Fig. 12, 15; Map 36.

Description. Holotype, male. Measurements: head 0.29 long, 0.46 wide; pronotum 0.41 long, 0.47 wide; elytra 0.82 long, 0.42 wide; antennomeres 1–11 total 0.88; total length 2.30. Body brown, maxillary palps paler. Body covered in elongate setae (greater than half the length of the eye).

Head. Eyes large, maximum length in dorsal view 0.74x length of first antennal segment, with approximately 70 facets. Antennomere 2 approximately 0.82x width of 1; 3 smallest.

Thorax. Elytra with indistinct sutural foveae; 2 foveae lateral to sutural fovea; central row of 3 foveae in basal 1/3. Winged. Metatibia unmodified.

Abdomen. Tergite IV with transverse patch of microtrichia narrowly interrupted at midline. Basal lateral foveae on ventrites obscured, weak if present. Basal pubescence present on all visible ventrites.

Aedeagus. Elongate. Left paramere: equal in length to endophallus; subequal in width from base to apex; with 3–4 stout apical setae and 3 ventral subapical setae. Endophallus: widest at basal 1/5; thin elongate processes arising 2/3 from base on right projecting posteriorly; apex bulbous with s-shaped apical process. Right paramere: 2/3 length left paramere; subequal in width from base to apex; with 2–3 stout apical setae and 3 ventral subapical setae.

Type Material. Holotype, male: * CALIF: Butte Co., 4.4 mi SW Rackerby II-6-80 to II-4-81 A. R. Hardy coll. Antifreeze Pit Trap / CDAE (1♂). Deposited in CSCA.

Geographical Distribution. Sonoma stewarti is known from a single specimen collected from Butte Co., California.

Comments. Sonoma stewarti was collected in a pitfall trap that was active for an entire year, so no meaningful collection date is available.

Aedeagal characters of S. stewarti are superficially similar to S. wintuorum, S. twaini, and S. colberti all of which share a similar gestalt comprised of narrow, elongate parameres and an elongate endophallus with elaborate apical hooks or processes. The flowing combination of characters will separate S. stewarti from the others: endophallus with single apical projection [S. wintuorum with two, S. colberti with three]; endophallus with elongate thin posteriorly directed process arising 2/3 from base not projecting beyond tip of endophallus [with process projecting beyond tip of endophallus in S. wintuorum; without process in S. twaini, and S. colberti].

Etymology. Sonoma stewarti is named for Jon Stewart (born Jonathan Stuart Leibowitz), a humanitarian, champion of science, and humorist best known for reintroducing skepticism and intelligence to news reporting through a television program called The Daily Show.