Stenhomalus (Stenhomalus) japonicus (Pic, 1904)
[= Obrium japonicum Pic, 1904]
[= Stenhomalus lighti Gressitt, 1935]
[= Stenhomalus vulcanus Tsherepanov et Tsherepanova, 1976]

Subfamilia: CERAMBYCINAE  /  Tribus: OBRIINI
Stenhomalus japonicus
[Photo © David Navrátil, click on the picture for 4K resolution]

Stenhomalus japonicus, a species occuring in Russian Far East and Japan, has been described from Sado Island (Niigata Prefecture, Japan) as Obrium japonicum by Maurice Pic in 1904 [❖]. S. japonicus is one of the most taxonomically problematic East Palaearctic species of the Stenhomalini tribe. Taxon was included in the genus Obrium for a long time (followed the original description) and its true systematic position in Stenhomalus genus (Stenhomalini tribe) as the result of reexamination of holotype was published by Tatsuya Niisato in 2006 [✧]. Moreover, the names S. lighti Gressitt, 1935 and S. vulcanus Tsherepanov et Tsherepanova, 1976 were suggested as junior synonyms of this taxon [☆][▾].

S. japonicus is a polyphagous species, its larvae develop in dying twigs of many deciduous trees and shrubs. Larvae feed in bark, then subcortically along shoot, plugging gallery deeply impressed on sapwood with a fine frass. Mature larvae enter the wood at end of gallery (up to 16 cm long), make hook-shaped pupal cell along twig at a depth of 4 - 10 mm and plug inlet with frass. Pupation and hatching during late summer / early autumn, young beetles overwinter in pupal cells. Life-cycle 2 year [▽].

Body length:4.4 - 9 mm
Life cycle:2 years
Adults in:May - August
Host plant:polyphagous in deciduous shrubs and trees (e.g. Cornus, Sydonia, Phellodendron)
Distribution:Russian Far East, Japan

The depicted beetle was reared from larva found on Mt. Tachibanayama (Fukuoka City environs, Fukuoka prefecture, Kyushu, Japan) in 1967.

Collected by Takahisa Watanabe

Pic M.:
Description d'un Obrium du Japon et note de chasse.
Matériaux pour servir à l'étude des Longicornes 5 (1): 22, 1904. [download pdf icon].

Niisato T.:
Taxonomic Disorder of Obrium japonicum (Coleoptera, Cerambycidae) and its Allied Species.
Elytra 34 (2): 379-395, 2006. [download pdf icon].

Niisato T. and Kinoshita T.:
Rediscovery of Stenhomalus japonicus (Coleoptera, Cerambycidae) from Island of Sado of Type Locality.
Elytra 37 (1): 69-70,, 2007. [download pdf icon].

Miroshnikov A.I.:
Little known species of longicorn beetles (Coleoptera: Cerambycidae) from the Russian Far East.
[ Малоизвестные виды жуков-дровосеков (Coleoptera: Cerambycidae) Дальнего Востока России.]
Proceedings of the Russian Entomological Society, St. Petersburg 77: 226–234, 2006. [download pdf icon]

Cherepanov A.I.:
Cerambycidae of Northern Asia, Volume 2 - Cerambycinae Part I.
Amerind Publishing, New Delhi: 304pp [pages 49-54 as Stenhomalus vulcanus], 1988. [download pdf icon]

SubfamiliaCerambycinae Latreille, 1802
TribusObriini Mulsant, 1839
GenusStenhomalus White, 1855
SubgenusStenhomalus White, 1855
SpeciesStenhomalus (Stenhomalus) japonicus (Pic, 1904)