Orizabus pyriformis (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 : 9-11

Orizabus pyriformis (LeConte)

Fig. 6 , 16, 17 , 32-34 ; Map 3

Bothynus pyriformis LeConte 1847: 88 . Type. Lectotype female ( MCZC #3718 ) here designated, labeled “[pale green disc] // Type [T] / 3718 [H, red label] // Aphonus / pyriformis / Lec. [H] // LECTOTYPE [T] / Bothynus / pyriformis / LeConte [H] / des. W. B. Warner [T], 1994 [H, red label].” The LeConte collection contains two specimens with data similar to those of the lectotype; these specimens are here considered syntypes. Type locality: “Habitat ad furcationem fluminis Platte: habitat etiam in Oregon.” The type locality is here restricted to: Nebraska, forks of the Platte River .

Aphonus pyriformis, LeConte 1856: 21 .

Pseudaphonus pyriformis, Casey 1915: 211 .

Cheiroplatys pyriformis, Saylor 1946: 18 ; Ritcher 1966: 138.

Orizabus pyriformis, Endrödi 1969: 89, 1985: 246 , Morón 1981: 136, Delgado and Deloya 1990: 305, Ratcliffe 1991: 272, Dechambre 1993: 342, Ratcliffe and Paulsen 2008: 451, Ratcliffe and Cave 2010: 11.

Pseudaphonus debiliceps Casey 1915: 211 (syn. Saylor 1946: 18). Type. Holotype female (USNM #48610); type locality: Colorado.

Pseudaphonus ovalis Casey 1915:212 (syn. Saylor 1946: 18). Type. Holotype (USNM #48611); type locality: Ft. Wingate, New Mexico.

Pseudaphonus repens Casey 1915:212 (syn. Saylor 1946: 18). Type. Holotype female (USNM #48613); type locality: Santa Fe, New Mexico.

Pseudaphonus lucidus Casey 1915:213 (syn. Saylor 1946: 18). Type. Lectotype female (USNM #48614) here designated; labeled “COLO [T] / 506 [H] // Casey / bequest / 1925 [T]// Type USNM [T] / 48614 [H, red label] // lucidus / Csy. [H] // LECTOTYPE / Pseudaphonus / lucidus / Casey / des. W. B. Warner, 1994 [H, red label]”. Four (2 males, 2 females) of the additional specimens in the Casey collection have data consistent with Casey’s description (they are also the only others with USNM type labels); these four are here considered to be syntypes.

Pseudaphonus puncticollis Casey 1924:335 (syn. Saylor 1946: 18). Type. Holotype female ( USNM #48612 ); type locality: Denver , Colorado.

Diagnosis. Length 12.5 to 19.0 mm; width at humeri 6.0 to 9.0 mm, widest width 8.0 to 12.0 mm. Body shiny, very convex and pyriform ( Fig. 16, 17 ), reddish brown to piceous. Head strongly narrowed to rounded or truncate apex; clypeal carina high, straight to shallowly emarginate in anterior view, in most specimens anteriorly concavely weakly angulate in dorsal view, straight in others; apparently apical to slightly subapical ( Fig. 6 , 32 ). Pronotum strongly narrowed to acute or subacute anterior angles; disc without anterior fovea, densely punctate, especially anterolaterally; anterior margin with posterior edge of bead not posteriorly prolonged at midline; posterior margin subtrilobate, with bead mostly to entirely effaced. Elytron with strial punctures coarse, shallow, umbilicate. Pygidium densely punctulate to punctatorugulose, punctures usually becoming sparser apically. Male with dorsal margin of protibiae tridentate as in female, apex transversely rounded (subtruncate). Paramera thin in dorsal view, submedially weakly dentate on external margin ( Fig. 33, 34 ).

US Distribution. NE, SD, WY, CO, NM, TX, KS, AZ. The Arizona, Kansas, South Dakota, Texas, and Wyoming localities are all new state records.

Specimens Examined. 239; see appendix for locality data.

Remarks. Orizabus pyriformis is easily told from other US species except O. mcclevei by its smaller size, strongly pyriform shape, more densely sculptured pygidium, and protibiae which are apically subtruncate to transversely rounded and tridentate in both sexes. From O. mcclevei (and other species) it may be separated by the usually obtusely angulate (in dorsal view) and apparently apical clypeal carina, pronotum with mostly to completely effaced posterior marginal bead, longer paramera with weak submedial tooth, and antennal club which is shorter than the clypeus. Additionally, the frontoclypeal tubercle and prosternal process are usually more conical in O. pyriformis (though the frontoclypeal tubercle is occasionally transversely so), whereas in O. mcclevei the tubercle is normally broader and transversely subcariniform, and the prosternal process is usually more laterally compressed apically. In very worn specimens of O. pyriformis , the clypeal tubercle (and adjacent frontoclypeal suture) may appear as a rounded-- though obviously abraded-- transverse carina. It is possible that Saylor’s (1946) Colorado record for O. isodonoides refers to such a specimen. Specimens of O. pyriformis from the southern

extent of its range (e.g., Fig. 6 ) tend to have a

broader clypeal apex (especially in females) and

hence a longer clypeal carina. Male genitalia of

specimens from the most southern localities also

tend to have apically more subfalcate paramera.

The unusual facies of this species--reminiscent

of the genus Aphonus LeConte--prompted Casey

(1915) to erect a separate genus ( Pseudaphonus )

to receive it. Unpublished DNA evidence developed

by D. Hawks and A. B. T. Smith (2005, pers. com.)

indicates that O. pyriformis may indeed belong

with Aphonus rather than Orizabus . The

“ Aphonus phenotype characters” (transversely

rounded protibial apex, pyriform shape, distinct

genital form) are also shared by O. mcclevei , O.

isodonoides, and O. ratcliffei Delgado. Further

work on the Aphonus-Orizabus-Xyloryctes com-

plex of genera may result in a different placement

of these species; however, that determination is

beyond the scope of the present paper.

The larva was described by Ritcher (1944, Map 3. Orizabus pyriformis .

1966). Orizabus pyriformis is primarily a grass-

land species and has been taken at light, but re-

mains relatively uncommon in collections.

Figures

Figures 5-7. Dorsal views of head and anterior third of pronotum (males): 5) O. mcclevei holotype. 6) O. pyriformis (Texas). 7) O. isodonoides.

Figures 16-19. Dorsal habitus: 16) O. pyriformis male. 17) O. pyriformis female. 18) O. isodonoides male. 19) O. isodonoides female.

Figures 32-35. Orizabus spp. 32-34) O. pyriformis: 32) Female (Colorado) dorsal view of head and anterior pronotum. 33-34) Dorsal and lateral views of paramera. 35) O. mcclevei allotype, dorsal view of right protibia.