Lomachaeta powelli (Mickel, 1964)

(Figs 35, 39, 48)

Smicromutilla powelli Mickel, 1964: 108 . Holotype, ♂, USA, California, San Luis Obispo Co. (CISC). Williams & Pitts (2009): Combination under Lomachaeta .

Diagnosis. MALE. The following combination of characters is diagnostic for males of L. powelli: the body is entirely black, except T2–3 are largely orange; the mandible lacks a ventral tooth basally; the head and T2 disc have separated punctures; the forewing venation is restricted to the basal half of the wing; the T1 shape is subsessile; the T2 fringe is composed of simple setae; and the paramere is virtually straight, subcylindrical, and lacking tufts or rows of long setae. Body length: 3–6 mm.

FEMALE. This species can be recognized by the numerous elongate blackish dorsal bristles throughout the body. The following characters will also aid in diagnosis: the baso-ventral mandibular margin lacks a hyaline lamella; the head width is 1.2 × the mesosomal width; the mesosoma is compact, with the thoracic dorsal length 0.85 × its width; the pronotal spiracle is weakly swollen; the lateral mesonotal tooth is indistinct; the propodeal spiracle is weakly swollen; the lateral propodeal face is impunctate; the mesosomal dorsum has about 10 areolations between the pronotal spiracles, many intervals are partially obliterated; the T1 shape is sub-sessile; T2 has sparse punctures and smooth intervals; and the S6 lateral carina is low rounded. Body length 2–3 mm.

Material examined. USA: California: Fresno Co., Panoche Road, S 31 T15 R12 MO, 14.VI.1982, R. F. Gill & N. J. Smith (2♀, CSCA); Monterey County, Arroyo Seco Camp, 15.VI.1957, R.C. Bechtel (1♀, EMUS, Figs 35, 39); San Diego County, San Diego, Harkins Collection (1♀, EMUS); San Luis Obispo County, Pozo, 30.IV.1962, J. Powell (1♂, paratype, CISC, Fig. 48) .

Distribution. Known only from the Central Valley and Coast Range areas of California, USA.

Remarks. Both sexes of this species were collected in nesting aggregations of Diodontus occidentalis Fox, a ground-nesting pemphredonine wasp (Mickel 1964). Where known, the other North American species parasitize twig nesters (Pitts & Manley 2004).