Xylosandrus subsimiliformis (Eggers, 1939)

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 subsimiliformis (Eggers, 1939) Fig. 97C, D, H

Xyleborus subsimiliformis Eggers, 1939a: 11.

Xylosandrus subsimiliformis (Eggers): Wood and Bright 1992: 800.

Type material.

Holotype (NHRS).

New records.

Vietnam: Lao Cai, Hoang Lien N.P., 22.35, 103.77, 1500-2000 m, 20.v.2019, VN185, S.M. Smith, A.I. Cognato, ex 1-2 cm branch (MSUC, 37).

Diagnosis.

2.45-3.0 mm long (mean = 2.6 mm; n = 5); 1.96-2.14 × as long as wide. This species is distinguished by its large 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 and interstriae setose, setae recumbent, very fine, hair-like, equal to the width of an interstria; interstriae granulate, granules multiseriate, confused; with a uniseriate row of erect hair-like setae equal in length to the width of an interstria; strial granules 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. brevis , X. jaintianus , X. subsimilis .

Distribution.

China (Yunnan), Myanmar, Vietnam*.

Host plants.

Unknown.

Remarks.

This species was collected in great abundance by SMS and AIC in Lao Cai province, Vietnam. In nearly all collecting events the species was found in small branches (1-4 cm in diameter) that were dry and often exposed to full sun, an unusual feeding habit, as most other xyleborines are unable to thrive under these conditions. Records from Thailand ( Dole and Cognato 2010; Beaver et al. 2014) should be referred to X. beesoni .

Figures

Figure 97. Dorsal, lateral and declivital view of Xylosandrus spinifer holotype, 3.3 mm (A, B, G), X. subsimiliformis holotype, 2.45 - 3.0 mm (C, D, H), and X. subsimilis, 2.5 - 2.9 mm (E, F, I).