Stiliderus sp. Y

Rougemont, Guillaume De, 2015, Studies on Stiliderus Motschulsky and Stilicoderus Sharp: biogeographical notes and descriptions of new species (Coleoptera: Staphylinidae: Paederinae), Stuttgarter Beiträge zur Naturkunde A, Neue Serie 8, pp. 113-130 : 128

Stiliderus sp. Y

1 ♀, Indonesia, Lombok , Sapit–Sembalun Bumbung, 900 –

1500 m, 14.–16.II.1994, leg. BOLM ( SMNS) .

Description

Body length 6 mm. Proportions: length of head: 90; breadth of head: 95; diameter of eye: 26; length of antenna: 175; length of pronotum: 88; breadth of pronotum: 80; length of elytron: 103; breadth of elytra: 117; metatibia: 98; metatarsus: 57.

Black, abdomen and legs pitchy brown, the tibia and tarsi somewhat paler; labrum and antennae brown, first antennomere infuscate; palpi dark testaceous. Pubescence of fore-body fairly sparse, short, erect. A squat, robust species with relatively short appendages. Head only slightly transverse, the puncturation moderately fine and close, the interstices on disc about as wide as diameter of punctures. Pronotum broadest at anterior angles which are situated at a little more than one-fourth from centre of anterior margin; the sculpture of pronotum is unique in the genus, consisting of fine transverse parallel rugae disposed in a slight arc and extending right across disc from lateral margins; a trace of an impunctate mid-longitudinal band exists, but only briefly at either extremity; elsewhere the raised mid-longitudinal axis is overlaid by the transverse rugae. Elytra ample, only slightly transverse, the surface between serially arranged large foveate punctures densely covered with setiferous granules.

Remark

This species belongs by definition to the heterogeneous, pan-oriental cicatricosus group. Its closest affiliation is not known. In my 1986d key to the species of Stiliderus this species runs to S. simoni Rougemont , being the only other Stiliderus with the combination of granulose elytra and absence of an entire impunctate mid-longitudinal band on the pronotum, but the two species are quite unlike each other and are not closely related. S. simoni is a much smaller insect with the pronotum entirely covered by isolated setiferous granules. Sp. Y is easily recognised by its type of pronotal sculpture alone.