Cycadophila nigra (Gorham) Gorham, 2015

Xu, Guang, Tang, William, Skelley, Paul, Liu, Nian & Rich, Stephen, 2015, Cycadophila, a new genus (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting Cycas debaoensis (Cycadaceae) in Asia, Zootaxa 3986 (3), pp. 251-278 : 267-270

Cycadophila nigra (Gorham) , new combination

( Figure 8 )

Thallis ? nigra Gorham, 1895: 324 .

Pharaxonotha nigra (Gorham) ; Arrow, 1925: 255; Schenkling, 1928: 31; Chûjô, 1964: 224, pl. 14, fig. 7; Chûjô, 1967: 41. Pharaxonotha indica Grouvelle, 1903: 127 ; Grouvelle, 1916: 62 (sp. bona); Schenkling, 1923: 15 (sp. bona); Arrow, 1925: 255 [syn.]; Schenkling, 1928: 31; Chûjô, 1964: 224.

Adult diagnosis. Distinguished from other Cycadophila spp. by its larger, entirely brown body, distinct supraocular stria that is half the length of the eye, weakly depressed submental-gular region, and male with a large angulate swelling near the middle of the medial mesotibial margin.

Adult male description. Length 4.35–4.59 mm, width 1.65–1.76 mm. Body in dorsal view elongate, sides evenly arcuate, greatest width at middle of elytra; in lateral view convex dorsally. General body and appendage color entirely dark reddish-brown; elytra lacking maculation of any kind, although lateral margins may be paler; dorsal surface distinctly punctate, surface appearing slightly shining, dorsally appearing glabrous, short procumbent hairs barely protruding out of punctures, ventrally mostly covered with short procumbent setae ( Figs. 8 A–C).

Head in dorsal view conical, gradually narrowed anteriorly, surface convex, distinctly punctured ( Fig. 8 E); width 1.0– 1.1 mm; dorsal interocular distance 0.63–0.68 mm, head width/dorsal interocular distance ratio 1.56– 1.60, ventral interocular distance 0.40–0.45 mm, head width/ventral interocular distance ratio 2.33–2.50. Eye globular; bordered dorsally with strong supraocular stria at basal 1/2 of eye; projecting laterally, with large black facets and short, inconspicuous interfacetal setae. Frons with a 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 about 3/4 pronotal width, slightly longer than head width, antennomere relative lengths approximately 13:10:12:10:10:10:10:10:13:13:17; antennomere I (scape) fairly large, slightly elongate, antennomere II slightly smaller than III; IV–VIII small, width equals length; club fairly large, IX–XI similar in length, XI globular. Clypeus anteriorly rounded, 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 hairs along dorsal base that extends to the proximal apical tooth; mola with carinulation and small spines. Labrum transverse, about 2 times 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 palp 4-segmented, palpomere I very small; II, III slightly longer than wide, IV elongate oval, apex densely papillate, relative lengths of II–IV approximately 4:3:7. Labium with mentum pentagonal with carina forming triangular plate projecting medially, with distinct lateral pockets; labial palp 3-segmented; palpomere I small, elongate; II transverse; III large, ovate. Mentum and submentum with moderate punctation and setation, setae short. Gular area smooth, without setae or punctation, except near suture with submentum, where shallow circular depression is present with setose punctures.

Thorax with pronotum transverse in dorsal view with marginal beads on all sides; length/width ratio 0.69–0.71, convex, nearly parallel-sided; anterior angles projecting, weakly angulate; lateral margins nearly straight, with thin bead, bead bearing row of setose punctures; posterior angles sharp, nearly 90o; posterior margin projecting medially; with a narrow, short longitudinal furrow posterolaterally, beginning at pore on posterior margin, extending forward and ending abruptly, length of furrows relative to pronotal length 0.21–0.22. Prosternum in ventral view convex; anterior margin slightly emarginate, finely denticulate with row of long, anteriorly directed setae; prosternal process truncate apically. Hypomeron laterally with coarse punctures, medially without longitudinal striations. Scutellar shield transverse, posterior margin clearly projected, pentagonal. Elytra in dorsal view elongate, evenly arcuate along sides, convex; length/width 3.47–3.57, greatest width near midlength; with marginal line basally, 10 complete striae of moderate puncture size, scutellary striole with 9–10 punctures; intervals of striae with distinct 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 distinct. Metaventrite long, convex laterally, slightly impressed medially, metathoracic discrimen extending slightly over half metaventrite length. Legs narrow, similar in length; procoxa oval; mesocoxa globular; metacoxa transversely elongate-oval; trochanters obliquely truncate apically; femora compressed laterally; tibiae shorter than femora, weakly dilated to narrow apex. Protibia not dilated apically, with fine setal fringe ventrally, lateral margin smooth, lacking stout spinules. Meso- and metatibia narrow, similar to protibia. Metatibia with angulate swelling on apical half of medial margin ( Fig. 8 F).

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 adjacent to the midline (at least none were observed on available specimens); II–IV subequal in length; V slightly longer than IV with lateral margins converging posteriorly to a rounded apex, with row of short appressed, densely arranged setae.

Male genitalia (tegmen and median lobe of aedeagus) twisted approximately 45o toward the left 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 coniform-shaped parameres. Parameres apically with long setae; length/width ratio 2.5. Aedeagus with median lobe short, slender, highly sclerotized, apex long and acuminate. Ratio of penile strut length to median lobe length 5:1.

Female similar to male except lacking swelling on inner metatibial margin; with pygidium truncate, not as well developed. Genitalia with gonocoxites triangular, gradually narrowing posteriorly; apices of gonocoxites laterally with concave impression and setae. Gonostylus small, inserted at the concave impression of the gonocoxite, with several short setae and 1 long seta. Valvifers expanded posteriorly. Spermatheca elongate, Cshaped.

Type locality. Kanara, S. India.

Range. S. India, Thailand, China.

Material examined. Lectotype (female) here designated of Thallis nigra Gorham with the following labels ( Figs. 8 A–D): 1) [rectangular; white with yellow horizontal line; printed in black ink] Kanara, S. India; 2) [rectangular; white; printed in black ink] Andrewes Bequest B. M. 1922–221; 3) [white circle, ringed with red ink; printed in black] Type; 4) [rectangular; red; handwritten in black ink] Type Gorham; 5) [rectangular; white; hand written in black ink] nigra (Gorh.; 5) [rectangular red paper] LECTOTYPE Thallis nigra Gorham , des. P. Skelley 2014 ( BMNH, examined). Paralectotype (female) here designated of Thallis nigra Gorham with the following labels: 1) [rectangular; white with yellow horizontal line; printed in black ink] Kanara, S. India; 2) [rectangular; red; handwritten in black ink] Type Gorham; 5) [rectangular; white; hand written in black ink] Thallis nigra, Gorh. 6) [rectangular yellow paper] PARALECTOTYPE Thallis nigra Gorham , des. P. Skelley 2014 ( BMNH, examined).

Holotype (teneral female) of Pharaxonotha indica Grouvelle with the following labels: 1) [rectangular; white with yellow horizontal line; printed in black ink] Kanara, S. India; 2) [rectangular; white; printed in black ink] Andrewes Bequest B. M. 1922–221; 3) [rectangular; white; printed in black ink] Kanara; 4) [white circle, ringed with red ink; printed in black] Type; 5) [rectangular; red; printed in black ink] Type; 6) [rectangular; white; hand written in black ink] Pharaxonota [sic] indica 5. Grouv ( BMNH, examined).

Other materials examined: [ India:] JAMUN, 22-7-69, Durgapura, C.I.E. Coll. A.3753, V235/133, Pres by Com Inst Ent B M 1970-1, Pharaxonotha nigra (Gorh.) R. Madge det 1970 (1M-BMNH) [Although there is a Jamun, India, we suspect Jamun is a plant on which it was collected, and Durgapura is a locality name of multiple localities in India]. Central India, Pachmarhi, Sept. 1970, T. R. Nathan leg. (1F-FSCA). CHINA: Guangxi: [Napo Co.]: Dingye, ex ♂ cone Cycas debaoensis , N23°24'26”, E106°02’27”, 22-V-2006, W. Tang, #1 (21); #2 (1). These Chinese specimens are deposited at FSCA, IZCAS, and NZAC.

Remarks. Smaller females of C. nigra are difficult to distinguish from unicolorous C. yunnanensis . Gorham did not designate a holotype from the specimens he studied. The specimen here designated as the lectotype is Gorham’s darker and more intact specimen. It is unfortunate he only had females to study because sexual dimorphisms are important for species delineation. With the types of C. nigra being from southern India, there is reason to question whether the Chinese specimens here considered to be C. nigra are truly conspecific. More material is needed from southern India to better establish character states (both morphological and molecular) of those populations in comparison with those from China. For now, they are considered the same species. In Cycas debaoensis adults of this species have only been detected in small numbers on male cones of the Dingye population. The relative abundance of this species among Cycadophila -inhabiting cones at Dingye ranges 1.5– 24.1% (mean = 12.8%, n = 2 cones). No larval morphotypes have been observed in cones that may correspond to this species. Their infrequent occurrence on cones and their apparent distribution into southern India, well beyond the range of C. debaoensis or related species, suggest that this beetle is not a specialist on C. debaoensis , but an opportunistic visitor that may feed and reproduce on alternative hosts.

Figures

FIGURE 8. Photographs of Cycadophila nigra, lectotype female: A – B) Dorsal and ventral habitus; C) Head to metaventrite, ventral view; D) Labels of lectotype. E – G) Non-type specimen from India; E) SEM of head and pronotum; F) Male hind leg, ventral view; G) Male genitalia.