Arcastes suturalis Jacoby, 1884

Hazmi, Izfa Riza & Wagner, Tomas, 2010, Revision of Arcastes Baly, 1865 from the Oriental Region (Coleoptera, Chrysomelidae, Galerucinae), ZooKeys 42 (42), pp. 79-99 : 92-94

Arcastes suturalis Jacoby, 1884

Arcastes suturalis Jacoby, 1884: 217 .

= A. ismaili Mohamedsaid, 2000: 282 ; syn. n.

Total length. 4.70–6.35 mm (mean: 5.30, n=12)

Head. Reddish-brown to red. Details of mouthparts and impressions on vertex like the description of the genus. Antennae entirely black and only the terminal three antennomeres usually contrasting pale yellow to reddish (Figs 11, 12). Shape of antennomeres like the description of the genus. Ratio length of second to third antennomere 0.50–0.57 (mean: 0.54), ratio length of third to fourth antennomere 0.67–0.70 (mean: 0.68), apical three antennomeres significantly slenderer (Fig 14).

Thorax. Shape and coloration of pronotum and scutellum like in the description of the genus (Figs 11, 12, 13). Pronotal width 1.55–2.10 mm (mean: 1.80 mm), ratio

Figure |7. Distribution of A. suturalis Jacoby, 1884 .

length to width 0.50–0.55 (mean: 0.53). Scutellum in about one third of material studied black, others brown, red or yellowish-red. Elytra elongated, black throughout in 35 % of the material examined, about 10 % with yellowish scutellar elytral spot, 50 % with entirely yellowish-red suture, and remaining material with enlarged yellowishred elytral disc like in the specimens of A. ismaili (Fig. 13). Elytral length 3.80–5.05 mm (mean: 4.40 mm), maximal width of both elytra together 1.50–3.30 mm (mean: 2.40 mm), ratio of maximal width of both elytra together to length of elytra 0.63–0.69 (mean: 0.66). Underside and legs like in the description of the genus.

Abdomen. Pale yellow to brown on the sides of sternites, dark brown to black in the middle, terminal sternite usually completely black.

Male genitalia. The outer shape as in the description of the genus. Endophallus with three spur located at the upper part, the biggest one next to the lateral spiculae. Tectum not incised at apex, slender, almost reaching towards the apex of the median lobe (Fig. 15).

Female genitalia. Spermatheca with slender to oval nodulus. Middle part moderately long and slightly curved, cornu long and curved (Fig. 16).

Distribution. Recorded from Malaysia, Singapore and Indonesia (Fig. 17).

Diagnosis. Arcastes suturalis can be distinguished from the other two species of Arcastes by the elytral coloration, which is either completely black, or posses a yellowish to reddish sutural coloration that can be occasionally enlarged to pale a yellowish elytral disc. No specimen examined had longitudinal elytral stripes as it is typical for A. biplagiata (Figs 1, 7). Finally a check of genitalia can confirm the identification ( Figs 9 , 15).

Type material. Arcastes suturalis : Lectotype: ♁, “ Arcastes suturalis Jac. / Dr. B. Hagen, Tandjong Morawa Serdang, (N.O. Sumatra).” (Fig. 12) ( NNML). Type locality: 1°21'N / 103°49'E . – Paralectotypes: 11 ex., same data as lectotype ( NNML), and at least one additional type specimen is deposited in MCZH. We herein designate a lectotype to fix the name on single specimen. – Invalid types: 2 ex. from Sumatra, Lianggas, and Soekaranda, Januar 1894, Dohrn ( MNHU) are labelled as co-type, but are not from the type series.

Arcastes ismaili : Holotype: ♁, “ Malaysia, Sabah, Danum, Ekspedisi Gunung Danum, 6–12.vi.1989, Ismail ” (Fig. 13) ( UKM) . Holotype by original designation. Type locality: 5°8'N / 117°24'E. – Paratypes: 7 ♁, 9 ♀, same data as holotype ; 1 ♀, Sabah, Lembah Danum , 21.VIII.1989, Salleh, Ismail & Nor ; 2 ♁, 1 ♀, 16.–19.V.1991, Zaidi, Ismail & Ruslan; 1 ♁, 1 ♀, 27.–31.VIII.1991, Salleh, Zaidi, Mail & Lan; 1 ♁, 3 ♀, 17.–20.IV.1992, Ismail, Yusuf & Razali; 4 ♁, 2 ♀, 22.–25.VIII.1992, Ismail, Yusuf & Sham; 1 ♁, 5.–8.XII.1992, Ismail, Yusuf & Razali. Due to the original publication, the holotype is deposited in the Center for Insect Systematics, Universiti Kebangsaan Malaysia, Bangi ( UKM), and two pairs of paratypes (2 ♁, 2 ♀) in the Insect Collection, Forest Research Centre, Sandakan, Sabah .

Further material examined. Indonesia. 1 ex., Borneo, Kalimantan Tengah, Busang / Rekut. Confl. FIT, Primary Forest, Brendell / Mendel , August 2001, 1°40'S / 113°22'E ( BMNH) ; 1 ex., Bari, Jan. 190?, Jacoby Coll. 1909–28 a, 0°31'S / 104°30'E ( BMNH) ; 1 ex., Soekaranda , Januar 1894, Dohrn, 0°37'S / 94°29'E ( NNML) ; 2 ex., Sumatra, Manna 1902, M Knap Pert., 4°27'S / 102°59'E ( NNML) ; 1 ex., Dohrn, Sumatra. Lianggagas, 0°37'S / 94°29'E ( NNML) ; 3 ex., Medan, Sumatra, J. J. D. V, 3°30'N / 98°37'E ( NNML) ; 9 ex., N. E. Sumatra, Deli, Kuala Simpang , VIII 1953, A. Sollart, Lowland forests, Museum Leiden, 3°33'N / 98°40'E ( NNML) ; 1 ex., Dohrn, Sumatra, Lianggagas, co-type, 0°37'S / 94°29'E ( MNHU) ; 1 ex., Soekaranda , Januar 1894, Dohrn, co-type, 0°37'S / 94°29'E ( MNHU) ; 1 ex., Tamiang, Sumatra, 2°29'S / 103°54'E ( MNHU). – Malaysia. 10 ex., Sarawak, 4th Division, Gn. Mulu NP, nr Base Camp, 50–100 m, P. M. Hammond & J. E. Marshall , V.–VIII.1978, B. M. 1978–49, 3°52'N / 114°46'E ( BMNH) ; 11 ex., Quop , W. Sarawak, II.–IV.1914, G. E. Bryant, G. Bryant 1919–147, 1° 33'N / 101°24'E ( BMNH) ; 6 ex., Mt. Matang , W. Sarawak, Dec. 1913, G. F. Bryant, G. Bryant coll. 1919–147, 1.55N / 110.35E ( BMNH) ; 3 ex., Sarawak, C. J. Brooks, B. M. 1928–193, 2°30'N / 113°15'E ( BMNH) ; 1 ex., Sarawak, 1907–1909, C. J. Brooks, B. M. 1936–681 ( BMNH) ; 2 ex., Mt. Matang , 3 1/ 2 mile, 8.V.1909, Sarawak, J. E. A Lewis, 1910–116, 1.55N / 110.35E ( BMNH) ; 1 ex., N. Borneo, Samawang, Nr. Sandakan , July 1927, 5°50'N / 118°6'E ( BMNH) ; 1 ex., Johor, Kota Tinggi , 27.XI.2007, M. Y. Ruslan, 1°43'N / 103°54'E ( UKM) ; 4 ex., Johor, Endau Rompin , 1.–4.VI.2007, B. H. Izfa, 2°38'N / 103°39'E ( UKM) ; 1 ex., Malaysia, prov. Pahang, Tasik Chini ( Lake ), primaval forests surrouding lake, 2.–5.III.2007, V. Hula, L. Purchart, Růžička F., 3°23'N / 102°55'E ( CJB) ; 1 ex., Malaysia, Pahang prov., Taman Negara, N.P., Kuala Tahan , 14.III.2007, Igt. Jiří Foit, 4°19'N / 102°20'E ( CJB) ; 1 ex., Pahang, Hutan Simpan Kuala Lompat , 24–26.V.1990, Zaidi, Ismail & Ruslan, 3°41'N / 102°13'E ( CJB) ; 2 ex., Malaysia, Taman Negara NP, Kuala Tahan, primaval forests, 5–9.III.2007, V. Hula, L. Purchart, Růžička F., 4°19'N / 102°20'E ( CJB). – Singapore. 3 ex., Nee Soon, 14.X.2005, Swamp Forest , Malaise trap 1, station 25388, leg. P. Grootaert, 1°21'N / 103°49'E ( IRSN) .

Figures

Figure 9. Arcastes biplagiata Baly, 1865. Median lobe: a dorsal b lateral c ventral.