Pharaxonotha clarkorum Pakaluk

Tang, William, Skelley, Paul E., Taylor B, Alberto S. & Salzman, Shayla, 2024, Review of Pharaxonotha Reitter (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting cones of the cycad Zamia L. (Cycadales) in Panama, with descriptions of five new species, Insecta Mundi 2024 (43), pp. 1-40 : 9-11

Pharaxonotha clarkorum Pakaluk

Figures 3A–J , 4A–J (illustrations 2, 5, 8 in Pakaluk 1988)

Pharaxonotha clarkorum Pakaluk 1988: 448–449 ; Chaves and Genaro 2005: 143 (species list); Skelley and Segalla 2019: 188 (discussion); Skelley and Tang 2020: 4 (key).

Diagnosis. Pharaxonotha clarkorum is distinguished from other members of the genus by a combination of characters: body length 1.98–2.63 mm, among the smallest members of the clarkorum species group; pronotal length/ width (PL/PW) = 0.68–0.79; head width/dorsal interocular length = 1.65–1.86; head width/ventral interocular length = 2.21–2.61; spermatheca with width of apical third about twice the minimum width of the basal third.

Redescription. Length 1.98–2.63 mm, width 0.61–0.99 mm (n = 86). Body in dorsal view elongate-oval ( Fig. 3A–C , 4A–C ), greatest width at middle of elytra; in lateral view convex dorsally ( Fig. 3B , 4B ). General body color entirely orange-brown; dorsal surface punctate, shining and appearing glabrous, short procumbent hairs associated with punctation on pronotum and elytra, ventrally shining and appearing glabrous except mesosternum and abdomen mostly covered with short procumbent setae.

Head not broad, width = 0.72–0.82× pronotal width; in dorsal view conical, gradually narrowed anteriorly, surface flat to slightly convex, finely, moderately punctured, average distance between closest punctures 2–3× width of puncture; head width 0.47–0.60 mm; dorsal interocular distance 0.27–0.34 mm, head width/dorsal interocular distance ratio 1.65–1.86, ventral interocular distance 0.20–0.25 mm, head width/ventral interocular distance ratio 2.21–2.61. Eye with large black facets, about 3× diameter of head punctures. Antennal length slightly shorter than pronotal width, 1.5× head width; antennomere I (scape) fairly large, slightly elongate; antennomere II slightly shorter than III; IV–VIII small, width equals length; club fairly large, IX and X similar in length; XI enlarged, 1.6× longer than X, globular with rounded apex ( Fig. 3D , 4D ). Clypeus weakly concave anteriorly, moderately punctate. Mentum ( Fig. 3E , 4E ) finely punctate, submentum more coarsely punctured, 2–3× diameter of those on mentum, distance between nearest punctures approximately 1× own diameter, each puncture with a short seta. Gular area smooth, without punctation or setae, border with submentum marked by change in punctuation and with a shallow transverse depression.

Thorax with pronotum transversely quadrate in dorsal view, length/width ratio 0.68–0.79; with distinct marginal beads laterally and basally, anteriorly with fine marginal bead medially; convex; anterior angles broadly rounded, not projecting forward; posterior angles weakly developed, with small denticle at angle; lateral carina parallel-sided or evenly shallowly arcuate for entire length; posterior margin slightly projecting medially, projection beginning approximately by pair of small, dark pores in margin located 1/4 width from posterior angles, each pore marks base of a distinct sulcus extending anteriorly onto disc 1/4 length of pronotum. Prosternum in ventral view convex, with few scattered punctures; anterior margin slightly emarginate, finely denticulate with row of long, anteriorly directed setae, longest setae approximately 1/3 length of eye; prosternal process expanded apically, truncate and convex at apex. Hypomeron laterally with few minute punctures, medially lacking distinct longitudinal striations. Scutellar shield distinctly transverse pentagonal, posterior margin weakly rounded. Elytra in dorsal view elongate-oval, convex; length/width ratio1.78–1.96, greatest width near midlength; with distinct marginal line basally; 10 complete striae of moderate puncture size; scutellary striole extending 1/4 elytral length, with 10–15 punctures; punctures of elytral striae as large as pronotal punctures, weakly impressed; intervals of striae with fine, shallow punctures, 1.2× size of strial punctures; all punctures of elytra bearing a single short seta; seta only visible in profile, extending slightly out of puncture. Mesoventrite with strong punctation, distance between nearest punctures approximately equal to diameter of punctures, puncture depth moderate. Metaventrite glossy, with strong lateral punctation separated by 2–3× own diameter; medial surface finely punctured, separated by 5–6× own diameter; entire surface convex, metathoracic discrimen extending approximately 3/4 metaventrite length. Legs narrow, relatively similar in length and shape. Procoxa oval; mesocoxa globular; metacoxa transversely elongate-oval; trochanters obliquely truncate apically; femora robust, moderately compressed laterally; tibiae shorter than femora, gradually dilated to obliquely truncate apices; protibia with apical lateral tooth distinct, with apical fringe of short spinules of concave ventral apical margin usually lacking near lateral tooth; meso- and metatibia with apical fringe of short spinules on anterior margin, finer setae on posterior margins.

Abdomen. Ventrite I 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 longer medially than II; II–IV subequal in length; V slightly longer than IV with lateral margins converging posteriorly to a rounded apex; apical margin bearing short, sparse setae; all ventrites bearing moderate, shallow punctation across surface, distance to nearest puncture approximately 2× diameter of puncture, punctures bearing mostly reclining setae; ventrite V with setae length nearly uniformly approximately 2× diameter of puncture; I–IV each with 2 or more median pairs of longer, semi-erect sensory hairs (difficult to see in poor lighting, often abraded). Male genitalia similar to all others in the genus ( Fig. 3F–H , 4F–H ), with dorsoventrally flattened tegmen, elongate cylindrical median lobe, and long coiled flagellum.

Female. Similar to male, no sexual dimorphism observed. Genitalia elongate ( Fig. 3I , 4I ); gonostylus set apically on gonocoxite, gonostylus length = 4–5× width. Spermatheca with basal third narrow, length> 8× maximum width of basal third, apical third swollen, nearly 2× maximum width of basal third ( Fig. 3J , 4J ).

Type locality. Costa Rica, Heredia Province, Puerto Viejo de Sarapiquí, Finca La Selva.

Range. The type locality for Pharaxonotha clarkorum is in northern Costa Rica, some 160 km from the Panama border. The host of the type specimens, Z. neurophyllidia , as currently understood, has a widespread and historically nearly continuous distribution along the Atlantic drainage of Costa Rica to across the border of Panama into Bocas del Toro province (M. Calonje and W. Tang, unpub. data). In central Bocas del Toro, Z. neurophyllidia is replaced by closely related species, Z. nesophila and Z. hamannii ( Taylor et al. 2008) . Morphologically the beetles inhabiting the cones of all three hosts within this range appear identical and are here considered conspecific and placed together within P.clarkorum .

Materials examined. Holotype male of Pharaxonotha clarkorum with the following labels: 1) [rectangular; white; printed in black ink] “ COSTA RICA: Heredia Prov., Puerto Viejo de Sarapiqui, Finca La Selva , 19.XI.82, in cone of Zamia skinneri [ Z. neurophyllidia ], David B. Clark coll. 1”. 2) [rectangular; red; printed in black ink, except as noted] “ HOLOTYPE, Pharaxonotha , clarkorum [handwritten], Pakaluk”. Deposited in the USNM.

Additional materials (124). Six paratypes with same label data as holotype ( USNM). COSTA RICA: Alajuela, P.N.V. Arenal, end Ceiba Tr., 630m, [GPS coord. omitted], Z. neurophyllidia ♂ cone, 10.X.2022, W. Tang (38); Heredia, La Virgen, Tirimbina res., 10.416, −84.12, cone ♂ Z. neurophyllidia , 1-X-2022, W. Tang (26); Limon, Aguas Frias, 70m, 10.45, -83.56, ♂ cone Z. neurophyllidia , 4-X-2022, W. Tang (9). PANAMA: Bocas del Toro, Isla Colón, 0–10 m asl, Jul-8-2000, A. Taylor, #9, Zamia neurophyllidia , wet, lowland tropical for. (6); Teribe Bonyic, ex ♂ cone Zamia neurophyllidia, Dec 2019 , I. Rayo (1); [island name omitted], Zamia nesophila ♂ cone, 18 Oct 2012, G. Holzman (21); [island name omitted], 0-5 m asl, Sept-19-2004, A. Taylor, #17, Zamia sp. [ Z. hamannii ], wet lowland tropical forest (5); [island name omitted], ex ♂ cone Zamia hamannii , early 2021, A. Ibañez, SMS20-165 (12). Specimens to be deposited in: ANIC, FSCA, NHMUK, NZAC, RHTC, SEMC, STRI, MIUP, TAMU, USNM.

Remarks. Pharaxonotha clarkorum is placed here in the “recent radiations” of Pharaxonotha based on analysis of the 16S rRNA gene ( Tang et al. 2018b, 2020). Within the clarkorum species group P.clarkorum appears most closely related to P. holzmani , which is distinguished from the former by the longer length, greater curvature and narrower apical width of its spermatheca, and is found further east in more inland habitats on Z. imperialis and Z. skinneri . Unlike P. pseudoparasitica , but similar to all other members of the clarkorum species group, it does not co-occur with Notorhopalotria weevils, either in Costa Rica or Panama ( O’Brien and Tang 2015; W. Tang unpublished data; D. Clark personal communication). It appears to be the sole beetle pollinator of Z. neurophyllidia , Z. nesophila and Z. hamannii .

Figures

Figure 3. Pharaxonotha clarkorum paratypes from Costa Rica, Heredia Province, Puerto Viejo de Sarapiquí, Finca La Selva (A–I: male). A–C) Dorsal, lateral and ventral habitus. D–E) Head, dorsal and ventral views. F) Male genital capsule, ventral view. G) Tegmen attached to median lobe, (top to bottom) ventral and lateral views.H) Parameres of tegmen, (top to bottom) ventral and lateral views. I) Retracted ovipositor with spermatheca, ventral view. J) Spermatheca.

Figure 4. Pharaxonotha clarkorum found on Zamia hamannii in Bocas del Toro, Panama (A–H: male). A–C) Dorsal, lateral and ventral habitus. D–E) Head, dorsal and ventral views. F) Genital capsule, ventral view. G) Tegmen attached to median lobe, (top to bottom) ventral and lateral views. H) Parameres of tegmen, (top to bottom) ventral and lateral views. I) Extended ovipositor with spermatheca, ventral view. J) Spermatheca.