(Figs 17, 18, 47, 72, 92, 119)
Pompilus trivialis Dahlbom, 1843: 65, Ƥ (lectotype, Ƥ, Sweden, designated by Day 1979: 12 [Universitetets Zoologiska Institution, Lund, Sweden]).
Psammochares corruptor Haupt, 1927: 224, 3 [holotype, 3, "bei Triest", 24.IV. 1896)]. Junior subjective synonym of Pompilus trivialis Dahlbom, 1843 according to Wahis 1986: 21.
Psammochares gibbus: Gussakovskij 1932: 44, 3.
Pompilus (Boreopompilus) trivialis insubricus Wolf, 1965 a: 90, Ƥ 3 (holotype, Ƥ "Caslano, Tessin (Wahis)" [Switzerland]); Wolf 1966: 48, 52, 62, 85, Ƥ 3. Junior subjective synonym of Pompilus trivialis Dahlbom, 1843 according to Wahis 1986: 21.
Pompilus (Boreopompilus) trivialis: Wolf 1966: 48, 52, 64, 88, Ƥ 3.
Arachnospila (Boreopompilus) trivialis trivialis: Wolf 1972: 96, 108, 110, Ƥ 3.
Arachnospila (Ammosphex) trivialis: Tobias 1978: 128, 132, Ƥ 3; Day 1979: 12; Wahis 1986: 21; Lelej 1995: 246, 3; v.d. Smissen 1996: 87, 97, Ƥ 3; Loktionov 2011: 83; Wahis 2011.
Arachnospila trivialis: Zonstein 2002: 138, Ƥ 3.
Psammochares michalki Haupt in Blüthgen, 1961: 69, Ƥ, nom. nud.
Diagnosis of male. The male of this species is similar to males of Arachnospila (Ammosphex) yasumatsui Wolf and Móczár, 1972 and A. (A.) wolfi Lelej, 1995 by having flattened hypopygium with short erect scattered setae, but is easily distinguished from the former by having penial valve not narrowed preapically and rounded apically (Fig. 47 vs. 51), and differs from the latter by having penial valve less setose, not constricted preapically (Fig. 47 vs. 52), by metasomal segments 1 and 2 ferruginous-red (metasomal terga 1 and 2 at most with brown-reddish spot baso-laterally in A. (A.) wolfi). Genitalia as in Fig. 47.
Diagnosis of female. The female of this species differs from other females of the subgenus Ammosphex by having ratio of eye width to half frontal width 0.8 and less (0.9 and more in Arachnospila (Ammosphex) anceps (Wesmael, 1851) and A. (A.) wolfi Lelej, 1995), by protarsomere 1 with three short spines of tarsal comb (four long spines in A. (A.) kaszabi Wolf and Móczár, 1972), by first flagellomere length 3.2–3.9 × its width (4.1 × and more in other females), by apical flagellomere length almost 3 × its width (2 × in A. (A.) orientausa sp. nov.), and by mesopleuron and propodeum with silver or gray micropubescence (brownish micropubescence in some other females). Clypeus as in Fig. 72. Metapostnotum as in Fig. 92. Venation of fore wing as in Fig. 119.
Material examined. RUSSIA. Magadan Prov.: 2 3, lower part of Bulun River, 28.VI. 1982; 1 Ƥ, Khatyngah River, 18–19.VII. 1981. Chukotka: 4 Ƥ, Omolon River, 180 km N Omolon, 17, 23.VII, 12, 23.VIII. 1976. BELARUS. 2 Ƥ, Pinsk, 20.IX. 1977 [IBSS].
Distribution. Russia (Kamchatka, Magadan Prov., *Chukotka; Siberia, European part), Ukraine, Belarus, Kazakhstan (Tobias 1978; Lelej 1995), Kyrgyzstan (Zonstein 2002), Albania, Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Great Britain, Greece, Italy, Norway, Poland, Romania, Slovakia, Spain, Switzerland, the Netherlands, Near East (Wahis 2011).
Biology. The cleptoparasite of Arachnospila (Ammosphex) trivialis is the pompilid Evagetes crassicornis (Shuckard) (v.d. Smissen 2003).
The prey consists of spiders Pardosa C.L. Koch, Trochosa C.L. Koch (Lycosidae), Xysticus C.L. Koch (Thomisidae) and also Agelenidae, Clubionidae, Gnaphosidae (WiŠniowski 2009).
Female nests in the ground mainly in pre-existing cavities, sometimes excavated in loose soil (WiŠniowski 2009).