Prionus (Homaesthesis) emarginatus Say 1824
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 emarginatus

description: Prionus (Homaesthesis) emarginatus Say, 1824
(Figs. 1–4, 83–86)
Prionus emarginatus Say, 1824: 327; Haldeman, 1847b: 31; LeConte, 1852a: 107; Melsheimer, 1853: 100 (cat.); White, 1853: 17; LeConte, 1859a: 19, 48 (pl. II, fig. 13); 1859b: 184; Lacordaire, 1868: 61 (note); Horn, 1872: 390 (distr.); Packard, 1877: 803 (pl. 70, fig. 6) (biol.); 1881: 161: fig. 73 (biol.); 1890: 703 (biol.); Lameere, 1912a: 247; 1913: 78 (cat.); 1919: 139; Gwynne & Hostetler, 1978: 347 (biol.); Weeks & McIntyre, 1997: 270; Weissmann & Kondratieff, 1999: 74 (distr.); Cervantes et al., 2006: 721.
Prionus (Homaesthesis) emarginatus; Linsley, 1957: 10; 1958: 110; 1962: 50 (fig. 17); Hatch, 1971: 94; Hovore & Turnbow, 1984: 4 (key); Chemsak et al., 1992: 21 (checklist); Monné & Giesbert, 1994: 15 (checklist); Monné, 1995: 56 (cat.); Chemsak, 1996: 118; Heffern, 1998a: 6 (distr.); Monné & Hovore, 2005: 20 (checklist); 2006: 19 (checklist); Özdikmen & Turgut, 2009: 410; Bezark & Monné, 2013: 26 (checklist).
Homaesthesis emarginata; LeConte, 1873: 288, 289; Lameere, 1883: 3 (cat.); LeConte & Horn, 1883: 273, 274.
Homaesthesis emarginatus; Crotch, 1873; 83 (checklist); LeConte, 1876: 520 (distr.); Snow, 1877: 19 (distr.); Crotch, 1880: 83 (checklist); Snow, 1883: 42 (distr.); Leng, 1884: 57, 59; Blanchard, 1887: 86; Beutenmüller, 1896: 74 (host plant); Snow, 1906b: 179 (distr.); Fall & Cockerell, 1907, 191 (distr.); Casey, 1912: 254; Craighead, 1923: 28 (larvae); 1950: 239 (larvae).
Prionus innocuus LeConte, 1862: 43; Lacordaire, 1868: 61 (note).
Homaesthesis innocua; Casey, 1912: 254; Henshaw, 1881: 247.
Homaesthesis innocuus; Crotch, 1873; 83 (checklist; syn.).
Homaesthesis pubicollis Casey, 1912: 254; Lameere, 1919: 139 (syn. in doubt); Linsley, 1957: 10 (syn.); Lingafelter et al., 2014: 304 (type).
Homaesthesis debiliceps Casey, 1912: 255; Lameere, 1919: 139 (syn. in doubt); Linsley, 1957: 10 (syn.); Lingafelter et al., 2014: 50 (type).
Integument from pale reddish-brown to dark-brown, frequently with dorsal side darker than ventral; antennae usually reddish-brown (in a female dark-brown).
Male (Figs. 83–84). Head, excluding mandibles, from 0.8 to 1.0 as long as prothorax at central area, moderately elongate behind eyes (distance from posterior ocular edge to the prothorax from 0.45 to 0.85 times greatest length of upper eye lobe). Longitudinal dorsal furrow distinct from clypeus to middle of area between posterior ocular edge and prothoracic edge (sometimes reaching, or almost reaching, prothoracic edge). Area between base of antennal tubercles and middle of upper eye lobes with sub-rhombus depression (sometimes slightly marked). Dorsal side of head moderately coarsely, confluently punctate (sometimes distinctly coarsely punctate, mainly near eyes), usually finer, somewhat sparsely punctate near prothorax; with long, moderately abundant setae throughout. Area behind upper eye lobes, moderately coarsely, shallowly, confluently punctate; with long, moderately sparse setae; area close to eye with very long, abundant setal brush (sometimes sparser). Area behind lower eyes lobes moderately rugose, with sparse, long setae; area close to eye with very long, abundant setal brush. Antennal tubercles coarsely, confluently punctate on base, gradually finer toward middle, smooth toward apex; with long, sparse setae on base, anteriorly and posteriorly, centrally glabrous. Postclypeus coarsely, abundantly punctate laterally, gradually finely, sparsely punctate toward middle that is shallow or almost so; with long, moderately abundant setae laterally, gradually shorter, sparser toward almost glabrous middle. Anteclypeus with anterior edge concave; glabrous or with long, sparse setae. Labrum centrally flat or depressed; with long, sparse setae; anterior edge with long setal brush. Eyes proportionally large; distance between upper eye lobes equal from 0.8 to 1.0 times length of scape; distance between lower eye lobes from 1.0 to 1.1 times length of scape. Submentum trapezoid, from distinctly to slightly depressed; moderately coarsely, shallowly punctaterugose; with long, moderately abundant setae. Apex of labial palpi nearly attaining middle of maxillary palpomere IV; apex of last maxillary and labial palpomere from 2.3 to 2.8 times as wide as its basal width. Mandibles from 0.45 to 0.55 times as long as head; latero-basal one-third distinctly depressed; narrow on lateral view; inferior outer margin usually sinuous; outer distal one-half distinctly curved, forming an obtuse angle with basal one-half (sometimes right angle). Antennae (Figs. 1, 2) with 14 segments, frequently with last segment fused with 13th; last segment complex (rarely simple); nearly attaining middle of elytra. Scape nearly attaining middle of upper eye lobe, not strongly enlarged toward apex; finely, sparsely punctate dorsally and laterally (more abundant on basal one-third). Antennomere III (including outer distal projection) from 1.9 to 2.1 times as long as scape, distinctly enlarged toward apex (distal width at apex of projection about twice basal width); on dorsal and ventral view, imbrication very distinct and projected (Figs. 1, 2); on lateral view, imbrication bifurcated; moderately finely, sparsely punctate dorsally. Antennomere IV about as long as 0.7 times III; moderately finely, sparsely punctate dorsally on inner side; imbrication as in III. Antennomeres V–VI with sculpture and imbrication as on IV. Antennomeres VII–XI/XII microsculptured dorsally; imbrication as in III.
Maximum prothoracic width from 0.60 to 0.65 times width of elytral base; anterolateral angle rounded; lateral tubercle placed between anterolateral angle and middle, from distinctly rounded to with short, acute spine; posterolateral angle slightly projected, from rounded to somewhat acute; margin slightly divergent from posterolateral angle and lateral tubercle; basal margin sinuous, usually distinctly emarginated centrally; distal margin from sublinear to concave. Pronotum from flat to slightly convex centrally, not strongly explanate laterally; callosities slightly marked; disc finely, abundantly punctate (sometimes moderately sparsely punctate); moderately coarsely, abundantly punctate laterally (usually with part of punctures confluent); with long, moderately abundant setae throughout. Prosternum moderately finely, abundantly punctate (usually slightly rugose laterally); with long, moderately abundant setae. Prosternal process not longitudinally sulcate; with long, moderately abundant setae. Scutellum with long, moderately sparse setae. Elytra coarsely, moderately abundant punctate-rugose; each elytron with three carinae (sometimes with additional carina between innermost; sometimes outermost almost absent); with long, sparse setae near humerus laterally; remaining surface glabrous. Metasternum and metepisterna with long, abundant setae.
Ventrites I–II with long, moderately abundant setae (longer and more abundant on I); ventrite III–IV with long, sparse setae on basal one-half, with short sparse setae on distal one half (sometimes absent, mainly on IV); ventrite V with moderately short setae, usually denser centrally, with long, sparse setae intermixed. Tarsomeres I–III moderately slender, not distinctly flattened; apices of tarsomeres I–III spined at apex (sometimes part of them just projected); pro- and mesotarsomeres I–III with spongy setal pads on ventral surface divided by moderately distinct, moderately narrow glabrous longitudinal sulcus; spongy setal pads of metatarsi distinctly less dense than on pro- and mesotarsi; metatarsomere I from slightly shorter to as long as II–III together.
Female (Figs. 85–86). Dorsal surface frequently darker. Head, excluding mandibles, from slightly shorter to as long as prothorax at middle. Dorsal sculpture on face of head and area behind eyes finer, distinctly sparser than in male. Distance between upper eye lobes from 1.2 to 1.5 times length of scape; distance between lower eye lobes from 1.1 to 1.5 times length of scape. Head, pronotum, scutellum, metasternum and metepisterna glabrous; prosternum with very short, sparse setae; prosternal process mostly glabrous, with short, moderately abundant setae at apex; apex of mesosternal process variable: from distinctly emarginate to distinctly truncate. Antennae (Fig. 3, 4) nearly attaining apex at basal one-third of elytra; scape more slender than in male, from 0.70 to 0.85 as long as antennomere III, nearly attaining middle of upper eye lobe; antennomeres IV–XII with short imbrication, distinctly emarginated centrally (mainly after VI) (Fig. 4), carinate ventrally. Prothorax as in male, but punctures usually finer. Metathorax distinctly shorter than in male.
Dimensions in mm (male/female). Total length (from mandibles to elytral apex), 18.8–23.6/21.4–26.0; prothoracic length at center, 2.9–3.3/3.6–3.9; greatest prothoracic width, 5.5–7.1/7.2–7.3; humeral width, 8.1–10.5/ 8.8–10.8; elytral length, 14.1–18.0/15.1–18.5.
Geographical distribution. USA [Colorado (Say, 1824), Arizona (Chemsak, 1996), Idaho (Linsley, 1962), New Mexico (LeConte, 1859a), Kansas (LeConte, 1859a), Wyoming (Linsley, 1962), Missouri (Chemsak, 1996), Nebraska (Chemsak, 1996), Utah (Packard, 1881), Texas (new state record)].
Types, type localities. Of Prionus emarginatus — syntypes (at least one male and one female) from Arkansas River (“near mountains”). According to Mawdsley (1993), only 10 specimens of Cerambycidae from Say’s Collection survived: “ Moneilema inaequalis Say 1835:193 (One specimen); 9 undetermined specimens.” Unfortunately, we were unable to determine if there were any Prionus among the undetermined specimens.
Say (1824) recorded as type locality: “Inhabits Arkansa”; and “I obtained it on the Arkansa river near to Mountains.” Between 1819 and 1824, Arkansas Territory comprised, mainly, the area that now forms Oklahoma and Arkansas. Arkansas River rises in Colorado. As Say (1824) recorded “near to Mountains”, the state of the type locality is Colorado, and not Arkansas.
Of Prionus innocuus — holotype female, from New Mexico (USA), deposited at MCZ. Figured at http:// www.mcz.harvard.edu/
Of Homaesthesis pubicollis — holotype male, from Colorado (USA), deposited at USNM. Figured at Lingafelter et al. (2016).
Of Homaesthesis debiliceps — holotype male, from Colorado (USA), deposited at USNM. Figured at Lingafelter et al. (2016).
Material examined. USA, Colorado: male, [no detailed place, date and collector indicated] (USNM); [no detailed place indicated], 1 male, 14.VII.1914, W.D. Edmonston col. (USNM); Boulder, 1 male, 7.VIII.1951, S. Shushan col. (ESSIG); El Paso County, 1 male, 21.VI.1950, [no collector indicated] (ESSIG); Great Sand Dunes National Monument (Alamosa County), 2 males, 1 female, 5.VII.1977, D. Guynne col. (ESSIG); Larkspur, 3 males, 14.VII.1915, W. D. Edmonston col. (USNM); 3 males, 15.VII.1915, W. D. Edmonston col. (USNM); 2 males, 1 female, 25.VII.1915, W. D. Edmonston col. (USNM); Littleton (5350 ft.), 1 male, 4.VII.1938, C.W. Dawson col. (ESSIG); Mesa Verde National Park, 1 male, 8.VII.1964, W. F. Chamberlain col. (USNM); Norwood, 4 males, 12.VI.1955, D. E. Bright col. (ESSIG); 1 male, 12.VI.1955, D. E. Bright col. (MZSP); Plainview (Jefferson County; 7–8000 ft.), 2 males, 9–14.VII.1922, [no collector indicated] (USNM); Weld County (near Owl Creek, 15 km NNE of Nunn, Pawnee National Grassland), 1 male, 24.VI.1977, D. L. Wagner col. (ESSIG); 2 males, 27.VI.1977, D. L. Wagner col. (ESSIG). Missouri: Boone County, 1 male, 15.VIII.1968, Frederick Johannsen col. (ESSIG). New Mexico: female holotype of Prionus innocuus; Las Vegas (San Miguel County), 1 male, 12.VII.1959, E. G. Linsley col. (ESSIG); McGaffey (Zuni Mountains, McKinley County, 7500 ft.), 1 male, 22.VII.1962, E. & I. Munroe col. (ESSIG); Harding County, 1 male, 2 females, 29.VI.2000, J. Wappes col. (MZSP); 2 males, 10 females, 29.VI.2000, J. E. Wappes col. (USNM); Nogal Lake, 1 male, 9.VII.1964, W. F. Chamberlain col. (USNM); Capulin Volcano National Monument (Union County, 7500’), 1 male, 14.VII.1968, [no collector indicated] (USNM); Santa Fe County, 15 males, 166 Nugent Rd., Edgewood, 35˚7’38.08”N, 106˚13’14.52”W, 20-VII-2009, A. Johnson (ENPC); 4 males, same data except: 1-VII-2009 (ENPC); 1 female, same data, except: 15.VII.2009.
Remarks. Monné (1995) did not indicate who placed Prionus innocuus as a synonym of P. emarginatus. LeConte (1873) suggested the synonym between these species: “ Homaesthesis (P. integer Lec., emarginatus Say) found in Colorado and New Mexico. P. innocuus Lec. is the female of one of these species, probably emarginatus.” However, the formal synonym is by Crotch (1873), who listed P. innocuus under synonym of P. emarginatus (both mentioned in Homaesthesis).
Linsley (1962) wrote on the female of P. emarginatus: “Form very robust; integument rufopiceous; antennae 13-segmented, external processes deeply cleft; pronotum with or without distinct lateral tooth; elytra with apices separately rounded”. Chemsak (1996) repeated this description. The description of the antennae is, at least, strange. The antennomeres in females of Prionus lack an external processes as distinct as in males and, frequently, they are absent or nearly so. Females of P. emarginatus have the outer apical projection of antennomeres from slightly emarginated to irregularly dentate.
The holotype of P. innocuus has the elytral apices separately rounded. However, we examined females of that species with a small, but distinct, sutural tooth at the elytral apices. The holotype of P. innocuus is particularly notable by its very wide body, but specimens were also examined with a slender body.
Lameere (1919) was the first who considered P. debiliceps and P. pubicollis as synonyms of P. emarginatus (in doubt). Linsley (1957) formalized the synonym: “Casey’s types of pubicollis and debiliceps fall well within the usual range of individual variation of emarginatus. The median lateral angle of the pronotum may be spiniform, acutely produced, obtuse, or absent. The photographs of the holotypes of P. debiliceps and P. pubicollis prove that Lameere and Linsley were right.
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 30-33, DOI: 10.11646/zootaxa.4134.1.1, http://zenodo.org/record/399754