Cycadophila (Strobilophila) kwaiensis Skelley, Xu & Tang

Skelley, Paul, Xu, Guang, Tang, William, Lindström, Anders J., Marler, Thomas, Khuraijam, Jibankumar Singh, Singh, Rita & Rich, Stephen, 2017, Review of Cycadophila Xu, Tang & Skelley (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting Cycas (Cycadaceae) in Asia, with descriptions of a new subgenus and thirteen new species, Zootaxa 4267 (1), pp. 1-63 : 53-55

Cycadophila (Strobilophila) kwaiensis Skelley, Xu & Tang , new species

Figs. 18 A–E

Adult diagnosis. A member of the Cycadophila (Strobilophila) tansachai complex distinguished by the pronotal posterior lateral carina lacking an abrupt inward curve at posterior angle, lacking a distinct projection behind the posterior angle pore, a nearly straight basal pronotal margin, and with no dimorphism on the female abdomen. They are also distinguishable by DNA analysis of the 16S rRNA mitochondrial gene (GenBank Accession number KY365221 ).

Adult description. Length 4.07–4.65 mm; width 1.58–1.70 mm. Body in dorsal view elongate, sides nearly straight, greatest width at middle of elytra; in lateral view convex dorsally. General body and appendage color solid reddish-brown; dorsal surface distinctly punctate, surface appearing slightly dulled, dorsally appearing glabrous, with short procumbent hairs associated with punctation behind eyes and along lateral sides and declivity of elytra, ventrally mostly covered with short procumbent setae.

Head in dorsal view conical, gradually narrowed apically, surface flat to slightly convex, distinctly punctured; width 0.9–1.0 mm; dorsal interocular distance 0.60–0.66 mm, head width/dorsal interocular distance ratio 1.49–1.52, ventral interocular distance 0.38–0.43 mm, head width/ventral interocular distance ratio 2.34–2.47. Eye globular; bordered dorsally with supraocular stria; projected laterally, with large black facets and short, inconspicuous interfacetal setae. Frons with short, dark, subcuticular suture on each side, approximately 1/4 width of frons in length, extending obliquely to lateral margin above and anterior to antennal insertion. Antennal length about 3/4 pronotal width, and slightly longer than head width, antennomere relative lengths from base to end approximately 21:12:11:10:10:10:10:10:15:15:19; antennomere I (scape) fairly large, slightly elongate, antennomere II–III slightly longer than IV–VIII; club fairly large, IX–XI similar in length, XI globular. Clypeus truncate anteriorly, anterior margin with long setae; densely punctate; somewhat emarginate, with narrow margin. Maxillary palpomeres II, III slightly longer than wide; IV elongate oval, apex densely papillate; relative lengths of II–IV approximately 3:3:5. Labium with mentum pentagonal with carina forming triangular plate projecting medially, lacking distinct lateral pockets; labial palpomere III elongate-oval. Mentum and submentum with moderate punctation and setation, setae short. Gular area smooth, without setae or punctation, except near suture with submentum where a shallow transversely elongate fovea is present bearing dense setose punctures, fovea dark brown.

Thorax with pronotum transverse in dorsal view, with marginal beads on all sides; length/width ratio 0.69– 0.75, convex, nearly parallel-sided; anterior angles rounded; lateral carina with thickened bead, bead bearing scattered setose punctures; posterior angle exteriorly angulate, not indented at pore; posterior margin projecting medially; with narrow, short longitudinal furrow posterolaterally, beginning at pore on posterior margin, extending forward and ending abruptly, length of furrows relative to pronotal length 0.19–0.23. Prosternum with anterior margin slightly emarginate, finely denticulate with fringe of long, anteriorly directed setae; posterior prosternal process round and convex. Hypomeron with coarse punctures laterally, medially with longitudinal striations.

Scutellar shield transverse, posterior margin projected, pentagonal. Elytra elongate, nearly parallel sided, convex; length/width 3.50–3.67, greatest width near midlength; with marginal bead basally, scutellary striole with 10–13 punctures; intervals of striae with distinct punctures. All elytral punctures bearing a single short seta; seta barely emerging out of puncture. Punctation on meso- and metaventrite distinct. Metaventrite long, convex laterally, slightly impressed medially, metathoracic discrimen extending slightly over half metaventrite length. Legs stout, similar in length; femora compressed laterally; tibiae shorter than femora, dilated to wide apex. Protibia triangularly dilated at apex, apex and apical 1/3 of lateral margin with stout spinules, marginal spinules separated by less than length. Meso- and metatibia less triangularly dilated.

Abdomen with 5 ventrites bearing fine punctures; anterior margin with intercoxal process narrow, with triangular point anteromedially, lateral edges slightly projected, lateral and posterior margins arcuate, converging posteriorly; anterior and posterior margins of ventrites more or less straight; ventrite I lacking subcoxal line, slightly longer medially than II; I–IV each with pair short hairs located adjacent to midline (often abraded); II–IV subequal in length; V slightly longer than IV with lateral margins converging posteriorly to a rounded apex bearing row of short appressed, densely arranged setae.

Male genitalia (tegmen and median lobe of aedeagus) twisted approximately 45° toward the left side of animal and resting on side. Tegmen sclerotized, triangular, gently twisted; with anterior region ring-like, posterior region sheath-like, posterior margin slightly arcuate; lateral margins gradually converging posteriorly; dorsally with 2 large, elongate, somewhat coniform parameres. Parameres with long setae apically; length/width ratio 2.20. Aedeagus with median lobe short, slender, highly sclerotized, apex long and acuminate. Ratio of median lobe length to penile strut length 1:5. Female similar to male, except with pygidium truncate, not as well developed.

Type locality. Thailand: Kanchanaburi Province, 14°2′N, 99°29′E.

Range. Thailand (Kanchanaburi).

Material examined. Holotype (by designation, with damaged left elytron) male with the following labels: 1) [rectangular; white; printed in black ink] “ THAILAND, Kanchanaburi, 14°2′N, 99°29′E, karst tower, ex crown hair of Cycas sp. aff. pectinata , 29-VII-2002, W. Tang ”; 2) [rectangular; red; printed in black ink] “ HOLOTYPE ♂ Cycadophila kwaiensis, W. Tang, G. Xu & P. Skelley 2015 ”. Deposited in the FSCA . Allotype and 4 paratypes (same label data) deposited at FSCA.

Etymology. Named for the locality of collection in the vicinity of the Kwai River Bridge in Kanchanaburi Province, Thailand.

Remarks. This species of Cycadophila appears to be restricted to a currently undescribed species of Cycas that inhabits karst towers in Kanchanaburi Province at elevations below 100 m . Although Cycadophila tansachai occurs on Cycas pectinata some 100 km north at elevations above 600 m in mountains in Kanchanaburi Province, DNA analysis indicates that Cycadophila kwaiensis is also closely related to Cycadophila hiepi in Vietnam, over 1000 km to the east. This suggests that C. kwaiensis and its host cycad are relicts with formerly wider distribution in lowland forests.

Figures

FIGURE 18. Photographs of Cycadophila (Strobilophila) kwaiensis, A) dorsal habitus; B) ventral habitus; C) lateral habitus; D) head and prosternum, ventral; E) male genitalia.