Adelius Haliday, 1833

Adelius, Haliday 1833: 262 (Mason 1985, correct spelling). Type: Adelius subfasciatus Haliday.

Acaelius, Haliday 1834: 231 (Emendation)

Acoelius, Haliday 1835: 539; Marshall 1885: 153 (Emendation)

Pleiomerus, Wesmael 1837: 67 .

Anomopterus Rohwer 1914: 80 . Type: Anomopterus fasciipennis Rohwer.

Myriola Shestakov 1932: 259 . Type: Myriola gussakovskii Shestakov.

Diagnosis. Small size (ranging from 1.0 to 2.4 mm); antenna with 20 segments in all known species; occipital carina present; epicnemial carina absent; labrum concealed by clypeus; vein r absent or present, short; vein r-m absent, second submarginal cell open; vein RS not reaching wing margin; propodeum short and frequently carinate; T1–3 fused and weakly sclerotized, covering most of the length of metasoma, although T4–6 always apparent in dorsal view; metasoma smooth or very weakly sculptured, divisions between T1 and T2, and T2 and T3 absent; spiracles on T6 and T7 absent; ovipositor very short, usually barely exerted.

Distribution. Widely distributed globally in temperate and tropical areas.

Included species. Palearctic: Adelius clandestinus (Förster, 1851), Adelius erythronotus (Förster, 1851), Adelius subfasciatus Haliday, 1833; Western Palearctic (only): Adelius determinatus (Förster, 1851), Adelius dubius (Förster, 1851), Adelius germanus (Haliday, 1834), Adelius hyalinipennis (Förster, 1851), Adelius rudnikovi (Perepechayenko, 1994), Adelius viator (Förster, 1851); Eastern Palearctic (only): Adelius amplus Belokobylskij, 1998, Adelius aridus (Tobias, 1967), Adelius ferulae (Tobias, 1964), Adelius gussakovskii (Shestakov, 1932), Adelius magna (Tobias, 1967); Afrotropical: Adelius cadmium (Papp, 2003), Adelius stenolcos de Saeger 1944; Australasia: Adelius angustus (Papp 1997); Nearctic (Fig. 139): Adelius canadensis Shimbori,& Shaw sp. n., Adelius coloradensis Muesebeck, 1922, Adelius fasciipennis (Rohwer, 1914), Adelius floridiensis Shimbori & Shaw sp. n., Adelius nigripectus Muesebeck, 1922; Neotropical (Fig. 140): Adelius adeleae Shimbori & Shaw sp. n., Adelius bolivariensis Bortoni & Penteado-Dias sp. n., Adelius boliviensis Bortoni & Penteado-Dias sp. n., Adelius caatinga Bortoni, Shimbori & Penteado-Dias sp. n., Adelius excelsus Bortoni & Shimbori sp. n., Adelius ecuadoriensis Bortoni & Penteado-Dias sp. n., Adelius gauldi Shimbori & Shaw sp. n., Adelius janzeni Shimbori & Shaw sp. n., Adelius monteiroi Souza-Gessner, Cerântola & Penteado-Dias sp. n., Adelius morretesiensis Bortoni, Shimbori & Penteado-Dias sp. n., Adelius quiteriae Souza-Gessner, Cerântola & Penteado-Dias sp. n., Adelius sancticaroli Bortoni, Penteado-Dias & Shimbori sp. n., Adelius panamensis Shimbori & Shaw sp. n., Adelius pentagonalis Shimbori & Shaw sp. n.

Comments. Adelius is certainly the most common and diverse genus of Adeliini . The first specimens of Adelius from the Neotropical Region were recorded from Costa Rica, without a further taxonomic treatment (Whitfield 1997), therefore all Neotropical species treated are new to science.