Philonthus yaqui Navarrete­Heredia sp. nov.

(Figs. 1–4)

Description: Length 10.4–14.0 mm (from anterior border of head to apex of tergite VIII). Black, head and pronotum with faint luster, elytra pale red, abdomen iridescent; maxillary and labial palpi piceous to piceous­black, antennae black; legs piceous, iridescent, protibia with a yellow macula on posterior face, with last four tarsomeres brunneous to brunneotestaceous. Head of rounded quadrangular shape, with obtusely rounded hind angles, moderately wider than long (HW/HL= 1.20–1.38) and slightly narrower than pronotum (HW/ PW= 0.81–0.98)); eyes large, tempora about as long as length of eyes; lateral and medial interocular punctures moderately distant, distance separating medial punctures 2.1–2.8X as large as distance separating medial punctures from lateral punctures; temporal area with moderately dense and coarse punctation; entire dorsal surface with fine and dense microsculpture of transverse and oblique waves mixed with sparse micropunctules. Antennomeres 1–3 with few macrosetae, antennomeres 4–11 with few macrosetae (number decreasing to outer segments) and many microsetae, antennomere 2 shorter than antennomere 3, antennomeres 4, 5 and 6 each slightly longer than wide, length of 5–10 decreasing, their width increasing but never strongly transverse, last antennomere shorter than two preceding antennomeres combined. Pronotum somewhat wider than long (PW/PL= 1.08– 1.09), about equally narrowed both posteriad and anteriad; microsculpture similar to that on head but micropunctules hard to see. Scutellum densely punctate, with golden­rusty pubescence. Elytra moderately long, a little shorter at suture than sides; punctation fine and dense, transverse distance between punctures no more than twice diameter of punctures; pubescence fine, golden­rusty with few scattered black macrosetae; surface between punctures without microsculpture. Profemur on apical anterior lower edge with four to six distinct spine­like setae. Abdomen with tergite VII with distinct whitish apical border (“palisade fringe”); punctation of tergites fine and sparse, becoming in general sparser toward apex of abdomen; pubescence black, surface between punctures with exceedingly fine and dense microsculpture of transverse striae.

Male. First four tarsomeres of front tarsus moderately dilated, sub­bilobed, each moderately densely covered with modified pale setae ventrally; segment four narrower than three preceding segments. Sternite VII vaguely sinuate in middle of apical margin; sternite VIII with deep and wide, obtuse medio­apical emargination partially filled by semi­membranous extension with shallow, arcuate medio­apical emargination. Genital segment with tergite X minutely emarginate apically, with numerous apical and two subapical setae; sternite IX deeply emarginate, with two subapical large setae. Median lobe of the aedeagus narrowed into slender apical portion, with a small tooth opposite the basal ⅛ of peg setae area of paramere; paramere elongate, apical portion more or less parallel­sided, with apex not reaching narrowed apical portion of median lobe; peg setae on underside of paramere numerous, forming longitudinal bands along the margins, which meet at apex of paramere (Figs. 2–4).

Female. First four tarsomeres of front tarsus vaguely dilated, much narrower than those of male, each ventrally with pale setae only at apical margin. Genital segment with second gonocoxite with minute stylus bearing two long setae; tergite X strongly narrowed to apex, with numerous apical setae.

Type material: Holotype (male), and 35 paratypes (22♂, 13♀): México: Sonora, Yécora, bosque de encino­pino, 1400m, necrotrampa calamar, 10­17.VIII.2000, G.A. Quiroz, L.A. Navarrete­Quiroz, and J.L. Navarrete­Heredia cols.; same data except for: 1650m, bosque de pino (11♂, 4♀), 9.VIII.2000, ex excremento. Holotype and 20 paratypes deposited in CZUG. Other paratypes will be deposited in: CNIN, IEXA, FMNH, CNC, BMNH, and JLN.

Distribution. Philothus yaqui is known only from Yécora in the State of Sonora in México.

Bionomics. The adults were collected with carrion traps using squid, and in dung. As for other members of this genus, the adults of this species presumably occur in these habitats for food, usually immatures of other insects, primarily maggots.

Discussion. Within the Philonthus furvus group, P. yaqui sp. nov. closely resembles P. roscius Smetana, 1995 from Arizona (U.S.), P. hoegei Sharp, 1885, and P. testaceipennis Erichson, 1840, the last two from some Mexican States (Navarrete­Heredia et al. 2002; Asiain 2002). These species share the red elytra, in contrast with the remaining species of the group, that the elytra have different colors, including bright blue (Smetana 1991, 1995).

Etymology. The specific name refers to one of the most important ethnic groups from Sonora, the yaquis; it is a noun in apposition.

Taxonomic comments: The Philonthus furvus group is represented in México by at least the following species: Philonthus alutaceus Horn, P. f l o h r i Sharp, P. f u r v u s, P. hoegei, P. melampus Smetana, P. nigerrimus Erichson, P. oenotrus Smetana, P. s a l l a e i Sharp, P. testaceipennis Sharp and P. y a q u i, however additional species probably will be included here after more taxonomic work can be done in the future.