Elytrogona Chevrolat

Chaboo, Caroline S., 2000, Revision And Phylogeny Of The Caribbean Genus Elytrogona Chevrolat (Coleoptera: Chrysomelidae: Cassidinae: Stolaini), The Coleopterists Bulletin 54 (3), pp. 379-394 : 384-386

Elytrogona Chevrolat

Elytrogona Chevrolat, 1837: 394 ; Boheman, 1850: 438 [description]; Boheman, 1856: 72 [catalog]; Chapuis, 1875: 404 [description; placed in Elytrogonites]; Gemminger and Harold, 1876: 3638 [catalog]; Champion, 1893: 125 [character]; Spaeth, 1914: 51 [catalog]; Blackwelder, 1946: 743 [checklist]. Borowiec (1999) cited the type species as by monotypy. However Chevrolat (1837) included four nominal names of which two were unavailable. Of the other two, quatuordecimmaculata Latreille was cited as a junior synonym of ampulla Olivier. The type species fixation therefore cannot be by monotypy. Since there are two nominal species and Chevrolat did not designate a type species, any type designation must be by subsequent designation. Therefore Borowiec (1999) designated the type species by subsequent designation. Type species: Cassida quatuordecimmaculata Latreille, 1802 . Type fixed by subsequent designation.

Cyphoptera Hope, 1840: 160 [placement in Mesomphaliidae].

Type species: Cassida ampulla Olivier, 1808 . Type fixed by monotypy.

Diagnosis. Elytrogona can be distinguished from Stoiba by the following unique combination of features. The elytra are inflated creating a highly convex lateral profile ( Fig. 1 ), with the disc sharply demarcated from the explanate margin. In Stoiba ( Fig. 2 ) the elytra are not inflated and the body is not dorsally convex. The posterior margin of the pronotum is truncate. The hind wing is either vestigial or absent. Stoiba species have hind wings that range from macropterous to brachypterous. The elytral dorsal surface sculpturing of Elytrogona is coarsely punctate ( Figs. 3, 5–7 ), with the exception of E. bulla which is finely punctate ( Fig. 4 ). The dorsal surface sculpturing in Stoiba is smooth or finely punctate in all species except S. marginata Blake which is coarsely punctate on both the elytra and pronotum. The basal tooth on the tarsal claws are pointed with a curved ventral margin ( Figs. 8–12); Stoiba ( Figs. 13–14) and other stolaines have the tooth quadrate with a straight ventral margin.

Description. Body: Length 4.27–10.9 mm; width 3.6–9.1 mm. Color yellowish brown to reddish brown, some with black elytral maculation. Head: Antennae with short fine pubescence increasing distally. Eyes placed well above labrum. Coronal sulci present, continuous with anterior medial margin of clypeus and not extended beyond dorsoposterior eye margin. Clypeus protuberant, margins well developed, with sparse punctures and hairs. Labrum with medial emargination on distal margin. Thorax: Pronotum lobed or curved laterally, truncate posteriorly, anterior margin entire or shallowly emarginate; margins smooth, posterior margin black; dorsal surface with fine microreticulation of isodiametric meshes, some with sparse micropunctures. Prosternal collar protuberant; prosternal process, smooth, narrow, parallel sided or slightly inflated, tightly interlocked with mesosternum. Metasternum narrowed, 2–3 times wider than long, flat or concave. Elytra inflated into globose dome, margins smooth, elytral suture flat or elevated; explanate margin widest anteriorly and narrowed posteriorly; punctation as dense as or less dense than disc punctation. Hind wings brachypterous or absent. Spermatheca ( Figs. 20– 22 ): well­sclerotized, with pump and receptacle broadly joined. Pump sickle­shaped; apex of pump always with appendix. Receptacle inflated or not. Spermathecal duct and gland open separately into receptacle; duct short with few coils (4–20) or long with many tight coils proximally and looser coils distally.

Key to Species of Elytrogona

1 Body outline continuous ( Figs. 15, 18–19 ) -------------------------------------------------------- 2

1̍ Body outline discontinuous ( Figs. 16–17 ) ---------------------------------------------------------- 3

2 Elytral punctation fine, elytral explanate margin lobed, scutellum not apparent ( Fig. 16 ) ------------------------------------------------------------------------------------------------ E. bulla

2̍ Elytral punctation coarse, elytral explanate margin tapered, scutellum apparent ( Fig. 17 ) ---------------------------------------------------------------------------------------- E. gemmata

3 Elytral maculation absent, elytra uniform brown ( Fig. 15 ) ---------- E. bacca

3̍ Elytral maculation present ---------------------------------------------------------------------------------------- 4

4 Elytral disc black, with brown margin ( Fig. 19 ) ---------------- E. nigrodorsata

4̍ Elytral disc with discoid maculation (10–14), highly variable in size ( Fig. 18 ) -------------------------------------------------------------------------------------- E. quatuordecimmaculata

Figures

Figs. 1–7. 1–2) Profiles, scale bar = 2 mm; 1) Elytrogona gemmata, profile; 2) Stoiba swartzii, profile; 3–7) Elytral punctation, square = 1 mm2; 3) E. bacca; 4). E. bulla; 5) E. gemmata; 6) E. nigrodorsta; 7) E. quatuordecimmaculata. Figs. 8–14. Claw tooth, scale bar = 0.125 mm. 8) E. bacca; 9) E. bulla; 10) E. gemmata; 11) E. nigrodorsata; 12) E. quatuordecimmaculata; 13) Stoiba indivisa; 14) Stoiba swartzii.

Figs. 20–22. Elytrogona spermatheca. 20) E. bulla, scale bar = 0.3 mm; 21) E. gemmata, scale bar = 0.2 mm; 22) E. quatuordecimmaculata, scale bar = 0.2 mm.

Figs. 15–19. Habitus, scale bar = 1 mm. 15) E. bacca; 16) E. bulla; 17) E. gemmata; 18) E. nigrodorsata; 19) E. quatuordecimmaculata.