Pharaxonotha dimorpha 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 : 27-30

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

Figure 10A–L

Diagnosis. A member of the kirschii group; this species has the most striking sexual color dimorphism of any known Pharaxonotha , with the dorsal color of the male a uniform medium brown, while the pronotum and elytra of the female is almost completely dark brown to black, except for edges of the pronotum and the apex of the elytra. Additional diagnostic characters include small antennomere XI, the female spermathecal apex abruptly

curving to a truncated point, and the male paramere width in lateral view <3.4× own length. It has been found at El Farallón, Veracruz, Mexico on Dioon edule .

Description. Length 3.44–4.35 mm, width 1.22–1.62 mm. General body color ( Fig. 10A–D ) with the dorsal color of the male a uniform medium brown, while the pronotum and elytra of the female is almost completely dark brown to black, except for edges of the pronotum and the apex of the elytra. Dorsal surface glossy, with very short setae in punctures.

Head. Not broad, width = 0.62–0.67× pronotal width ( Fig. 10E–F ); in lateral view robust, clypeus to base of head dorsally convex; in dorsal view conical, gradually narrowed anteriorly, surface convex, coarsely punctured, average distance between closest punctures 2–3× width of puncture; head width 0.70–0.88 mm; dorsal interocular distance 0.46–0.60 mm, head width/dorsal interocular distance ratio 1.45–1.56, ventral interocular distance 0.40–0.53 mm, head width/ventral interocular distance ratio 1.45–1.75. Eye with large black facets, similar diameter of head punctures; head posterior of eye with a small tooth (temple) in dorsal profile. 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 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 small, 1.1× longer than X, globular with rounded apex. Clypeus weakly concave anteriorly, moderately punctate. Transverse occipital line [vertexal line] distinct nearly from eye to eye. Mentum and submentum coarsely punctured, ½–¾× 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 0.70–0.75; with distinct marginal carina laterally and basally, anteriorly with fine marginal carina medially; dorsally flattened; anterior angles sharply rounded, projecting forward; posterior angles developed, with small denticle at angle; lateral margin weakly angulate 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 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 flattened apically, expanded and truncate at apex. Hypomeron smooth, with few punctures. Scutellar shield distinctly transverse, posterior margin weakly roundly pentagonal. Elytra in dorsal view elongate, flattened dorsally; length/width 1.83–1.87, greatest width near midlength; with distinct marginal line basally; 10 complete striae of moderate puncture size; scutellary striole extending 1⁄5 elytral length, with 7–8 punctures; punctures of elytral striae 2× larger than pronotal punctures, striae weakly impressed; intervals of striae with fine, indistinct, shallow punctures, 1⁄5 size of strial punctures; all punctures of elytra bearing a single very 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 1–2× own diameter; medial surface finely distinctly punctured, separated by 3–4× own diameter; surface medially flattened, metathoracic discrimen extending approximately ½ metaventrite length. Legs narrow, relatively similar in length and shape. Procoxa oval; mesocoxa globular; metacoxa transversely elongate-oval; trochanters obliquely truncate apically; femora narrowly oblong, compressed laterally; tibiae shorter than femora, weakly 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 ventrite 5 with small denticle at apex. Male genitalia (n = 2): not dorsoventrally flattened, tegmen in dorsal view with basal piece ring-like and narrow; parameres in dorsal view with lateral margins approximately straight to midlength, apical half with inner and outer margins curving and bulging, apex rounded with slight curve toward one another, in lateral view length = 2.7–3.3× greatest width; elongate cylindrical median lobe with lateral margins nearly parallel; long coiled flagellum ( Fig. 10G–J ).

Female. Similar to male. Female differs in darker dorsal coloration with nearly completely dark elytra; female protibial and protarsus narrow, male with weakly dilated protibial and basal protarsomeres. Female lacking apical denticle on terminal abdominal ventrite. Genitalia (n = 1); gonostylus cylindrical, widest at apex, tapering slightly and gradually to base, set apically on gonocoxite, gonostylus length = 4.2–4.6× greatest width ( Fig. 10K ). Spermatheca hook-shaped, widest just apicad of rounded base, then narrowing evenly until reaching unsclerotized arc at central third, apical third narrowing evenly from junction with central third, until abrupt bend to a truncated apex, length = 5.4× greatest width ( Fig. 10L ).

Distribution. This species is known only from El Farallón, Veracruz, Mexico on Dioon edule . This is a stabilized dune, beach habitat. The plants are exposed to nearly full sun, with only scattered low tree cover, and are likely subject to salt spray during storms.

Material examined. Holotype (by designation) male of Pharaxonotha dimorpha with the following labels: 1) [rectangular; white; printed in black ink] “ MEXICO, V.C., Farallón , [GPS omitted] ex ♂ cone Dioon edule , 16-XI- 2012, W. Tang ”; 2) [rectangular; red; printed in black ink] “ HOLOTYPE ♂ Pharaxonotha dimorpha Skelley, Tang and Pérez-Farrera 2022 ”. Deposited in the FSCA.

Paratypes (total 3). Allotype and 2 paratypes with same data as holotype deposited at the FSCA .

Etymology. The species is named for its striking sexual color dimorphism.

Remarks. Only four specimens of Pharaxonotha dimorpha were found together with over 120 individuals of P. vovidesi on a male cone of D. edule that was at the end stage of pollen shedding. The difference in numbers bring up the possibility that these two species of Pharaxonotha , while sharing the same spatial niche, may have differing temporal niches, with preferences to feed and/or reproduce in the cone at different stages of cone development. See remarks under P. sclerotiza . In D. edule cones at this site, P. dimorpha also occurs with the weevils Parallocorynus (P.) perezfarrerai and P. (Neocorynus) iglesiasi ( O’Brien and Tang 2015) .

Figures

Figure 10. Pharaxonotha dimorpha from El Farallón, Veracruz, Mexico (B–G: male holotype). A) Female allotype, dorsal habitus. B–D) Male dorsal, lateral and ventral habitus. E–F) Male head, dorsal and ventral views. G) Tegmen attached to median lobe and genital capsule, lateral view. H) Male genital capsule, dorsal view.I) Tegmen attached to median lobe, lateral view top and ventral view bottom. J) Parameres of tegmen, ventral view top and lateral view bottom. K) Retracted ovipositor, ventral view. L) Spermatheca (fully inflated).