Parastasia, Westwood, 1841

Hongsuwong, Thitipong, Sanguansub, Sunisa & Jaitrong, Weeyawat, 2022, A new species and a new synonym in the scarab genus Parastasia Westwood, 1841 (Coleoptera: Scarabaeidae: Rutelinae), with a key to species from Thailand, Zootaxa 5205 (6), pp. 547-562 : 556-560

Key to species of Parastasia known from Thailand

1 Small to medium in size, total length ˂ 20 mm; elytra with distinct rows of punctures; in lateral view, parameres not bilobed. ................................................................................................... 2

- Large in size, TL ≥ 20 mm; rows of punctures on elytra indistinct ( Fig. 51 ); parameres slightly asymmetric, apex bilobed in lateral view ( Figs. 61–62 )............................................................ P. birmana Arrow, 1899

2 All claws simple, sickle-shaped without branching ( Fig. 58 ); male aedeagus asymmetric, parameres fused together ( Figs. 48–50 )............................................................. P. bimaculata ( Guérin-Méneville, 1843)

- External claw of meso- and metatarsi bifurcate; aedeagus symmetric or asymmetric, but parameres not fused together..... 3

3 Propygidium and pygidium covered with decumbent setae ( Figs. 35–36 )......................................... 4

- Propygidium and pygidium without long setae ( Fig. 4 )........................................................ 7

4 Eyes narrow, ratio of IOD and HW ˃ 0.67 ( Fig. 56 ); antennal clubs distinctly shorter than antennal segment 1–7 combined; mesotarsi of male somewhat enlarged, segment 5 as long as or longer than segment 1–4 combined ( Fig. 56 ); median sac of endophallus membranous without any appendages or spines, but sometimes distinctly with sclerotic surface ( Fig. 67 )...... 5

- Eyes broad, ratio of IOD and HW ˂ 0.60 ( Fig. 57 ); antennal clubs clearly longer than antennal segment 1–7 combined; mesotarsi simple in both sexes, tarsal segment 5 shorter than segment 1–4 combined ( Fig. 60 ); median sac of endophallus with numerous spines ( Fig. 68 )................................................................. P. bigibbosa Nonfried, 1891

5 Dorsal surface mostly brownish ( Fig. 53 ); mesotarsi clearly enlarged in male, segment 5 much longer than segments 1–4 combined............................................................................................ 6

- Dorsal surface mostly orange-reddish ( Fig. 52 ); segment 5 of mesotarsi as long as segments 1–4 combined in male......................................................................................... P. anomala Arrow, 1899

6 Ground color of dorsal surface reddish brown to dark brown, posterolateral portions of pronotum with a yellow to testaceous patch; in dorsal view, male aedeagus symmetric. India, Bhutan, China, Vietnam, Laos, and northern Thailand.............................................................................................. P. indica Ohaus, 1898

- Ground color of dorsal surface brownish with dark brown brands on pronotum and elytra ( Fig. 53 ); aedeagus curve and asymmetric. Southern Thailand, Malaysia, Indonesia, and Philippines................... P. westwoodii Westwood, 1841

7 Ground color of dorsal surface reddish, elytra unicolor ( Figs. 1 , 55 ); external margin of parameres sinuate in dorsal view ( Figs. 13 , 65 ); in lateral view, ventral margin of parameres plain without distinct concavity ( Figs. 15 , 66 ); anterior portion of median sac of endophallus with small spines, remaining followed by large spines ( Figs. 16 , 70 ).............................. 8

- Ground color of dorsal surface orange, external and posterior portions of elytra black ( Fig. 54 ); in dorsal view, parameres without concavity ( Fig. 63 ); in lateral view, ventral margin of parameres thickly marginated and deeply concave one-fifth from base ( Fig. 64 ); anterior portion of median sac of endophallus with few large spines, remaining followed by medium spines ( Fig. 69 )................................................................. P. masumotoi Wada & Muramoto, 1999

8 Scutellum and ventral surface reddish to dark reddish brown ( Figs. 1–2 , 55 ); in lateral view, basal of ventral margin of parameres without protrusion.................................................................................... 9

- Scutellum and ventral surface nearly black; in lateral view, basal of ventral margin of parameres clearly protruding backward, process sharp and elongate as spinose formed................................. Parastasia selangorica Kuijten, 1992

9 Rather small in size ( Fig. 1 ); first row of punctures on elytra sinuate; metasternal process stout; in dorsal view, apex of parameres roundly convex ( Fig. 13 ); in lateral view, dorsal and ventral margins almost straight ( Fig. 15 ); median sac of endophallus with a cluster of dense small spines anteriorly, posterior part of median sac with five dark large spines ventrally ( Fig. 16 )....................................................... P. spinosa Hongsuwong, Sanguansub & Jaitrong , new species

- Medium in size ( Fig. 55 ); first row of punctures on elytra mostly straight; metasternal process sharply produced; in dorsal view, apex of parameres almost truncate with a small carina near internal margin ( Fig. 65 ); in lateral view, dorsal margin weakly concave, while ventral margin convex ( Fig.66 ); median sac of endophallus with sparse small spines anteriorly, ventral of posterior part without dominantly large spines ( Fig. 70 ).................................... sulcipennis Gestro, 1888

Figures

FIGURES 51–60. Characteristics of Parastasia species, non-type specimens. 51, Parastasia birmana Arrow, 1899, male (THNHM-I-09992); 52, 56, 59, Parastasia anomala Arrow, 1899, male (THNHM-I-09977); 53, Parastasia westwoodii Westwood, 1841, female (CTH); 54, Parastasia masumotoi Wada & Muramoto, 1999, male (CTH); 55, Parastasia sulcipennis Gestro, 1888, male (CTH); 57, 60, Parastasia bigibbosa Nonfried, 1891, male (THNHM-I-09982); 51–55, habitus in dorsal view; 56–57, head in dorsal view; 58–60, mesotarsus.

FIGURES 61–70.Male genitalia of Parastasia species, non-type specimens.61–62, Parastasia birmanaArrow, 1899(THNHM- I-09992); 63–64, 69 Parastasia masumotoi Wada & Muramoto, 1999 (CTH); 65–66, 70, Parastasia sulcipennis Gestro, 1888 (CTH); 67, Parastasia anomala Arrow, 1899 (THNHM-I-09977); 68, Parastasia bigibbosa Nonfried, 1891 (CUT); 61, 63, 65, parameres in dorsal view; 62, 64, 66, aedeagus in lateral view; 67–70, endophallus.

FIGURES 40–50. Parastasia bimaculata (Guérin-Méneville, 1843), non-type specimens. 40–42, 46, male (CTH); 43–45, 47, female (CTH); 48–50, aedeagus of male; 40, 43, 48, dorsal view; 41, 44, 49, ventral view; 42, 45, 50, lateral view; 46–47, caudal view.

FIGURES 29–39. Parastasia bigibbosa Nonfried, 1981, non-type specimens. 29–31, 35, male (THNHM-I-09982); 32–34, 36, female (THNHM-I-09981); 37–39, aedeagus of male; 29, 32, 37, dorsal view; 30, 33, 38, ventral view; 31, 34, 39, habitus in lateral view; 35–36, caudal view.

FIGURES 1–5. Parastasia spinosa Hongsuwong, Sanguansub & Jaitrong, new species (holotype, male, THNHM-I-09998). 1, habitus in dorsal view; 2, habitus in ventral view; 3, habitus in lateral view; 4, habitus in caudal view; 5, inner side of right protarsus.

FIGURES 6–16. Mouthparts and male genitalia of Parastasia spinosa Hongsuwong, Sanguansub & Jaitrong, new species (holotype, male, THNHM-I-09998). 6, 7, labrum; 8, 9, left mandible; 10, 11 maxillae; 12, mentum; 13, 14, 15, male parameres; 16, endophallus; 6, 8, 10, 13, dorsal view; 7, 9, 11, 12, 14, ventral view.