Orizabus clunalis (LeConte)

Warner, William B., 2011, Review of the genus Orizabus Fairmaire in the United States of America (Coleoptera: Scarabaeidae: Dynastinae), Insecta Mundi 2011 (174), pp. 1-42 : 4-5

Orizabus clunalis (LeConte)

Fig. 1, 2 , 26, 28 , 36 , 37 ; Map 1

Aphonus clunalis LeConte 1856: 23 . Type. Holotype female ( MCZC #5720 ); type locality: “...found by Dr. Thos. H. Webb, of the Boundary Commission, and probably in the valley of the Gila.” Given the species’ habitat, this locality is most probably in mountainous pine forests of the east central portion of modern-day Arizona or adjacent area of New Mexico.

Cheiroplatys clunalis Bates 1888: 321 , Fall 1905: 272, Saylor1946: 17, Young 1969: 927.

Orizabus clunalis Casey 1915: 226 , Endrödi 1969: 85, 1985: 243, Morón 1981: 131, Delgado and Deloya 1990: 301, Morón et al. 2003: 7, Delgado 2008: 56, Ratcliffe and Cave 2006: 206, 2010: 1.

Orizabus cultripes Fairmaire 1878: 261 , Bates 1888: 321 (syn. Saylor 1946: 17). Type. Lectotype male (MNHN) here designated, labeled “ Orizabus / cultripes / Fairm. / Orizaba[H] // Museum Paris / collection Léon Fairmaire / 1906[T, blue label] // SYNTYPE [T, red label] // LECTOTYPE [T] / Orizabus / cultripes / Fairmaire / des. W. B. Warner[H, red label].”

Orizabus marginatus Fairmaire 1878: 262 , Horn 1885: 125 (syn. Bates 1888: 321). Type. Type (apparently) not seen. Four specimens purportedly from the type series were received from MNHN, including three Sallé specimens labeled as syntypes, and one Palmer specimen with Bates (1888) “Biol. Cent. Amer.” labels. All four specimens were 22-23 mm long vs. Fairmaire’s description of “Long. 26 à 28 mill;” therefore no lectotype was designated from this series.

Orizabus sallei Fairmaire 1878: 262 (syn. Bates 1888: 321). Type. Lectotype male (MNHN) here designated, labeled “Jalapa / Mexico [T] // ex museo / A. Sallé / 1897[T] // Museum Paris / ex coll. / R. Oberthur [T, blue label] // Orizabus / Sallei Fair[H] // LECTOTYPE [T] / Orizabus / sallei / Fairmaire / des. W. B. Warner [H, red label].”

Orizabus snowi Horn 1885: 124 (syn. Bates 1888: 321). Type. Lectotype male ( MCZC #3704 ) here designated, labeled “ New Mexico / F. H. Snow [T] // Type No. [T] 3704 [H] / Orizabus / snowi [H]/ G. H. Horn [T, red label] // Orizabus / Snowi / Horn [H] // LECTOTYPE [T] / Orizabus / snowi / Horn [H] / des. W. B. Warner [T], 1994 [H, red label].” Although Horn described this species from a series, the only other specimen associated with the lectotype in the Horn collection now at MCZC is labeled “Ari.”. The LeConte collection (MCZC) contains one specimen from “ S. Fe Canon, N.M., 7000 ft., Aug., 1880 ( Snow )” and two unlabeled specimens determined as O. snowi which may be syntypes. Type locality: New Mexico.

Orizabus fontinalis Casey 1915: 225 (syn. Saylor 1946: 17). Type. Lectotype male (USNM #48608) here designated, labeled “NM [T] // Casey / bequest /1925 [T] // Type USNM [T] / 48608 [H, red label] // fontinalis / Csy. [H] // LECTOTYPE [T] / Orizabus / fontinalis / Casey / des. W. B. Warner, 1994 [H, red label]”. One female syntype is also present in the Casey collection (USNM). Type Locality: Jemez Springs, New Mexico.

Orizabus frontalis Saylor (nomen nudum) 1946: 17, nec Casey 1915: 225.

Orizabus ponderosus Casey 1915: 225 (as “ ponderosae ”; syn. Saylor 1946: 17). Type. Lectotype male (USNM 48607) here designated, labeled “Albuquerque / N. M.: Snow / August 1894 [T] // Casey / bequest / 1925 [T] // Type USNM [T] / 48607[H, red label] // Orizabus / ponderosus / Csy. [H] // LECTOTYPE / Orizabus / ponderosus / Casey / des.W. B. Warner, 1994 [H, red label]”. Twelve syntypes (5 male, 7 female) are present in the Casey collection (USNM).

Diagnosis. Length 19.0 to 26.0 mm, width 11.0 to 14.5 mm. Large for genus, parallel sided to wider behind but not distinctly pyriform. Clypeus parabolic with apex broadly rounded; clypeal carina obviously subapical, bidentate, teeth rounded, usually separated by more than a dorsal eye width ( Fig. 1 , 37 ); maximum dorsal eye width usually less than 1/4 of minimum dorsal interocular width. Pronotum with posterior marginal bead distinct (in all US specimens examined). Male with dorsal margin of protibia edentate, bladelike; pronotum anteromedially with perceptible to large depressed area, anterior marginal bead posterodorsally prolonged at midline into triangular tubercle; paramera ( Fig. 26, 28 ) without apical incisure, but with weak lateral tooth subapically, apex incompletely sclerotized, appearing “fleshy”.

Female with dorsal margin of protibia tridentate, its apex oblique ( Fig. 37 ); pronotum with posterior margin of anterior marginal bead varying from subangularly broadened to forming tubercle as in males, disc without or with weak anteromedial depressed area behind tubercle.

US Distribution. See Map 1. Many records from AZ, NM, and western TX. Single “state only” records were seen from Colorado and Kansas (the latter in the Horn collection at MCZC) ; but because no recent material from those states was seen, I consider the data as suspect until confirmed. Endrödi’s (1985) Ohio record is erroneous, and several old “El Paso,” TX, records possibly were extended from mountains in the vicinity as the desert habitat in El Paso is unlikely to support this species .

Specimens Examined. 1074; see appendix for locality data.

Remarks. Orizabus clunalis , although similar in size and general habitus to O. ligyroides , may be immediately differentiated from that species by its parabolic clypeus and obviously subapical clypeal carina with widely spaced teeth. Orizabus ligyroides has a triangular clypeus and apparently apical carina with contiguous teeth. Additionally, specimens of O. ligyroides tend to have larger eyes (maximum dorsal width usually between one-third to one-fourth of minimum dorsal interocular width), and the clypeus (posterior to the carina) in lateral view is much thicker than in specimens of O. clunalis , and have a stronger marginal carina (fresh specimens). In O. clunalis the clypeus is only about half as thick (in lateral view) as that of O. ligyroides , the marginal carina often being weak or effaced (compare Fig. 1- 4 ).

The US populations of O. clunalis form a subcontinuous cline in gross morphology from west to east where western populations are typical (muted pronotal fossa and tubercle, smooth pygidium; Fig. 1 , 37 ), and eastern populations are of the “ snowi ” form originally described by Horn as a distinct species. The latter form ( Fig. 36 ) tends to have a deeper pronotal depression, more pronounced pronotal and cephalic tubercles, and a moderately punctate pygidium. Some females from the Chisos Mountains in Texas lack the angular expansion of the anterior pronotal marginal bead, and have shorter antennal clubs than specimens from more western (or northern) localities. Males from the same series, however, are easily referred to O. clunalis .

Additionally, a small, reddish brown form of this species (which Casey (1915) described as “ O. fontinalis ”) occurs sporadically in New Mexico and occasionally elsewhere. Macroscopically this form looks very different (color, size) from “typical” O. clunalis ; but it does not differ otherwise in any important characters, and usually forms only a part of any one population, with intergrades to the more typical form for the area.

Saylor listed both O. marginatus and O. snowi as “New Synonymy” in his 1937 revision; however, previously Bates (1888) had clearly established both synonymies. Several morphologically distinct forms from south of the US border are currently placed under “ clunalis ” in collections, and the species as defined at present appears to possibly represent a species complex. Detailed analysis of material from south of the US border may reveal a need to revise the above synonymy. Several neotropical species (under the current classification) are also very similar externally to O. clunalis ; but with the removal of O. ligyroides from synonymy, the US populations appear to be conspecific.

Cheiroplatys verticalis Fall (1905:272) was listed by Saylor (1946) as a new synonym of O. clunalis , a status that was accepted by subsequent authors. However, as correctly noted by Casey (1915), the holotype of C. verticalis is actually a small female Xyloryctes jamaicensis (Drury) . Saylor (1946) also incorrectly listed Orizabus parvitarsis Casey (1915:227) as a synonym of O. clunalis . Examination of Casey’s

Figures

Figure 36. Orizabus clunalis: Anterolateral view of male (Texas) head and pronotum.

Figures 1-4. Dorsal and right lateral views of head and anterior third of pronotum: 1-2) O. clunalis. 3-4) O. ligyroides.

Figures 26-31. Dorsal and lateral views of paramera: 26, 28) O. clunalis. 27, 29) O. ligyroides. 30) O. pinalicus holotype. 31) O. rubricollis.

Figures 37-38. Dorsal view of female head and anterior pronotum: 37) O. clunalis (Arizona), 38) O. ligyroides.