Cycadophila (Cycadophila) cyclochasma 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 : 27-29

Cycadophila (Cycadophila) cyclochasma Skelley, Xu & Tang , new species

Figs. 8 A–E

Adult diagnosis. A member of Cycadophila (Cycadophila) nigra species group as discussed above readily distinguished from all others by its large body size, large deep submental-gular pit, and elongate pronotum with nearly straight sides.

Adult description. Length 6.90 mm, width 2.50 mm. Body in dorsal view elongate, sides gradually arched, almost parallel-sided, greatest width at middle of elytra; in lateral view convex dorsally. General body color entirely dark reddish-brown, appendages and lateral margins lighter; dorsal surface distinctly punctate, surface appearing slightly shiny, dorsal punctation with short procumbent hairs barely protruding out of punctures, ventrally mostly covered with short procumbent setae.

Head in dorsal view conical, gradually narrowed apically, surface convex, appearing swollen above eye, distinctly coarsely punctured; width 1.05 mm; dorsal interocular distance 0.67 mm, head width/dorsal interocular distance ratio 1.57, ventral interocular distance 0.55 mm, head width/ventral interocular distance ratio 1.91. Eye globular; bordered dorsally by swollen head, so that dorsal margin of eye with deep groove, supraocular stria less than half length of eye but coarsely punctured; 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 16:11:13:10:10:10:10:11:16:16:17; antennomere I (scape) fairly large, slightly elongate, antennomere II slightly shorter than III; IV–VIII small, width equals length; club fairly large, IX–XI similar in length, XI globular. Clypeus rounded apically, anterior margin with long setae; densely punctate; somewhat emarginate, with narrow margin.

Maxillary palpomeres II, III slightly longer than wide; IV elongate, apex densely papillate; relative lengths of II–IV approximately 4:2:6. Labium with mentum pentagonal with carina forming triangular plate projecting medially, with 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 at suture with submentum where a deep circular depression surrounds a central area with setose punctures; gula with deep groove surrounding medial and posterior eye margins.

Thorax with pronotum transverse in dorsal view, with marginal beads on all sides; length/width ratio 0.82, convex, nearly parallel-sided, vaguely narrowing anteriorly; anterior angles projecting, weakly angulate; lateral carinae nearly straight, with thin bead, bead bearing row of setose punctures; posterior angles sharp, nearly 90o; 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 0.25. Prosternum with anterior margin slightly emarginate, finely denticulate with fringe of long, anteriorly directed setae; posterior prosternal process truncate, not turning inward at apex. Hypomeron with coarse punctures laterally, medially without longitudinal striations. Scutellar shield transverse, posterior margin roundly projected, pentagonal. Elytra elongate with sides gradually arched, convex; length/width 3.52, greatest width near midlength; with marginal bead basally, scutellary striole with 9 punctures; intervals of striae with distinct punctures. All elytral punctures bearing a single short seta; seta length just reaching outside of punctures. Punctation on meso- and metaventrite distinct. Metaventrite long, convex laterally, slightly impressed medially, metathoracic discrimen extending slightly over half metaventrite length; line behind mesocoxae with distinct, coarse punctures. Legs narrow, similar in length; femora compressed laterally; male with metafemur swollen basally, posterior margin curved; tibiae shorter than femora, weakly dilated to narrow apex. Protibia not dilated at apex, with fine setal fringe on ventral, lateral margin smooth without stout spinules; few small stout spinules at disto-lateral angle. Meso- and metatibia narrow, similar to protibia.

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 lacking pair of erect sensory hairs located on either side of the middle; 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 45o toward the left side of animal and resting on side ( Fig. 8 G). 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 spatula-shaped parameres. Parameres with long setae apically; length/ width ratio 2.00. Aedeagus with median lobe short, slender, highly sclerotized, apex long and acuminate. Ratio of median lobe length to penile strut length 1:5. Female unknown, but as with C. abyssa , they are expected to have narrow metafemora.

Type locality. Vietnam, Vinh Phuc Province.

Range. Vietnam, Vinh Phuc Province.

Material examined. Holotype (by designation) male with the following labels: 1) [rectangular; white; printed in black ink] “ VIETNAM: Vinh Phuc Prov., Me Linh Biodiv. Sta.; Dai Lai Lake , 27–29.ix.2013 ; 100m, Col. J. B. Heppner”; 2) [rectangular; red, printed in black ink] “ HOLOTYPE ♂ Cycadophila cyclochasma P. Skelley, G. Xu & W. Tang 2017 ”. Deposited in the FSCA.

Etymology. The species epithet comes from the Greek, ‘cyclo’- for circular, and ‘khasma’—for deep void, pit, in combination referring to the ‘circular pit’ at the submental-gular juncture.

Remarks. Cycadophila cyclochasma is most similar in all morphological characters to C. abyssa . The key differences are subtle, but these differences are consistent in available specimens. Over 15 species of Cycas occur in the general region of northern Vietnam and adjacent regions of southeastern China ( Osborne et al. 2007). All these Cycas belong in the Section Stangerioides. Only one species of Cycas , C. balansae , belonging in Subsection Stangerioides, is currently known from the type locality of Vinh Phuc province and this species ranges north into Guangxi province , China. The closely related Cycadophila abyssa is known from Cycas hainanesis on Hainan Island and habitat of C. fairylakea in Guangdong province , China (both belonging to Section Stangerioides, Subsection Taiwaninae), farther to the east. Based on these differences in geographical distributions, available hosts and morphology we consider these beetles to be separate species. Although molecular evidence is not currently available to confirm this conclusion, describing the species officially recognizes these differences and provides a name for future research. Cycadophila cyclochasma and C. abyssa differ from all other members of the genus by sharing a number of unique features on the head, most notably the deep pit at the submental-gular juncture, but also the swollen head that creates a deep groove around the eyes.

Figures

FIGURE 8. Phorographs of Cycadophila (Cycadophila) cyclochasma, holotype: A) dorsal habitus; B) ventral habitus; C) lateral habitus; D) head and prosternum, ventral; E) male genitalia.