Ischalia (s. str.) laosensis Kazantsev et Telnov, 2019

Kazantsev, Sergey V. & Telnov, Dmitry, 2019, New species of Ischalia Pascoe, 1860 (Coleoptera: Ischaliidae), with a key to aposematically coloured species from continental Asia, and new notes on their mimicry, Zootaxa 4555 (3), pp. 441-450 : 443-445

Ischalia (s. str.) laosensis Kazantsev et Telnov , sp. nov.

( Figs 5–7 )

Material. Holotype ♂ [ ICM], NE Laos, Hua Phan prov., Ban Saleui, Phou Pan Mt. , ~20˚12′N, 104˚01´E, 1300– 1900 m, 1–31.V.2011, C. Holzschuh leg. ; Paratypes 3♂♂ [1 DTC & 2 ICM], same label .

Description. Measurements. Total length: 6.6–6.8 mm. Head length: 0.7–0.8 mm. Head width: 0.8–0.9 mm. Pronotal length: 0.8–0.9 mm. Pronotal width: 1.1–1.2 mm. Elytral length: 5.0– 5.1 mm. Elytral width at humeri: 2.0– 2.1 mm.

Male. Dark brown to black; head, except anteriorly, pronotum, except at disk and near anterior angles, and tarsi reddish brown; elytra ochre, with narrow dark brown longitudinal vittae along suture in proximal third ( Fig. 5 ).

Head transverse, posteriorly smooth and flattened, steeply rounded to narrow parallel-sided neck. Eyes rather small, ca. 2.5 times longer than wide, separated by ca. 1.3 times their length as viewed from above, conspicuously emarginate at inner border. Clypeus transverse, ca. 2 times wider than long, almost rectangular; frontoclypeal suture represented by smooth transverse impression, with traces of suture noticeable at sides. Labrum transverse. Terminal segment of labial and maxillary palps bulbous, strongly securiform. Antennae filiform, extending to elytral midlength, with antennomere 3 about twice as long as antennomere 2 and ca. 1.2 times shorter than antennomere 4 ( Fig. 5 ).

Pronotum transverse, 1.5 times wider than long, opaque, almost parallel-sided and slightly convex anteriorly, with completely rounded anterior and strong acute laterally produced posterior angles; disc with narrow median longitudinal carina in basal half; postmedian transverse depressions almost straight; two pairs of pores located in transverse depressions in posterior third, first near the carina, second more than half a distance from the carina towards lateral margin. Scutellum distally slightly emarginate ( Fig. 5 ).

Elytra opaque, moderately long, together ca. 2.5 times longer than wide at humeri, parallel-sided, flattened, with lateral costa nearly reaching apex and less strong humeral costa reaching basal third of elytra; dorsal surface densely punctate, punctures small; lateral interstice with four rows of punctures; pubescence very short and decumbent ( Fig. 5 ).

First abdominal ventrite with median intercoxal carina present in proximal two fifths, penultimate ventrite truncate distally. Legs with almost straight femora and conspicuously widened tarsomeres.

Aedeagus elongate, narrow, widest in proximal third; parameral blade distally parallel-sided and emarginate; median lobe subequal in length to parameral blade, apically noticeably widened in lateral aspect ( Figs 6–7 ).

Sexual dimorphism. Female is unknown.

Diagnosis. Ischalia laosensis sp. nov. is distinguishable from I. acco Satô et Ohbayashi, 2001 (which has pale elytra with dark colouration not prominent) primarily by the presence of dark brown longitudinal vittae along the elytral suture ( Fig. 5 ). From the very similar I. sasajii Satô et Ohbayashi, 2001 (which has elytra with narrow and incomplete dark longitudinal vittae) our new species differs in the deeply emarginate tip of scutellum (scutellum distally very shallowly emarginate in I. sasajii ). It is easily separable from I. fischeri Young, 2008 (which has black area along the elytral suture) by the non-gibbous pronotum. It also differs from all the congeners, where the male copulatory organs were studied and illustrated, in the details of the aedeagus ( Figs 6–7 ).

Etymology. The name of the new species is derived from the country where the type series was taken.

Variation. The dark elytral vittae vary in length from almost absent (in one of the paratypes) to almost reaching the elytral apex (in another paratype).

Figures

FIGURES 1–7. General view and details of Ischalia spp., holotypes males: 1—I. (s. str.) ancora sp. nov., general view, dorsally, 2—same, invaginated tergite, ventrally, 3—same, aedeagus, ventrally, 4—same, laterally; 5—I. (s. str.) laosensis sp. nov., general view, dorsally, 6—same, aedeagus, ventrally, 7—same, laterally. Scale bars: 1.0 mm.