Boreocanthon melanus (Robinson, 1948), restored generic combination.

Fig. 45, 110–119

Canthon melanus Robinson 1948: 88 .

Boreocanthon melanus (Robinson) (new combination per Halffter 1958: 209).

Canthon (Boreocanthon) melanus Robinson (new combination per Howden 1966: 727).

Boreocanthon melanus Robinson, restored generic combination.

Type. Syntype (sex undetermined). National Museum of Natural History, Washington, D.C. Not examined.

Type locality: Arizona, base of Pinal Mts.

Diagnosis. Head: Clypeus (Fig. 112) lightly roughened, weakly glistening anteriorly; bearing four strong marginal teeth; posteriorly, along with remainder of head, densely alutaceous, conspicuously punctate. Paraocular notch small, setting off small, angulate corner of paraocular area. Labio-gular fimbria (Fig. 117) curved posteriorly, followed medially by V-shaped field of coarse, setose punctures. Prothorax: Pronotum evenly punctate on shagreen background (Fig. 110, 118); anterolateral angles at most only very weakly upturned, posteromedian angle not noticeably impressed. Circumnotal ridge smooth, not serrate posteriorly. Hypomeral carina usually present, curving laterad to point one-eighth to one-fourth distance to outer margin (as in Fig. 108). Pterothorax: Mesoventrite smooth; metaventrite evenly, sharply punctate. Elytra: Striae (Fig. 115) lacking carinulate margins. Interstriae densely alutaceous, weakly microspotted; anterior ends of interstriae 2 and 3 weakly swollen (Fig.110– 111, 118), interstriae 3 and 5 with minute, acute tubercle in middle of anterior margin. Subhumeral (8 th) stria carinulate, usually strongly so (Fig. 115); epipleural (9 th) stria effaced. Legs: Protibia evenly dilated, inner margin not offset; apical spur sexually dimorphic, apically acute in female (Fig. 116a), bifurcate in male (Fig. 116b). Hind femora lacking anterior row of longer setae, distal end bearing several conspicuous setae. Abdomen: Pygidium (Fig. 119) weakly punctured, apex sometimes distinctly more convex and shinier than remainder of surface. Sixth ventrite punctate medially; other ventrites smooth. Genital capsule: Laterally compressed distal portion of parameres shortened, truncate (“snub nosed”), almost right-angled (Fig. 113); ventral apical angles in form of rounded knobs (Fig. 114). General: Black, sometimes with green or blue highlights. Length: 4.0 – 6.5 mm. Geographic distribution (Fig. 45): Southern Arizona and northern Sonora, Mexico. Ecogeographic environment (Fig. 2): Deserts and Xeric Shrublands biome (Sonoran Desert ecoregion). Specimens examined: 645.

Collection localities.

MEXICO — CHIHUAHUA: Mpio. Janos ● Colonia Dublán ● 45 mi N Casas Grandes. SONORA: Mpio. Alamos ● Alamos [Feb]; Mpio. Altar ● Llano Blanco [Jul]; Mpio. Agua Prieta ● 10 mi SE Agua Prieta [Sep] ● 15 mi SW Agua Prieta [Aug]; Mpio. Hermosillo ● Hermosillo [Sep]; Mpio. Naco ● Naco, 5000 ft [Aug]; Mpio. Santa Ana ● 6 mi S Benjamin Hill [Aug] ● 4mi, 17 mi S Santa Ana [Aug].

UNITED STATES — ARIZONA: Cochise Co. ● Dragoon [Aug] ● 12 mi NE Douglas [Aug] ● Palominas [Aug] ● Tombstone [Aug] ● 6 mi E Tombstone [Aug] ● Texas Pass (hwy I-10) [Aug] ● 1 mi E Douglas [Aug] ● Apache, 5000 ft [Aug] ● Douglas [Jul-Aug] ● 12 mi E Douglas [Aug] ● 28 mi E Douglas, Guadalupe Canyon [Jul, Sep] ● Sierra Vista [Aug] ● Sunsites [Jul] ● 5 mi SW Portal, Southwest Research Station [Jul, Sep] ● Willcox Dry Lake [Jul-Sep] ● San Pedro Riparian National Conservation Area [Oct] ● Coronado National Forest, Parker Canyon, 4800 ft [Sep] ● Courtland [Jul] ● Gleeson [Jul] ● Chiricahua Mountains, El Dorado, 5600 ft [Aug]; Gila Co. ● Globe [May]; Graham Co. ● Gila Valley /Safford [Aug]; Maricopa Co. ● Seven Springs Camp [Jun] ● El Dorado [Jul]; Pima Co. ● Hwy 89, 1 mi W Continental [Sep] ● 11 mi E Continental [Sep] ● 2 mi N Continental, 932 m, 31°50 ʹ 19 ʺ N 110°56 ʹ 56 ʺ W [May] ● Tumacacori [Aug] ● Rio Rico [Jul] ● Santa Rita Mountains, Madera Canyon, 16 km SE Green Valley, 4454 ft [Aug] ● Arivaca [Sep] ● Proctor Ranch, Madera Canyon [Jul] ● Green Valley [SepOct] ● Jct. Hwy 86 and 386, entrance to Kitt Peak National Observatory [Sep] ● Hwy 286, 8 mi S. Three Points [Aug] ● Tucson [Aug-Sep]; Santa Cruz Co. ● Pajarito Mountains, Peña Blanca Canyon [Aug] ● Amado [Jul] ● 7 mi E Sonoita [Aug] ● 2.5 mi E Lochiel [Sep] ● Peña Blanca Lake [Jul] ● Duquesne Road, 2 mi E jct. Hwy 82 [Aug] ● 4 mi N Nogales [Jul] ● 10 mi NE Nogales [Jul] ● Nogales [Aug-Sep] ● Patagonia [Aug-Sep] ● 10 mi W Patagonia ● Box Canyon, Santa Rita Mts. [Aug]; Yavapai Co. ● Yarnell [Sep] ● 20 mi W Prescott [Aug].

Comments. Boreocanthon melanus is a common species south of the Colorado Plateau in southern Arizona, where it is sympatric with B. puncticollis and, less frequently, B. simplex . Its range extends to southern Sonora, where it apparently contacts its sister species, B. forreri (q.v.). There is a specimen in the Snow Entomological Collection (University of Kansas) labeled “S. Fe Canon [sic] 7000ft Aug 1880 (Snow)” presumably from F. H. Snow’s trip to area in the summer of 1880; it is not referenced in Snow’s report on the trip (Snow 1880). It, like a similar record for B. simplex (q.v.), I regard as a labeling error.

Label data record Boreocanthon melanus from human and cattle excrement. William Warner (pers. comm.) has collected it at blacklight and in flight intercept traps.