennal scape about 2.45 times as long as wide; digitus gradually widened from base to near apex, then abruptly curved to a sharp point at apex; penis valves short, slightly more than half as long as basal apodeme.

Description.

Female (Fig. 10 ). Body length (head + mesosoma + first two metasomal segments) 8.14-10.62 mm (holotype: 9.22 mm); forewing length 6.8-8.5 mm (holotype: 8.08 mm).

Head black; clypeus yellow to orange, dorsal margins black, with two black spots medially; spot at inner orbit close to clypeus and spot between antennal toruli (usually separated into paired smaller spots) brown; ill-defined spot above yellow spot at inner orbit, central spot behind posterior ocelli (usually absent), and most of gena (sometimes reduced to posterior band narrowing ventrally) reddish-brown; mandible brown in apical half, ivory white basally. Antenna brown to dark brown, but yellowish beneath. Mesosoma black; pronotum reddish-brown, except black pronotal collar and yellow band along carina. Tegula brown; mesoscutum black with two triangular orange spots at anterior margin; disc of mesoscutellum dull orange with black anterior margin and yellow to light brown posterior margin, metanotum yellow, propodeum black, propodeal teeth and propodeal valvula brown. First metasomal segment reddish-brown, with wide, pre-apical yellow band on tergum (sometimes interrupted medially on tergum); second metasomal segment black, thin lamella brown; third to sixth metasomal segments black. Legs reddish-brown; coxae black with a yellow spot; trochanters black basally; femora black basally. Wings hyaline, with subapical blackish cloud; pterostigma yellowish-orange; veins brown.

Body covered with appressed tomentum and dense, suberect, silvery setae; setae longer on apical part of clypeus and apical margin of propodeum than on other body parts. Clypeus with sparse, shallow punctures; frons with dense, deep punctures, interspaces between punctures much narrower than their diameters; vertex less densely punctured, interspaces between punctures narrower than their diameters; punctures on gena large, sparse, shallow, interspaces between punctures wider than their diameters. Pronotum, mesoscutum, metapleuron, and lateral surfaces of propodeum with dense punctures as on frons; punctures on mesoscutellum and metanotum slightly larger, with interspaces slightly wider than those on mesoscutum; posterior margin of metanotum impunctate and polished; median concavity of propodeum with fine, transverse striae; dorsolateral surface of propodeum with distinct and oblique striae. First metasomal tergum impunctate on anterior surface, with ill-defined punctures preapically; punctures on second metasomal tergum relatively large, their interspaces smaller than their diameters; punctures on second sternum similar to those on second tergum.

Head: In frontal view (Fig. 1 ) about 1.13 times as wide as high; in dorsal view (Fig. 2 ) about 2.5 times as wide as long, with gena slightly convex and distinctly narrowing posteriorly. Distance between posterior ocelli 2.25 times as long as their diameter, about 0.59 times as long as distance between posterior ocellus and inner compound eye margin; area between ocelli slightly raised. Vertex (Fig. 2 ) weakly sloping down to occipital carina. Inner compound eye margins converging ventrally; distance between them at vertex nearly 1.25 times as wide as at clypeus. Clypeus weakly convex, pointed below, transverse, nearly 1.53 times as wide (excluding lateral lobes) as high (measured from bottom of dorsal emargination to apex). Mandible normal, not twisted. Gena (Fig. 4 ) in profile weakly widening ventrally to level of compound eye mid-height, then slightly narrowing further ventrally, about 1.26 times as wide as compound eye; occipital carina complete, fine, smoothly and weakly curved. Malar space short, about 0.70 times as wide as diameter of antennal torulus. Antenna as in Fig. 3 ; scape slightly curved, slightly more than 3.60 times as long as wide; flagellum weakly thickened apically to FIX; FI about 2.71 times as long as its own apical width, about 1.41 times as long as FII and FIII combined; each of FII to FIX wider than long; FIX slightly more than 1.46 times as wide as FI; FX nearly bullet-shaped, about 1.1 times as wide as long.

Mesosoma: Rather thick, about as long as thorax, and as wide as mesoscutum between tegulae. Pronotum (Fig. 5 ) in dorsal view with anterior margin weakly rounded; lateral sides slightly concave and weakly diverging posteriorly; pronotal carina complete, raised into low lamella, barely sinuate at humeral angles. Mesoscutum strongly convex, about as long as wide (Fig. 5 ). Disc of mesoscutellum trapezoidal, nearly flat, with lateral margins truncate. Disc of metanotum weakly produced posteromedially, nearly on same level of mesoscutellum (Fig. 6 ), with fine lateral marginal carinae. Concavity on posterior surface of propodeum (Fig. 7 ) deep and wide, its margins marked laterally by ridges; posterior surface broadly angled at two-thirds anteriorly of propodeum; propodeal orifice rounded above, about 1.65 times as long as wide; propodeal valvula small (most of propodeal tooth visible in lateral view), with broadly rounded triangular outline and marginal carina at base.

Metasoma: First metasomal segment short, TI in dorsal view (Fig. 8 ) strongly widened after short, basal, parallel-sided part, then almost not constricted near apical margin; maximum width of posterior widened part nearly 3.27 times as wide as width of basal, parallel-sided part; in profile (Fig. 9 ) abruptly swollen dorsally at posterior end of basal slit, then dorsal margin weakly and broadly convex and broadly curved down to posterior lamella near apical margin, posterior lamella depressed, wide and flat, in dorsal view barely narrowing posteriorly near posterior margin; sternum emarginate posteriorly. Second metasomal segment about 1.06 times as long as wide, about 2.06 times as wide as maximum width of first tergum; suture between TII and SII barely visible; posterior lamella narrow, weakly depressed.

Male. Similar to female except as follows: Body length (head+mesosoma+first two metasomal segments) 8.32-9.22 mm; forewing length 6.84-8.04 mm.

Coloration generally as in female, but markings partly reduced or absent: head black, clypeus entirely black, spot at inner orbit and spot between antennal sockets light-brown, mandible dark brown with a large yellow mark in the middle, mesosoma entirely black, propodeum black with short narrow yellow band, tegulae pale yellow, first metasomal segment (Fig. 13 ) orange with wide, yellow band on pre-apical tergum (sometimes interrupted medially on tergum).

Head: In frontal view relatively wider than in female (Fig. 12 ), about 1.26 times as wide as high; compound eye slightly more swollen laterally; inner compound eye margins more strongly converging ventrally than in female, their distance at vertex about 1.43 times as long as that at clypeus; clypeus less produced below, about 1.54 times as wide as high; gena in profile proportionally slightly wider than in female, about 1.27 times as wide as compound eye; posterior ocelli more widely separated from each other, distance between them about 0.58 times as long as distance from posterior ocellus to inner compound eye margin, area around ocellus strongly elevated. Mandible with deep and wide emargination between dorsal first and second teeth. Antennal (Fig. 13 ) scape short, thick, swollen medially, about 2.45 times as long as wide; flagellum much less strongly swollen apically, widest at FVII, then weakly narrowed apically; FXI rounded apically, nearly 0.67 times as long as its own basal width; apical third of FI, FII to FX, and basal half of FXI with longitudinal ridge-like tyloids.

Genitalia: As in Figs 14-17 . Parameral spine lacking setae. Volsella flattened, strongly spatulate, and wide in inner aspect (Fig. 14 ). Digitus gradually widened from base to near apex, then abruptly curved to a sharp point at apex (Fig. 15 ). Penis valves short, slightly more than half as long as basal apodeme (about 0.51 times as long as basal apodeme); in ventral view proximal part strongly produced laterally into fin-like shape (Fig. 16 ); apical part curved ventrally in profile (Fig. 17 ); proximal margin without teeth.

Nest (Figs 11 , 18 , 19 ; note that the photos of the nest were taken on different dates). One nest (Nest#VN-TN-2020-R-01, QHoa-A11-12) together with nine females and three males was collected in Dray Sap, Krong Ana, Dak Lak Province, at 12°32'53.5"N, 107°58'27.9"E on 19 June 2020. The nest was found in a pepper ( Piper nigrum L.) and coffee ( Coffea robusta Chev.) tree garden, with 5 to 6 year old pepper and 15 year old coffee plants. The nest was constructed on the leaf of a pepper tree about 1 m from the ground, which was under the shade of a large coffee tree. It was horizontally attached to the dorsal surface of the dried pepper leaf. It had one main terminal and seven smaller pedicels (Figs 18 , 19 ). The length of the main pedicel was 5.2 mm, the width was 12.16 mm. The lengths of seven smaller pedicels ranged from 4.0 mm to 6.88 mm and the widths from 2.06 mm to 7.36 mm. The color of the nest was light brown with dark brown and white bands interleaved, indicating that the nest was made from different material sources. The nest carton was brittle, made from small chips of plant fiber mixed with a small amount of oral secretion. The nest was under construction with 86 completed cells and eight unfinished cells. Among 86 cells, 20 cells had larvae, there were no egg cells, and 32 cells had cocoon caps. The outer cells were elliptical or rounded, with an average depth and diameter of 8.1 mm (n = 12, range 6.12-11.48 mm) and 4.1 mm (n = 12, range 3.38-4.82 mm), respectively. The cells inside were hexagonal in section, average depth and diameter of cell with cocoon caps were 10.43 mm (n = 19, range 9.02-12.78 mm) and 4.55 mm (n = 12, range 4.2-4.88), respectively; non-cocoon cap cells were usually shorter than cells with cocoon caps, with depths ranging from 8.54 to 11.18 mm, and side to side diameters from 3.92 to 4.78 mm. The cocoon cap was light brown, and became dark brown with time, and was strongly convex.

Distribution.

Vietnam (Tay Nguyen highland).

Etymology.

The specific epithet refers to the name of the province where the holotype was collected.

Remarks.

The new species is compared with R. rufoplagiata based on the description of Kojima et al. (2002) and the one specimen of this species from Vietnam. The new species comes close to R. rufoplagiata in the following characters: medial concavity of propodeum deep and wide, with distinct lateral edges; metanotum slightly produced medioposteriorly; penis valves short, slightly more than half as long as basal apodeme; first metasomal tergum in profile relatively weakly swollen dorsally in posterior half with posterior lamella depressed and flattened. It is differentiated by: mesoscutellum in lateral view smoothly passing to mesoscutum (strongly convex at the anterior margin in R. rufoplagiata ); gena of female in profile wider than compound eye, about 1.26 times as wide as the compound eye (about 0.9 times as wide as the compound eye in R. rufoplagiata ), distance between posterior ocelli 2.2 times as long as their diameter (slightly more than twice in R. rufoplagiata ); clypeus of male about 1.54 times as wide as high (1.4 times as wide as high in R. rufoplagiata ), distance between posterior ocelli about 0.58 times as long as distance from posterior ocellus to inner compound eye margin (0.85 times in R. rufoplagiata ), antennal scape about 2.45 times as long as wide (slightly less than 3 times as long as wide in R. rufoplagiata ), digitus gradually widened from base to near apex, then abruptly curved to a sharp apex (digitus gradually narrowed from midlength to apex, with a bluntly pointed apex in R. rufoplagiata ) [the characters of the male of R. rufoplagiata were taken from Kojima et al. (2002)].

Figures

Figures 1 - 11. Ropalidia daklak sp. nov. 1 - 10 female 1 head, frontal view 2 head, dorsal view 3 antenna 4 gena 5 mesosoma, dorsal view 6 mesosoma, lateral view 7 propodeum 8 metasoma, dorsal view 9 metasoma, lateral view 10 habitus 11 nest (photo was taken on 19 June 2020). Scale bars: 1 mm.

Figures 12 - 19. Ropalidia daklak sp. nov. 12 - 17 male 18, 19 nest (photos were taken on 12 March 2023) 12 head, frontal view 13 antenna 14 inner aspect of paramere with digitus and volsella 15 digitus 16, 17 aedeagus (16 ventral view 17 lateral view) 18 nest, view from cell opening 19 nest, beneath. Scale bars: 1 mm (12 - 14, 18); 0.5 mm (15 - 17).