Ips subelongatus, frons
Ips subelongatus, declivity
Ips subelongatus, lateral habitus

Scientific Name

Ips subelongatus (Motschulsky, 1860)

Synonyms

Common names: larch bark beetle, oblong bark beetle (English)

Diagnostic notes

-Has four spines on the elytral declivity; spine 3 petiolate, obtuse to right angled; spine 1 about equidistant from second spine and elytral suture; surface of elytral declivity shiny; elytral interstriae punctate throughout on disc.
-Frons densely tuberculate without central tubercle, central carina, or central fovea.
-Most specimens are distinguished by their large size (5-7 mm) from  morphologically similar North American Picea-feeding species (I. borealis, I. perterbatus, I. pilifrons, I. tridens) and from I. cembrae, which are usually only 3 to 5 mm. 
This species is distinguished from most I. typographus by the shiny elytral declivity and presence of interstrial punctures of the elytral disc, and from I. stebbingi by more densely tuberculate frons.

Morphological Summary

sexes combined
Body. 4.2-6.5 mm long, 2.6 times longer than wide; pronotum 1.1-1.2 times longer than wide.
Head. Epistomal margin with uniseriate row of tubercles 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; central tubercle absent, without pair of circular tubercles on either side of midline; transverse carina absent; frons central fovea absent; circular tubercles above top of eyes present - up to, or more than one third of all tubercles. Vertex and pronotum without stridulatory apparatus (pars stridens). Antennal club sutures bisinuate.
Prothorax. Protibiae with three socketed teeth on apical half (does not include apical spine).
Elytra. Interstriae punctate (observed on interstriae 2 and 3 on middle third of elytral disc), punctures 0.3-0.5 times diameter of adjacent strial punctures (punctures and striae measured at steepest part of puncture wall), interstrial setae shorter than width of scutellar shield or longer than width of scutellar shield, interstriae 3-5 times as wide as adjacent striae. Elytral declivity with four spines per side, spine 3 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; spine 3 pedunculate (capitate), apex right-angled or obtuse to rounded, with apical half asymmetrical in lateral view; spines 2 and 3 not on shared tumescence, not in line with spines 1 and 4 (posterodorsal view); declivital integument shiny.

Geographic Distribution

China (Heilongjiang, Henan, Hubei, Inner Mongolia, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, Xinjiang); Japan; Mongolia; North Korea; Russia (eastern (native) and western (introduced)); South Korea; Taiwan.

Hosts

Larix spp. (also Abies, Picea, Pinus)

Notes

I. cembrae, I. subelongatus, and I. woodi form clade (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.

EPPO. No date. Data Sheets on Quarantine Pests: Ips cembrae and Ips subelongatus. European and Mediterranean Plant Protection Organization. 

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/141798