Pharaxonotha confusa Pakaluk, 1988

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 : 21-24

Pharaxonotha confusa Pakaluk

Figures 8A–J (illustrations 6, 9 in Pakaluk 1988)

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

Diagnosis. Pharaxonotha confusa can only be distinguished from other members of the genus by a combination of characters: Body length 2.13–3.38 mm, among the intermediate-sized members of Panamanian Pharaxonotha ; head width/pronotal width = 0.67–0.80, within the range typical for the majority of Panamanian species; pronotal L/W = 0.60–0.80 (mean = 0.74) intermediate in range for Panamanian species; elytra L/W = 1.66–1.87 (mean = 1.79) intermediate in range for Panamanian species; spermatheca with insertion point of spermathecal and glandular ducts flat, not raised, smooth portion at basal end usually abruptly transitioning to wider, annulated section, annulations at basal third at 90° angle to margins; inhabiting cones of Zamia fairchildiana and Z. pseudomonticola , in western Chiriqui province and across the border to Puntarenas province, Costa Rica, at elevations from 1–1500 m asl.

Description. Length 2.13–3.38 mm, width 0.84–1.29 mm (n = 116). Body in dorsal view elongate-oval ( Fig. 8A–C ), greatest width at middle of elytra; in lateral view convex dorsally ( Fig. 8B ). 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 mesoventrite and abdomen mostly covered with short procumbent setae.

Head not broad, width = 0.66–0.81× 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 0.51–0.77 mm; dorsal interocular distance 0.29–0.41 mm, head width/dorsal interocular distance ratio 1.73–1.97, ventral interocular distance 0.20–0.31 mm, head width/ventral interocular distance ratio 2.19–2.83. 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. 8C ). Clypeus weakly concave anteriorly, moderately punctate. Mentum ( Fig. 8E ) 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 0.60–0.80; 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 ratio 1.66–1.91, 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. 8F–H ), with dorsoventrally flattened tegmen, elongate cylindrical median lobe, and long coiled flagellum.

Female. Similar to male. Genitalia elongate ( Fig. 8I ); gonostylus set apically on gonocoxite, gonostylus length = 5–6× width. Spermatheca C-shaped, evenly curved, approximately equal width for most of length, except slightly narrower at its basal 1/5–1/6, length <6× maximum width of basal third, apical third not more swollen than maximum width of basal 1/3 ( Fig. 8J ).

Type locality. Costa Rica, Puntarenas province, San Vito de Coto Brus, Las Cruces, Wilson Botanical Garden.

Range. As delimited here, known from Chiriqui province, Panama extending west into Puntarenas province, Costa Rica in cones of Zamia fairchildiana and Z. pseudomonticola , at elevations from 1–1500 masl. Zamia fairchildiana occurs as far northwest as San José province, Costa Rica and this beetle likely occurs there as well.

Materials examined. Holotype male of Pharaxonotha confusa with the following labels: 1) [rectangular; white; printed in black ink] “ COSTA RICA: Puntarenas, Prov., San Vito de Coto Brus , Las Cruces, Wilson Botanical Garden, ex., male cones of Zamia fairchildeana [sic, see Remarks] 25.II.85, G. E. Schatz coll.”. 2) [rectangular; red; printed in black ink, except as noted] “ HOLOTYPE, Pharaxonotha , confusa [handwritten], Pakaluk”. Deposited in the USNM.

Additional materials (987). Two paratypes with same label data as holotype ( USNM). COSTA RICA: Puntarenas: Las Cruces, Coto Brus , 1100m, II-1994, Luis D. Gomez, ex male Zamia , #94767 (111) ; Osa Pen., Corcovado

Nat. Park, Pop#1, 8-XII-2005, C. Lopez Gallego, Zamia fairchildiana ♂ cones (57); Las Cruces, Loop Trail, ♂ cone Z. pseudomonticola , 1300m, [GPS coord. Omitted], W. Tang, XI-24-2010 (177); Wilson Botanical Garden, ex ♂ cone Z. pseudomonticola , N8°47.150′ W47°57.570′, 1235m, W. Tang, XI-24-2010 (54); Golfo Dulce, beach nr. Rincon, ♂ cone Zamia fairchildiana , [GPS coord. Omitted], W, Tang, XI-26-2011 (238); PANAMA: Chiriquí, Burica Pen., San Bartolo Limite, 13.5 km WNW of Puerto Armuelles, 440m, [GPS coord. omitted], ♂ cone Zamia fairchildiana , I-8-2008, M. Calonje et al. (206); Santa Clara, Finca Hartmann, Z. pseudomonticola, Alberto Taylor 29-XII-2001 (93); 30-XII-2001 (21); Hartman-Enders, 1500m asl, 30-XII-2001 (10); Porton, ex ♂ cone Zamia . sp. aff. pseudomonticola , 7-XII-2013, A. Taylor (18). Specimens to be deposited in: ANIC, FSCA, NHMUK, NZAC, RHTC, SEMC, STRI, MIUP, TAMU, USNM.

Remarks. Describing P. confusa, Pakaluk (1988) cited the host as best understood at the time with the advice of regional botanists. Zamia from various localities are planted in Wilson Botanical Garden, so the cone from which type specimens of P. confusa were collected may have been a cultivated Zamia fairchildiana . However, that individual cycad will never be known to confirm that identification.

In the 1980s, there was taxonomic confusion on the identity of “ fairchildiana ” and “ pseudomonticola ” ( Calonje et al. 2023). Gómez (1982) described both Z. fairchildiana and Z. pseudomonticola in the same paper. Prior to this, there was no official name for any Zamia in southeastern Costa Rica. Unfortunately, Gómez (1982) did not clearly cite holotypes, thus Z. pseudomonticola did not become an available name until Stevenson and Sabado (1986) provided additional information to make it valid. For many years afterward confusion continued, with the name “ Zamia fairchildiana ” being used for all the common arborescent understory Zamia in the region, while the identity of Z. pseudomonticola remained unclear. Although Stevenson and Sabado (1986) claimed to have found and examined the type for Z. pseudomonticola and validated the name, the issue was not fully resolved until Acuña and Gómez (2009) designated a lectotype (from the Osa peninsula) for Z. fairchildiana . Years later, after more field work, morphological studies and DNA analyses, it is generally understood that Z. fairchildiana is the lowland form, while Z. pseudomonticola is the highland form which occurs naturally around the Wilson Botanical Garden. Thus, the natural host for the nominal population of P. confusa is Z. pseudomonticola .

As may be expected from a beetle that occurs within a wide range of elevations and diverse habitats (lowland rainforest and beach habitat to premontane forest), P. confusa exhibits some variation. Lowland populations inhabiting Z. fairchildiana are on average smaller (mean length = 2.47 mm) than highland forms inhabiting Z. pseudomonticola (mean length = 2.69–3.00 mm). However, DNA analysis ( Tang et al. 2018b, 2020; Salzman et al. unpublished data) did not detect sufficient genetic differences among populations to warrant demarcation into more than one species. The elevational ranges of the two host species meet and appear continuous (Calonje, personal communication) and there does not appear to have been any recent geographic barriers to prevent gene flow from lowland to highland populations. The male cones of host Z. pseudomonticola are larger than those of Z. fairchildiana and the difference in available nutrition may account for differences in beetle size. The lowland and highland forms are otherwise nearly identical in their external morphological proportions. Until definitive characters are found to separate them, we treat the lowland form as a variety of the nominal highland form. As a member of the confusa species group, P. confusa appears most similar to P. panamensis , based on the overall shape of the spermatheca and genetic analysis ( Tang et al. 2018b, 2020; Salzman et al. unpublished data). Like most other members of the confusa species group, this beetle co-occurs in the male cones of its hosts with Notorhopalotria weevils, in this case with N. montgomeryensis O’Brien and Tang ( O’Brien and Tang 2015).

Figures

Figure 8. Pharaxonotha confusa from Z. fairchildiana from Burica Peninsula (A–H, J). A–C) Female dorsal, lateral and ventral habitus. D–E) Female head, dorsal and ventral views. F) Tegmen attached to median lobe, ventral view. G) Parameres of tegmen, (top to bottom) ventral and lateral views. H) Male genital capsule, ventral view. I) Retracted ovipositor from Z. pseudomonticola from Porton, ventral view. J) Spermatheca.