Cycadophila (Cycadophila) collina 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 : 15-18

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

Figs. 2 K, 2O, 4A–E

Adult diagnosis. Morphologically distinguishable from other C. ( Cycadophila ) spp. by the long supraocular striae, head width/ventral interocular distance ratio <3.50; width of elytra greatest at middle, without fine acute projection at posterior pronotal hind angle, and strong distal dilation of mesotibia and mesofemora in major males. Morphologically most similar to C. (C.) debaonica which has a fine obtuse projection at posterior pronotal hind angle and major males with mesofemora narrowing from middle to apex. Most confidently distinguished from C. (C.) debaonica by analysis of the 16S rRNA gene (GenBank Accession numbers KY 365227 and KY365247 ), host and distribution.

Adult male description. Length 4.19–5.85 mm, width 1.88–2.40 mm. Body elongate-oval in dorsal view, greatest width at middle of elytra; in lateral view convex dorsally. General body color reddish-brown ( Figs. 4 A–D), head darker than pronotum and lateral halves of elytra; elytra with large central black maculation occupying roughly half of elytral length from near the scutellum to 2/3 length of elytra and roughly 2/5 of the elytral width, dorsal surface punctate, shining and dorsally appearing glabrous, 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 anteriorly, surface flat to slightly convex, finely, sparsely punctured; width 1.12 mm; dorsal interocular distance 0.68 mm, head width/dorsal interocular distance ratio 1.65, ventral interocular distance 0.39 mm, head width/ventral interocular distance ratio 3.05. Eye globular; bordered dorsally with long supraocular stria reaching anterior angle of eye; 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 anterior to antennal insertion. Antennal length slightly shorter than pronotal width, slightly longer than head width, antennomere relative lengths from base to end approximately 14:10:12:10:10:10:9:9:10:10:10, antennomere widths of II–VII subequal, I and VIII subequal and about 1.30× width of II–VII, width equals length; IX and X subequal and about 2.00× width of II–VII, XI about 1.50× width of II–VII, globular. Clypeus truncate anteriorly, anterior margin with long setae; densely punctate; somewhat emarginate, with narrow margin. Mandible with 3 apical teeth; prostheca extending from mola halfway to apical teeth, length about ½ width, edge nearly straight, with fringe of hair along dorsal base that extends to the proximal apical tooth; mola with carinulation and small spines. Labrum transverse, about 2.00× broader than long; anterior margin fringed with long bristles, especially dense medially. Hypopharynx with thin setae directed medially. Maxilla with cardo expanded apically; stipes narrowly triangular, apically acute, partially overlapping with palpiger; galea and lacinia with long, densely aligned setae; setae on the lacinia thick and strong, but distinguishable hooks absent from surrounding dense setae; galea wider than lacinia. Maxillary palpomeres II, III and IV longer than width; IV elongate oval, apex densely papillate; relative lengths of II–IV approximately 5:3:7. 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 shallow transversely elongate foveae are present bearing dense setose punctures ( Fig. 4 D), foveae dark brown.

Thorax with pronotum transverse in dorsal view with marginal beads on all sides; length/width ratio 0.69, convex, wider at base; anterior angles weakly developed; posterior angles exteriorly angulate; posterior margin projecting medially; with a narrow longitudinal furrow posterolaterally, beginning at pore on posterior margin extending forward and ending abruptly, length of furrows relative to pronotal length 0.22. Prosternum with anterior margin slightly emarginate, finely denticulate with row of long, anteriorly directed setae; prosternal process round and convex apically. Hypomeron laterally with few punctures, medially without longitudinal striations. Scutellar shield transverse, posterior margin clearly projected, pentagonal. Elytra in dorsal view elongate-oval, convex; length/width 3.30, greatest width near midlength; with marginal line basally, scutellary striole extending ¼ elytral length, with 10–13 punctures; intervals of striae with fine, shallow punctures. All punctures of elytral striae bearing a single short seta; seta only visible in profile, extending slightly out of puncture. Punctation on meso- and metaventrites shallow, small. Metaventrite long, convex laterally, slightly impressed medially, metathoracic discrimen extending slightly over half metaventrite length. Legs stout, relatively similar in length and shape. Femora compressed laterally; tibiae shorter than femora, gradually dilated to narrow apex; protibia distinctly dilated apically, with apical fringe of short, stout spinules ventrally, inner margin with fine setae.

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 of long erect sensory 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 90˚ toward the left side of the animal and resting on side. Tegmen sclerotized, triangular, but twisted medially; 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 apically with long setae; length/width ratio 2.60. Aedeagus with median lobe slender, highly sclerotized, apex long and acuminate. Ratio of penile strut length to median lobe length 3:1.

Female similar to male except with pro- and mesotibiae and femora less robust and not dilated apically, pygidium truncate, apical edge fairly straight with 7 long setae and a fringe of setae about 1/2 as long. Genitalia with gonocoxites triangular, gradually narrowing posteriorly; apices of gonocoxites laterally with concave impression and setae. Gonostylus inserted at the concave impression of the gonocoxite, with several short setae and 1 long seta. Valvifers expanded posteriorly. Spermatheca elongate, C-shaped.

Variation. In some individuals the dark elytral mark is slightly larger or smaller, and varies from a lighter to darker brown. In some this mark is pale enough to be indistinct. Variation in pro- and mesotibial dilation appears to be sexually dimorphic. Males usually have these tibiae more strongly dilated. However, there is enough variation that distinguishing weakly developed males from strongly developed females can be problematic. Weakly developed females have the mesotibia almost parallel-sided to the apex. Strongly developed males have the outer margin of the mesotibia slightly swollen to a widened apex. Similarly, mesofemoral development varies in males from strongly to weakly dilated toward apex. Major males of C. collina and C. debaonica are distinctly different in this character. Minor males of either species are difficult to distinguish. Figures used in the key are major males. Type locality. Laos, Houphan Province, Viengxay District, Vieng Xai village , 20˚23’41”N 104˚13’44” E. Range. Known from Houphan Province in northern Laos and Son La Province , Vietnam on Cycas collina , and the southern portion of Yunnan Province , China on Cycas sp. aff. collina and C. tanqingii .

Material examined. Holotype (by designation) male with the following labels: 1) [rectangular; white; printed in black ink] “ LAOS, Houphan Pr., Viengxay Ds., Vieng Xai vill., 20°23'41″N, 104°13'44″E, 7-IV-2015, N.T. Hiep, L. Averyanov, N.S. Khang, N.Q. Hieu, T. Maisak, Somneux ”; 2) “ex ♂ cones Cycas collina (LA-VN 1124)”; 3) [rectangular; red, printed in black ink] “ HOLOTYPE ♂ Cycadophila collina P. Skelley, G. Xu & W. Tang 2017 ”. Deposited in the FSCA . Allotype female and 45 paratypes: CHINA, Yunnan Province, Guanping Reserve , 22°10'N 100°50'E, 10 May 1996, W. Tang, ex spent ♂ strobilus of Cycas sp. aff. collina , WT 44 (2); ex early pollen-shedding ♂ strobilus of Cycas sp. aff. collina , WT 45 (allotype, FSCA; 20); ex receptive ♀ strobilus of Cycas sp. aff. collina , WT 46 (2) ; VIETNAM, Son La Province, nr. Mai Son , 21°8'630″N 104°1'731″E, Cycas collina, Apr 4, 1996, S.L. Yang SLY777 (21). Paratypes deposited in ANIC, FSCA . Others Examined: China, Yunnan Province, Luchun Co , Cycas tanqingii ♂ cone, 27 March 2008, He Jianghai [specimen destroyed during DNA analysis; pin and label remain].

Etymology. The species is named after one of its host species, Cycas collina .

Remarks. DNA analysis of the 16S rRNA gene indicates that Cycadophila collina forms part of a cryptic species complex with C. debonica and that this beetle is associated with two hosts, Cycas tanqingii and the Cycas collina species complex. These two host Cycas species inhabit rugged terrain south of the Red River while the two known hosts of its sister taxon, Cycadophila debaonica , occur either far north of the Red River ( Cycas debaoensis ) or farther east and south of the Red River on limestone towers ( Cycas hoabinhensis ). Other possible host Cycas species for Cycadophila collina include Cycas dolichophylla , C. bifida and C. fugax , which occur in regions just north or east of Cycas collina and C. tanqingii ( Osborne et al. 2007) .

Morphologically, C. collina is most similar to C. lata in development of male sexual dimorphisms. These species also appear to occupy distinct, but neighboring distributions (see Remarks under C. lata ). Even without molecular analyses, the striking difference in ventral interocular distance and different distributions allow us to maintain C. lata and C. collina as valid species within the species complex.

Considering the morphological similarity in species of the lata complex, the Laos holotype of C. collina was chosen because it was distinguished with both molecular and morphological evidence. Although the series of Chinese and Vietnamese paratypes match the Laos specimen morphologically, they have not been confirmed with 16S rRNA evidence.

Figures

FIGURE 2. Key characters of adults: photographs of lateral head and pronotal margin: A) Cycadophila (C.) fupingensis; B) C. (Strobilophila) tansachai; C) C. (C.) yunnanensis; SEM of protibia, ventral view: D) C. (C.) fupingensis; E) C. (C.) debaonica; F) C. (S.) tansachai; G) C. (S.) yangi; photographs of mesotibia, ventral view: H) C. (C.) debaonica female; I) C. (C.) debaonica male; J) C. (C.) lata male; photographs of left half of pronotum: K) C. (C.) collina; L) C. (C.) debaonica; M) C. (S.) kwaiensis; N) C. (S.) tansachai; photographs of mesofemur of major male: O) C. (C.) collina ex Vietnam; P) C. (C.) debaonica.

FIGURE 4. Photographs of Cycadophila (Cycadophila) collina major male from Vietnam, paratype: A) dorsal habitus; B) ventral habitus; C) lateral habitus; D) head and prosternum, ventral; E) male genitalia.