Microperus sagmatus, Smith & Beaver & Cognato, 2020

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

Microperus sagmatus sp. nov. Fig. 70A, B, E

Type material.

Holotype, female, Thailand: Suranthani [= Surat Thani], durian or[chard], 01.xii.[20]10, Wisut Sittichaya, EToH-trap (MSUC). Paratypes, female, Malaysia: Penang, B[atu] Ferringhi, 6.i-1.ii.1981, T. Palm (RABC, 1); Thailand: as holotype (MSUC, 1); Prachuab Khiri Khan: Kui Buri N.P., 27.iii.2008, S. Stevens et al., ex ‘krachid’ (NHMUK, 2; MSUC, 2; QSBG, 1; RABC, 2); Songkhla, Ratthapum distr., ex durian branch, 4.xi.2008, W. Sittichaya (RABC, 1; QSBG 1).

Diagnosis.

1.75-1.95 mm long (mean = 1.83 mm; n = 5); 2.69-2.79 × as long as wide. This species is distinguished by the elytral disc shallowly transversely impressed with a saddle-like depression; elytral interstriae costate with strong interstrial spines posterior to the saddle; and declivity steep, slightly flattened.

Microperus sagmatus closely resembles M. undulatus but is distinguished by the discal impression deeper, antero-posteriorly narrower, with steeper anterior and posterior slopes, strial punctures on impression with rounded granules, interstrial spines on disc behind saddle stronger, and backwardly hooked, not pointing dorsally.

Similar species.

Microperus cruralis , M. nugax , M. undulatus .

Description

(female). 1.75-1.95 mm long (mean = 1.83 mm; n = 5); 2.69-2.79 × as long as wide. Body ferruginous. Legs and antennae light brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes, shagreened, punctate; punctures large, shallow, sparse, setose; punctures bearing a long, erect hair-like seta. Eyes shallowly emarginate just above antennal insertion, upper part smaller than lower part. Submentum large, distinctly triangular, slightly impressed. Antennal scape short and thick, as long as club. Pedicel as wide as scape, shorter than funicle. Funicle 4-segmented, segment 1 shorter than pedicel. Club longer than wide, obliquely truncate, type 2; segment 1 corneous, feebly convex on anterior face, occupying basal 1/3, nearly covering posterior face; segment 2 narrow, soft; segment 1 present on posterior face. Pronotum: 1.05 × as long as wide. In dorsal view subquadrate and parallel-sided, type 3, sides parallel in basal 2/3, weakly rounded anteriorly with prominent anterolateral corners; anterior margin without a row of serrations. In lateral view tall, type 2, disc flat, summit at midpoint. Anterior slope with densely spaced, broad asperities, becoming lower and more strongly transverse towards summit. Disc shagreened, alutaceous, impunctate, glabrous, some moderately long hair-like setae at margins. Lateral margins obliquely costate. Base weakly bisinuate, posterior angles acutely rounded, almost subquadrate. Elytra: 1.7 × as long as wide, 1.6 × as long as pronotum. Scutellum minute, convex, slightly raised above elytral surface. Elytral mycangium present as a dispersed median setal tuft of setae extending along elytral base. Elytral base transverse, edge oblique, humeral angles rounded, parallel-sided in basal 4/5, then narrowly rounded to apex. Disc shiny, a moderately deep transverse saddle-like impression at midpoint, striae and interstriae flat, nearly glabrous anteriad of depression, strial punctures on impression with rounded granules, interstriae costate with strong backwardly hooked spines posteriad of depression, spines setose with long hair-like setae. Declivity occupying 1/3 of elytral length, shagreened, dull, steeply rounded, face slightly flattened; striae flat, parallel, punctate, punctures very large, shallow subcontiguous, setose, setae recumbent, as long a puncture; interstriae irregularly denticulate along their lengths, denticles small, irregularly spaced and sized, each bearing a long, erect hair-like seta, interstriae 1 and 3, weakly convex, 2 and 4 flat. Posterolateral margin carinate to interstriae 7. Legs: procoxae contiguous; prosternal coxal piece tall, conical. Protibiae obliquely triangular, broadest at apical 1/3; posterior face smooth; apical 1/3 of outer margin with seven moderate socketed denticles, their length approximately as long as basal width. Meso- and metatibiae flattened; outer margin evenly rounded with nine and eight moderate to large socketed denticles, respectively.

Etymology.

G. sagma = pack-saddle. In reference to the shape of the elytra. An adjective.

Distribution.

West Malaysia, Thailand.

Host plants.

Recorded from Durio zibethinus (durian) ( Malvaceae ), and an undetermined tree, ‘krachid’.

Remarks.

The specimens from Thailand were included under M. undulatus by Beaver et al. (2014).

Figures

Figure 70. Dorsal, lateral and declivital view of Microperus sagmatus holotype, 1.75 - 1.95 mm (A, B, E), and M. undulatus, 2.0 - 2.1 mm (C, D, F).