Vespa ducalis Smith 1852
Creators: name: Kim, Jaehee
name: Kwon, Oh-Seok
name: Yamane, Seiki
name: Choi, Moon Bo
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Vespidae
Vespa
Vespa ducalis

description: Vespa ducalis Smith, 1852
Description.
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. 4 D, E), with a diameter of 0.09 mm and moderate sclerotization (Fig. 4 D). Temporal band (Fig. 4 D, 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. 4 H). Ventral edge positioned slightly above the level of the dorsal margin of the antenna (Fig. 4 E). Paired suprafrontal marks well-defined (Fig. 4 E). 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. 4 D, 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. 4 E). Labrum (Fig. 4 F, left) with numerous sensory bristles, except in the dorsal region. Palate (Fig. 4 F, 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. 4 B, F). Mandible (Fig. 4 A, C, G) slightly sclerotized (Fig. 4 C), bearing numerous pits on its outer surface (Fig. 4 A). 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. 4 G). Maxilla with approximately 30 setae. Prelabium with approximately 30 setae.
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.
Remarks.
The cranium is orangish in color except in the area surrounding the antennae, a characteristic unique to V. ducalis (Fig. 4 D). The dorsal (upper) region (main disc) of the clypeus is large and over three times the height of the ventral (lower) region (Fig. 4 E). Mandibular tooth III is relatively small, measuring less than half as the length of tooth II (Fig. 4 C, G).
Specimens examined.
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.
description: Published as part of Kim, Jaehee, Kwon, Oh-Seok, Yamane, Seiki & Choi, Moon Bo, 2025, Comparative morphological analysis of mature larvae of eight Vespa Linnaeus, 1758 species (Hymenoptera, Vespidae) in South Korea, pp. 435-465 in Journal of Hymenoptera Research 98 on pages 435-465, DOI: 10.3897/jhr.98.141572