Gyrinidae
Creators: name: Suksai, Benjamart
name: Gustafson, Grey T.
name: Sites, Robert W.
name: Sangpradub, Narumon
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Gyrinidae

description: Key to the tribes and genera of adult Gyrinidae in Thailand,
including species of adult Gyrinini and Dineutini
1 Dorsal surface of pronotum and elytron with pubescence; abdominal sternite VIII narrow and long....... Orectochilini, 2
- Dorsal surface of pronotum and elytron completely glabrous (Figs. 1A–H); abdominal sternite VIII broad and short....... 3
2 Antenna with six flagellomeres; surface of pronotum and elytron with glabrous regions medially and pubescence marginally............................................................................................... Patrus
- Antenna with nine flagellomeres; surface of pronotum and elytron without glabrous regions, entirely covered with pubescence.................................................................................... Orectochilus
3 Size smaller, length <6.0 mm; pronotum with median transverse depression; scutellum visible; elytron with 11 longitudinal striae (Figs. 1A–B, 2A–B).............................................................. Gyrinini, Gyrinus, 4
- Size larger, length 6.0–17.0 mm; pronotum without median transverse depression; scutellum not visible (Figs. 1C–H); elytron without evident longitudinal striae.............................................................. Dineutini, 5
4 Dorsally metallic in appearance lateral sides of elytra with bronzy sheen (Fig. 1A), intervals VI–X not sulcate............................................................................................ Gyrinus sericeolimbatus
- Dorsally iridescent in appearance (Fig. 1B); lateral sides of elytra without bronzy sheen, intervals VI–X strongly sulcate (Fig. 2B)............................................................................... Gyrinus smaragdinus
5 Labrum short and broad, not triangular in form (Figs. 1C–G); apex of protibia without spine................ Dineutus, 6
- Labrum long and triangular in form (Fig. 1H); apex of protibia with spine (Fig. 1H)......... Porrorhynchus marginatus
6 Size smaller, length 6.0– 8.2 mm; profemur of males without sub-apicoventral tooth; protibia wedge-shaped; elytral apices variously shaped........................................................................................ 7
- Size larger, length 13.4–17.0 mm; profemur of males with sub-apicoventral tooth; protibia club-shaped; elytral apices rounded (Figs. 1E, 5F).................................................................................. D. sitesi
7 Apex of flagellomere VI darkly colored; elytral apices without parasutural spines; lateral margin of pronotum and elytron black.............................................................................................. 8
- Apex of flagellomere VI lightly colored; elytral apices with parasutural spines (Figs. 1F, 5J); lateral margin of pronotum and elytron orange or yellow...................................................................... D. spinosus
8 Size smaller, length 6.0– 6.9 mm; body form narrowly oval; elytral apices with epipleural spines (Figs. 1G, 6A) evident in both sexes; elytral apex truncate and straight (Figs. 1G, 6A); protrochanter of male apically without patch of thick setae on ventral surface (Fig. 4D)......................................................................... D. unidentatus
- Size larger, length 7.6–8.2 mm; body form oval; elytral apices of male only with epipleural spines (Figs. 1C, 5A), female without epipleural spines (Figs. 1D, 5B); elytral apex obliquely truncate (Figs. 1C–D, 5A–B); protrochanter of male apically with patch of thick setae on ventral surface (Fig. 4A).................................................... D. australis
description: Published as part of Suksai, Benjamart, Gustafson, Grey T., Sites, Robert W. & Sangpradub, Narumon, 2021, The Gyrinidae (Coleoptera) fauna of Thailand: Key to tribes and genera, with new records and keys to species of Dineutini and Gyrinini, pp. 97-117 in Zootaxa 5071 (1) on page 114, DOI: 10.11646/zootaxa.5071.1.5, http://zenodo.org/record/5723327