Araeodontia marginalis Barr, 1952a

Burke, Alan & Zolnerowich, Gregory, 2017, A taxonomic revision of the subfamily Tillinae Leach sensu lato (Coleoptera, Cleridae) in the New World, ZooKeys 179, pp. 75-157 : 83-86

Araeodontia marginalis Barr, 1952a Figs 1B, 18B

Paratype.

One male examined.

Type locality.

Mexico, Samalayuca, Chihuahua. Type depository: American Museum of Natural History (AMNH).

Distribution.

USA: TX; Mexico: Chihuahua, Coahuila, Sonora.

Differential diagnosis.

Araeodontia marginalis is most similar to A. isabellae . The fascia pattern on the elytral disc can be used to separate these species. Araeodontia marginalis has two longitudinal fasciae that extend from the elytral base to the apex, the first band is located adjacent to the elytral suture and the second runs along the epipleural fold; for some specimens, the latter band can be absent on the anterior half of the elytral disc; both fasciae are interconnected at the apex (Fig. 1B). Araeodontia isabellae has the elytral disc uniformly light testaceous and each elytron has one brown macula (Fig. 1A).

Redescription.

Male. Form: Body relatively stout, elongate. Color: Head, anterior margin of pronotum and mouthparts brown to dark brown; pronotum, thorax, elytra, abdomen and legs testaceous to light brown; two brown, longitudinal fasciae on each elytron, the first located on the elytral suture, and extends from anterior margin of elytra and reaches apex, this fascia abruptly reduced in width on second and last fourth, the second adjacent to epipleural fold, and also extends from anterior margin of elytron and reaches apex, this fascia may be reduced to absent on the anterior half of elytral length, both fasciae may be interconnected at the elytral apex (Fig. 1B).

Head: Feebly vested by light, recumbent setae; surface weakly punctate; frons bi-impressed; eyes enlarged, bulging laterally, coarsely faceted; antennae extending to anterior third of elytra; third antennomere about twice the length of second antennomere; antennomeres 3-10 about the same length; antennomeres 4-10 somewhat robust, slightly serrate; eleventh antennomere robust, subacuminate.

Thorax: Pronotum scarcely punctate; faintly rugose laterally, smooth; vested by semierect seta interspersed with fine, recumbent setae; broadest at middle; disc flat, very feebly impressed in front of middle, more strongly constricted behind middle, subbasal tumescence absent. Mesoventrite very finely vested, smooth. Metaventrite smooth, convex, puncticulate; covered with fine, semi-recumbent setae. Scutellum subquadrate, notched posteriorly.

Legs: Vested with short, recumbent setae intermixed with long, erect and semi-erect setae. Femora rugulose; finely punctate. Tibiae longitudinally rugose, punctate, vested with short, recumbent setae intermixed with semi-erect setae.

Elytra: Humeri rounded, indicated; sides subparallel, widest behind middle; base wider than pronotum; disc flattened apically; apices subtriangular, slightly dehiscent; disc convex; vestiture composed of stiff, erect and semi-erect setae intermixed with stiff, semirecumbent setae; sculpturing consisting of small, shallow punctations arranged in striae that gradually reduce in size on middle third and do not reach elytral apex; interstices smooth, 4.0 × the width of punctuation at anterior margin.

Abdomen: Ventrites 1-4 rugulose, feebly vested with short, recumbent setae, indistinctly, finely punctate. First visible ventrite about the same length of second ventrite, ventrite 3-4 subquadrate, smooth, feebly vested with fine recumbent setae. Fifth visible ventrite reduced, convex, lateral margins subparallel, posterior margin broadly, slightly emarginate. Sixth visible ventrite subquadrate, surface somewhat concave medially, convex laterally, feebly punctate; lateral margins oblique; posterior margin broadly, moderately deeply emarginate, emargination V-shaped, posterolateral angles rounded. Fifth tergite convex; finely punctate; rugulose; lateral margin subparallel; posterior margin broadly, shallowly, slightly, emarginate. Sixth tergite subtriangular; surface convex; longer than broad; finely punctate; scarcely covered with short, recumbent setae; lateral margins oblique; posterior margin narrowly, very shallowly emarginate; hind angles rounded. Posterior margin of sixth tergite produced ventrally, fully covering sixth visible ventrite.

Aedeagus: Phallobasic apodeme present; phallus with copulatory piece expanded at apex; phallic plate without denticles; intraspicular plate present, elongate; phallobasic apodeme long, expanded distally; phallobase trigonal; parameres free; tegmen complete, covering phallus; parameres pointed anteriorly; endophallic struts long, the length of tegmen; endophallic struts slender distally (Fig. 18B).

Sexual dimorphism: The female of A. marginalis can be separated from males based on the structure of the last abdominal segment. In females, the lateral and posterior margins of the sixth tergite and the sixth visible ventrite are broadly rounded, making a single semicircular margin; males have the sixth tergite and the sixth visible ventrite subquadrate in shape, and the posterior margin narrowly, shallowly emarginate, the emargination seen in the sixth visible ventrite is slightly deeper than that observed in the sixth tergite. Remaining characters are similar.

Material examined.

PARATYPE: 1 male: Pine Springs, TX, VII-12-16-1928, W. Benedict.

Additional material examined.

USA: 1 male: Hudspeth Co., TX, 9 mi SW Dell City, VII-31-1950, R. F. Smith; 2 males: Valentine, TX, VI-25-1947, R. H. Beawer. MEXICO: 1 male, 1 female: Sonora, Mexico, near San Jose beach, Ciudad Obregon, 40 mi SW of V-16-23-1961, Howden and Martin; 1 female: Coahuila, Mexico, sand dunes, near Bilbao, 8 mi N of Viesca, V-30-31-1981, J. Doyen and J. Liebherr.