Calyxochaetus syilx Runyon, 2024, sp. nov.

Calyxochaetus syilx sp. nov. (Figs 38, 67, 71) Type material. HOLOTYPE ♂, labeled: “ Tonasket, WN./ 7-16-1960 ”; “HOLOTYPE/ Calyxochaetus / syilx / J.B. Runyon [red label]” (CAS) (Fig. 67). Diagnosis. This species is most similar to C. clavicornis but males are distinguished by the arista-like stylus having a wider apical lamella with nearly straight ventral margin (cf. Figs 30 and 38), foreleg with tarsomeres 3 and 4 subequal in length (tarsomere 3 is 1.4X length of tarsomere 4 in C. clavicornis), wing with anal lobe broader at base and forming distinct angle, and distal section of M 4 about 3X longer than crossvein dm-m (4X longer in C. clavicornis). Description. Male: Wing length 2.5 mm. Similar to C. clavicornis except as noted: Head: Arista-like stylus (Fig. 38) with apical lamella wider, with ventral margin straight, not concave. Legs: Foreleg: Tarsomeres 3 and 4 subequal in length. Wing: Anal lobe broader at base, forming distinct angle (similar to C. arizonicus, Fig. 56). Distal section of M 4 about 3X longer than crossvein dm-m. Female. Unknown. Distribution and seasonal occurrence. Known only from the holotype male, collected in mid-July in northcentral Washington State, USA (Fig. 71). Etymology. Named in honor of the Syilx (pronounced see-yilks), First Nations and Native American people whose traditional territory spans the Canada – USA border in Washington state and British Columbia (Okanogan Country). The type locality is named after Chief Tonasket, leader of the American Syilx after the Oregon Treaty of 1846. The species name is considered a noun in apposition.