Rutelarcha quadrimaculata Waterhouse, 1874

Hongsuwong, T., Jaitrong, W., Tasen, W. & Zorn, C., 2020, New records of the chining leaf chafer beetles (Coleoptera: Scarabaeidae, Rutelinae) from Thailand and Laos, Far Eastern Entomologist 398, pp. 8-17 : 9-10

Rutelarcha quadrimaculata Waterhouse, 1874

Figs 1–6

Rutelarcha quadrimaculata Waterhouse, 1874: 52 . Type Locality: Penang, Malaysia

(BMNH).

Rutelarcha quadrimaculata: Westwood, 1875: 235 ; Nonfried, 1891: 355; Ohaus, 1900:

260; Ohaus, 1918: 39; Ohaus, 1932a: 122; Kuijten, 1988: 79; Kuijten, 1992: 19; Wada, 1988: 5,

2015: table III-2.

MATERIAL EXAMINED. Thailand: Trang province, Huai Yot District, Huai Yot Subdistrict , 6.III 2019, 1 female ( THNHM –I–09976), S. Amuntaikul & P. Wannaput leg.

MEASUREMENTS. Female: TL 15.6 mm; EW 9.4 mm; PW 5.1 mm; PL 8.3 mm.

DIAGNOSIS. Rutelarcha quadrimaculata is a conspicuous species, which can be distin-

guished from the only other known species in this genus ( R. bakeri Ohaus, 1915 from the

Philippines) and similar species in the closely related genera Cyphelytra Waterhouse, 1875

and Lutera Westwood, 1875 by the combination of the following characters: head black,

anterior clypeal margin medially with two weak denticles; lateral face of pronotum densely longitudinally striated. Pronotum largely black with its lateral face yellowish orange, with black spot located in middle of orange area; elytra with several rows of rounded punctures and smooth and shiny interspaces.

Ground color of elytra yellowish orange, with small black spot behind humeral callus and large transverse spot in posterior half ( Figs 1–2 ); mesosternal process extending antero-

ventrally beyond base of mesocoxa ( Fig. 3 ).

dorsal view; 2 – habitus, lateral view; 3 – habitus, ventral view; 4 – fore leg; 5 – middle leg;

6 – hind leg.

DISTRIBUTION. Thailand (new record), Borneo (Ohaus, 1900, 1932a; Wada, 2015),

West Malaysia (Kuijten, 1988; Ohaus, 1900; Waterhouse, 1874) and Sumatra (Ohaus, 1918).

REMARKS. Rutelarcha quadrimaculata has a typical sundaic distribution. The record in the present study is the northernmost in its distribution range. A larva of this species was collected from a rotten log.

Figures

Figs 1–6. Rutelarcha quadrimaculata, Thailand: Trang province, female: 1 – habitus,