Scirtes canescens Motschulsky 1863
Creators: name: Ruta, Rafał
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scirtidae
Scirtes
Scirtes canescens

description: Scirtes canescens Motschulsky, 1863: 483
(Figs. 13, 62–67)
=? Scirtes grandis: Novorjee 1912 (Champion 1918: 263)
Type material. Holotype, male: [small round yellow label]; “ Type ” [small rectangular label, handwritten]; [rectangular red label]; “ Scyrtes / canescens / Ceylon Motsch. / Colombo” [rectangular yellow label, handwritten]; deposited in ZMUM.
Additional material studied. Male: Sri Lanka, Southern Province, Galle Distrikt, Habaraduwa, 20.8– 4.9.1982, H. J. Bremer leg.; deposited in HNHM.
Diagnosis. Similar to Scirtes sericeus Waterhouse. Distinguishable from this, and other externally similar uniformly light brown species, on the basis of genital morphology: trigonium regularly tapered; lateral processes of tegmen short and straight.
Redescription. Holotype, male. Measurements: TL 3.50, EW 2.30, EL 3.00, PW 1.55, PL 0.60, HW 0.95, HL 0.60, interocular space 0.50, greatest depth of body 1.15.
Body of moderate length, oblong oval, somewhat depressed, covered with yellowish setae. Entire body yellowish-brown, antennae yellowish. Body length 1.5X width.
Head width 1.5X length, 1.9X width of interocular space, with distinct punctation, eyes large, moderately protuberant. Antennae filiform (only 5 basal antennomeres present in the holotype), antennomere 1 cylindrical, slightly curved, antennomere 2 subcylindrical, narrower and shorter than antennomere 1, antennomere 3 smallest, slightly shorter than antennomere 2, antennomeres 4 and 5 as long as 2 and 3 combined; length ratios of antennomeres 2.1: 1.2: 1.0: 2.4: 2.4; L/W ratios of antennomeres 1.8, 1.5, 1.7, 4.0, 4.0. Anterior clypeal margin slightly explanate, with protruding anterolateral angles. Labrum very small, transverse, partly hidden under clypeus. Mandibles symmetrical, broad in basal part, with sharp, tapering Pronotum width 2.6X length, pronotum widest at base. Disc of pronotum with distinct punctation, a bit stronger than on head. Posterior margin of pronotum bisinuate. Anterior angles produced, posterior angles more or less straight. Lateral margins narrowing anteriorly. Scutellum subtriangular, with even punctation.
Angle between pronotum and elytra not marked in dorsal outline. Elytra elongate, with remnants of 2 indistinct ridges, and a subtle adsutural one, length 1.3X width and 5.0X length of pronotum, broadest in the middle of its length. Lateral margins slightly explanate in anterior half. Sides regularly converging to apex in posterior half. Humeri clearly evident. Punctation dense and distinct, slightly denser than on pronotum, distance between punctures ca. 1.0 diameter. Epipleura abruptly narrowed beyond metaventrite, present till apex. Hind wings fully developed.
Prosternal process short, laminar. Mesocoxae separated by a subparallel process (length ca. 3.0X width), metaventral discrimen present in posterior 2/3. Metaventrite short, ratio of ventrites’ lengths: 1.0: 1.5: 1.3: 1.3: 1.3.
Metafemora width ca. 6.0X width of metatibia. Metatibia armed with long spurs, the longer one as long as 0.7 length of tarsomere 1, slightly curved. Smaller spur curved, almost as long as 0.5 length of the longer one.
Male genitalia. Penis (L 0.85, W 0.14) symmetrical, trigonium elongate, subtriangular and regularly tempered, almost as long as parameroids, parameroids long and narrow; tegmen (L 0.71, W 0.20) symmetrical, narrow, with short and straight lateral processes; sternite 8 (L 0.23, W 0.25) reduced, U-shaped; sternite 9 (L 0.50, W 0.28) lyriform, consisting of two hemisternites, each of which has sparse apical setation; tergite 8 (L 0.55, W 0.35) with relatively long apodemes and row of setae on apical margin; tergite 9 (L 0.38, W 0.42) with apodemes diverging anteriorly, and small plate-like portion.
Variability. TL of additional specimen studied 3.45, antennae of specimen from HNHM slightly darkened apically.
Remarks. This species belongs to the micronesianus -group of Scirtes, proposed by Yoshitomi (2009) to accomodate an assemblage of species sharing the following characters: testaceous to brown, unicolored; body oval; narrow, symmetrical penis with pala and apical part of similar lengths; parameroids undivided; symmetrical, tubular tegmen often with a pair of lateral outhgrowths; lyriform sternite 9 in males; bursal sclerite consisting of dorsal projection and ventral plate (Ruta 2008). Presently, the following species are known: Scirtes affinis Motschulsky (Sri Lanka), Scirtes canescens Motschulsky (Sri Lanka), Scirtes grandis Motschulsky (Sri Lanka), Scirtes micronesianus Yoshitomi (Micronesia), Scirtes sericeus Waterhouse (Thailand), and an undescribed species occurring on New Caledonia. There appear to be many more species requiring revision occur in SE Asia. It is probable that Scirtes affinis (Motschulsky) is a female of Scirtes canescens Motschulsky.
description: Published as part of Ruta, Rafał, 2009, Revision of Scirtidae (Insecta: Coleoptera) described by Victor Ivanovitsch Motschulsky, pp. 26-50 in Zootaxa 2210 on pages 43-45, DOI: 10.5281/zenodo.189843