Lionothus Brown

Lionothus Brown, 1937: 170 . Type species: Lionothus ulkei Brown, 1937; by original designation. Daffner 1988: 288.

Pseudocyrtusa Portevin, 1942: 78 . Type species: Pseudocyrtusa australis Portevin, 1942, by monotypy; synonymy by Newton 1983: 175.

Diagnosis. Body convex. Antenna with 11 antennomeres with 5-antennomere club interrupted at antennomere 8, which is narrow and disc-shaped but clearly visible. Mandibles variable, left mandible usually with one or two small blunt teeth on anterior one-third. Ventral side of head with or without well defined antennal grooves. Mesosternum vertical between mesocoxae, not carinate. Tibiae uniformly widened to apex; protibiae with tarsal grooves; outer margins of all tibiae with strong spines. Tarsal formula 5-5- 4 in both sexes. Abdominal sternites III–VII each with basal transverse row of large punctures. Males are distinguished by larger, often sinuate spur on inner apical margin of usually straight mesotibia; inner apical margin of mesotibia not produced; and apical tooth-like expansion of the lower margin of the metafemur.

Distribution. The distribution of the genus is Nearctic and northern Neotropical (Mexico, Colombia) (Newton 1998).

Key to species of male Lionothus of the continental United States and Canada

1. Male mesofemur with acute tooth-like expansion at apex of inner margin ..... L. ulkei Brown

– Male mesofemur without acute tooth-like expansion at apex of inner margin .......................... 2

2(1). Smaller species, total length (pronotum + elytra) less than 1.5 mm; apical antennomere as wide as penultimate antennomere ........................................... L. exiguus Peck and Cook, n. sp.

– Larger species, total length (pronotum + elytra) 1.8-2.6 mm; apical antennomere narrower than penultimate antennomere .......................................................................................................... 3

3(2). Antennal grooves well defined, outer margins demarked by carinae extending posteriorly beyond the eye ................................................................................................... L. forticornis Daffner

– Antennal grooves not well defined, outer margins not demarked by carinae ............................ 4

4(3). Mandibles short, together forming semicircle, left mandible with 2 small teeth on apical onethird; eye of normal size, about half length of head .. L. bidentatus Peck and Cook, n. sp.

– Mandibles elongate, not forming semicircle when closed; left mandible with single tooth near middle; eye reduced, about one-third length of head.................................................................. ..................................................................................... L. parvoculus Peck and Cook, n. sp.