Updated key for the New Word species of Olixon

(modified from Bulbol et al. (2023a))

1. Malar space with sulcus from eye to mandible.............................................................. 2

– Malar space without sulcus............................................................................. 6

2. T 1 with median sulcus posterior to transverse carina (northern Argentina)........ O. bicolor Roig Alsina & Martínez, 2010

– T 1 without median sulcus posterior to transverse carina...................................................... 3

3. Temple length about width of scape (southeastern USA and Paraguay)............... O. melinsula Lohrmann et al., 2012

– Temple length less than half width of scape................................................................. 4

4. Propodeum posteromedially without process between posterolateral processes; volsella with few bristles on the membrane that unites them.—Penis valve narrow, space between head of penis valve and preapical process smooth; color varies from bright stramineous to brown; head, meso- and metasoma (except for darker marking on metasomal segment II) of same color; (Arizona to northern Argentina).................................................. O. testaceum Cameron, 1887

– Propodeum with one or two posteromedian processes between posterolateral process; volsella with bristles all over the membrane that joins both and at the apex of each one........................................................ 5

5. Posteromedian process without protuberance; penis valve, margin between the head of penis valve and the second pre-apical process slightly concave (northeastern Brazil)............................ O. caju Celante, Martins & Bulbol, sp. nov.

– Posteromedian process bilobed; penis valve, margin between the head of penis valve and preapical process with a bulging dimple; (midwestern Brazil)................................ O. pantanensis Bulbol, Bartholomay & Somavilla, 2023

6. Metasoma dark brown to black; transverse carina on T 1 evenly arched (Colombia)............................................................................................... O. atlanticum Fernández & Sarmiento-M., 2002

– Metasoma brownish; transverse carina on T 1 forming a narrow posterad angle on midline (southeastern Canada, eastern USA, and northern Mexico).............................................................. O. banksii (Brues, 1922)