Tachytes Panzer

Back, Yeong-Bin & Kim, Jeong-Kyu, 2014, Review of the genus Tachytes Panzer (Hymenoptera: Crabronidae: Crabroninae) of South Korea, with description of one new species, Zootaxa 3795 (3), pp. 301-310 : 302

Key to the South Korean species of the genus Tachytes Panzer

(If sex not stated, the character is applicable to both)

1. Length more than 18 mm in female, more than 17 mm in male. Metasomal tergum I with silvery transverse apical setal band narrower than MOD and often confined to extremely apicolateral margins; terga II–III (often also tergum IV) with silvery apical setal bands broad, three to four times as broad as MOD ( Fig. 1 A). Female: bristles on pygidial plate black. Male: sternum VIII with apical margin very slightly emarginated and sinuous, not forming apicolateral point; distal quarter of sternum VIII distinctly widened ( Fig. 4 B)................................................................ T. sinensis Smith

- Length less than 16 mm in female, less than 15 mm in male. Metasomal terga I–IV with broad brassy golden or silvery apical setal bands ( Fig. 1 B–F). Female: bristles on pygidial plate golden yellow or dark-blackish brown. Male: sternum VIII with apical margin roundly emarginate, forming a pair of apicolateral roundish teeth or triangular point ( Fig. 4 C, E, G and J); distal part of lateral margins of sternum VIII not distinctly widened, almost parallel or at most slightly convex..................... 2

2. LID in female slightly shorter than flagellomere I ( Fig. 2 C), in male ca. 0.6–0.8 × as long as flagellomere I ( Fig. 2 D). Female: bristles on pygidial plate golden yellow; apicomedian part of clypeus produced, forming a mammiform or reversed trapezoid protuberance ( Fig. 2 C, bottom line drawing). Male: apical emargination of sternum VIII narrow and deep, forming a pair of rounded apicolateral teeth ( Fig. 4 C)............................................. T. etruscus sibiricus Gussakovskij

- LID wider than flagellomere I. Female: bristles on pygidial plate blackish brown or dark brown; apicomedian part of clypeus evenly rounded, without protuberance, or at most low and broadly produced but not forming distinct protuberance ( Fig. 2 E–J). Male: apical emargination of sternum VIII broader, forming a pair of triangular apicolateral points ( Fig. 4 E, G and J)...... 3

3. Vestiture on frons below ocellar scars and on clypeus silvery to pale yellow in female ( Fig. 2 E), golden in male ( Fig. 2 F); appressed setae on pronotal dorsum silvery white; mesonotum, mesopleuron, scutellum and metanotum without dense appressed setae, at most with small and sparse silvery whitish setal patches; apical setal bands on metasomal terga I–IV yellowish. Clypeus not notched apicomedially ( Fig. 2 E and F). Male: apical emargination of sternum VIII shallow, much less than semicircular ( Fig. 4 E). All legs black........................................................ T. fruticis Tsuneki

- Corresponding vestiture golden ( Fig. 2 G–J); pronotum, both basomedian and lateral parts of mesonotum, larger median area of mesopleuron, almost entire metanotum and propodeum with dense golden appressed setae ( Fig. 1 D–F); apical setal band on metasomal tergum I pale yellow; setal bands on terga II–IV silvery white. Clypeus notched apicomedially, often forming a pair of small teeth ( Fig. 2 G–J). Male: apical emargination of sternum VIII somewhat deep, almost semicircular or slightly shallower ( Fig. 4 G and J). At least apical parts of femora, entire tibiae and larger part of tarsi of all legs brownish to ferruginous. 4

4. LID ca. 1.3 × as long as flagellomere I ( Fig. 3 D). Propodeal dorsum from anterior margin to propodeal impression with weak but well discernible median longitudinal furrow equipped with weak cross ridges ( Fig. 3 E). Female: pygidial plate longer and more slender, an isosceles triangle in shape ( Fig. 3 F). Male: apical emargination of metasomal sternum VIII deeper, almost semicircular ( Fig. 4 G).................................................................... T. modestus Smith

- LID ca. 1.5 × as long as flagellomere I ( Fig. 3 A). Propodeal dorsum without median longitudinal furrow or at most with very short evanescent furrow basally ( Fig. 3 B). Female: pygidial plate shorter and broader, almost an equilateral triangle in shape ( Fig. 3 C). Male: apical emargination of metasomal sternum VIII shallower, less than semicircular ( Fig. 4 J)..................................................................................................... T. gyusanus n. sp.

Figures

FIGURE 1. Female habitus of Korean Tachytes species. A, T. sinensis. B, T. etruscus sibiricus. C, T. fruticis. D, T. modestus. E, T. gyusanus n. sp., in dorsal view. F, T. gyusanus n. sp., in profile. Scale bars: 1 mm.

FIGURE 2. Head in full frontal views and clypeal apical margin (bottom line drawing of each image) of Korean Tachytes species. A, T. sinensis, female. B, T. sinensis, male. C, T. etruscus sibiricus, female. D, T. etruscus sibiricus, male. E, T. fruticis, female. F, T. fruticis, male. G, T. modestus, female. H, T. modestus, male. I, T. gyusanus n. sp., female. J, T. gyusanus n. sp., male.

FIGURE 3. Selected characteristics of T. gyusanus n. sp. and T. modestus. A-C, T. gyusanus n. sp.: A, head, in dorsal view, showing broader LID; B, propodeal dorsum with dense appressed setae in median part; C, pygidial plate. D-F, T. modestus: D, head, in dorsal view, showing narrower LID; B, propodeal dorsum with shallow median longitudinal furrow, but without dense appressed setae in median part; C, pygidial plate.

FIGURE 4. Male genitalia and sternum VIII. A, genitalia of T. sinensis, in dorsal view. B, sternum VIII of T. sinensis. C, sternum VIII of T. etruscus sibiricus. D, genitalia of T. etruscus sibiricus, in dorsal view. E, sternum VIII of T. fruticis. F, genitalia of T. fruticis, in dorsal view. G, genitalia and sternum VIII of T. modestus, in dorsal view. H, genitalia of T. gyusanus n. sp., in dorsal view. I, genitalia of T. gyusanus n. sp., in lateral view. J, sternum VIII of T. gyusanus n. sp.