Pharaxonotha bicolor 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 : 8-11

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

Figures 1B , 3A–K , illustration 1D in Vovides (1991)

Diagnosis. Pharaxonotha bicolor is easily distinguished from all members of the genus by the distinct long elytral setation, elytral surface dulled with striae weakly impressed; pronotal anterolateral angles not projecting forward, broadly rounded in dorsal and lateral view; eyes small, not or barely encroaching the gula or frons, HW/DI <1.45 and HW/VI <1.73; protibia narrow to apex; and with a known distribution in Mexico [Oaxaca, Puebla] on Dioon califanoi , D. caputoi and D. purpusii .

Description. Type series length 2.72–3.97 mm, width 1.07–1.63 mm. General body color ( Fig. 3A–C ) orangebrown, elytra usually black to dark brown; dorsal surface punctate, alutaceous, shining, procumbent hairs associated with punctation on pronotum and elytra, hair length reaching or exceeding nearest punction; ventrally shining.

Head. Not broad ( Fig. 3D–F ), width = 0.66–0.75× 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 0.62–0.78 mm; dorsal interocular distance 0.45–0.58 mm, head width/dorsal interocular distance ratio 1.33–1.44 (1.54), ventral interocular distance 0.40–0.51 mm, head width/ ventral interocular distance ratio 1.48–1.72. Eye small, finely facetted, 3–4 facets = length of antennomere II; facets about 3× diameter of head punctures. Antennal length slightly shorter than pronotal width, 2× head width; antennomere I (scape) fairly large, slightly elongate; antennomere II slightly shorter than III; IV circular; IV–VIII small, width slightly less than length, gradually widening to a nearly circular VIII; club fairly large, IX and X similar in length; XI not enlarged, slightly longer than X, width ¾ length, globular with acuminate apex. Clypeus weakly concave anteriorly, moderately punctate. Transverse occipital line [vertexal line] distinct medially, absent laterally. Mentum and submentum moderately punctured, half diameter of facet, distance between nearest punctures approximately 1× own diameter, each puncture with a long seta. Gular area smooth, without punctation or setae, border with submentum marked by change in punctation and with a shallow transverse depression.

Thorax. With pronotum transversely rectangular in dorsal view, length/width ratio 0.68–0.76; with distinct marginal carina laterally and basally, anteriorly lacking marginal carina; surface convex; anterior angles broadly rounded in dorsal and lateral view, not projecting forward; posterior angles weakly developed, with small denticle at angle; lateral margin medially parallel-sided or converging slightly posteriorly, evenly shallowly arcuate basally, broadly inwardly arcuate anteriorly; 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 convex apically, expanded and truncate at apex. Hypomeron laterally with indistinct seta bearing punctures, medially with few longitudinal striations. Scutellar shield distinctly transverse, posterior margin weakly roundly pentagonal. Elytra in dorsal view elongate-oval, convex; length/width 1.66–1.89, greatest width near midlength; with distinct marginal line basally; 8 complete striae of moderate puncture size, striae IV–X hidden in alutaceous surface; scutellary striole extending ¼ elytral length, with 10–15 punctures; punctures of elytral striae slightly larger than pronotal punctures, striae visibly impressed; intervals of striae with fine, shallow punctures, ½ size of strial punctures; all punctures of elytra bearing a single prominent long seta, extending past next puncture in series. Mesoventrite with strong punctation, distance between nearest punctures approximately equal to diameter of punctures, puncture depth moderate. Metaventrite weakly glossy, with moderate 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 ¾ metaventrite length. Legs narrow, relatively similar in length and shape. Procoxa oval; mesocoxa globular; metacoxa transversely elongate-oval; trochanters obliquely truncate apically; femora narrowly robust, moderately compressed laterally; tibiae shorter than femora, parallel-sided to obliquely truncate apices; protibia with apical lateral tooth small, with apical fringe of (~5–6) long stout spinules on concave ventral apical margin continuous to lateral tooth; meso- and metatibia with apical fringe of long spinules on anterior and posterior margins.

Abdomen. Ventrite apical margin bearing long setae; all ventrites bearing moderate, shallow evenly distributed 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 4× diameter of puncture; if I–IV each with 2 or more median pairs of longer, semi-erect sensory hairs, they are obscured in other setation. Male genitalia (n = 4) not distinctly dorsoventrally flattened; tegmen in dorsal view with basal piece ring-like; parameres in dorsal view gradually widening to a rounded apex, lateral margins approximately straight, in lateral view length = 3.9–4.7× width ( Fig. 3H ); elongate cylindrical median lobe narrowing apically; long coiled flagellum ( Fig. 3G–I ).

Female. Similar to male. Sexual dimorphism present with male protibia weakly triangularly dilated apically, female protibia parallel-sided, narrow to truncate apex; and basal protarsomeres of male more robust than female. Genitalia (n = 5): gonostylus cylindrical, widest at apex, tapering slightly and gradually to base, set apically on gonocoxite, gonostylus length = 3.4–4.5× greatest width ( Fig. 3J ). Spermatheca C-shaped, length = 3.0–4.4× maximum width, asymmetric, widest in apical third, basal third with longitudinal wrinkles, apical third with weakly annulated, semi-reticulated texture, dorsally swollen in basal portion of apical third ( Fig. 3K ).

Distribution. Known from subhumid to arid habitats at elevations between 1300–1900m on Dioon califanoi , D. caputoi , D. purpusii in northern Oaxaca and southern Puebla ( Gutiérrez-Ortega et al. 2018).

Material examined. Holotype (by designation) male of Pharaxonotha bicolor with the following labels: 1) [rectangular; white; printed in black ink] “ MEX, Oax., San Andres Pápalo, ♂ cone Dioon sp. aff. purpusii , late Oct 2016, M. A. Perez Farrera. 2) [rectangular; red; printed in black ink] “ HOLOTYPE ♂ Pharaxonotha bicolor Skelley, Tang and Pérez-Farrera 2022 ”. Deposited in the FSCA.

Paratypes (total 170). Allotype ( FSCA) and 50 paratypes with same data as holotype: MEXICO: Oaxaca: Santa Catarina, [GPS omitted], 1400m, Dioon purpusii ♂ cone, 5-XI-2012, W. Tang (21); Teotitlán, 1600m, 25-II-1989, A. Vovides, ex male cone of Dioon califanoi (1); Teotitlán, 12-X-1991, A. Vovides, 20A, Dioon califanoi (4); Teotitlán de camino, 12-X-1991, A. Vovides, 24A, Dioon califanoi (1); MEXICO: Oaxaca, Teotitlán de Flores, Magón, 24-VIII-1991, A. Vovides, 36A, Dioon califanoi (2); same data only, 44A (3); Teotitlán de Flores, Magón, 15-IX- 1999, A. Vovides, 8A, unknown cycad (8). Puebla: Coatepec, [GPS omitted], 1842m, ex ♂ cone Dioon caputoi , 6-XI-2012, W. Tang (10); Santiago, Coatepec, 13-X-1993, A. Vovides, C. Iglesias & P. Aguilar, Dioon caputoi cone debris (8); same locality except, IX-2004, F. Nicolalde, Dioon caputoi (3); Oax. border, Teotitlán, [GPS omitted], 1890m, ex Dioon califanoi ♂ cone, 7-XI-2012, W. Tang (58). Paratypes to be deposited in ANIC, CUIC, CZUG, FSCA, IEXA, NHMUK, NZAC, UAQM, UNAM, USNM.

Etymology. The species epithet refers to the usually contrasting colors of the black to dark brown elytra and the orange pronotum.

Remarks. This species has been found together in the male cones of two of its hosts, Dioon califanoi and D. purpusii , with two species of Allocorynina weevils, Parallocorynus (P.) gregoryi O’Brien and Tang and P. (Eocorynus) chemnicki Tang and O’Brien. On another host species, D. caputoi , this species occurs with Parallocorynus (P.) bicolor (Voss) ( O’Brien and Tang 2015; Tang unpub. data). These weevils have an orange pronotum and black to dark brown elytral color scheme similar to that of Pharaxonotha bicolor , suggesting that there may be a mimicry complex in these associated insects. More intensive sampling from this host complex may also reveal the presence of P. bicolor in D. argenteum and D. planifolium , which have adjacent ranges to these other hosts.

Vovidesi species group

Adult diagnosis. In the vovidesi species group the dorsal surface is yellow-brown to orange-brown, with the pronotum often being slightly darker than the elytra, and the head in lateral view is flattened anteriorly and more convex between the eyes. 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 or exceeding the distance to nearest puncture. Length ranges from 2.48–3.91 mm.

Remarks. This species group is established based on analyses of the 16S rRNA gene from five populations sampled from both species described herein and are part of the early diverging lineages in Tang et al. (2018b, 2020). Materials of P. vovidesi analyzed by Tang et al. (2018b: 8, fig. 4; 2020: 18, fig. 3) are presented in their trees labeled as follows: “D0250 Farallon, D. edule ”, “D0324 Palm Sola, D. edule ” and “D0253 Mt. Oscuro, D. edule ”. Materials of P. fawcettae analyzed by Tang et al. (2018b: 8, fig. 4; 2020: 18, fig. 3) are presented in their trees labeled as follows: “D0322 SLP, D. angustifolium ” and “D0323 Tamaulipas D. angustifolium ”.

The group is distributed widely along the Atlantic drainage of eastern Mexico, in Hidalgo, Nuevo León, Querétaro, San Luis Potosí, Tamaulipas and central Veracruz on the Dioon edule - angustifolium complex. Dissected adult specimens from both species of the vovidesi group usually have their guts packed with the distinctive monosulcate pollen grains of cycads, indicating that this is a major food source.

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 3. Pharaxonotha bicolor (A–J from San Andres Pápalo, Oaxaca, Mexico; female allotype: A–D, F). 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) Male genital capsule. J) Spermatheca (partially collapsed) with retracted ovipositor, ventral view. K) Spermatheca (fully inflated) from Puebla, Mexico, near Teotitlán.