Xylosandrus discolor (Blandford, 1898)

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Xylosandrus discolor (Blandford, 1898) Fig. 94E, F, K

Xyleborus discolor Blandford, 1898: 429.

Xylosandrus discolor (Blandford): Browne 1963: 55.

Xyleborus posticestriatus Eggers, 1939b: 119. Synonymy: Dole and Cognato 2010: 488.

Type material.

Holotype Xyleborus discolor (NHMUK). Lectotype Xyleborus posticestriatus (NMNH).

New records.

China: Chongqing, Peng Shui, 10.v.2015, Tian-Shang, ex Castanea molissima (RABC, 1). Guangxi, Beihai, Yintan, viii.2015, Su T-L. (RABC, 1). Hong Kong, Pokfulan, 150 m, 31.v.1964, J.L. Gressitt (BPBM, 1). Jiangxi, Gan Zhou, 5.vii.2015, Lv-Jia (RABC, 1); as previous except: Jin Xian, 4.v.2016, Lv-Jia, ex Cinnamomum camphora (RABC, 1). Laos: Bolikhamxai, Ban Nape (8 km NE), 18°21'N, 105°08'E, 600 m, 1-18.v.2001, V. Kubáň (NHMB, 1). Louangnamtha, Namtha to Muang Sing, 21°09'N, 101°19'E, 900-1200 m, 5-31.v.1997, V. Kubáň (RABC, 1). Vietnam: Ninh Binh, Cuc Phuong N.P., 10-16.ix.2013, J.B. Heppner (FSCA, 5); as previous except: Mac Lake. 20°15'29.0"N, 105°42'27.5"E, 155 m, 4-7.v.2009, ex blacklight trap (FSCA, 1).

Diagnosis.

2.0-2.4 mm long (mean = 2.02 mm; n = 5); 2.0-2.29 × as long as wide. This species is distinguished by its moderate size; elytral disc flat, longer than declivity; declivital face steep, abruptly separated from disc; elytra obliquely truncate; posterolateral margins of elytra carinate to interstriae 7; declivital face with four apparent granulate striae (striae 5 short, converging with striae 4 forming a loop); declivital face convex; declivital striae setose, setae semi-recumbent hair-like and equal to the width of an interstria; interstriae granulate, granules multiseriate, confused, with a uniseriate row of erect bristles equal in length to the width of an interstria; strial granules at least 2 × larger than those of interstriae; pronotum longer than wide, from dorsal view conical frontally (type 6) and lateral view taller (type 2), summit at basal 1/4, basal 1/4 shagreened, dull, densely punctate; and broad, dense mycangial tuft on the pronotal base.

Similar species.

Xylosandrus beesoni , X. borealis , X. diversepilosus .

Distribution.

Within the study region recorded from China (Chongqing*, Fujian, Guangdong, Hainan, Hong Kong*, Jiangxi*, Sichuan, Yunnan), India (Andaman Is, Assam, Karnataka, Meghalaya, Sikkim, Tamil Nadu, Uttarakhand, West Bengal), Laos*, Myanmar, Taiwan, Thailand, Vietnam*. Also recorded from Australia, Indonesia, Japan (Ryukyu Is), Malaysia, New Guinea, Philippines, Sri Lanka.

Host plants.

Polyphagous ( Dole and Cognato 2010).

Remarks.

The biology is described by Kalshoven (1959b) and Browne (1961a). Le Pelley (1968) notes that the species attacks green, living branches of coffee in Sri Lanka, but is not considered an important pest.

Figures

Figure 94. Dorsal, lateral and declivital view of Xylosandrus dentipennis paratype, 2.15 - 2.4 mm (A, B, I), X. derupteterminatus, 2.0 - 2.3 mm (C, D, J), X. discolor, 2.0 - 2.4 mm (E, F, K), and X. diversepilosus, 2.1 - 2.4 mm (G, H, L).