Pharaxonotha gigantea Skelley, Tang and Pérez-Farrera, 2022

Skelley, Paul E., Tang, William & Pérez-Farrera, Miguel Angel, 2022, Review of Pharaxonotha Reitter (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting the cycad genus Dioon Lindl. (Cycadales), with descriptions of nine new species and comments on P. kirschii Reitter, Insecta Mundi 2022 (917), pp. 1-41 : 17-19

Pharaxonotha gigantea Skelley, Tang and Pérez-Farrera , new species

Figures 6A–H

Diagnosis. This is the largest known Pharaxonotha with a length of 5.08 mm. Other distinguishing characters include the wide, transversely rectangular pronotum (length/width = 0.71) with punctures large, impressed, sharply defined.

Description. Length 5.08 mm, width 1.95 mm. General body color ( Fig. 6A–C ) red-brown, pronotum slightly darker than elytra; dorsal surface punctate, with a procumbent hair associated with each punctation on head, pronotum and elytra, length of hairs reaching or nearly reaching nearest puncture (many hairs may have been broken off during the cleaning of the specimen, which was originally encased in pollen and other debris).

Head. Not broad, width = 0.68× pronotal width ( Fig. 6D–E ); in dorsal view conical, gradually narrowed anteriorly, surface flat to slightly convex, finely, densely punctured, average distance between closest punctures 1–2× width of puncture; head width 1.07 mm; dorsal interocular distance 0.68 mm, head width/dorsal interocular distance ratio 1.57, ventral interocular distance 0.50 mm, head width/ventral interocular distance ratio 2.14. Eye with large black facets, about 2× diameter of head punctures. Antennal length slightly shorter than pronotal width, 1.2× head width; antennomere I (scape) fairly large, slightly elongate; antennomere II shorter than III; IV small, circular; V–VII same length as IV, gradually becoming wider with VIII transverse and flattened apically; club fairly large, IX and X similar in length; XI not enlarged, 1.3× longer than X, globular with rounded apex. Clypeus weakly concave anteriorly, moderately punctate. Transverse occipital line [vertexal line] distinct, laterally nearly reaching eye. Mentum and submentum finely punctured, ½–1/3× diameter of facet, 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 punctation.

Thorax. With pronotum transversely rectangular in dorsal view, length/width ratio 0.71; with distinct marginal carina laterally and basally, anteriorly with fine marginal carina medially; dorsally flattened; anterior angles narrowly rounded, projecting forward; posterior angles weakly developed, with small denticle at angle; lateral margin parallel-sided in medial half, shallowly arcuate inward anteriorly and posteriorly; posterior margin slightly projecting medially, projection beginning approximately by pair of small, dark pores in margin located ¼ width from posterior angles, each pore marks base of a distinct sulcus extending anteriorly onto disc ¼ length of pronotum. Prosternum in ventral view convex, with fine dense punctures; anterior margin slightly emarginate, finely denticulate with row of long, anteriorly directed setae, longest setae approximately 1/3 length of eye; prosternal process flattened apically, weakly expanded and truncate at apex. Hypomeron rugose with dense moderate punctures. Scutellar shield distinctly transverse, posterior margin weakly roundly pentagonal. Elytra in dorsal view elongate, flattened dorsally; length/width 1.71, greatest width near midlength; with distinct marginal line basally; 10 complete striae of moderate puncture size; scutellary striole extending ¼ elytral length, with 15 punctures; punctures of elytral striae same size as pronotal punctures, striae weakly impressed; intervals of striae with fine, shallow punctures, ¼ size of strial punctures; all punctures of elytra bearing a single short seta; seta most visible in profile, extending to reach next puncture. Mesoventrite with strong coarse punctation, narrowly separated, hidden in rugose surface. Metaventrite glossy, with strong lateral punctation separated by 1–2× own diameter; medial surface finely distinctly punctured, separated by 3–4× own diameter; surface medially flattened, metathoracic discrimen extending approximately ¾ metaventrite length. Legs broadened, relatively similar in length and shape. Procoxa oval; mesocoxa globular; metacoxa transversely elongate-oval; trochanters obliquely truncate apically; femora robust, compressed laterally; tibiae shorter than femora, narrowly triangularly dilated to obliquely truncate apices; protibia with apical lateral tooth small, with complete apical fringe of very short stout spinules on straight ventral apical margin; meso- and metatibia with apical fringe of short stout spinules on anterior margin, finer setae on posterior margins.

Abdomen. Ventrite apical margin bearing short, sparse setae; all ventrites bearing moderate, shallow punctation evenly distributed 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 (n = 1): moderately dorsoventrally flattened; tegmen in dorsal view with basal piece ring-like and wide; parameres in dorsal view narrowing slightly 1/3 of length from the base then expanding gradually to a rounded apex, apical 2/3 slightly asymmetric with inner margin straight and outer margin with slight curvature, in lateral view length = 4.9× width; elongate cylindrical median lobe with strong taper apically; long coiled flagellum ( Fig. 6F–H ).

Female. Not known.

Distribution. Currently known only in the Mexican state of Guerrero on Dioon stevensonii .

Material examined. Holotype (by designation) male of Pharaxonotha gigantea with the following labels: 1) [rectangular; white; printed in black ink] “ MEXICO, Guerrero, Achotla, oak forest, [GPS omitted], ex: Dioon tomasellii [ D. stevensonii ] male cone, coll. J. Chemnick, 18May2004, TW2004-18, elev. 1380 m; 2) [rectangular; red; printed in black ink] “ HOLOTYPE ♂ Pharaxonotha gigantea Skelley, Tang and Pérez-Farrera 2022 ”. Deposited in the FSCA.

Etymology. Named for its size; this is the largest Pharaxonotha known.

Remarks. The sole type specimen of Pharaxonotha gigantea was found together on a male cone of D. stevensonii with a species of Allocorynina weevil, Parallocorynus (Dysicorynus) andrewsi Tang and O’Brien ( O’Brien and Tang 2015) . Two specimens of Pharaxonotha gigantea were originally collected, however, one was sacrificed for genetic analysis, but did not yield usable DNA.

Figures

Figure 6. Pharaxonotha gigantea from Achotla, Guerrero, Mexico (male holotype). A–C) Dorsal, lateral and ventral habitus. D–E) Head, dorsal and ventral views. F) Tegmen attached to median lobe, ventral view top and lateral view bottom. G) Parameres of tegmen, ventral view top and lateral view bottom. H) Genital capsule, ventral view.