Nitidulidae
Creators: name: Ewing, Curtis
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Nitidulidae

description: Key to the genera of endemic Hawaiian Nitidulidae
A key to the 19 species of adventive sap beetles naturalized in Hawaii is provided in Ewing & Cline (2005). The following key continues from couplet 3, which separates the endemic species.
1 Form depressed, elongate, and parallel sided, posterior width of 6th abdominal segment only slightly narrower than 5th, elytron more than 2x as long as wide, striae regular (fig. 14); tarsomere 3 little dilated (fig. 15); prosternal process enlarged apically with margin broadly rounded (fig. 16) ......... Cillaeopeplus Sharp
1' Form sub-depressed to convex, abdomen evenly tapered, posterior width of 6th abdominal segment much narrower than 5th, elytron 2x as long as wide or less (figs. 17, 18), striae often irregular to confused, usually irregular at apex; tarsomere 3 usually strongly dilated (fig. 19), if not then wings reduced; prosternal process variable, small and upturned sharply (Figs. 20–22), small and upturned slightly (figs. 23–25), or expanded apically and little upturned (figs. 26, 27), apical margin truncate to broadly rounded .............. 2
2 Pronotum with patch of forward directed setae behind head (fig. 28), remaining setae directed posteriorly; prosternal process of prosternum expanded and little upturned; eyes never reaching posterior margin of postgenae (fig. 29), temple wide and distinct; large species 5–8 mm, closely associated with native Hawaiian lobelioids .......................................................................................................... Orthostolus Sharp
2' Pronotum without patch of forward directed setae behind head, remaining setae variable, from regular to confused; prosternal process variable, from small and upturned sharply to expanded and little upturned; eyes variable, from large and continuous with post genae (Figs. 30–32) to small with temple wide (figs. 33, 37); size variable, from 2.5– 10 mm; sometimes associated with Hawaiian lobelioids; never with all characters as above ..................................................................................................................................... 3
3 Antennal club robust, integument with prominent spiculate microsculpture, setae fine; 9th antennomere subquadrate to trapezoidal, length and width subequal (fig. 34, 35); eyes coarsely faceted, usually large with posterior margin meeting post-genae, temple linear (figs. 30, 36), if eyes smaller and temple present than prothorax distinctive, strongly transverse, much wider anteriorly with sides rounded, constricted behind and margin strongly explanate (fig. 38); large species 4.5–10.0 mm .................. Gonioryctus Sharp
3' Antennal club less robust, integument with microsculpture fine and less prominent, setae fine to elongate; 9th antennomere transverse (fig. 39, 40); eyes finely faceted, usually small with posterior margin before postgenae, temple narrow to wide, usually convex laterally (fig. 29, 31–33); size from 2.5–8.0 mm ....... 4
4 Prosternal process little expanded posteriorly in ventral view (figs. 21, 24), sharply to moderately upturned behind coxae (figs. 22, 23, 25, 41), never strong projected posteriorly; explanate margin of elytron always narrow, 2x width of bead or less except rarely 3x at humeral angle (fig. 42a); striae always obsolete at apex of elytron with punctures shallow and confused; pronotum usually strongly convex, sometimes with two shallow depressions sub-basally, metathoracic wings always complete ...... Prosopeus Murray
4' Prosternal process usually strongly expanded posteriorly, usually little upturned behind coxae, if small and upturned then wings reduced; explanate margin usually wide, often very wide, always at least 4x the marginal bead at humeral angle (fig. 42b); striae always distinctly impressed, often irregular, pronotum usually depressed with surface irregular, if convex than wings reduced; metathoracic wings commonly reduced to less than the length of the elytra ................................................................................................ 5
5 Third labial palpomere strongly transverse, 2x as wide as long (fig. 43), many species common .............. ............................................................................................................................................. Eupetinus Sharp
5' Third labial palpomere elongate to sub-quadrate (fig. 44), external form diverse, internal copulatory sac of male always as in fig. 12, all species rarely encountered .................................................. Apetasimus Sharp
description: Published as part of Ewing, Curtis, 2007, Phylogenetic analysis of the genera of endemic Hawaiian sap beetles (Coleoptera: Nitidulidae) based on morphology with redescription and key to the genera of endemic Hawaiian Nitidulidae, pp. 1-36 in Zootaxa 1427 on pages 11-12, DOI: 10.5281/zenodo.175765