Parastasia bigibbosa Nonfried 1891
Creators: name: Hongsuwong, Thitipong
name: Sanguansub, Sunisa
name: Jaitrong, Weeyawat
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Rutelidae
Parastasia
Parastasia bigibbosa

description: Parastasia bigibbosa Nonfried, 1891
(Figs. 29–39)
Parastasia bigibbosa Nonfried, 1891: 238. Type locality: Siam (ZMB).
Parastasia bigibbosa: Ohaus 1898: 15; Ohaus 1918: 32; Ohaus 1934: 100; Machatschke 1972: 37; Kuijten 1992: 33, figs. 21–24; Wada 2013: 8, figs. 12–21.
Parastasia sulcicollis Ohaus, 1911: 331.
Type locality: Matang, Borneo; Kuijten 1992: 33 [junior synonym of Parastasia bigibbosa].
Subpeltonotus andamanae Ghai, Chandra & Ramamurthy, 1988: 21, figs. 1–12.
Type locality: South Andamans, India; Jameson & Wada 2004: 6 [transferred to Parastasia]. New synonymy
Material examined. Western Thailand: 1 male (CUT), Kanchanaburi province, Thong Pha Phum district, Pilok subdistrict, 29.V.2017, T. Unnahachote leg. Northeastern Thailand: 1 male (THNHM-I-09978, THNHM). Nakhon Ratchasima province, Research site Pakthongchai, 24–26.IV.1967, Dr. Roth leg.; 1 female (THNHM-I-09979, THNHM), Nakhon Ratchasima province, Sakaerat Environmental Research Station, dry evergreen forest, light trap, 8.IV.1969. Eastern Thailand: 2 males (THNHM-I-09982 and THNHM-I-09983, THNHM), Trat province, Ko Kut district, Klong Yai Ki waterfall, 11º37'28.4"N, 102º32'48.6"E, 18.IV.2009, T. Jeenthong leg.; 1 female (THNHM-I-09981, THNHM), Trat province, Ko Kut district, Klong Yai Ki waterfall, 11º37'28.4"N, 102º32'48.6"E, 18.IV.2009, T. Jeenthong leg.; 1 male (THNHM-I-09980, THNHM), Trat province, Ko Kut district, Klong Yai Ki waterfall, 11º40'45.5"N, 102º32'35.9"E, 17.IV.2009, T. Jeenthong leg.
Diagnosis (based on Thai specimens). Male: Elongate oval in dorsal view; entire body black to dark; antennae, propygydium, pygidium, tarsi, and abdominal ventrites somewhat lighter in coloration. Eye large, ratio of IOD and HW 0.51; frons partly covered with erect setae; antennal clubs clearly longer than antennal segments 1–7 combined. Pronotum bigibbous with a longitudinal groove medially and lateral portions of pronotum with impressed areas; posterior margin of pronotum with incomplete rim; area around anterolateral corners of pronotum with suberect setae. Elytra with 10 rows of round punctures, distinctly impressed as shallow grooves. Pygidium suboval, 0.58 as long as width; surface of pygidium setigerous reticulate. Male genitalia: Aedeagus symmetric (Figs. 37–39); in dorsal view, external margin of parameres convex third-fifth from anterior, apex truncate and sharply carinate backward. Female: Generally similar to male. However, body size relatively larger than male; antennae somewhat shorter; pygidium shorter than long, oval, 0.53 times as long as width; external claws of meso- and metatarsi narrowly bifurcate (wider in male); in lateral view, abdominal sternites slightly convex, while feebly concave in male.
Measurements. Male: TL 14.26–15.46 mm; BH 6.12–6.56 mm; EL 8.43–9.06 mm; EW 7.73–8.36 mm; PL 5.21–5.71 mm; PW 7.03–7.63 mm; HW 3.52–3.65 mm; IOD 1.81–1.92 mm; ED 1.48–1.59 mm. Female: TL 17.26–17.46 mm; BH 7.41–7.47 mm; EL 9.78–9.81 mm; EW 9.58–9.69 mm; PL 6.15–6.31 mm; PW 8.51–8.66 mm; HW 3.94–4.00 mm; IOD 1.95–2.05 mm; ED 1.73–1.75 mm.
Differential diagnosis. The species can be separated from the other Thai Parastasia species as follows: 1) body elongate, oval and black to dark color; 2) eyes large (ratio of IOD and HW 0.51); 3) antennal clubs longer than antennal segments 1–7 combined; 4) galea of maxillae without distinct teeth; 5) pronotum bigibbous; 6) head, pronotum near anterolateral corners, propygidium and pygidium covered with setae; 7) parameres symmetric with apex truncate and sharply carinate backward.
Distribution. Thailand (Kanchanaburi, Nakhon Ratchasima, and Trat provinces), India (South Andaman Islands) (Ghai et al. 1998), Malaysia (Borneo) (Ohaus 1911).
Remarks. The species was originally described from “ Siam ” with no more precise locality (Nonfried 1891). Since then, the subsequent records (as P. sulcicollis) were from Borneo (Ohaus 1911; Kuijten 1992) and there were no more records from Thailand. Therefore, the distribution of this species in Thailand was questioned. However, we finally found 7 specimens of the species from northeastern, eastern, and western Thailand which are deposited in THNHM and CUT. We confirm that Parastasia bigibbosa can be found in Thailand. We have compared images of the Subpeltonotus andamanae holotype (Ghai et al. 1988) reaching the conclusion that it has the same external morphology and male genitalia with P. bigibbosa. Wada (2015b) in his dissertation already recognized these characteristics and pointed out that S. andamanae was a junior synonymy of P. bigibbosa, but it was not a publication in accordance of ICZN (1999) and unfortunately disclaimed. Thus, in the present paper we synonymize P. andamanae with P. bigibbosa.
description: Published as part of 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, pp. 547-562 in Zootaxa 5205 (6) on page 554, DOI: 10.11646/zootaxa.5205.6.3, http://zenodo.org/record/7318720