Pharaxonotha occidentalis 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 : 22-24

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

Figures 1C , 2B , 8A–J

Diagnosis. As in most Pharaxonotha inhabiting Dioon , the dorsal surface of the head, pronotum and elytra have long setae emerging from punctures, with setal length reaching to the nearest puncture. Other diagnostic characters include body color a uniform brown, posterior lateral margin of eye with small distinct fringe of setae separated from facets, and pronotum relatively short, pronotal length/width = 0.71–0.79 (mean for each of three populations = 0.75). It is known to inhabit Dioon species on the Pacific drainage of Oaxaca and Chiapas, Mexico.

Description. Length 2.77–4.01 mm, width 0.96–1.56 mm. General body color ( Fig. 8A–C ) uniform pale brown. Dorsal surface distinctly setose with long setae reaching neighboring punctures.

Head. Not broad, width = 0.68–0.73× pronotal width ( Fig. 8D–F ); in lateral view notably narrow, flattened; 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 0.54–0.76 mm; dorsal interocular distance 0.34–0.45 mm, head width/dorsal interocular distance ratio 1.54–1.67, ventral interocular distance 0.27–0.36 mm, head width/ventral interocular distance ratio 1.93–2.45. Eye with large black facets, about 2× diameter of head punctures; posterior lateral margin of eye with small distinct fringe of setae separated from facets. Antennal length nearly equal to pronotal width, 1.5× head width; antennomere I (scape) fairly large, slightly elongate; antennomere II slightly shorter than III; IV circular; V–VII same length as IV, gradually becoming wider with VIII distinctly 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] absent medially. Mentum and submentum fine punctured, 1/3× diameter of facet, distance between nearest punctures approximately 2–3× 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 0.71–0.79; 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 weakly arched 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 fine 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 minute punctures. Scutellar shield distinctly transverse, posterior margin weakly roundly pentagonal. Elytra in dorsal view elongate, flattened dorsally; length/width 1.78–2.38, greatest width near midlength; with distinct marginal line basally; 10 complete striae of moderate puncture size; scutellary striole extending ¼ elytral length, with 10–15 punctures; punctures of elytral striae 1.5× larger than 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 only visible in profile, extending almost to next 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 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, fine 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 = 3): moderately dorsoventrally flattened; tegmen in dorsal view with basal piece ring-like; parameres in dorsal view narrowing slightly 1/3 of length from the base then expanding slightly to maximum width at 2/3 length from base, apical 2/3 slightly to moderately asymmetric with inner margin straight and outer margin curved and slightly bulging, apex rounded, in lateral view length = 3.8× width; elongate cylindrical median lobe narrowing apically; long coiled flagellum ( Fig. 8G–H ).

Female. Similar to male, sexual dimorphism weakly evident in pronotal shape with mean pronotal length/ width in males = 0.76–0.77 (range = 0.74–0.79, n = 25) and mean length/width in females = 0.74–0.75 (range = 0.71–0.77, n = 30) in three populations examined, with some overlap between males and females; femora, protibia and basal protarsomeres of male more broadly dilated. Genitalia (n = 8): gonostylus cylindrical, widest at apex, tapering slightly and gradually to base, set apically on gonocoxite, gonostylus length = 3.6–4.7× greatest width ( Fig. 8I ). Spermatheca arcuate, but not C-shaped, length = 2.9–3.7× greatest width, asymmetric, widest in apical half, basal third with longitudinal wrinkles, apical portion weakly annulated, apex slightly tapering and with slight, abrupt bend ventrally ( Fig. 8J ).

Distribution. Known distribution along the Pacific drainage of Oaxaca and Chiapas on Dioon holmgrenii and D. merolae .

Material examined. Holotype (by designation) male of Pharaxonotha occidentalis with the following labels: 1) [rectangular; white; printed in black ink] “ MEX., Chiapas, El Campanario, 2k Ejido Andres Quintana Roo, ♂ cone Dioon merolae , XI-2011, M. A. Perez Farrera ”; 2) [rectangular; red; printed in black ink] “ HOLOTYPE ♂ Pharaxonotha occidentalis Skelley, Tang and Pérez-Farrera 2022 ”. Deposited in the FSCA.

Paratypes (total 184). Female allotype ( FSCA) and 183 with same data as holotype deposited in ANIC, CUIC, CZUG, FSCA, IEXA, NHMUK, NZAC, UAQM, UNAM, USNM.

Additional specimens (total 428). Material studied presently considered to be P. occidentalis , but not designated as paratypes: MEXICO: Oaxaca, Buenos Aires [GPS omitted], 1120m, Dioon merolae ♂ cone, 11-XI- 2012, W. Tang (1); Rancho Limón, ex ♂ cone Dioon holmgrenii , [GPS omitted], 620m, 12-XI-2012, W. Tang (411); San Bartolomé Loxicha, ex ♂ cone Dioon holmgrenii , 5-XII-2008, F. Maldonado-Ruiz (16). These will be deposited in institutions stated above.

Etymology. The species epithet, occidentalis, derives from the Latin for west, referring to distribution in western Mexico, along the Pacific drainage of Oaxaca and Chiapas states.

Remarks. Pharaxonotha occidentalis lives sympatrically on D. holmgrenii with the Allocoynina weevils Parallocorynus (P.) salasae Tang and O’Brien and P. (Eocorynus) schiblii Tang and O’Brien and on D. merolae with Parallocorynus (P.) jonesi O’Brien and Tang ( O’Brien and Tang 2015, Navarrette-Heredia 2018). While the 16S rRNA gene used in the phylogenetic analysis of Pharaxonotha ( Tang et al. 2018b, 2020) has a moderate rate of evolution, it did not detect significant genetic differences between Pharaxonotha inhabiting D. holmgrenii and D. merolae . Nor did we find significant morphological differences. Further studies with a more in-depth analysis using a greater number of genes may result in the taxonomic separation of these populations in the future.

Figures

Figure 1. Pharaxonotha heads, lateral view. A) P. kirschii, Mpio. Jalpan, Querétaro, Mexico. B) P. bicolor, paratype, San Andres Pápalo, Oaxaca, Mexico. C) P. occidentalis, paratype, El Campanario, Chiapas, Mexico. D) P. vovidesi, paratype, Mt. Oscuro, Veracruz, Mexico.

Figure 2. Pharaxonotha body parts. A–C) Dorsal view of head. A) P. kirschii, Mpio. Jalpan, Querétaro, Mexico. Arrow points to temple. B) P. occidentalis, paratype, El Campanario, Chiapas, Mexico. C) P. vovidesi, paratype, Mt. Oscuro, Veracruz, Mexico.D) P. kirschii, abdominal ventrites, Mpio. Jalpan, Querétaro, Mexico. Arrow points to tooth on ventrite 5. E–F) Antennal clubs. E) P. kirschii, Santa Isabel, Chiapas, Mexico.F) P. sclerotiza, holotype. G) Spermatheca of Pharaxonotha fawcettae from Jalpan de Serra, Querétaro, Mexico indicating the diagnostic structures and orientations used in descriptions.

Figure 8. Pharaxonotha occidentalis from El Campanario, Chiapas, Mexico (A–D, F: female allotype). A–C) Dorsal, lateral and ventral habitus. D–F) Head, dorsal, lateral and ventral views. G) Tegmen attached to median lobe, ventral view top and lateral view bottom. H) Parameres of tegmen, ventral view top and lateral view bottom. I) Retracted ovipositor, ventral view. J) Spermatheca (partially inflated).