Orgilus lautus Muesebeck 1970

Mich.

Orgilus lautus

This species is very similar to melissopi, new species, but it is distinguished by its smoother face, its smoother, virtually impunctate metapleuron and outer side of hind coxa, the much less extensively punctate mesoscutum, and the paler antennae, which differ also in having fewer segments.

FEMALE.—Length about 3.8 mm. Head fully twice as wide as long in dorsal view; face flat, smooth and shiny, with only faint, minute punctures, slightly wider than eye height (in ratio of 70:65); malar space about one-fourth as long as eye height, shagreened and mat like the cheeks and lower temples; temples a little more than half as wide as eyes, sharply receding from eye margins and rather flat, smooth and polished above mideye level; occipital carina complete; ocellocular line at least twice as long as diameter of an ocellus; antennae of holotype 27-segmented, even the shortest segments of flagellum slightly longer than broad.

Mesoscutum smooth and shiny, very weakly punctate on the lobes, smooth and polished along posterior margin behind the large punctate depression at the end of the middle lobe; notauli complete and finely foveolate; propodeum nearly smooth laterally, somewhat rugulose punctate medially, the stubs of the apical longitudinal carinae weak; side of pronotum smooth and polished behind and above the impression, a little shagreened anteriorly; mesopleuron smooth and polished, the longitudinal furrow complete, strongly sinuate and finely foveolate; metapleuron smooth and shiny. Hind coxa smooth on outer side; hind femur 3.6 times as long as wide; longer calcarium of hind tibia just about half as long as metatarsus; tarsal claw with a broad subbasal tooth. Radial cell on wing margin 1.5 times as long as stigma; second abscissa of radius not nearly on a line with intercubitus; stub of third abscissa of cubitus extremely short, punctiform; nervulus postfurcal by half its length; hind wing about 4.4 times as long as wide; lower abscissa of basella longer than nervellus and nearly half as long as mediella.

Abdomen about as broad as thorax; first tergite 1.3 times as long as wide at apex, the surface finely alutaceous and with some weak rugulae, the dorsal keels well developed and extending to the middle of the tergite; second tergite about 1.5 times as wide at base as long, faintly alutaceous and shiny; remainder of abdomen smooth and shiny; ovipositor sheath as long as distance from base of scutellum to end of abdomen.

Head testaceous but with a large median blackish area on frons and vertex that extends onto the back of the head where it broadens considerably; palpi pale; antennae brownish yellow below on more than basal half, darkened above and toward apices; thorax dark ferruginous, with the mesonotal lobes, upper parts of the pleura and the propodeum black or blackish; legs, including all coxae, testaceous, the hind tibia darkened narrowly near base and at apex but the extreme base whitish, apical tarsal segments dark; tegulae and wing bases pale yellow; wings hyaline; abdomen above largely piceous varied with ferruginous, especially on the third and fourth tergites; venter of abdomen entirely yellow.

HOLOTYPE.—USNM 70173.

DISTRIBUTION.—Known only from the holotype female taken in Livingston County, Michigan, 28 May 1944, by R. R. Dreisbach.