Subgenus Arachnospila Kincaid 1900

Arachnospila Kincaid 1900: 509 (type species Arachnospila septentrionalis Kincaid 1900, by monotypy). Pycnopompilus Ashmead 1902: 83 (type species Pompilus scelestus Cresson 1865, by original designation); Šustera 1938: 211 (as subgenus of Psammochares). Junior subjective synonym of Arachnospila Kincaid 1900 according to Haupt 1927: 195. Arachnospila (as subgenus of Pompilus): Wolf 1964a: 4, Ƥ 3; 1964b: 321, Ƥ 3; 1965: 25, Ƥ 3; Krombein 1979: 1562. Arachnospila (as subgenus of Arachnospila): Priesner 1968: 177, Ƥ 3; Wolf 1972: 108; 1992: 63 (Ƥ), 76 (3); Tobias 1978: 126 (Ƥ), 127 (3); Day 1979: 11; Wahis 1986: 18; Oehlke & Wolf 1987: 350, Ƥ 3; Lelej 1995: 237 (Ƥ), 240 (3); Shimizu 1996: 510.

Psammochares fumipennis species-group: Haupt 1927: 195; 1929: 129; Haupt 1933: 64.

Diagnosis of males. The males are easily diagnosed by the morphology of the sternum 8 (hypopygium), which is wide and has more or less a high carina (Figs 6–25), by having 2r-m and 3r-m cells of fore wing, which is wider than its length, and by having trapeziform 3r-m cell (Figs 36, 40, 44, 48, 52, 56, 60, 64, 69). This is contrary to species of the other Arachnospila subgenera, which have narrower hypopygium without a high carina and have fore wing with 2r-m and 3r-m cells, which is not wider than its length. The head, pronotum and propodeum have long dense setae.

Diagnosis of females. The females are easily distinguished by having 2r-m and 3r-m cells of fore wing, which is wider than its length, and by having trapeziform 3r-m cell (Figs 38, 42, 46, 50, 54, 58, 62, 66–68). The head, pronotum and propodeum have long dense setae. The fore leg has a well developed tarsal comb.