Xanthonomus, Bernhauer, 1926

Shavrin, Alexey V., 2024, Twenty-one new species of Omaliini from the Papuan Region (Coleoptera: Staphylinidae: Omaliinae), with diagnostic and faunistic notes on some species of the genus Paraphloeostiba Steel, 1960, Zootaxa 5424 (3), pp. 251-307 : 306

Key to species of the genus Xanthonomus

1 Pronotum with distinct obtuse hind angles. Abdomen very wide. Habitus as in Fig. 2 in Steel (1955). Body length: 2.50 mm. Malaysia............................................................................ X. latus Steel, 1955

- Pronotum with widely rounded hind angles. Abdomen distinctly narrower........................................ 2

2 Pronotum slightly transverse, with two median, shallow and oval impressions. Elytra yellow. Habitus as in Fig. 1 in Steel (1955). Body larger: 2.50–2.80 mm. Aedeagus as in Fig. 5 in Steel (1955). Indonesia (Buru)................................................................................................... X. toxopeanus ( Bernhauer, 1926)

- Pronotum distinctly transverse, without median impressions. Elytra darker. Body smaller............................ 3

3 Median lobe moderately wide; parameres distinctly not exceeding apex of median lobe ( Fig. 152 ). Habitus asi n Fig. 142 . Body larger: 1.87–2.25 mm. Indonesia (New Guinea).............................................. X. guineensis sp. n.

- Median lobe narrow; parameres reaching apex of median lobe ( Fig. 159 ). Habitus as in Fig. 143 . Body smaller: 1.61–1.80 mm. Papua New Guinea...................................................................... X. thayerae sp. n.

Figures

FIGURES 1–6. Habitus of Omaliini: 1–Nipponophloeostiba hornabrooki (holotype), 2–Paraphloeostiba assimile (holotype), 3–P. atramentaria (holotype), 4–P. attenuata (paratype), 5–P. barclayi (paratype), 6–P. betlephila (holotype). Scale bars: 1.0 mm.

FIGURES 152–157. Xanthonomus guineensis (paratypes): 152–aedeagus, parameral view, 153–aedeagus, lateral view, 154– male abdominal tergite VIII, 155–male abdominal sternite VIII, 156–female abdominal tergite VIII, 157–female abdominal sternite VIII. Scale bar: 0.1 mm.

FIGURES 141–143. Habitus of Omaliini: 141–Paraphloeostiba telnovi (holotype), 142–Xanthonomus guineensis (holotype), 143–X. thayerae (paratype). Scale bars: 1.0 mm.

FIGURES 159–165. Xanthonomus thayerae: 159–aedeagus, parameral view (holotype), 160–aedeagus, lateral view (holotype), 161–male abdominal tergite VIII, 162–male abdominal sternite VIII, 163–female abdominal tergite VIII, 164–female abdominal sternite VIII, 165–female accessory sclerite. Scale bar: 0.1 mm.