Stenothemus Bourgeois 1907
Creators: name: Yang, Yuxia
name: Ge, Shujuan
name: Yang, Xingke
name: Liu, Haoyu
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Cantharidae
Stenothemus

description: Key to the species of Stenothemus from Southwest China
1. Pronotum subrounded, with protruding and acute posterior angles ................................................. 2
– Pronotum subquadrate, with nearly rectangular and obtuse posterior angles .................................. 7
2. Elytra yellow, with irregular dark brown markings .......................................................................... 3
– Elytra yellow or brown, without dark markings ............................................................................... 4
3. Aedeagus (Fig. 2G‒I): ventral process of each paramere nearly parallel to dorsal plate in lateral view, laterophyses feebly exceeding middle emargination between dorsal plates; female reproductive system (Fig. 4C): spermathecal duct very long, slightly longer than diverticulum ............................ .................................................................................................................... S. diffusus Wittmer, 1974
– Aedeagus (Fig. 6A‒C): ventral process of each paramere at an obvious angle to dorsal plate in lateral view, laterophyses clearly exceeding middle emargination between dorsal plates; female reproductive system (Fig. 8A): spermathecal duct moderately long, much shorter than diverticulum .............................................................................................. S. grahami Wittmer, 1974
4. Aedeagus: dorsal plate of each paramere acute at apex .................................................................... 5
– Aedeagus: dorsal plate of each paramere rounded at apex ............................................................... 6
5. Body larger, more than 7.5 mm in length; aedeagus (Švihla 2004: figs 155‒156): apical part of dorsal plate strongly narrowed, middle emargination between dorsal plates very deep, longer than half its length .............................................................................................................. S. jindrai Švihla, 2004
– Body smaller, 6.6 mm in length; aedeagus (Fig. 10G‒I): apical part of dorsal plate slightly narrowed, middle emargination between dorsal plates moderately deep, nearly as long as half its length ........ ...................................................................................... S. jindraimimus Y. Yang & X. Yang sp. nov.
6. Body yellow, pronotum darkened at anterior angles; aedeagus (Švihla 2004: figs 161‒163): dorsal plates of parameres separated from each other, ventral process of each paramere slightly thickened apically ............................................................................................................. S. benesi Švihla, 2004
– Body brown, pronotum lightened at anterior angles; aedeagus (Fig. 2A‒C): dorsal plates of parameres approaching each other, ventral process of each paramere distinctly thickened apically .................. ............................................................................................... S. shaanxiensis Švihla, 2004 stat. nov.
7. Body uniformly black (Fig. 1E) ..................................................................... S. dundai Švihla, 2004
– Body at least bicolored ..................................................................................................................... 8
8. Pronotum distinctly widened anteriorly; aedeagus (Fig. 6D‒F): dorsal plates of parameres conjoined, with a rounded emargination in middle of apical margin .... S. minutissimus (Pic, 1933) comb. nov.
– Pronotum nearly parallel-sided; aedeagus: dorsal plates of parameres separated ............................ 9
9. Middle antennomeres without smooth impressions in males ......................................................... 10
– Middle antennomeres with smooth impressions in males ...............................................................11
10. Head, pronotum and scutellum testaceous, elytra yellow .... S. singularicollis (Pic, 1933) comb. nov.
– Head and pronotum black brown, scutellum yellow, elytra black (Fig. 5C) .. S. tryznai Švihla, 2004
11. Antennae flattened or thickened, very long, almost reaching apices of elytra in males ................. 12
– Antennae simple filiform, moderately long, at most extending to ¾ length of elytra in males ...... 13
12. Antennomeres IV‒XI flattened; aedeagus (Fig. 11A‒C): ventral process distinctly thickened apically, bent dorsally in lateral view; apex of laterophyses exceeding middle emargination between dorsal plates ..................................................................................... S. laticornis Y. Yang & H. Liu sp. nov.
– Antennomeres IV‒XI cylindrically thickened; aedeagus (Fig. 10A‒C): ventral process slightly narrowed apically, bent ventrally in lateral view; apex of laterophyses not reaching middle emargination between dorsal plates ............................ S. chongqingensis Y. Yang & H. Liu sp. nov.
13. Pronotum yellow, nearly as long as wide; aedeagus (Fig. 10D‒F): lateroapical part of dorsal plate longitudinally ridged; female reproductive system (Fig. 12C): diverticulum and spermatheca extremely long, diverticulum much shorter than spermatheca ........................................................... ................................................................................................. S. flavicollis Y. Yang & S. Ge sp. nov.
– Pronotum reddish brown or black, distinctly longer than wide; aedeagus: dorsal plate not ridged; female reproductive system: diverticulum and spermatheca moderately long, diverticulum much or slightly longer than spermatheca .................................................................................................... 14
14. Aedeagus (Fig. 2D‒F): ventral process of each paramere moderately long, apex of laterophyses not reaching middle emargination between dorsal plates; abdominal sternite VIII (Fig. 3B): lateroapical angles widely rounded, posterior margin roundly emarginate in middle, sclerotized membrane simple, without rectangular longitudinal sclerite ............................. S. davidi (Pic, 1926) comb. nov.
– Aedeagus (Fig.6G‒I): ventral process of each paramere short, apex of laterophyses clearly exceeding middle emargination between dorsal plates; abdominal sternite VIII (Fig. 7D): lateroapical angles triangular and protruding, posterior margin rectangularly emarginate in middle, sclerotized membrane with a rectangular sclerite present at center and a small longitudinal sclerite on each side ............... ................................................................................................ S. gracilis Y. Yang & X. Yang sp. nov.
Note
Stenothemus kansuensis Pic, 1933 is not included in the key because the type was not located by us.
description: Published as part of Yang, Yuxia, Ge, Shujuan, Yang, Xingke & Liu, Haoyu, 2021, Taxonomic revision of the species of Stenothemus from Southwest China (Coleoptera, Cantharidae), with the descriptions of five new species, pp. 1-36 in European Journal of Taxonomy 757 (1) on pages 32-34, DOI: 10.5852/ejt.2021.757.1409, http://zenodo.org/record/5033100