Vespa simillima simillima Smith, 1868

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, Journal of Hymenoptera Research 98, pp. 435-465 : 435-465

Vespa simillima simillima Smith, 1868

Description.

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. 8 D, E ), faintly sclerotized or nearly transparent (Fig. 8 D – F ). Temporal band (Fig. 8 F, 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. 8 D, 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. 8 D – 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. 8 H , left) with numerous sensory bristles, except in the dorsolateral region. Palate (Fig. 8 H , 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. 8 H ); spicules present in the medioventral part and along the lateral margin of the palate, as well as on the conical papillae (Fig. 8 C, H ). Mandible (Fig. 8 A, F, I ) with strongly sclerotized teeth; surface lacking pits but bearing a few stumps (Fig. 8 A ). 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.

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).

Remarks.

The antenna is typically nearly hyaline, as seen in V. velutina (Fig. 9 D ); however, it may be slightly sclerotized, as in V. analis parallela (Fig. 6 C ). 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).

Specimens examined.

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 .

Figures

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)

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).

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); 0.1 mm (B, F, G); 0.3 mm (D, E).