Aphodius matiganae Paulsen, 2006

Paulsen, M. J., 2006, A new species of Aphodius Illiger (Coleoptera: Scarabaeidae: Aphodiinae) from the central United States, Zootaxa 1185, pp. 61-68 : 63-68

Aphodius matiganae Paulsen , new species

( Figs. 1, 4–5 , 7–9 )

Type material

Holotype male ( UNSM) labeled as: a) “ NEBR: ARTHUR Co. / Arapaho Prairie Nat. Con. / Reserve, in flight at dusk / 5­IX­2004 MJ Paulsen”; b) holotype label (red paper): “ Aphodius matiganae / Paulsen / HOLOTYPE ” . Allotype female ( UNSM) labeled: a) “NE: ARTHUR Co. / Arapaho Prairie / VIII­11 1987 / M.E. Jameson ”; b) allotype label (red paper): “ Aphodius matiganae / Paulsen / ALLOTYPE ” . Paratypes (13 male, 3 female) labeled: Same data as holotype. Male paratype labeled: “Milburn / Custer Co. / NE BRASKA / VIII­1970 ”. Male and disarticulated female paratype labeled: “ NEBR: ARTHUR Co. / Arapaho Prairie, ex / Geomys burrow pitfall / (became unburied); set / 5.IX.2004; MJ Paulsen” . Paratypes (11 males, 8 females) labeled: a) “ Texas: Bastrop Co. / Bastrop St. Pk. / X­5­1996, UV light / E.G. Riley ­395"; b) “ Aphodius / rubeolus Beauvois / Det. R. Gordon 97” . Paratype (male) labeled: “ TEXAS: Hardin Co. / I mi. W Silsbee / IX­29­1990 / E.G. Riley & C. Wolfe ” . Paratype (female) labeled: “ TEXAS: Brooks Co. / 10 mi. S Falfurrias / 24­X­1992 / D.W. Sundberg / at blacklight trap ” . Paratype (male) labeled: “ USA: TEXAS: Brazos Co. / College Sta., Riley Estate / 30º35’18”N, 96º15’12”W / IX­26­2004, E.G. Riley ” . Paratype (female) same as preceding except date “ X­22­2004 ”. Paratype (female) same as preceding except date “ X­30­2005 ”. Paratypes (2 females) labeled: “TEX., Brooks Co. / 10 mi N of Encino / on Rt. 755 / 10–11 Nov 2002 / D. Hildebrandt ”. All paratypes labeled (on yellow paper): “ Aphodius matiganae / Paulsen / PARATYPE ” .

Paratypes deposited in EGRC, MJPC, PESC, PKLC, TAMU, UNSM, USNM , and WBWC.

Description

Holotype male. Length: 5.2 mm. Width: 2.5 mm. Form robust, elongate ( Fig. 1 ). Color: Everywhere yellowish red except elytral suture darker, clypeal margin and femora lighter yellowish red, abdomen and antennae lighter reddish yellow. Head: Clypeus broadly rounded on either side of median emargination, center with tumid transverse ridge ( Fig. 4 ), surface punctate; punctures moderate to large. Frontoclypeal suture feebly impressed, weakly trituberculate (best seen in posterodorsal view, Fig. 4 ). Frons shining, punctate; punctures large, dense, separated by 1 diameter. Maxillary palpus with last segment longer than protibial spur. Pronotum: Shape weakly convex, narrowed anteriorly, feebly rounded laterally; lateral and basal margins with bead; lateral margin in lateral view nearly straight ( Fig. 7 ). Surface smooth, shining, punctate; punctures at center of disc uniform in size, size moderate, separated by 2–4 times puncture diameter ( Fig. 8 ); lateral declivity with punctures becoming less uniform, large and moderate punctures present near posterior angles and near base. Scutellum: Shape triangular. Size small (less than 1/6 length of elytra). Elytra: Surface shining, intervals almost flat on disc, slightly convex on apical declivity, finely punctate; punctures in 2–3 irregular rows, separated by more than 5 puncture diameters; striae moderately impressed, margins more or less straight (not crenate), width uniform from base to apex, punctate; punctures moderate, separated by 1–2 puncture diameters. Metasternum: Center along midline depressed; depression ovoid, longer than wide, shining, punctate; punctures large, pubescent. Anterolateral corners strongly alutaceous, deeply punctate; punctures large, pubescent. Posteromedial surface feebly alutaceous but shining, impunctate, glabrous. Legs: Protibia impunctate on dorsal surface, tridentate, serrate behind basal tooth; apical tooth long, strongly curving to outside. Protibial spur simple, triangular, laterally flattened. Mesotibia with apex fringed with unequal spinules; mesotibial spurs unmodified. Metatibia with apex fringed with more or less equal spinules; spinules extremely short, blunt (apparently worn); metatarsus with basal segment subequal in length to superior spur. Genitalia: Parameres convergent, narrowed to rounded apex ( Fig. 5 ).

Description

Allotype female. Length: 4.6 mm. Width: 2.2 mm. Externally similar to holotype male except: Head: Clypeus with transverse ridge reduced. Frontoclypeal suture distinctly impressed, trituberculate (best seen in posterodorsal view), tubercles more strongly developed. Maxillary palpus with last segment shorter, subequal in length to protibial spur.

Variation

Male paratypes (n = 28). Length: 3.7 to 5.0 mm. Width: 1.7 to 2.2 mm. Female paratypes (n = 17). Length: 4.0 to 4.6 mm. Width: 1.8 to 2.2 mm. The tumid clypeal ridge varies from simply punctate to strongly, transversely rugose. Several males possess a more strongly impressed frontoclypeal suture than the holotype, although it appears that the suture is most evident in females. In addition, the frontoclypeal tubercles are weakly developed in some males but are consistently well developed in the females examined. In many specimens the fringe of the metatibial apex is less worn and the unequal spinule lengths more evident.

Diagnosis

This species is most similar to A. rusicola ( Fig. 2 ), one of the most widespread and commonly collected species of North American Aphodius and will key to A. rusicola in Ratcliffe (1991) . The yellowish red color and uniformly, moderately punctate pronotal disc characterize A. matiganae . Large pronotal punctures are present in A. matiganae only near the posterior angles and rarely near the basal margin. The usually dark reddish­brown to piceous A. rusicola frequently has large punctures mixed among the smaller punctures on the pronotal disc. Despite their overall external similarities, these two species possess distinct male genitalia; the parameres of A. matiganae are narrow and convergent to the apex ( Fig. 5 ), while those of A. rusicola are broad with sub­parallel sides ( Fig. 6 ). In addition, the variably developed, transverse ridge of the clypeus (best seen in dorsal view) and less convex pronotum and elytra of A. matiganae will separate the two species. In lateral view, the pronotal margin appears almost straight in A. matiganae , while in A. rusicola the margin is curved. Due to their coloration, specimens of A. matiganae may also be confused with A. rubeolus ( Fig. 3 ); however, the latter species has the dorsal surface of the protibia punctate.

The most apparent sexually dimorphic character of A. matiganae is the form of the last segment of the maxillary palpus: long and cylindrical in males, shorter and weakly dilated medially in females.

Geographic distribution ( Fig. 9 )

UNITED STATES: Nebraska: Arthur Co.: Arapaho Prairie; Custer Co. : Berwyn . Texas: Bastrop Co.: Bastrop State Park; Brazos Co. : College Station ; Brazos Co. : College Station ; Brooks Co. : Encino , Falfurrias ; Hardin Co. : Silsbee. Given the known distribution, this species probably occurs in Oklahoma and Kansas as well. No specimens were located in the collection at the Snow Museum, University of Kansas.

Temporal distribution

August (2), September (21), October (22), November (2). Most Nebraska specimens were collected in September. All but two Texas specimens were taken in October or November.

Etymology

This species is named for my niece, Matigan M. Paulsen (Lincoln, Nebraska), in honor of her appreciation for nature, including tiny six­legged things.

Remarks

Aphodius matiganae is recorded from the Nebraska Sandhills and from Texas. The majority of Nebraska specimens in the type series were collected in flight over short­grass prairie just before sunset. Thus, the life history of this species remains unknown. Two specimens were collected concurrently with the type series in a dung­baited pitfall trap in a pocket gopher burrow, but I am not convinced that this species is a mammal burrow associate. Another surface species ( A. distinctus Müller ) was also present in the trap, indicating that the burrow was not completely reburied or had become opened. In Nebraska, no specimens were collected at blacklight traps operating at the same locality less than a half hour after the type series was collected. In contrast, the Texas specimens were collected at blacklight traps.

Although the name A. rusicola has two junior synonyms neither could pertain to A. matiganae . Both A. aurelianus Harold, 1863 and A. curtus Haldeman, 1848 are described as black. Furthermore, the description of A. aurelianus mentions the lack of a transverse clypeal ridge ( Harold 1863), a character that is present in A. matiganae . It should be noted that A. rusicola as currently delineated is an extremely variable species and may actually refer to a complex that includes more than one taxon.

Acknowledgments

I thank Robert Gordon (Northern Plains Entomology, Willow City, ND) and Paul Skelley (Florida State Collection of Arthropods, Gainesville, FL) for their generous assistance and Paul Skelley, Ed Riley, and Paul Lago for providing specimens for study. I also thank Paul Skelley for providing SEM images. Automontaged images were supported, in part, by NSF­DBI 0 500767. This project was supported by an NSF/PEET grant (DEB­0118669) to M. L. Jameson and B. C. Ratcliffe. Support for collecting was provided, in part, by a University of Nebraska Center for Great Plains Studies grant to the author.

References

Gordon, R.D. & Salsbury, G.A. (1999) Studies on the genus Aphodius of the United States and Canada (Coleoptera: Scarabaeidae). IX. A new species from Kansas and Texas. Journal of the New York Entomological Society, 107, 64–67.

Harold, E. von (1863) Beitrage zur Kenntnis eingier coprophagen Lamellicornien. Berliner Entomologische Zeitschrift, 7, 326–389.

Ratcliffe, B.C. (1991) The scarab beetles of Nebraska. Bulletin of the University of Nebraska State Museum, 12, 1–333.

Samuelson, A., Evenhuis, N. & Nishida, G. (2001) The Insect and Spider Collections of the World Web Site. Bishop Museum, Honolulu, HI. Available from: http://hbs.bishopmuseum.org/ codens/codensearch.html (accessed 22 AUG 2005).

Skelley, P.E. & Gordon, R.D. (1995) A new species of Aphodius (Coleoptera: Scarabaeidae) from Alabama pocket gopher burrows. Insecta Mundi, 9, 217–219.

Skelley, P.E. & Gordon, R.D. (2001) Scarab beetles from pocket gopher burrows in the southeastern United States (Coleoptera: Scarabaeidae). Insecta Mundi, 15, 77–93.

Skelley, P.E. & Woodruff, R.E. (1991) Five new species of Aphodius (Coleoptera: Scarabaeidae) from Florida pocket gopher burrows. Florida Entomologist, 64, 517–536.

Wheeler, Q.D. & Platnick, N.I. (2000) The phylogenetic species concept (sensu Wheeler and Platnick). In: Wheeler, Q.D. & Meier, R., (Eds.), Species Concepts and Phylogenetic Theory, a Debate. Columbia University Press, New York City, pp. 55–69.

Figures

FIGURE 9. Distribution (by county) of A. matiganae.

FIGURES 1–6. 1, Aphodius matiganae, n.sp., dorsal habitus. 2, A. rusicola Melsheimer, dorsal habitus. 3, A. rubeolus Palisot de Beauvois, dorsal habitus. 4, head and pronotum of A. matiganae, showing transverse clypeal ridge and uniformly punctate pronotal disc. 5, male parameres of A. matiganae, with narrowed apex. 6, male parameres of A. rusicola, with apices widened.

FIGURES 7–8. 7, lateral view of pronotum of female A. matiganae. 8, dorsal view of pronotum of female A. matiganae.