Ips sexdentatus, male frons
Ips sexdentatus, male frons
Ips sexdentatus, female frons
Ips sexdentatus, male elytral disc
Ips sexdentatus, male declivity
Ips sexdentatus, male declivity
Ips sexdentatus, female declivity
Ips sexdentatus, male lateral habitus

Scientific Name

Ips sexdentatus (Boerner, 1767)

Synonyms

Bostrichus pinastri Bechstein, 1818

Bostrichus stenographus Duftschmid, 1825

Ips junnanicus Sokanovskiy, 1959

Common names: six-toothed bark beetle (English); stenographe (French); grosser 12-zähniger iefernborkenkäfer (German); tolvtannet barkbille (Norwegian)

Diagnostic notes

-Has six spines on the elytral declivity.
-Differs from all other Ips spp. by having the largest spine in the fourth position.
-Is unlike North American six-spined species I. calligraphus and I. apache, which have the largest spine in the third position.

Morphological Summary

females
Body. (5.0-)7.0-8.0 mm long, 2.6-2.8 times longer than wide; pronotum 1.1-1.2 times longer than wide.
Head. Epistomal margin with uniseriate row of tubercles uninterrupted medially, with elongate mesal tubercle or with gap at midline. Frons outline convex in lateral view; vestiture fine (not hiding part of integument); surface sculpture near epistoma densely tuberculate-punctate; central carina present or absent; central tubercle absent or present and single, separated from base of epistomal setae by 2-4(-5) tubercle diameters, without pair of circular tubercles on either side of midline; transverse carina present, impunctate; frons central fovea present; circular tubercles above top of eyes present - up to, or more than one third of all tubercles. Vertex and pronotum with stridulatory apparatus (pars stridens). Antennal club sutures bisinuate.
Prothorax. Protibiae with four or five socketed teeth on apical half (does not include apical spine).
Elytra. Interstriae impunctate (observed on interstriae 2 and 3 on middle third of elytral disc), interstriae 2(-3) times as wide as adjacent striae. Elytral declivity with six spines per side, spine 4 largest; spine 1 (largest on 2nd interstria) closer to spine 2 than suture or suture than spine 2; spines 1 and 2 separated at base by distance less or greater than height of spine 1; spine 2 closer to spine 1 than spine 3 or 3 than spine 1; spine 3 tapered, apex acute, with apical half symmetrical in lateral view; spines 2 and 3 not on shared tumescence, not in line with spines 1 and 4 (posterodorsal view); spine 4 closer to spine 3 than spine 5; declivital integument shiny.

males
Body. (5.0-)7.0-8.0 mm long, 2.6-2.8 times longer than wide; pronotum 1.1-1.2 times longer than wide.
Head. Epistomal margin with uniseriate row of tubercles uninterrupted medially, with elongate mesal tubercle or with gap at midline. Frons outline convex in lateral view; vestiture fine (not hiding part of integument); surface sculpture near epistoma densely tuberculate-punctate; central carina present or absent; central tubercle present and single, separated from base of epistomal setae by 1-3 tubercle diameters, without pair of circular tubercles on either side of midline; transverse carina present, impunctate; frons central fovea present or absent; circular tubercles above top of eyes present - up to, or more than one third of all tubercles. Vertex and pronotum with stridulatory apparatus (pars stridens). Antennal club sutures bisinuate.
Prothorax. Protibiae with four socketed teeth on apical half (does not include apical spine).
Elytra. Interstriae impunctate (observed on interstriae 2 and 3 on middle third of elytral disc), interstriae 2(-3) times as wide as adjacent striae. Elytral declivity with six spines per side, spine 4 largest; spine 1 (largest on 2nd interstria) closer to spine 2 than suture or suture than spine 2; spines 1 and 2 separated at base by distance less or greater than height of spine 1; spine 2 closer to spine 1 than spine 3 or 3 than spine 1; spine 3 tapered or straight sided with tapered apex, apex acute, with apical half symmetrical in lateral view; spines 2 and 3 not on shared tumescence, not in line with spines 1 and 4 (posterodorsal view); spine 4 closer to spine 3 than spine 5; declivital integument shiny.

Geographic Distribution

Austria; Belarus; Belgium; Bosnia-Herzegovina; Bulgaria; China (Gansu, Hebei, Heilongjiang, Henan, Hubei, Inner Mongolia, Jilin, Liaoning, Qinghai, Sichuan, Shaanxi, Shanxi, Yunnan); Corsica; Croatia; Czechia; Denmark; Estonia; Finland; France; Germany; Great Britain; Greece; Hungary; Italy; Japan; Kazakhstan; Latvia; Lithuania; Luxembourg; Macedonia; Moldova; Mongolia; Montenegro; Myanmar; The Netherlands; Norway; North Korea; Poland; Portugal; Romania; Russia (throughout); Serbia; Slovakia; Slovenia; South Korea; Spain; Sweden; Switzerland; Thailand; Turkey; Ukraine.

Hosts

Larix, Picea, and Pinus spp.

Notes

Clade formed by ((I. emarginatus + I. knausi) + I. sexdentatus), see Cognato and Sun (2007).

References

Cognato, A.I.2015. Biology, systematics, and evolution of Ips. In Bark beetles: biology and ecology of native and invasive species. Edited by F.E. Vega and R.W. Hofstetter. Elsevier, San Diego, California. Pp. 351–370.

Cognato, A.I. and Sun, J.H. 2007. DNA based cladograms augment the discovery of a new Ips species from China (Coleoptera: Curculionidae: Scolytinae). Cladistics, 23: 539–551.

EPPO. No date. Data Sheets on Quarantine Pests: Ips sexdentatus. European and Mediterranean Plant Protection Organization. 3 pp.

Grüne, S. 1979. Brief illustrated key to European bark beetles. Hannover, Germany, M. and H. Schaper.

Knížek M. 2011. Scolytinae. In Catalogue of Palaearctic Coleoptera, Vol. 7. Edited by I. Löbl and A. Smetana. Apollo Books, Stenstrup, Denmark,  Pp. 204–251.

Internet resources

http://www.padil.gov.au/pests-and-diseases/pest/main/135617