Acontosceles Champion, 1924

Yoshitomi, Hiroyuki, 2019, Review of the Asian Thaumastodinae (Coleoptera, Byrrhoidea, Limnichidae), with a phylogeny of the genera, European Journal of Taxonomy 583, pp. 1-45 : 6-7

Genus Acontosceles Champion, 1924

Acontosceles Champion, 1924a: 27 (type species: Acontosceles hydroporoides Champion, 1924 ).

Diagnosis

Body elongate. Gena wide; antennal groove absent. Antennae slender, relatively long, 11-segmented; antennal insertions situated near eyes. Legs long and slender; tarsal formula 4-5-5.

Remarks

This genus was subdivided into two species groups by Pütz (2008) mainly based on the male genital characters. However, the points differentiating the two groups are obvious and quantitative features (see also Yoshitomi & Putra 2011), and so the species-group concept needs to be revised.

Biological notes

The habitat of this genus ( Fig. 4A ) is freshwater environments, i.e., waterfalls (type locality of A. chujoi Yoshitomi & Satô, 2005 ), rivers and streams. The adults are found on wet rocks or actively flying. The larval stages are unknown.

Key to the males of the species of Acontosceles

1. Basal piece distinctly curved ventrally, expanded in basal part; parameres long and curved ventrally, minutely serrate on dorso-lateral margins in some species; body shape elongate to oblong-oval; legs relatively long; Japan to India, Indonesia....................................2 ( A. hydroporoides species group)

– Basal piece slightly curved ventrally, not expanded in basal part; parameres short and almost straight, lacking serrae on dorso-lateral margins; body shape oblong-oval; legs relatively short; Indochina to Himalayas ...................................................................9 ( A. quatuordecimmaculosus species group)

2. Aedeagus distinctly curved (about 90–100°) ventrally in basal piece............................................... 5

– Aedeagus gently curved (about 120°) ventrally in basal piece.......................................................... 3

3. Lateral lobes serrate on dorso-lateral margins................................................................................... 4

– Lateral lobes lacking serrae on dorso-lateral margins .................. A. hydroporoides Champion, 1924

4. Basal piece slightly expanded in basal part; Indochina ................. A. chujoi Yoshitomi & Satô, 2005

– Basal piece robust, expanded in basal part; Japan and Taiwan............................ A. yorioi Satô, 1966

5. Lateral lobes serrate on dorso-lateral margins................................................................................... 6

– Lateral lobes lacking serrae on dorso-lateral margins; Philippines........... A. negrosensis Pütz, 2008

6. Basal piece robust, expanded in basal part ........................................................................................ 7

– Basal piece slightly expanded in basal part; Borneo ........................................ A. borneensis sp. nov.

7. Basal piece curved in middle part...................................................................................................... 8

– Basal piece curved in caudal part; Philippines.................................................... A. jaechi Pütz, 2008 8. Lateral lobes shorter; Indonesia.............................................. A. javanicus Yoshitomi & Putra, 2011

– Lateral lobes longer; Philippines................................................................ A. tagalog Spilman, 1959

9. Apex of lateral lobes wide and truncate, with small denticles on lateral margins........................... 10

– Apex of lateral lobes pointed, lacking denticles...............................................................................11

10. Lateral margins of lateral lobes gently arcuate in dorsal view; Nepal....... A. siwalikensis Pütz, 2008

– Lateral margins of lateral lobes straight in dorsal view; Thailand and Laos....... A. zetteli Pütz, 2008

11. Basal piece relatively long; lateral lobes slightly curved in apical parts; Myanmar........................... .............................................................................................. A. quatuordecimmaculosus Pütz, 2008

– Basal piece relatively short; lateral lobes curved ventrally in apical parts; China.............................. .................................................................................................................. A. yunnanensis Pütz, 2008

Figures

Fig. 4. Habitats (A–C) and living adults (D–F) of Asian Thaumastodinae Champion, 1924. A. Dondong River, Pengkol, Yogyakarta special Region, Java, Indonesia (type locality of Acontosceles javanicus Yoshitomi & Putra, 2011 (F) and Pseudeucinetus javanicus Yoshitomi & Putra, 2010 (D)). B. Nusa Dua, Bali, Indonesia (type locality of Mexico baliensis sp. nov.). C. Hirashima, Ogasawara, Japan (type locality of Mexico ogasawaraensis sp. nov.). D. Type locality of Pseudeucinetus javanicus Yoshitomi & Putra, 2010. E. Mexico masamii (Satô, 1994) in Shikinejima, Izu Islands. F. Type locality of Acontosceles javanicus Yoshitomi & Putra, 2011.