Head (Fig. 3): CW/MW = 1.29–1.42 (n = 45, mean 1.39). Cranium moderately rugo-reticulated and transversely wrinkled. Antenna (ant) located at mid-height on the cranium, distinctly posterior to the dorsal margin of the clypeus (Fig. 3D, E), measuring 0.08 mm in width; antennal rim thin yet distinct, with weak ventrolateral margins (indicated by an arrow in Fig. 3H), and well-defined in other regions. Temporal band (tmb) clearly visible (Fig. 3D, E, G), with a narrow zone along its inner margin heavily pigmented with ferruginous coloration, except in the dorsal and ventral thirds. Ventral and dorsal edges distinctly margined, with remaining portions vaguely defined; ventral edge positioned slightly above the level of the dorsal margin of the antenna. Region around the frontal suture (fs) dorsally bearing setae (n = 7–12); frons (fr), except for the area near the fs, bearing several setae; frontal sutures originating from the mid-cranial sulcus (mcs) (Fig. 3E); paired suprafrontal marks (psm) well-defined (Fig. 3E). Faint dotted patches on the frons (Fig. 3E). Clypeus as depicted in Fig. 3D, E, G; main disc transverse, with a width exceeding the minimum distance between the antennae; dorsal margin shallowly and roundly convex and dorsolateral corners semi-angulate; lateral margin, which houses the tentorial pit, straight and without a pigmented spot; main disc relatively low, with a CLI of 1.5–2; main disc with approximately 80 setae. Labrum as shown in Fig. 3B, C, F (left), with numerous sensory bristles on its lower half. Palate (Fig. 3C, F: right) with or without a median patch (mpt) of variable size; sclerotized patch (sp, Fig. 3F) extending toward the dorsolateral corner of the palate, measuring approximately half the palate width; median area with dense conical papillae (cp), with the papillae sparser in the lateral area more sparsely distributed. Largest conical papilla approximately 0.03 mm in width and positioned ventrally on the palate. Spicules (spi) distributed on the medioventral portion and along the lateral margins of the palate. Mandible (md) with three teeth (Fig. 3A, D, I), which are heavily sclerotized with blunt apices; outer surface of the mandible entirely covered with numerous pits. Mandibular teeth I and II distinctly more projected than tooth III, which is apically bifid; Tooth I as long as tooth II, whereas tooth IIIb slightly more prominent than IIIa. Tooth I separated from II at an angle of 40°–70°, II from IIIa at 50°–70°, and IIIa from IIIb at 70°–105°. Tooth I slightly broader than II and ventrally thick; tooth II with a smooth ventral margin and a minutely gibbous dorsal margin; bifurcation point of teeth II and IIIa slightly deeper than other bifurcation points (Fig. 3H). Maxilla with approximately 25 setae, with those near the palpus being 1.5 times longer than those on other parts. Prelabium with approximately 30 setae.

Body (thorax and abdomen): Body 26–35 mm in length (n = 45, mean 31.2 mm) and 13–19 mm in width (mean 15.7 mm); integument with sparse setae and widely spaced, short spicules. Spiracles deep, generally uniform in size except for spiracles 1, 2, and 10, which are slightly smaller; largest spiracle 0.65 mm in diameter; rim of spiracle 0.06 mm in thickness, consisting of distinct, elongated processes; inner part with short and thick atrial processes.

In this species, the CW/MW ratio is consistently below 1.45. Yamane (1976) also used this smaller CW/MW ratio to distinguish V. mandarinia from other Vespa species. The median patch on the palate is absent in the Japanese and Taiwanese populations of V. mandarinia (Yamane 1976); however, some Korean specimens examined in this study exhibited this feature. Although this characteristic varied among our Korean samples, it remains unclear whether it is stable in the Japanese and Taiwanese populations.

South Korea • 15 mature larvae; Gwangju; 35°11'48"N, 126°53'24"E; 20 Oct. 2021; Choi and Kim • 5 mature larvae; Ulsan; 35°28'29"N, 129°11'30"E; 14 Sept. 2022; Ma • 30 mature larvae; Gyeongsangbuk-do, Uiseong-gun; 36°22'39"N, 128°38'08"E; 01 Sept. 2023; Choi and Kim • 5 mature larvae; Gyeonsangbuk-do, Uiseong-gun; 36°23'44"N, 128°26'44"E; 12 Sept. 2023; Ma • 10 mature larvae; Gyeongsangbuk-do, Gyeongju-si; 35°49'11"N, 129°18'16"E; 08 Aug. 2024; Ma • 10 mature larvae; Gangwon-do, Taebaek-si; 37°10'15"N, 128°58'16"E; 11 Sept. 2024; Choi • 15 mature larvae; Daejeon; 36°16'30"N, 127°22'33"E; 20 Sept. 2024; Choi and Kim • 20 mature larvae; Gyeongsangnam-do, Jinju-si; 35°11'10"N, 128°09'36"E; 4 Oct. 2024; Ma • 5 mature larvae; Gyeongsangbuk-do, Andong-si; 36°36'36"N, 128°48'55"E; 18 Oct. 2024; Choi.

Head (Fig. 4): CW/MW = 1.6–1.74 (n = 47, mean 1.67). Cranium moderately rugo-reticulated and transversely wrinkled in the ventral area from the lateral margin of the clypeus to the outer margin of the gena. Antenna located at mid-height on the cranium, distinctly behind the dorsal margin of the clypeus (Fig. 4D, E), with a diameter of 0.09 mm and moderate sclerotization (Fig. 4D). Temporal band (Fig. 4D, E, H) generally narrow, with a heavily margined dorsal edge, moderately margined ventral edge, and poorly defined lateral margins; inner part heavily ferruginous-pigmented except in the dorsal and ventral areas (Fig. 4H). Ventral edge positioned slightly above the level of the dorsal margin of the antenna (Fig. 4E). Paired suprafrontal marks well-defined (Fig. 4E). Area around the antenna milky, with faint dotted patches on the frons. Region around the frontal suture dorsally bearing setae (n = 8–12), which are densely distributed below the depression at the origin of the frontal muscle; frons, aside from this area, with fewer than eight setae. Clypeus as depicted in Fig. 4D, E, with its width slightly exceeding than the minimum distance between the antennae. Main disc with a shallowly convex dorsal margin; dorsolateral corner angulate; lateral margins straight and weakly divergent ventrad, with tentorial pits but lacking pigmented spots; main disc relatively high, with a CLI of 3.0–5.0; main disc with approximately 75 setae; ventral section strongly transverse (Fig. 4E). Labrum (Fig. 4F, left) with numerous sensory bristles, except in the dorsal region. Palate (Fig. 4F, right) with a small median patch (width × height ≤ 0.02 × 0.02 mm), a large sclerotized patch extending nearly to the dorsolateral extremity, and dense conical papillae concentrated medially, which become sparser laterad; largest conical papillae measuring 0.025 mm in basal width; spicules distributed in the medioventral region and along the ventrolateral margin (Fig. 4B, F). Mandible (Fig. 4A, C, G) slightly sclerotized (Fig. 4C), bearing numerous pits on its outer surface (Fig. 4A). Mandibular teeth I and II distinctly projected compared to IIIa and IIIb, with tooth I slightly more developed than tooth II, and tooth IIIa less produced than IIIb. Teeth I and II separated at an angle of 65°–85°, teeth II and IIIa separated at 60°–80°, and teeth IIIa and IIIb separated at 110°–160°. Teeth I and II stout, with triangular apices; tooth II with a slightly convex dorsal margin and a smooth, steep ventral margin. Teeth IIIa and IIIb directed downward; bifurcation point between teeth II and IIIa slightly deeper than other bifurcation points (Fig. 4G). Maxilla with approximately 30 setae. Prelabium with approximately 30 setae.

Figure 4. 

Vespa ducalis A left mandible in frontal view, with the arrow indicating pits B dorsolateral portion of the left half of the labrum in frontal view C right mandible D, E head in frontal view F labrum (left) and palate (right) in frontal view G two examples of the apical portion of the mandible, with the arrow showing the inclination of the dorsal margin of tooth III and red lines highlighting the acute apex of tooth I H temporal band. Scale bars: 0.2 mm (A, C); 0.03 mm (B); 0.3 mm (D, E, H); 0.1 mm (F, G).

Body (thorax and abdomen): Body 21–34 mm in length (n = 47, mean 28.7 mm) and 10.5–12 mm in width (mean 11.0 mm); integument with sparse setae and dense spicules. Spiracles deep, generally similar in size, except for the slightly smaller spiracles 1, 2, and 10 (occasionally spiracles 2 and 10 smaller); largest spiracle 0.3 mm in diameter; spiracular rim 0.035 mm in thickness but rim of spiracle 2 relatively thick and consisting of sparse processes; inner part with short collar processes and thick, large, and even atrial processes; rim with short and sparse spicules.

The cranium is orangish in color except in the area surrounding the antennae, a characteristic unique to V. ducalis (Fig. 4D). The dorsal (upper) region (main disc) of the clypeus is large and over three times the height of the ventral (lower) region (Fig. 4E). Mandibular tooth III is relatively small, measuring less than half as the length of tooth II (Fig. 4C, G).

South Korea • 10 mature larvae; Gyeongsangbuk-do, Seongju-gun; 35°57'37"N, 128°10'56"E; 2 Aug. 2022; Ma • 10 mature larvae; Jeollanam-do, Gwangyang-si; 35°02'00"N, 127°37'21"E; 4 Aug. 2022 • 5 mature larvae; Gangwon-do, Wonju-si; 37°13'01"N, 128°05'18"E; 30 Aug. 2022; Ma and Kim • 42 mature larvae; Gyeongsangbuk-do, Chilgok-gun; 36°00'08"N, 128°27'33"E; 17 Aug. 2023; Choi and Kim • 5 mature larvae; Gyeongsandbuk-do, Andong-si; 36°33'41"N, 128°47'36"E; 18 Aug. 2023; Choi and Kim • 5 mature larvae; Gyeongsangbuk-do, Andong-si; 36°41'02"N, 128°49'39"E; 31 July 2024; Choi and Kim.

Head (Fig. 5): CW/MW = 1.56–1.75 (n = 40, mean 1.66). Cranium with moderately strong, irregular rugo-reticulation, with the ventral area between the lateral margin of the clypeus and the outer margin of the cranium lacking this rugo-reticulation. Antenna positioned nearly at the level of the dorsal margin of the clypeus (Fig. 5E, F) with a distinctly sclerotized rim (Fig. 5E) and a diameter of 0.09 mm (Fig. 5E, F). Temporal band (Fig. 5I) with moderately defined lateral margins and a heavily margined dorsal edge, with moderate ferruginous pigmentation in the inner area, except for the ventral one-fifth region; ventral extremity positioned lower than the dorsal margin of the antenna (Fig. 5F). Faint dotted patches on the frons, with a few setae located around the frontal suture and fewer than 15 setae on other areas of the frons. Paired suprafrontal marks well defined (Fig. 5F). Clypeus width slightly exceeds the minimum distance between the antennae (Fig. 5F). Main disc with a broadly and roundly convex dorsal margin, merging with the lateral margin without separation from the latter; pigmented spots present along the margins except at the labroclypeal suture, with (Fig. 5C–E). Main disc relatively high, with a CLI of 1.5–3; main disc with approximately 80 setae; ventral section strongly transverse. Labrum (Fig. 5G, left) densely covered with small processes. Palate (Fig. 5G, right) with a large median patch; sclerotized patch dark, proximally wide, and narrowing distally, with conical papillae present in the proximal half; conical papillae also present in the ventral area of the palate; largest conical papillae 0.02 mm in diameter; spicules widely distributed in the medioventral region and dorsally along the lateral margin, and interspersed among the conical papillae (Fig. 5B). Mandible (Fig. 5A, E, H) with a heavily sclerotized apical third, with the entire surface containing numerous shallow pits (Fig. 5A). Mandibular teeth I and II distinctly projected in comparison to tooth III. Tooth I similar in size to or slightly more produced than tooth II, while IIIa similar to or smaller than IIIb; teeth I and II separated at an angle of 50°–70°, II and IIIa at 45°–80°, and IIIa and IIIb at 80°–105° (Type A) or 90°–135° (Type B, similar to the condition in V. ducalis); tooth I apically blunt and tooth II with a sharper apex (Type A); tooth II with a smooth dorsal margin and gibbous ventral margin; bifurcation point between teeth II and IIIa deeper than the other bifurcation points. Maxilla with 25‒30 setae. Prelabium with approximately 25 setae.

Figure 5. 

Vespa crabro flavofasciata A outer surface of the mandible B medioventral portion of the palate, showing minute spicules located on the conical papilla (indicated by an arrow) C, D clypeus in frontal view, highlighting pigmented spots on its dorsal and lateral margins E, F head in frontal view G labrum (left) and palate (right) in frontal view H two types of mandibular teeth. Scale bars: 0.03 mm (A, B); 0.3 mm (C–F, I); 0.1 mm (G, H)

Body (thorax and abdomen): Body 19.5–25 mm in length (n = 40, mean 21.5 mm) and 9–11 mm in width (mean 10.0 mm); integument with gradually increasing setae from the fifth integument posteriorly and with even spicules. Spiracles deep, generally uniform in size, except for spiracles 1, 2, and 10, which are slightly smaller; largest spiracle 0.3 mm in diameter; spiracular rim 0.03 mm in thickness, lacking any processes; collar processes thick and short (occasionally not thick).

This species exhibits numerous dark spots along the dorsal and lateral margins of the clypeus. However, the number of spots varied among individuals. This variation may be due to certain environmental or genetic (Fig. 5C–E). The dorsal and lateral margins of the clypeus form a broad, rounded convex shape, creating an almost semi-circular arc, a characteristic observed only in V. crabro flavofasciata (Fig. 5C–E). In this species, mandibular tooth III presents in two forms (Fig. 5H): Type A is observed in most individuals, and Type B, observed in a few individuals, resembles the form observed in V. ducalis. For Type B mandibles, the angle between tooth IIIa and IIIb ranges from 90° to 135° (Fig. 5H). Additionally, spicules are distributed along the lateral margin of the palate, with a characteristic that contradicts the observations reported for V. crabro by Kojima (1998).

South Korea • 10 mature larvae; Daegu; 35°59'27"N, 128°35'49"E; 27 July 2021; Choi and Kim • 10 mature larvae; Daegu; 35°53'31"N, 128°26'04"E; 28 July 2021; Choi and Kim • 10 mature larvae; Jeollanam-do, Naju-si; 35°01'46"N, 126°42'10"E; 18 Aug. 2021; Ma and Kim • 15 mature larvae; Gyeongsangbuk-do, Yecheon-gun; 36°40'16"N, 128°27'45"E; 2 Sept. 2022; Choi • 10 mature larvae; Gyeongsangbuk-do, Sangju-si; 36°21'58"N, 128°02'12"E; 5 July 2023; Choi and Ma • 30 mature larvae; Gyeongsangbuk-do, Andong-si; 36°35'12"N, 128°42'56"E; 18 Aug. 2023; Choi and Kim • 8 mature larvae; Gyeongsangbuk-do, Daegu; 35°54'59"N, 128°40'12"E; 20 Sept. 2023; Choi • 10 mature larvae; Gangwon-do, Hongcheon-gun; 37°47'19"N, 128°09'23"E; 22 Sept. 2023; Kim • 5 mature larvae; Gyeongsangnam-do, Gimhae-si; 35°21'36"N, 128°53'38"E; 10 Oct. 2023; Choi and Kim • 10 mature larvae; Gyeongsangbuk-do, Yecheon-si; 36°39'21"N, 128°24'10"E; 10 July 2024; Kim • 5 mature larvae; Gyeongsangbuk-do, Andong-si; 36°35'34"N, 128°46'35"E; 23 Oct. 2023; Choi and Kim.

Head (Fig. 6): CW/MW = 1.62–1.84 (n = 30, mean 1.71). Cranium with moderate, irregular rugo-reticulation. Antenna positioned well behind the level of the dorsal margin of the clypeus (Fig. 6C, D), with a diameter of 0.08 mm, rim thin yet strongly sclerotized. Temporal band (Fig. 6C, D, G) generally distinct, with relatively weakly defined edges and margins, except for the strongly margined and depressed dorsal edge; inner part moderately ferruginous-pigmented, except in the dorsal and ventral one-third portions; ventral edge positioned at the same level or slightly lower than the dorsal margin of the antenna. Dotted patches on the frons faint; region around the frontal suture and frons with setae in variable numbers. Paired suprafrontal marks relatively weak (Fig. 6D). Clypeus (Fig. 6C, D) with a maximum width similar to or slightly less than the minimum distance between the antennae; dorsal margin of the main disc shallowly convex; dorsolateral corner bluntly angulate; lateral margins slightly curved, diverging ventrad, and widest at the level of the interior mandibular articulation, lacking sclerotized pigmented spots, except in the tentorial pits; main disc not very high, with a CLI of 1.5–2; main disc with approximately 80 setae; ventral section distinctly transverse. Labrum (Fig. 6B, E, left), extensively covered with sensory bristles. Palate (Fig. E, right) with tiny median patch absent or present (width × height ≤ 0.02 × 0.02 mm) (Fig. 6E); sclerotized patch short and mostly faint, with a few conical papillae (up to 4) in the proximal area. Conical papillae aligned in line along the ventral margin; spicules widely and sparsely distributed in the medioventral area and along the lateral margin dorsally (Fig. 6B). Mandible (Fig. 6A, F) strongly sclerotized only in the extreme apical region, with numerous pits across the surface. Mandibular teeth smooth, sclerotized, and not strongly pronounced, with blunt apices (Fig. 6F); teeth I and II more produced than III; with tooth I slightly more produced than tooth II, with a significantly wider base; tooth IIIa less produced than IIIb; teeth I and II separated at an angle of 60°–80°, II and IIIa at 50°–80°, and IIIa and IIIb at 75°–105°; dorsal margin of tooth II slightly convex; bifurcation point between teeth II and IIIa relatively shallow, often shallower than other bifurcation points. Maxillar with approximately 25 setae (Sometimes lower than 15 setae). Prementeum with approximately 25 setae.

Figure 6. 

Vespa analis parallela A outer surface of the right mandible in frontal view B ventral portion of the palatolabral junction, with the yellow ring indicating the presence of spicules C, D head in frontal view E labrum (left) and palate (right) in frontal view F apical portion of the right mandible. Scale bars: 0.03 mm (A); 0.2 mm (B); 0.3 mm (C, D, G); 0.1 mm (E, F)

Body (thorax and abdomen): Body 22–27 mm in length (n = 30, mean 23.6 mm) and 10–11 mm in width (mean 10.7 mm); third, fourth, and fifth integuments with dense setae; spicules near spiracle 1 sparse and short. Largest spiracle 0.4 mm in diameter and shallow; approximately 0.7 times the size ratio of spiracles 1, 2, and 10, with sparse processes under 0.0025 mm in length on the inner edge; spiracular rim 0.04 mm in thickness with smaller and more sparse spicules on spiracles 1, 2, and 10.

Similar to V. velutina nigrithorax and V. simillima simillima, this species has a relatively narrow clypeus, with a width comparable to or less than the minimum distance between the antennae, and lackse. However, unlike V. velutina and V. simillima, this species has abundant pits on the outer surface of the mandible.

South Korea • 10 mature larvae; Gangwon-do, Gapyeong-gun; 37°50'45N, 127°30'44"E; 14 Sept. 2021; Choi • 10 mature larvae; Gyeongsangbuk-do, Gunwi-gun; 36°15'42"N, 128°30'36"E; 15 Sept. 2021; Choi and Ma • 5 mature larvae; Chungcheongbuk-do, Sejong-si; 36°33'39"N, 127°14'46"E; 19 July 2022; Choi and Ma • 7 mature larvae; Gyeongsangbuk-do, Seongju-gun; 36°00'18"N, 128°14'15"E; 5 Aug. 2022; Ma • 3 mature larvae; Daegu; 35°54'16"N, 128°42'46"E; 18 Oct. 2022; Ma • 10 Mature larvae; Gyeongsangnam-do, Goseong-si; 34°59'07"N, 128°08'34"E; 25 July 2023; Choi and Kim • 20 mature larvae; Daegu; 35°52'08"N, 128°31'35"E; 27 July 2023; Choi and Kim • 10 mature larvae; Gyeongsangbuk-do, Andong-si; 36°32'58"N, 128°48'11"E; 18 Aug. 2023; Choi and Kim • 15 mature larvae; Gyeongsangbuk-do, Pohang-si; 36°04'10"N, 129°09'44"E; 22 Aug. 2023; Choi and Ma • 20 mature larvae; Jeollabuk-do, Jeongeup-si; 35°34'45"N, 126°54'09"E; 17 Oct. 2024; Kim and Ma.

Head (Fig. 7): CW/MW = 1.55–1.75 (n = 30, mean 1.64). Cranium nearly circular in frontal view (Fig. 7B, C), with moderate irregular rugo-reticulation; rugo-reticulation absent in the ventral area of the cranium between the lateral margin of the clypeus and the outer margin of the cranium. Antenna positioned well behind the level of the dorsal margin of the clypeus (Fig. 7C), measuring 0.06–0.07 mm in diameter (Fig. 7B, C), with a heavily sclerotized rim. Paired suprafrontal marks well defined; dotted patches on the frons faint; area around the frontal suture with fewer than 10 widely distributed setae, with fewer than 10 setae on the frons. Temporal band (Fig. 7B, C, E) with heavily margined dorsal and ventral edges, with other parts exhibiting vaguely defined margins; inner region with moderate ferruginous pigmentation throughout; ventral edge positioned above the dorsal margin of the antenna (Fig. 7C). Clypeus as depicted in Fig. 7B, C; main disc with dorsal margin weakly convex, dorsolateral corner weakly angled, and lateral margin slightly curved and lacking pigmented spots, except in the tentorial pits; main disc not very high, with a CLI of 1.5–2; main disc with approximately 60 setae; ventral section with anterior margin shallowly concave medially. Labrum (Fig. 7D, left) with sensory bristles concentrated in the median half. Palate as shown in Fig. 7B, C, D (right); median patch and sclerotized patch absent; conical papillae densely distributed ventrally and evenly dispersed; largest conical papilla measuring 0.025 mm in diameter at the base; most spicules located on the medioventral region. Mandible (Fig. 6B, F) with the apical half heavily sclerotized; outer surface without pits but with a few bumps (Fig. 7A). Mandibular teeth I and II distinctly projected compared with tooth III; tooth I as large as II, and IIIa as large as IIIb; teeth I and II separated at an angle of 50°–80°, II and IIIa at 50°–80°, and IIIa and IIIb at 70°–105°; all teeth slick and relatively sharp at the apex, except for tooth II, which often has a faintly bifid dorsal margin; bifurcation point between teeth II and IIIa slightly deeper than other bifurcation points. Maxilla with approximately 20 setae. Prelabium with sparse setae.

Figure 7. 

Vespa dybowskii A outer surface of the right mandible, showing the absence of pits on the outer surface B, C head in frontal view D labrum (left) and palate (right) in frontal view E temporal band F apical portion of the right mandible, with the arrow indicating a shallow incision on the dorsal margin of tooth II. Scale bars: 0.03 mm (A); 0.3 mm (B, C, E); 0.1 mm (D, F).

Body (thorax and abdomen): Body 20–22 mm in length (n = 30, mean 21 mm) and 10–13 mm in width (mean 11.4 mm); integument with sparse setae. Spiracles shallow; generally uniform in size, except for spiracles 1, 2, and 10, which are slightly smaller; largest spiracle 0.3 mm in diameter, with a spiracular rim thickness of 0.025 mm, bearing dense processes.

This species is distinguished by an entirely weakly pigmented temporal band and by having conical papillae and spicules confined to a narrow ventral zone on the palate.

South Korea • 5 mature larvae; Jeollanam-do, Suncheon-si; 34°59'48"N, 127°24'54"E; 18 Aug. 2022; Choi and Ma • 9 mature larvae; Jeollanam-do, Gwangyang-si; 35°01'08"N, 127°39'28"E; 14 Oct. 2022; Choi and Ma • 11 mature larvae; Chungcheongbuk-do, Cheongju-si; 36°41'55"N, 127°39'19"E; 6 Sept. 2023; Choi and Kim • 20 mature larvae; Gyeongsangbuk-do, Andong-si; 36°38'01"N, 128°38'36"E; 01 Sept. 2023; Choi and Kim • 10 mature larvae; Gyeongsangbuk-do, Yeongyang-gun; 36°36'15"N, 129°04'31"E; 08 Sept. 2023; Choi et al. • 10 mature larvae; Gyeongsangbuk-do, Yeongyang-gun; 36°41'20"N, 129°08'48"E; 08 Sept. 2023; Choi et al. • 5 mature larvae; Gangwon-do, Bonghwa-gun; 36°58'35"N, 128°47'04"E; 19 Oct. 2022; Choi and Kim • 10 mature larvae; Gyeongsangbuk-do, Yeongyang-gun; 36°38'49"N, 129°09'24"E; 12 Sept. 2023; Kim.

Head (Fig. 8): CW/MW = 1.61–1.87 (n = mean 1.7). Cranium with moderate irregular rugo-reticulation, with some areas exhibiting parallel reticulation. Antenna positioned near the level of the dorsal margin of the clypeus (Fig. 8D, E), faintly sclerotized or nearly transparent (Fig. 8D–F). Temporal band (Fig. 8F, G, J) with variable width; edges generally weakly margined except for the dorsal edge; inner part with moderate ferruginous pigmentation, excluding the dorsal and ventral regions; ventral edge positioned slightly above the dorsal margin of the antenna. Paired suprafrontal marks faint; dotted patches on the frons distinct, often extending ventrad (Fig. 8D, E); region distal to the frontal suture with 15–22 setae concentrated mainly around the base of the antenna; frons with fewer than 14 setae distributed medially. Clypeus (Fig. 8D–G) width similar to the minimum distance between the antennae; main disc with dorsal margin shallowly convex, dorsolateral corner roundly angulated, lateral margin slightly curved and lacking pigmented spots, except in the tentorial pits; ventral margin broadly convex; main disc not very high, with a CLI of 1.5–2; main disc with 45–60 setae; ventral section strongly narrowed dorsoventrally, with a straight ventral margin. Labrum (Fig. 8H, left) with numerous sensory bristles, except in the dorsolateral region. Palate (Fig. 8H, right) with a median patch; sclerotized patch reaching the apex of the palate, with variable pigmentation intensity; conical papillae small and dense ventrally, with over seven papillae located in the sclerotized patch, primarily medially (Fig. 8H); spicules present in the medioventral part and along the lateral margin of the palate, as well as on the conical papillae (Fig. 8C, H). Mandible (Fig. 8A, F, I) with strongly sclerotized teeth; surface lacking pits but bearing a few stumps (Fig. 8A). All mandibular teeth moderately produced and apically blunt; tooth I largest, stumpy, and round apically; tooth II often weakly bifid or trifid apically; tooth IIIa similar in size or slightly smaller than IIIb; teeth I and II separated at an angle of 55°–85°, II and IIIa at 65°–85°, and IIIa and IIIb at 65°–105°; bifurcation point between teeth II and IIIa slightly shallower than the other bifurcation points. Maxilla with approximately 30 setae. Prelabium with 45–50 setae.

Figure 8. 

Vespa simillima simillima A basal portion of the right mandible, showing the absence of pits on the outer surface B minute spicules on the conical papillae (arrow) in the medioventral portion of the palate C spicules in the lateral part of the palatolabral junction D, E antenna and clypeus; black arrows indicate variations in antennal rim sclerotization, the blue arrow indicates a dotted patch on the frons, a blue line shows that the dorsalmost point of the clypeus and ventral margin of the antenna are at the same level, the red line is tangent to the inner margin of the antenna and the outermost point of the clypeus, and a yellow line showing the gap between the ventral margin of the temporal band and the dorsal margin of the antenna F, G head in frontal view H labrum (left) and palate (right) in frontal view I apical portion of the right mandible, with the arrow showing variation in the shape of tooth II J temporal band in Vespa simillima and V. velutina. Scale bars: 0.03 mm (A–C); 0.3 mm (D–G, J), 0.1 mm (H, I).

Body (thorax and abdomen): Body 20.5–23.5 mm in length (n = 60, mean 22.2 mm) and 11–13 mm in width (mean 11.4 mm); integument with setae gradually decreasing in density posteriorly from the fifth integument (often evenly distributed across all segments); sparse spicules near the rim of spiracles 1 and 10 Spiracles shallow; generally uniform in size, except for spiracles 1, 2, and 10, which are slightly smaller; largest spiracle 0.3 mm in diameter; spiracular rim 0.03 mm in thickness, bearing sparse large processes (0.008–0.012 mm in length) and dense tiny processes (<0.01 mm in length).

The antenna is typically nearly hyaline, as seen in V. velutina (Fig. 9D); however, it may be slightly sclerotized, as in V. analis parallela (Fig. 6C). This condition can vary even within a single colony. This species closely resembles V. velutina in both larval characteristics (Yamane 1976, present study) and adult features (Archer 1994; Carpenter et al. 2013).

Figure 9. 

Vespa velutina nigrithorax A basal area of the right mandible, showing the absence of pits B left half of the labrum in ventrofrontal view C lateral part of the labrum showing spicules on the palate (arrow) D, E head in frontal view, with the arrow indicating a dotted patch (dt) and an enlarged image F labrum (left) and palate (right) in frontal view G apical portion of the right mandible, with the arrow showing variations in the shape of teeth I and II. Scale bars: 0.03 mm (A, C); 0.1mm (B, F, G); 0.3 mm (D, E).

South Korea • 10 mature larvae; Chungcheongbuk-do, Goesan-gun; 36°48'42"N, 127°47'17"E; 29 Sept. 2022; Choi • 10 mature larvae; Gyeonsangbuk-do, Andong-si; 36°46'12"N, 128°47'48"E; 30 Sept. 2022; Ma • 30 mature larvae; Gyeongsangbuk-do, Yeongju-si; 36°50'09"N, 128°38'50"E; 12 Oct. 2022; Ma • 30 mature larvae; Gyeongsangbuk-do, Yeongyang-gun; 36°43'02"N, 129°05'48"E; 02 Aug. 2023; Choi and Kim • 5 mature larvae; Gyeonsangbuk-do, Yeongcheon-si; 36°04'00"N, 128°55'32"E; 5 Oct. 2023; Choi et al. • 5 mature larvae; Gyeonsangbuk-do, Yeongcheon-si; 36°04'05"N, 128°55'35"E; 5 Oct. 2023; Choi et al. • 10 mature larvae; Gyeonsangbuk-do, Yeongcheon-si; 36°03'35"N, 128°55'16"E; 5 Oct. 2023; Choi et al. • 10 mature larvae; Gangwon-do, Pyeongchang-si; 37°31'34"N, 128°30'08"E; 21 Aug. 2024; Ma and Kim • 15 mature larvae; Jeollanam-do, Gurye-gun; 35°14'40"N, 127°35'40"E; 22 Aug. 2024; Choi and Ma • 10 mature larvae; Gangwon-do, Hoengseong-gun; 37°31'31"N, 128°08'58"E; 5 Sept. 2024; Choi and Ma.

Head (Fig. 9): CW/MW = 1.64–1.76 (n = 1.68). Cranium with moderate, irregular rugo-reticulation, except for some parallel rugae between the temporal band and the mid-cranial sulcus. Antenna positioned near the level of the dorsal margin of the clypeus (Fig. 9D, E), measuring 0.08–0.1 mm in diameter (Fig. 9E), with very weak pigmentation and a hyaline antennal socket (Fig. 9D). Temporal band (Fig. 9D, E) similar to that in V. simillima (Fig. 8J), with variation in width; edges mostly weakly margined; inner part with moderate ferruginous pigmentation in the dorsal and ventral areas or mostly transparent; ventral edge positioned above the dorsal margin of the antenna. Paired suprafrontal marks relatively weak; dotted patches on the upper frontal area distinct and extending ventrad (Fig. 9D, E: arrow); region around the frontal suture with 18–23 setae, primarily in the dorsal area; frons, except for this region, with fewer than 14 setae distributed between the dfm and the clypeus. Clypeus (Fig. 9D, E) with a width similar to or less than the minimum distance between the antennae; dorsal margin of the main disc roundly convex; lateral margin slightly curved, without pigmented spots, except in the tentorial pit; ventral margin shallowly convex; main disc not very high, with a CLI of 1.5–2; main disc with 40–50 setae (sometimes lower than 60 setae); ventral section strongly transverse, with a straight anterior margin. Labrum (Fig. 9F, left) bearing numerous sensory bristles, except in the zone along the dorsal margin. Palate (Fig. 8B, C, F: right) with a small median patch (0.03 × 0.03 mm); sclerotized patch relatively poorly developed and pale in color, not extending to the dorsolateral part; conical papillae tiny and densely arranged ventrally; with fewer than 10 papillae present on the sclerotized patch; spicules distributed in the medioventral part, along the lateral margin of the palate, and on the conical papillae (Fig. 9C, F). Mandible (Fig. 9D, E, G) strongly sclerotized in the apical two-fifths; outer surface without pits but with a few bumps (Fig. 9A) or extensively smooth. All mandibular teeth smooth and moderately produced (Fig. 9G); tooth I similar in size to, or slightly larger and more produced than, tooth II, occasionally bearing small denticles on the dorsal margin; tooth IIIa similar to or more produced than IIIb; teeth I and II separated at an angle of 65°–90°, II and IIIa at 60°–90°, and IIIa and IIIb at 75°–105°; bifurcation point between teeth II and IIIa slightly deeper than the other bifurcation points. Maxilla with approximately 25 setae. Prelabium with approximately 45‒55 setae.

Body (thorax and abdomen): Body 21‒23.2 mm in length (n = 50, mean 21.8 mm) and 10–12 mm in width (mean 11.1 mm); integument with setae gradually decreasing in density posteriorly from the fifth integument (often evenly distributed across all segments) with dense spicules. Spiracle shallow; generally uniform in size, except for spiracles 1, 2, and 10, which are slightly smaller; largest spiracle 0.3 mm in diameter; spiracular rim 0.03 mm in thickness with dense spicules of variable sizes.

Mature larvae exhibit minimal variation within a single colony and consistently retain traits comparable to those of V. simillima simillima. However, distinguishing them from some individuals of V. simillima simillima based solely on morphology is challenging.

South Korea • 30 mature larvae; Jeonllanam-do, Gurye-gun; 35°25'57"N, 127°58'62"E; 10 Sept. 2021; Choi • 10 mature larvae; Gyeonggi-do, Pocheon-si; 37°58'36"N, 127°14'24"E; 13 Oct. 2022; Choi and Ma • 10 mature larvae; Gyeongsangnam-do, Sacheon-si; 35°01'37"N, 128°07'20"E; 19 Oct. 2022; Choi and Ma • 20 mature larvae; Daegu; 35°48'40"N, 128°33'07"E; 7 Sept. 2023; Choi et al. • 5 mature larvae; Gyeongsangbuk-do, Cheongdo-gun; 35°40'37"N, 128°43'19"E; 17 Oct. 2023; Choi and Kim • 5 mature larvae; Chungcheongbuk-do, Boeun-gun; 36°26'28"N, 127°41'35"E; 15 July 2024; Choi • 15 mature larvae; Gyeongsangbuk-do, Gyeongsan-si; 35°49'07"N, 128°43'14"E; 13 Aug. 2024; Ma and Kim • 10 mature larvae; Jeollabuk-do, Muju-gun; 35°52'13"N, 127°39'12"E; 19 Sept. 2024; Ma • 15 mature larvae; Gyeongsangbuk-do, Andong-si; 36°34'05"N, 128°43'33"E; 24 Sept. 2024; Ma and Kim • 15 mature larvae; Gyeongsangbuk-do, Andong-si; 36°33'54"N, 128°43'27"E; 25 Sept. 2024; Ma • 20 mature larvae; Gyeongsangbuk-do, Gyeongsangbuk-do, Andong-si; 36°56'80"N, 128°70'57"E; 02 Sept. 2023; Choi and Kim.

Head (Fig. 10): CW/MW = 1.56–1.68 (n = 10, mean 1.63). Cranium with moderate, irregular rugo-reticulation. Antenna positioned well behind the dorsal margin of the clypeus (Fig. 10D), with a diameter of 0.1 mm and a thin but heavily sclerotized rim (Fig. 10C). Temporal band (Fig. 10C, D, G) relatively broad, with its ventral half wider than the dorsal half; edges heavily margined; inner part with heavy ferruginous pigmentation, except for the ventral one-third portion, which is nearly transparent. Paired suprafrontal marks well defined (Fig. 10D); dotted patches on the frons faint; region around the frontal suture with 12 or 14 setae. Clypeus width larger than the minimum distance between the antennae. Clypeus as shown in Fig. 10C, D; main disc with dorsal margin convex, with lateral arms straight, and dorsolateral corner roundly angulate; lateral margin straight and lacking pigmented spots, except in the tentorial pit; ventral margin shallowly convex; main disc moderately high, with a CLI of 1.5–2.5; main disc with approximately 85 setae; ventral section strongly transverse, with dorsal and ventral margins nearly parallel. Labrum (Fig. 10E, left) with numerous sensory bristles widely distributed across its surface. Palate (Fig. 10E, right) without a median patch; sclerotized patch relatively poorly developed; conical papillae dense in the proximal half of the sclerotized patch and sparser distally; spicules distributed in the medioventral part of the palate (Fig. 10B, E). Mandible heavily sclerotized in the apical two-fifth portion (Fig. 10C), with numerous pits on the outer surface (Fig. 10A). Mandibular teeth (Fig. 10F) all smooth with relatively sharp apices; teeth I and II significantly more projected than IIIa and IIIb; tooth I as large as II; tooth IIIb slightly more produced than IIIa; teeth I and II separated at an angle of 50°–60°, II and IIIa at 60°–70°, and IIIa and IIIb at 90°–140°; tooth I triangular and raised basally; bifurcation point between teeth II and IIIa deeper than the other bifurcation points. Maxilla with approximately 25 setae. Prelabium with 25‒35 setae.

Figure 10. 

Vespa binghami A right mandible, with the arrow indicating pits B labrum in ventrofrontal view C, D head in frontal view E labrum (left) and palate (right) in frontal view F apical portion of the right mandible G temporal band. Scale bars: 0.1 mm (A, E, F); 0.03 mm (B); 0.3 mm (C, D, G).

Body (thorax and abdomen): Body 29.8–31.4 mm in length (n = 10, mean 30.6 mm) and 12 mm in width; integument with evenly distributed setae; sparse and short spicules near the rim of spiracles 1 and 10. Spiracles shallow; generally uniform in size, except for spiracles 1, 2, and 10, which are slightly smaller; largest spiracle 0.35 mm in diameter; inner wall of spiracle with dense, long atrial processes; collar processes thick; spiracular rim 0.04 mm in thickness.

As in V. ducalis, mandibular teeth I and II are strongly developed. The temporal band, antennal rim, and mandible are more heavily pigmented compared to those in other species.

South Korea • 10 mature larvae; Gyeongsangbuk-do, Andong-si, Namhu-myeon; 36°52'99"N, 128°67'48"E; 2 Sept. 2022; Choi.