Prionus (Prionus) imbricornis Linnaeus 1767
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 imbricornis

description: Prionus (Prionus) imbricornis (Linnaeus, 1767)
(Figs. 42–45, 95–98, 179–180)
Cerambyx imbricornis Linnaeus, 1767: 622; Villers, 1789: 224 (note).
Cerambyx (Prionus) imbricornis; Gmelin, 1790: 1815.
Prionus coriarius var. imbricornis; Fabricius, 1781: 206.
Prionus imbricornis; Olivier, 1795: 28 (replaced status); Palisot de Beauvois, 1805: 242; Schönherr, 1817: 340; Lepeletier & Audinet-Serville, 1825: 202; Audinet-Serville, 1832: 192; Burmeister, 1836: 68; Sturm, 1843: 239; Haldeman, 1847b: 31; LeConte, 1852a: 108; White, 1853: 17; Melsheimer, 1853: 100 (cat.); LeConte, 1859a: 48; Lacordaire, 1868: 61 (note); Riley, 1870: 89 (biol.); 1872: 140 (biol.); Horn, 1872: 390 (distr.); Crotch, 1873: 83 (checklist); Putnam, 1876: 172, 173 (distr.); Popenoe, 1877: 33 (distr.); Snow, 1878: 67 (distr.); Schwarz, 1878: 456; Webster, 1879: 20 (etology); Crotch, 1880: 83 (checklist); Riley, 1880: 238 (host); LeConte & Horn, 1883: 274; Leng, 1884: 57, 58; Horn, 1885: 89; 1886: 138; Hamilton, 1886: 112 (larva); Blanchard, 1887: 86; Marten, 1890: 60 (biol.); Riley & Howard, 1891: 407 (biol.); Bruner, 1891: 240 (biol.); Forbes, 1894: 106 (larva); Hamilton, 1895: 337 (distr.); Beutenmüller, 1896: 74 (host); Lugger, 1899: 194 (biol.); Ulke, 1903: 25 (distr.); Hebard, 1903: 261 (biol.); Tucker, 1906: 12 (distr.); Kellogg, 1906: 283; Wickham, 1909: 28 (distr.); Blatchley, 1910: 1012; Leng, 1911: 215 (distr.); Lameere, 1912a: 239; Fisher & Kirk, 1912: 309 (distr.); Lameere, 1913: 77 (cat.); Craighead, 1915: 18 (larva); Lameere, 1919: 137; Lutz, 1921: 338; Craighead, 1923: 29 (larva); Kirk & Knull, 1926: 21 (distr.); Leonard, 1928: 433 (distr.); Ware, 1929: 368 (distr.); Beaulne, 1932: 197 (host); Doane et al., 1936: 165 (distr.); Brimley, 1938: 210 (distr.); Löding, 1945: 113 (distr.); Knull, 1946: 146; Craighead, 1950: 261 (host); Jaques, 1951: 251; Beal et al., 1952: 71; Alexander, 1958: 49 (distr.); Anderson, 1960: 401; Dillon & Dillon, 1961: 580; Frost, 1969: 95 (distr.); Payne et al., 1970: 3; Baker, 1972: 200 (biol.); Swan & Papp, 1972: 442; Kirk & Balsbaugh, 1975: 96 (distr.); Payne et al., 1975: 680 (biol.); Mullins, 1975: 43 (biol.); Stein & Tagestad, 1976: 31; Payne et al., 1976: 9 (biol.); Turnbow & Franklin, 1980: 338 (distr.); White, 1985: 281; Yanega, 1996: 27; Linsley & Chemsak, 1997: 424 (host); Hanks, 1999: 487, 493, 494; Robimson, 2005: 85; Buck et al., 2005: 63; Kelley et al., 2006: 252, 253, 254, 255; Lingafelter, 2007: 18 (key), 138; Barbour et. al., 2011: 590, 591, 592; Hart et al., 2013: 134, 139 (distr.).
Prionus? imbricornis; Chevrolat, 1852: 650.
Prionus (Riponus) imbricornis; Casey, 1912: 248 (key).
Prionus (Neopolyarthron) imbricornis; Casey, 1924: 222 (key); Ortenburger & Hatch, 1926: 146 (distr.); Hatch, 1930: 26; Gilmour, 1954: 45 (distr.); Linsley, 1957: 9; Linsley, 1962: 46; Arnett, 1985: 360; Hovore et al., 1987: 294 (distr.); Chemsak et al., 1992: 21 (checklist); Lingafelter & Horner, 1993: 164 (distr.); McRae, 1993: 227 (distr.); Monné & Giesbert, 1994: 16 (checklist); Monné, 1995: 54 (cat.); Chemsak, 1996: 111; Heffern, 1998a: 6 (distr.); Shiefer, 1998: 115 (distr.); Peck & Thomas, 1998: 116 (distr.); Monné & Hovore, 2005: 21 (checklist); 2006: 20 (checklist); Özdikmen & Turgut, 2009: 410; Bezark & Monné, 2013: 27 (checklist).
Prionus (Riponus) imbricornis mimus Casey, 1912: 248; Linsley, 1957: 9 (syn.); Lingafelter et al., 2014: 78 (type).
Prionus (Neopolyarthron) imbricornis mimus; Casey, 1924: 222.
Prionus (Riponus) imbricornis brunneus Casey, 1912: 248; Linsley, 1957: 9 (syn.); Lingafelter et al., 2014: 78 (type).
Prionus (Neopolyarthron) imbricornis brunneus; Casey, 1924: 222.
Prionus (Riponus) diversus Casey, 1912: 247; Linsley, 1957: 9 (syn.); Lingafelter et al., 2014: 54 (type).
Prionus (Neopolyarthron) diversus; Casey, 1924: 222; Hatch, 1930: 26
Prionus robustus; Brimley, 1938: 210 (distr.);
Prionus (Neopolyarthron) imbricornis diversus; Ortenburger & Hatch, 1926: 146 (distr.).
Prionus imbricornis diversus; Alexander, 1958: 49 (distr.).
Prionus (Riponus) diversus cuneatus Casey, 1912: 247; Linsley, 1957: 9 (syn.); Lingafelter et al., 2014: 54 (type).
Prionus (Neopolyarthron) cuneatus; Casey, 1924: 222.
Prionus (Neopolyarthron) robustus Casey, 1924: 222; Linsley, 1957: 9 (syn.); Lingafelter et al., 2014: 310 (type).
Prionus debilis Casey, 1891: 21; Henshaw, 1895: 24 (cat.); Hamilton, 1896: 164 (syn.); Rice, 1981: 459 (distr.); Leng, 1927: 39; Yanega, 1996: 26; Lingafelter, 2007: 12 (key); 138; Lingafelter et al., 2014: 50 (type). Syn. nov.
Prionus (Riponus) debilis; Casey, 1912: 249.
Prionus (Neopolyarthron) debilis; Casey, 1924: 222; Linsley, 1962: 47 (revalidation); Chemsak et al., 1992: 21; McRae, 1993: 227 (distr.); Monné & Giesbert, 1994: 16 (checklist); Monné, 1995: 54 (cat.); Chemsak, 1996: 112; Heffern, 1998b: 174 (distr.); Peck & Thomas, 1998: 116 (distr.); Monné & Hovore, 2005: 21 (checklist); 2006: 20 (checklist); Özdikmen & Turgut, 2009: 410; Bezark & Monné, 2013: 27 (checklist). Syn. nov.
Prionus imbricornis debilis; Leng (1920): 266 (new status); Brimley, 1938: 210 (distr.).
Prionus imbricornis var. debilis; Knull, 1946: 146.
Prionus simplex; Alexander, 1958: 49 (distr.; error of identification).
Prionus beauvoisi Lameere, 1915: 60; 1919: 138 (syn.). Syn. nov.
Prionus brevicornis; Palisot de Beauvois, 1805: 216 (not Fabricius, 1801).
Prionus (Antennalia) fissicornis parviceps Casey, 1912: 250; Lameere, 1919: 138 (syn., in doubt); Linsley, 1957: 9 (syn.); Lingafelter et al., 2014: 62 (type). Syn. nov.
Prionus (Antennalia) parviceps; Casey, 1924: 223.
Integument from reddish to brown, distinctly darker dorsally (frequently dark-brown), mainly on head and pronotum (head always totally darker).
Male (Figs. 95–96). Head, excluding mandibles, from 0.95 to 1.15 times as long as prothorax at central area, elongate behind eyes (distance from posterior ocular edge to the prothorax slightly less than greatest length of upper eye lobe). Longitudinal dorsal furrow distinct from clypeus to level of posterior edge of upper eye lobes (sometimes distinct, or nearly so, up to anterior edge of prothorax). Frons moderately coarsely, sparsely punctate (sometimes punctures denser or partially confluent); area between antennal tubercles with variable sculpture (from as on frons to distinctly coarser and denser); area between upper eye lobes coarsely, confluently punctate (usually more so close to eyes), but sometimes finer, sparser toward longitudinal furrow; dorsal area between eyes and prothorax moderately finely, sparsely punctate, more so near prothorax (sometimes with central region almost smooth); dorsal area with short, sparse setae (denser near upper eye lobes); area behind upper eye lobes moderately finely, confluently punctate (more so close to eyes), but sometimes sparser, with short, moderately sparse setae; area behind lower eye lobes somewhat rugose about middle, moderately abundantly punctate toward inferior side, with short, sparse setae toward prothorax, with long, moderately abundant setae close to eye. Antennal tubercles moderately finely, sparsely punctate on basal one-half, gradually smoother toward apex; glabrous. Postclypeus coarsely, confluently punctate laterally, centrally smooth or almost so; with moderately abundant setae laterally, glabrous centrally. Anteclypeus not or distinctly separated from postclypeus; smooth, glabrous. Labrum with very long, moderately sparse setae on basal one-half, denser toward apex; brush with long setae along anterior margin. Eyes large; distance between upper eye lobes from 0.35 to 0.65 times length of scape; distance between lower eye lobes from 0.4 to 0.7 times length of scape. Submentum trapezoid, distinctly narrow toward gula, somewhat depressed, with anterior margin narrow, distinctly elevated; surface rugose, with short, sparse setae centrally, and long setae laterally. Apex of labial palpi surpassing middle of maxillary palpomere IV. Mandibles about 0.45 times as long as head; latero-basal one-third depressed. Antennae 17- to 20-segmented; nearly attaining distal one-third of elytra. Scape moderately finely, abundantly punctate dorsally on basal one-third, gradually sparser toward apex (sometimes with smooth area about middle); moderately finely and abundantly punctate laterally; glabrous or with short, sparse setae dorsally on basal one-third. Antennomere III (Fig. 43) slightly longer dorsally than scape, distinctly enlarged toward apex (largest greatest width from 1.65 to 1.80 times basal width); imbrication very distinct, clearly projected (Fig. 44); apex of imbrication slightly bifurcate (Fig. 45), but always with innermost portion much larger than outermost (frequently, difference almost indistinct); dorsal surface finely, sparsely punctate centrally on basal two-thirds, densely punctate on distal one-third (sometimes sparsely punctate). Dorsal surface of remaining antennomeres finely, densely punctate (sometimes partially sparsely punctate on basal onethird of basal antennomeres), gradually striate toward distal antennomeres. Last antennomere complex.
Maximum prothoracic width from 0.8 to 0.9 times elytral base; anterolateral angles rounded, projected forward (sometimes only slightly projected); sides with two distinct acute teeth, one close to anterolateral angle (sometimes almost absent) and another about middle; posterolateral angle from rounded to distinctly acute and projected. Pronotum moderately finely and abundantly punctate, usually slightly less dense laterally; glabrous; center of disc from convex to somewhat flat. Prosternum moderately finely, densely punctate, somewhat rugose laterally; with long, abundant setae laterally; usually almost glabrous centrally. Prosternal process not sulcate; almost glabrous centrally. Elytra moderately coarsely, abundantly punctate; each elytron with three carinae, innermost two most distinct; sutural spine short but distinct (sometimes sutural angle not spined, only slightly projected). Metasternum densely microsculptured; with very long, dense setae. Metepisterna with sculpture and setae as that of metasternum.
Ventrite I with moderately long setae on base, especially on anterior process; ventrites I–IV sparsely, finely punctate, more distinct on distal one-third (sometimes, punctures absent or almost so); ventrites II–IV glabrous or almost so; ventrite V finely, sparsely punctate on basal one-half, denser on distal one-half; ventrite V with short, sparse setae on basal one-half, slightly longer, denser on distal one-half. Tarsomeres I–III moderately slender, mainly metatarsomeres; protarsomeres I–II not or slightly acute at apex, not projected; mesotarsomeres I–II acute and projected at apex; metatarsomeres I–II spined at apex of lobes; tarsomeres I–III with spongy setal pads on ventral surface with distinct longitudinal sulcus centrally, wider on metatarsomeres.
Female (Figs. 97–98). Head, excluding mandibles, from 0.8 to 0.9 times length of prothorax at middle. Sculpture on dorsal face of head and area behind eyes similar to that in male, but more distinct smooth central area on vertex. Distance between upper eye lobes equal to about 0.7 times length of scape; distance between lower eye lobes equal to about 0.9 times length of scape. Submentum as in male. Antennae with 17–22 segments, nearly reaching basal one-third of elytra; scape similar to that in male; antennomere III from 0.80 to 0.85 times length of scape; antennomeres (Fig. 42) ventrally carinate after VI–VII, with apex slightly emarginate from about middle of antenna. Prothorax similar to that in male. Metasternum densely microsculptured laterally, gradually finer, sparser toward center; glabrous or with very short, sparse setae near metacoxae. Metepisterna microsculptured, glabrous throughout.
Dimensions in mm (male/female). Total length (including mandibles), 23.8–37.5/36.8–43.3; prothoracic length at center, 3.1–5.5/5.3–5.9; widest prothoracic width, 7.1–12.2/12.1–14.0; humeral width, 8.5–14.4/13.4– 16.1; elytral length, 17.9–27.6/25.7–30.4.
Geographical distribution. Canada [Ontario (Beaulne, 1932)], United State [South Caroline (Linnaeus, 1767), North Caroline (Leng, 1911), Illinois (Webster, 1879), District of Columbia (Ulke, 1903), Texas (Tucker, 1906), Georgia (Hebard, 1903), Indiana (Casey, 1891), New York (Casey, 1912), Mississippi (Lameere, 1912), Louisiana (Lameere, 1912a), Kansas (LeConte, 1859a), Virginia (Linsley, 1962), West Virginia (Craighead, 1915), South Dakota (Gilmour, 1954), Florida (Schwarz, 1878), Connecticut (Linsley, 1962), Nebraska (Bruner, 1891), Alabama (Löding, 1945), Arkansas (Hatch, 1930), Colorado (Chemsak, 1996), Iowa (Putman, 1876), Kentucky (Linsley, 1962), Maryland (Linsley, 1962), Minnesota (Linsley, 1962), Missouri (Riley, 1870), Montana (Chemsak, 1996), New Hampshire (Heffern, 1998), Ohio (Knull, 1946), Oklahoma (Ortenburger & Hatch, 1926), Pennsylvania (Gronovius, 1764), Tennessee (Linsley, 1962), New Mexico (LeConte, 1859a), Delaware (Linsley, 1962), North Dakota (Chemsak, 1996)], Wisconsin (new state record), and Dominican Republic (Palisot de Beauvois, 1805).
Types, type localities. Of Cerambyx imbricornis: According to Linnaeus (1767): “C. thorace marginato bidentato, corpore ferrugineo, elytris mucronatis, antennis perfoliato imbricates brevioribus”; and “Statura C. coriarii. Antennae subtus imbricate 17 laminis ovato-oblongis.”; “Habitat in Carolina.” Linnaeus (1767) recorded two works where the species was described and/or figured: “ Gron. mus. 529 ” and “ Roes. ins. scar. 2. T. 1. fig. 1 ”. The figure in Rösel (1746) shows a male with anterolateral angles of prothorax very prominent. This feature does not agree with the species currently known as P. imbricornis. However, it is not possible to affirm anything based only on that poor drawing. But we can affirm that the specimen used by Rösel (1746), mentioned by Linnaeus and Gronovius (1764), is a syntype of C. imbricornis (ICZN (1999: Articles 3.2, 12.2 and 72.4.1.1). In the same way, the specimen described by Gronovius (1764) is also a syntype of C. imbricornis. Thus, C. imbricornis was described from “ Carolina ” (Linnaeus, 1767) and Pennsylvania (Gronovius, 1764). We do not know where the specimens recorded by Rösel and Gronovius are deposited, or if they survived. According to Deny (1948): “If readers of the twelfth edition of the Systema Naturae (1766–1768) mark well the words “Habitat in Carolina. D. Garden,” they will be impressed by the frequency with which that expression appears in Volumes 1 and 2. Linnaeus’ references were to Dr Alexander Garden who made his home in Charleston, South Carolina, until the outbreak of the American Revolution. It is not possible to know how many specimens Linnaeus (1767) used to describe C. imbricornis. We know that at least a syntype is deposited at LSL. Apparently, there are no types of this species deposited at UUZM, because Wallin (2001) did not list Cerambyx imbricornis in this collection. LSL website (2013) records two specimens from Linnaeus’ collection identified as C. imbricornis. The specimen “LINN 3650”, is certainly not Prionus imbricornis: it is a male of P. c o r i a r i u s (Linnaeus, 1758) from Darenth (Kent, England). The other specimen, “LINN 3649”, we believe is a syntype of C. imbricornis. The specimen agrees well with the original description, including having 19 antennal segments (scape, pedicel, and 17 imbricate segments, as indicated by Linnaeus). Syntype figured at http://linnean-online.org/linnaeus.html
Of Prionus (Riponus) diversus: described based on males (at least two specimens) and a single female. All specimens are from USA (Indiana) and are deposited at USNM. Lingafelter et al. (2014) designated lectotype. Lectotype figured at Lingafelter et al. (2016).
Of Prionus (Riponus) diversus cuneatus: described from at least two males from North Carolina (Southern Pines). The specimens are deposited at USNM. Lingafelter et al. (2014) designated lectotype. Lectotype figured at Lingafelter et al. (2016).
Of Prionus (Riponus) imbricornis brunneus: Holotype male, from North Caroline (Southern Pines), deposited at USNM. Figured at Lingafelter et al. (2016).
Of Prionus (Riponus) imbricornis mimus: Holotype male (type locality unknown), deposited at USNM. Figured at Lingafelter et al. (2016).
Of Prionus (Neopolyarthron) robustus: Holotype female from North Carolina (Southern Pines), deposited at USNM. Figured at Lingafelter et al. (2016).
Of Prionus debilis: Described based on seven males from Indiana, Missouri, and Kansas, deposited at USNM. Lingafelter et al. (2014) designated lectotype, with Indiana becoming the type locality. Lectotype figured at Lingafelter et al. (2016).
Of Prionus beauvoisi: holotype female from Dominican Republic (Santo Domingo), deposited at MNHN.
Of Prionus (Antennalia) fissicornis parviceps (Figs. 179–180): holotype female from USA (Texas), deposited at USNM. Figured at Lingafelter et al. (2016).
Material examined. USA, Georgia: Athens, 1 male, 24.VI.1994, [no collector indicated] (UNESP); Atlanta, 1 male, VII.01.1965, R. E. Fontaine col. (ESSIG); 1 male, VII.09.1966, R. E. Fontaine col. (ESSIG); Tattnall County (3 miles E Hwy 147, near Ohoopee), 1 male, VI.19 –20.1998, Wappes & Morris col. (MZSP). Missouri: Barnhart (Jefferson County), 1 male, VII.31.1937, E. P. Meiners col. (ESSIG). South Carolina: Wellford, 1 female, VI.16.1937, R. M. McKenzie. Oklahoma: Catoosa, 1 male, VI.08.1939 [no collector indicated] (ESSIG). Nebraska: Valentine (Cheery County), 1 male, VII.05.1964, J. W. Johnson col. (ESSIG). North Dakota: Walcott Dunes, 1 male, VII.17.1975, Doug Scott col. (ESSIG). South Dakota: Lawrence County (McNenny Fish Hatchery, 11 mi. NW Spearfish, 1 female, VII.21.1953, [no collector indicated] (ESSIG). Louisiana: Chicot State Park, 1 male, VI.23.1971, [no collector indicated] (MZSP). Wisconsin: Beloit, 1 male, VII.11.1971, [no collector indicated] (MZSP).
Remarks. Linsley (1962) and Chemsak (1996) indicated that the antennae in Prionus (Neopolyarthron) have from 15 to 20 segments. All specimens examined by us have at least 17 segments, although it is certainly possible that specimens exist with 15 segments.
According to Linnaeus (1767) [translation]: “ Cerambyx with thorax marginate, bidentate, body ferruginous, elytra mucronate, antennae perfoliate, imbricate, short”; and “Length as in Cerambyx coriairus. Antennae underneath imbricate with 17 segments ovate-oblong.” Linnaeus (1767) recorded two works where the species was described and/or figured: “ Gron. mus. 529 ” and “ Roes. ins. scar. 2. T. 1. fig. 1 ”. As seen above, the figure in Rösel (1746) does not agree with the species currently known as P. imbricornis. However, it is not possible to affirm anything based only on that poor drawing.
Fabricius (1781: 206) considered C. imbricornis as a variety of C. coriarius [translation]: “ Cerambyx imbricornis … Linn. Syst. Nat. 2. 622. 5. It is just a variety. Lives in rotten birch in Europe and North America.” Villers (1789: 224) did not make clear his opinion when he wrote on C. coriarius, but apparently he did not agree with Fabricius [translation]: “Obs. 2. Cerambyx imbricornis Linn. mere variety, according to D. Fab.” Gmelin (1790: 1815) listed C. imbricornis with doubtful status [translation]: “Lives in Carolina, stature of coriarius, is this mere variety?” We consider that Olivier (1795: 66: 28, 66: 29) elevated C. imbricornis to species status, although mistakenly attributed the status of this variety to Linnaeus [translation]: “It is of the shape and size of Prione tanner [P. cori arius], which Linnaeus said it could be a variety; it differs in the shape and number of antennal segments, which in Prione tanner are composed of only twelve segments, whereas in the latter [P. imbricornis] they are twenty in number..” Those changes on the status of C. imbricornis are not mentioned in catalogues (e.g. Monné 1995).
Hamilton (1896) synonymized Prionus debilis under P. imbricornis: “ Prionus debilis Casey, 1891, An. N. Y. Acad. Sci. vi, 21. This is a synonym of IMBRICORNIS, being a description of a small and well-known race of that species.” Lameere (1912a) also considered Prionus debilis a synonym of P. imbricornis [translation]: “the small newly hatched male specimens with pale elytra were described as distinct species under the name of P. debilis by Casey.” The synonym was simply ignored by Casey (1924). Brimley (1938), apparently following Leng (1920), considered P. debilis as subspecies of P. imbricornis. Knull (1946), without explanation on the status, recorded P. debilis as a variety of P. imbricornis: “Smaller than imbricornis, less convex, light brown in color.” Linsley (1962), also without explanation on the formal revalidation or on the status, considered P. de b i l i s as a distinct species, condition maintained up to now: “This species is very closely related to imbricornis and the two are sympatric over much of the western part of the range of the latter. P. debilis has a smaller average size, however, is apparently always pale rufotestaceous in color, and differs by having the antennae sparsely, coarsely punctate above.”
According to Casey (1891) P. debilis differs from P. imbricornis by “its much smaller size, narrower, more parallel and less convex form, less chitinized and paler elytra, in the more widely separated eyes and in the vestiture of the hind tarsi.” For Linsley (1962), P. debilis differ from P. imbricornis: “Antennae coarsely, sparsely punctate above; color rufotestaceous”, besides smaller size (P. imbricornis —“Antennae finely, closely punctate above; color brown, rarely rufotestaceous”, and larger size). Chemsak (1996) recorded the same description for males, and added for females: “Elytra with disk finely punctate, scarcely rugose; color reddish-brown”, for P. debilis; and “Elytra strongly punctate, rugose; color dark brown to piceous, for P. imbricornis.” Lingafelter (2007) separated P. de b i l i s from P. imbricornis in the couplet 16: “Maximum width of pronotum (including spines) distinctly narrower than elytral base. Color reddish-brown”, for P. debilis; and “Maximum width of pronotum (including spines) about equal to elytral base. Color light to dark reddish-brown”, for P. imbricornis, P. laticollis, and P. pocularis.”
All these features are variable in P. imbricornis. As for differential characters pointed out by Casey (1891), we can affirm that size is highly variable in all species of Prionus, and usually also in nearly all Prioninae. Thus, it is not a reliable feature to separate the species. Regarding body form, we examined specimens with the body shape somewhat variable. Also, comparing the body shape of holotypes males of P. debilis and P. imbricornis brunneus, it is possible to see that they are very similar. The “less chitinized and paler elytra” suggests a newly emerged specimen, as indicated by Lameere (1912a). The distance between upper eye lobes is slightly variable in males of P. imbricornis, as we could see in the specimens examined (independent of size and/or color). Also, comparing this feature in the holotypes of P. diversus and P. imbricornis mimus (both currently in the synonymy of P. imbricornis) it is evident that the distance between upper eye lobes are different. Also comparing the syntype of C. imbricornis with the lectotype of Prionus debilis, it is possible to see that there is no difference between distance of upper eye lobes, and the elytral color is nearly the same. According to Casey (1891) on the metatarsus: “posterior tarsi very slender, the under surface densely pubescent only in two small spots at the apices of joints one to three.” This description does not agree with the metatarsus of a paralectotype examined. Actually, the metatarsus is identical to that in P. imbricornis.
For the two differences recorded by Linsley (1962), we examined specimens with different size, color, and with antennomeres sparsely or closely punctate above (mainly on III and IV), showing that those features are variable in P. imbricornis. In the specimens examined, when the dorsal area of antennomeres are finely and closely punctate (microsculptured), the area covered by this punctation is variable, being more evident laterally, and always there is a shining, almost impunctate area dorsally; frequently, there are also coarse punctures mixed laterally and/or dorsally. Specimens were examined that agree very well with the lectotype of P. debilis (shape, size, color, etc.) that have very different kind of sculpture on dorsal surface of antennomeres (mainly on III and IV), being laterally microsculptured or only coarsely, sparsely punctate.
The differences between females of P. imbricornis and P. debilis recorded by Chemsak (1996) are inconsistent as the elytral sculpture is highly variable in males and females of P. imbricornis. The holotype male of P. debilis also has the elytra very coarsely and abundantly punctate while the elytral sculpture of typical P. imbricornis is usually not so evident. Thus, if males of P. de b i l i s have elytral punctation coarser than males of P. imbricornis (or at least, equal), there would be no reason to suppose that the elytral punctation in females is any different. In the key to Prionus (Neopolyarthron) males, Chemsak (1996) figured antennomere III completely finely punctate dorsally. We did not see this condition in the specimens examined, but it is possible that this happens in the species. The antenna figured as being from a male of P. debilis is a female antenna. As in males, the sculpture of female antennae is variable.
The differences recorded by Lingafelter (2007) are also variable in P. imbricornis. Comparing the lectotype of P. diversus with the lectotype of P. diversus cuneatus, and also with the type males of P. imbricornis brunneus and P. i. mimus, it is possible to see just how much the width and shape of the prothorax can vary.
Based on the mix of differential characters for the two species, we place P. de b i l i s as a new synonym of P. imbricornis.
Casey (1924), without explanation, considered Prionus cuneatus, described as subspecies of Prionus diversus, as a distinct species. Ortenburger & Hatch (1926) recorded: “In the list the numbers before the species are those used in C. W. Leng’s “Catalogue of the Coleoptera of America North of Mexico ” (1920).” According to Leng (1920): “In cataloguing the names proposed by Casey in Prionus, the introductory paragraph on p. 215 of his Mem. III, stating that some apply to forms connected by intermediates and destined to speedy extinction, coupled with the suggestion on p. 245 that the abnormal characters employed to distinguish some might not prove constant with more material, has been assumed to warrant doubt to their standing, as to cause the omission of numbers”. Leng (1920) also recorded: “89. imbricornis (L.) 67-622 Ind. Ill.-La. Fla. N.Y. / a. debilis Csy. 91-21 Ind. Mo. Kan. / diversus Csy. 12-247 Ind. / cuneatus Csy. 12-247 B.C. / mimus Csy. 12-248? / brunneus Csy. 12- 248 N.C.” In his catalogue, Leng (1920) used a letter to indicate when he considered a species as subspecies. Thus, he considered Prionus debilis as a subspecies of Prionus imbricornis, disagreeing with Hamilton (1896), although, Leng (1920) was apparently following Lameere (1919), who followed the former. As seen above, Lameere (1919) considered the species listed above by Leng (1920) as possible synonyms, except P. debilis, listed as a true synonym by Lameere (1912, 1913, 1919). Using this concept, and the explanation above on Casey’s species (and subspecies), based on the position in which Leng (1920) included those names (“ diversus ”, “ cuneatus ”, “mimus”, and “brunneus”), it is possible to infer that Leng (1920) was considering them as possible subspecies of P. imbricornis. However, the citations by Leng (1920) are very confused, because “ mimus ” and “brunneus” were described as subspecies of P. imbricornis, and “ cuneatus ” as subspecies of P. debilis. Thus, as it is not possible to know if Leng (1920) was suggesting synonyms or subspecies, it is obligatory to consider without change the condition of the species and subspecies between Lameere (1919) and Linsley (1957), except the status of Prionus debilis that was formally listed as subspecies of Prionus imbricornis. Apparently Ortenburger & Hatch (1926) considered that Leng (1920) changed the status of Prionus diversus to subspecies of P. imbricornis. Alexander (1958) followed Ortenburger & Hatch (1926), recording Prionus imbricornis diversus.
Lameere (1919), in doubt, considered Prionus (Riponus) imbricornis mimus, P. (R.) imbricornis brunneus, P. (R.) diversus, and P. (R.) diversus cuneatus, as synonyms of Prionus imbricornis. However, it was Linsley (1957) who formally established the synonym of those species under P. imbricornis: “I have been unable to detect any population significance for any of the variants named by Casey. Three of his names were based on specimens from Southern Pines, North Carolina (brunneus, cuneatus, robustus). A fourth was from Indiana (diversus). The type locality for mimus was not indicated.”
Lameere (1919) also indicated as synonyms of P. imbricornis, without any explanation: P. beauvoisi Lameere, 1915, and P. brevicornis sensu Palisot de Beauvois, 1805 (not P. brevicornis Fabricius, 1801). Linsley (1957, 1962), and Chemsak et al. (1992) did not include the first as a valid species or as a synonym of any species. Monné & Giesbert (1994), Monné (1995), Monné & Hovore (2005, 2006), and Monné & Bezark (2011) recorded P. beauvoisi as synonym of P. laticollis. We do not know why those latter authors of catalogues and checklists transferred P. b e au v o i s i from the synonym of P. imbricornis to the synonym of P. laticollis. According to Lameere (1915) [translation]: “One female of Prionus from Santo Domingo, with antennae with 14 segments, was described and figured by Palisot de Beauvois (Ins. Afr. et Amer., 1805, p. 216, t. 34, f. 3) under the wrong name of P. brevicornis F. It does not belong to any known species, and I propose to designate this insect, that needs to be found, under the name of P. Beauvoisi.” According to Palisot de Beauvois (1805) [translation]: “ PRIONUS BREVICORNIS. FAB? Piceous; thorax tridentate, dark, shiny; antennae short, 14-segmented, latest 10 antennomeres laterally serrate on one side; elytra punctate (Fig. 3). Santo Domingo ”; “Obs. This insect has much to do with PRIONUS coriarius. It is much thicker. Although the description of Fabricius is very terse and incomplete, I think that this species is the same that he named BREVICORNIS.”
Prionus beauvoisi cannot be P. laticollis, because the holotype has antennae with 14 segments, while in the latter the females have antennae with 12 segments. According to Linsley (1962) and Chemsak (1996), females of P. imbricornis have antennae with from 15 to 18 segments. However, the holotype female of P. ro bu s t u s, synonymized with P. imbricornis by Linsley (1957), has antennae with 19 segments (according to Casey). In turn, the holotype of P. beauvoisi has antennae with 14 segments. Thus, both holotype specimens do not agree with the description by Linsley (1957) and Chemsak (1996) on the number of antennal segments. Also, the drawing of P. beauvoisi, does not agree with P. imbricornis as its prothorax seems different.
Curiously, either P. b e au v o i s i is not mentioned in the synonymic list of P. laticollis (or P. imbricornis) or, when it is listed, Dominican Republic is not mentioned as the country where the species occurs (P. laticollis).
It is not possible to affirm anything about P. beauvoisi without examining the holotype female. If P. beauvoisi really is not P. laticollis, then P. brevicornis sensu Palisot de Beauvois (1805) cannot be listed in the reference list of P. laticollis, because the specimen used as model to the drawing is the holotype of Lameere’s species.
The holotype of Prionus (Antennalia) fissicornis parviceps has the typical antennomeres of P. (P.) imbricornis. Thus, we are transferring the subspecies from the synonymy of P. (P.) fissicornis to that of P. (P.) imbricornis.
In summary, we agree with the synonyms of P. imbricornis established by Linsley (1957), and consider as synonyms of this species: Prionus (Riponus) diversus, P. (R.) diversus cuneatus, P. (R.) imbricornis mimus, P. (R.) imbricornis brunneus, P. (Neopolyarthron) robustus, P. debilis, P. b e au v o i s i, Prionus (Antennalia) fissicornis parviceps, and P. brevicornis sensu Palisot de Beauvois (adding three species and one reference).
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 39-45, DOI: 10.11646/zootaxa.4134.1.1, http://zenodo.org/record/399754