Prionus (Prionus) mexicanus Bates 1884
Creators: name: Santos-Silva, Antonio
name: Nearns, Eugenio H.
name: Swift, Ian P.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Cerambycidae
Prionus
Prionus mexicanus

description: Prionus (Prionus) mexicanus Bates, 1884
(Figs. 33–37, 114–117)
Prionus mexicanus Bates, 1884: 227; Heyne & Taschenberg, 1908: 237, p. 33, fig. 19; Lameere, 1913: 78 (cat.); 1919: 139; 1920: 143; Blackwelder, 1946: 556; Chemsak et al., 1992: 288 (checklist); Terrón, 1992: 21 (distr.); Noguera & Chemsak, 1996: 396 (distr.).
Prionus (Prionus) mexicanus; Monné & Giesbert, 1994: 15 (checklist); Monné, 1995: 53 (cat.); Monné & Hovore, 2005: 19 (checklist); Monné, 2006: 87 (cat.); Monné & Hovore, 2006: 19 (checklist); Özdikmen & Turgut, 2009: 411; Bezark & Monné, 2013: 28 (checklist); Monné, 2015: 177 (cat.).
Prionus Flohri; Lameere, 1912a: 244 (error of identification).
Prionus (Riponus) townsendi Casey, 1912: 245; Lingafelter et al., 2014: 334 (type). Syn. nov.
Prionus Townsendi; Lameere, 1919: 139.
Prionus townsendi; Blackwelder, 1946: 556.
Prionus (Neopolyarthron) townsendi; Chemsak et al., 1992: 21 (checklist); Monné & Giesbert, 1994: 16 (checklist); Monné, 1995: 55 (cat.); Noguera & Chemsak, 1996: 396 (distr.); Monné & Hovore, 2005: 20 (checklist); Monné, 2006: 88 (cat.); Monné & Hovore, 2006: 20 (checklist); Özdikmen & Turgut, 2009: 410; Bezark & Monné, 2013: 27 (checklist); Monné, 2015: 178 (cat.).
Prionus (Riponus) curticollis Casey, 1912: 246; Lingafelter et al., 2014: 49 (type). Syn. nov.
Prionus curticollis; Lameere, 1920: 143; Blackwelder, 1946: 556; Barbour et al., 2011: 590.
Prionus (Neopolyarthron) curticollis; Chemsak et al., 1992: 21 (checklist); Monné & Giesbert, 1994: 15 (checklist); Monné, 1995: 54 (cat.); Noguera & Chemsak, 1996: 396 (distr.); Monné & Hovore, 2005: 20 (checklist); Monné, 2006: 87 (cat.); Monné & Hovore, 2006: 20 (checklist); Özdikmen & Turgut, 2009: 410; Bezark & Monné, 2013: 27 (checklist); Monné, 2015: 177 (cat.).
Prionus (Neopolyarthron) batesi; Komiya & Nogueira, 2014: Fig. 2.
Integument dark-brown dorsally, reddish ventrally, usually with some parts darker, but sometimes entirely brown; antennae usually dark-brown on basal antennomeres, gradually brown or reddish toward apex; legs brown with darker parts, or entirely dark-brown.
Male (Figs. 114–115). Head, excluding mandibles, from 0.85 to 1.15 times as long as prothorax at central area, elongate behind eyes (distance from posterior ocular edge to the prothorax from equal to shorter than greatest length of upper eye lobe). Longitudinal dorsal furrow from clypeus to anterior edge of prothorax (sometimes ending slightly before prothorax). Frons short, depressed, usually entirely smooth, but sometimes laterally punctate. Area between antennal tubercles deeply sulcate, from densely to moderately sparsely punctate (punctures from coarse to somewhat fine); with moderately short, sparse setae. Area between upper eye lobes coarsely, confluently punctate, more so toward eyes; with short, sparse setae. Dorsal area between eyes and prothorax smooth centrally (sometimes moderately finely punctate), coarsely, abundantly, confluently punctate laterally; with short, sparse setae (usually glabrous centrally or almost so). Area behind upper eye lobes from moderately finely to coarsely, abundantly punctate; with long, moderately abundant setae. Area behind lower eye lobes moderately finely, abundantly punctate (sometimes somewhat rugose); with long, moderately sparse setae toward prothorax, forming brush close to eyes. Antennal tubercles coarsely, moderately sparsely punctate on inner basal one-half, finely, densely punctate on frontal area close to scape, with remaining surface smooth or almost so. Postclypeus coarsely, confluently punctate laterally, usually with finer, sparser punctures centrally; with long, sparse setae. Anteclypeus not or distinctly separated from clypeus. Labrum with long, abundant setae. Eyes large; distance between upper eye lobes from 0.7 to 0.9 times length of scape; distance between lower eye lobes from 0.95 to 1.15 times length of scape. Submentum trapezoid, distinctly narrower toward gula, somewhat depressed, with anterior margin narrow, distinctly elevated; surface rugose, with moderately long, abundant setae. Apex of labial palpi nearly attaining middle of maxillary palpomere IV. Mandibles from 0.5 to 0.6 times as long as head; latero-basal one-third depressed. Antennae 14- to 15-segmented; slightly surpassing middle of elytra. Scape nearly reaching posterior ocular edge; moderately coarsely, sparsely punctate dorsally; usually coarsely, abundantly punctate laterally, more so on basal one-third, but sometimes distinctly sparsely punctate, toward apex; with short, sparse setae laterally. Antennomere III (Fig. 33) from 1.1 to 1.3 times longer than scape dorsally, distinctly enlarged toward apex (widest width from 1.8 to 2.3 times basal width); imbrication very distinct (Fig. 34, 35); apex of imbrication forming two distinct lobes: outermost wide, emarginated at level of longitudinal carina, with outermost portion distinctly smaller; inner lobe slender, separated from the former by very deep emargination; dorsal surface moderately finely, sparsely punctate. Dorsal surface of antennomeres IV–VI/VIII as on III, usually slightly denser on V–VII/VIII; dorsal surface of remaining antennomeres finely, densely punctate. Imbrication of antennomeres IV–XIII/XIV as in III, but emargination between lobes gradually less deep toward distal antennomeres. Last antennomere variable: from simple to distinctly complex.
Maximum prothoracic width from 0.75 to 0.85 times elytral base; anterolateral angles spined (spine from moderately short to distinctly long), sometimes with anterior edge rounded, projected forward; with long spine laterally about middle; posterolateral angle from rounded to acute. Pronotum finely, from sparsely to densely punctate centrally; center of disc from convex to somewhat flat; coarser punctate laterally; center with short, sparse setae (sometimes absent); with sparse, moderately long setae laterally. Prosternum moderately finely, densely punctate, slightly rugose laterally; with long, abundant setae. Prosternal process not sulcate; with short, sparse setae dorsally (sometimes almost absent). Elytra moderately coarsely, abundantly punctate, sometimes moderately rugose; each elytron with three carinae, innermost two more distinct; sutural spine usually short, but distinct. Metasternum and metepisterna densely microsculptured; with long, dense setae.
Ventrite I finely, sparsely punctate on basal three-fourths, with long, moderately abundant setae (sometimes present only centrally); ventrites II–IV finely, sparsely punctate on basal three-fourths, centrally glabrous (sometimes with long, sparse setae on basal one-fourth), with short, sparse setae laterally (sometimes absent); ventrite V with short, sparse setae. Pro- and mesotarsomeres I–III wide; apex of pro- and mesotarsomeres I–II acute (sometimes slightly spined, especially at I); metatarsomeres distinctly slender, more so in I, with apex of I–III projected (sometimes spined).
Female (Figs. 116–117). Head, excluding mandibles, from 0.8 to 0.9 times length of prothorax at middle. Sculpture on dorsal surface of head and area behind eyes similar to that in male. Distance between upper eye lobes from 0.65 to 0.85 times length of scape; distance between lower eye lobes from 0.8 to 1.0 times length of scape. Submentum as in male. Antennae with 14–15 segments, reaching or surpassing basal one-third of elytra; scape slender, longer than in male; antennomere III (Fig. 36) equal to about 1.3 times length of scape; antennomeres (Fig. 37) ventrally carinate, more distinctly from V, with apex projected at level of carina, widely emarginated between projection and inner side. Prothorax as in male. Metasternum and metepisterna as in male, but with pubescence less conspicuous around metasternal suture.
Dimensions in mm (male/female). Total length (including mandibles), 27.6–38.5/33.5–40.2; prothoracic length at center, 3.7–5.2/4.3–5.4; widest prothoracic width, 9.3–11.9/10.2–12.4; humeral width, 11.3–15.0/13.3– 15.0; elytral length, 21.1–30.0/26.7–32.3.
Geographical distribution. Mexico [Durango (Bates, 1884), Chihuahua (Casey, 1912, as P. townsendi and P. curticollis), Michoacán de Ocampo (Lameere, 1912a) (as P. flohri), Zacatecas (new state record), Sinaloa (new state record)].
Barbour et al. (2011) recorded the state of Sonora: “The study site in Mexico was in Sonoran oak-pine woodland on Mesa de Campañero near Yécora, Sonora. Prionus species known from the area include P. californicus, Prionus aztecus Casey, Prionus curticollis Casey, and Prionus flohri Bates (Monné and Hovore 2005).” However this state record is in error. Monné & Hovore (2005) recorded P. curticollis in “nMexico (CHA)”. Thus, only listing the state of Chihuahua.
Types, type localities. Of Prionus mexicanus: described based on male and female (number of specimens not indicated), from Mexico (Durango, “Ciudad in Durango, 8100 feet ”), deposited at BMNH. Syntypes figured at Bezark (2016).
Of Prionus (Riponus) townsendi: holotype female, from Mexico (Chihuahua, Colonia Garcia), deposited at USNM. Figured at Lingafelter et al. (2016).
Of Prionus (Riponus) curticollis: holotype male, from (Chihuahua, Colonia Garcia), deposited at USNM. Figured at Lingafelter et al. (2016).
Material examined. MEXICO, Sonora: Las Antennas, 19.1 km NNW Nacozari de Garcia (Reserva Forestal Nacional; 30º54’17”N / 109º74’86”W; 2467 m), 1 male, VII.17.2013, Van Devender & Palting col. (ACMT); Cañon de Evans (30º97’N / 109º70’W; 1900 m; Sierra de los Ajos), 1 male, VII.12.2014, Van Devender et al. col. (ACMT). Chihuahua: Arroyo Mesterno (Sierra del Nido, 7600’), 1 male, VII.21.1959, W. C. Russell col. (ESSIG); Creel, 1 male, VII.22.1968, T. A. Sears, R. A. Gardner & C. S. Glaser col. (ESSIG); Yaguirachic (8500’, 130 mi. W Chihuahua), 1 male, VIII.8.1937, W. C. Russell col. (ESSIG). Sinaloa: 13 mi. E Concordia (800’), 1 male, VIII.9.1964, L. A. Kelton col. (ESSIG). Durango: 10 miles W El Salto (8800’), 1 female, VII.5.1964, H. F. Howden col. (MZSP); 1 female, VII.18.1964, J. Powell col. (ESSIG); 1 male, VII.21.1964, J. A. Chemsak & J. Powell col. (ESSIG); 1 male, VIII.2.1964, J. Powell col. (ESSIG); (9000’), 1 male, VI.16.1964, J. E. H. Martin col. (MZSP); 33 miles W El Salto, 1 male, VI.7.1962, E. Sleeper, R. A. Anderson, A. Hardy & R. Somerby col. (ESSIG); Km 1019, Hwy 40, 30 mi. W Durango, 1 female, VI.23.1967, W. H. Clark col. (ESSIG).
Remarks. Bates (1884) described Prionus mexicanus and commented: “Resembles P. f l oh r i; but certainly distinct, not only in the number of antennal joints in both sexes and the shorter and broader joints of the male, but in the form of the thorax in both sexes. In P. f l o hr i the front edge is nearly straight, or describes a single gentle curve from spine to spine; whilst in P. mexicanus (in both sexes) it is trisinuate, the middle sinuation remarkably deep. The hind margin shows also a striking difference, being strongly bisinuated in P. mexicanus, so that the middle part forms a broad lobe; whilst in P. flohri it is nearly straight, but abruptly sinuate from the angle to the long and sharp basal spine.”
Comparing the types of P. mexicanus with P. f l oh r i, it is possible to see that the antennae of the former are not broader than in the latter: they are very similar in width. However, the antennomeres in males (except III) are shorter than in males of P. flohri. Although this feature is apparently unreliable. Nearly all specimens of P. mexicanus examined have antennomeres proportionally shorter (primarily IV–VI), although one specimen with 14- segmented antennae, has the antennomeres as long as in the syntypes males of P. f l o hr i. Regarding the front edge of prothorax, all specimens of P. mexicanus examined have it from distinctly to slightly trisinuate. Thus, this character also seems unreliable. The hind margin of prothorax in all males of P. mexicanus examined is as described by Bates (1884). Thus, the only reliable feature separating P. mexicanus and P. f l o hr i is the number of antennal segments: 14−15 in the former; 13 in the latter.
Casey (1912) described two new species from Mexico, P. curticollis and P. townsendi, collected at the same place, but did not compare them to other Mexican species: P. mexicanus or P. flohri.
Lameere (1912a) wrote on P. flohri [translation]: “Length from 32 to 38 millimeters, dark-brown; slightly narrow than P. californicus, from which it distinctly differs by its antennae with 14 or 15 segments in both sexes (H. W. Bates recorded 13 segments, but he obviously omitted the two basal); the last segment is appendiculate in male, very short in female; the segments are as in californicu s [sic], but the outer process of apex of the segments is longer and narrower, as in P. Horni; the projections of inner apex are slightly cracked at level of carina; the antennae are proportionally shorter than in P. californicus and P. Horni; the head is narrower; the elytra have coarse, sparse punctures slightly distinct toward in a weak roughness; the lobes of metatarsomere III are distinctly dentate; the intercoxal projection of abdomen of female is narrow as in P. californicus.”
Later, Lameere (1915) wrote on P. flohri sensu Lameere (1912a) [translation]: “In my Revision des Prionides, I described Prionus Flohri from the museum of Brussels and San Petersburg that are not of Bate’s species, but that that M. Casey described the female under the name of Prionus Townsendi and, I believe, the male under the name of Prionus curticollis.” Lameere (1919) very clearly made this synonym. Incomprehensibly, Lameere (1920) mentioned P. curticollis as a valid species, and recorded on the specimen examined by him [translation]: “This insect is neighbor of the Prionus that I described in my Revision des Prionides [Lameere (1912a)] under the name of P. Flohri, but that is not the true P. Flohri H. W. BATES that I described in the Bulletin du Muséum de Paris (1915, p. 59). It [the specimen that Lameere identified as P. curticollis] is very probably P. Townsendi Casey described based in a single female from Colonia Garcia at Chihuahua.” With this confused and ambiguous nomenclatural act, Lameere (1920) revalidated P. curticollis based, more on his doubts than on his convictions. Lameere (1920) also wrote on the specimen examined by him [translation]: “The male from the Collection of M. BOPPE agree very well to the description de M. CASEY, but I strongly suspect that it is a male of P. mexicanus H.-W. BATES. I observed, however, some differences with the female reported above [P. mexicanus]: the eyes are slightly more convex, the prothorax is wider and shorter, less widely emarginated anteriorly, the elytra less rough, showing coarse, abundant punctures, more or less confluent, mainly posteriorly…” It is not clear if Lameere was suggesting synonym between P. curticollis and P. mexicanus, or if he was only saying that he had doubt on the identification.
Lameere (1915) also wrote on P. mexicanus [translation]: “The Prionus mexicanus H. W. Bates could, despite its antennae with 14 segments and a prothorax with anterior and posterior edges slightly different, to be a synonym of P. F l o hr i.” This statement cannot be considered a formal synonym. Also, Lameere (1919) recorded P. mexicanus as distinct species from P. f l oh r i. Lameere (1920) also recorded P. mexicanus as a valid species. Still according to Lameere (1915), the specimens mentioned by Lameere (1912a) as P. mexicanus belong to P. aztecus. Finally, Lameere (1920) described P. batesi and recorded that this new species corresponded to P. mexicanus sensu Lameere (1912a), and P. aztecus sensu Lameere (1915).
We agree with Lameere (1915): P. curticollis is equal to P. townsendi. The female of P. townsendi was collected in the same place of P. curticollis. So, although it has antennae with 15 segments (according to Casey, 1912), we believe it is a female of P. curticollis, and thus a female of P. mexicanus. The color and shape of antennomeres in females of P. aztecus and P. mexicanus, apparently, are highly variable: from light to dark; with or without projection on apex. Also, the number of antennomeres is variable in the females examined: 14 or 15, independent of the body color, antennal color, shape of apex of antennomeres. In some cases, the same specimen has one antenna with the last antennomere distinctly free and the other with it whole or partially fused to the anterior, making it impossible to affirm if the antennae are 14- or 15-segmented. The holotype female of P. townsendi has the apex of basal antennomeres distinctly spined, while in the syntype female of P. mexicanus they are not. However, as pointed out above, we examined specimens with intermediate conditions. This suggests that both specimens are extreme examples of the same species. The lateral spines of prothorax also seem different in both specimens, but this feature is also variable in the specimens studied, with forms linking them.
The holotype of P. townsendi agrees very well with the holotype male of P. curticollis and, despite the number of antennal segments (15 in the former; 14 in the latter), we are convinced that they belong to the same species. Based on the variations in the males examined (pronotal shape: from narrow to moderately long; pronotal spines: from prominent to not so; elytral shape: from wide to long; elytral sculpture: from coarsely to moderately finely punctate; emargination of projections of antennomeres: from very to moderately deep; etc.) we also think that P. curticollis is a male of P. mexicanus. Despite the information in the original description on the number of antennomeres in P. mexicanus (14), we studied specimens with from 14 to 15 segments. As in females, the last antennomere may be free, whole or partially fused to the anterior one, or different in both antennae. Those variations are not related to geographic distribution either.
The variations in the antennae of females make it difficult (or even impossible) to separate females of P. mexicanus from those of P. aztecus, because both species occur in the same area, and because females with similar antennae (shape and number of antennal segments) could have different body color. However, females of P. azt ecus have antennae slightly wider than in those of P. mexicanus (a feature which normally can only be seen with direct comparison between females).
Males of P. mexicanus differ from those of P. aztecus, by the elytral color (usually lighter in P. az t ec u s), and antennal shape (Fig. 33) (wider in P. az t e cu s — Fig. 32). In males of P. mexicanus, the imbrication is also deeper on inner side than in P. aztecus.
description: Published as part of Santos-Silva, Antonio, Nearns, Eugenio H. & Swift, Ian P., 2016, Revision of the American species of the genus Prionus Geoffroy, 1762 (Coleoptera, Cerambycidae, Prioninae, Prionini), pp. 1-103 in Zootaxa 4134 (1) on pages 53-59, DOI: 10.11646/zootaxa.4134.1.1, http://zenodo.org/record/399754