Ips subelongatus (larch bark beetle)
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Distribution Table
- Risk of Introduction
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Growth Stages
- List of Symptoms/Signs
- Biology and Ecology
- Natural enemies
- Means of Movement and Dispersal
- Pathway Vectors
- Plant Trade
- Wood Packaging
- Impact Summary
- Similarities to Other Species/Conditions
- Prevention and Control
- Links to Websites
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Ips subelongatus (Motschulsky, 1860)
Preferred Common Name
- larch bark beetle
Other Scientific Names
- Ips fallax Eggers, 1915
International Common Names
- English: oblong bark beetle
- Russian: bol'shoi listvennichn'iy koroed; prodolgovatyi koroed
Local Common Names
- Germany: Borkenkäfer, Osteuropäischer Lärchen-
- Japan: Karamashiyashibakikuimushi
- IPSXFA (Ips subelongatus)
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Arthropoda
- Subphylum: Uniramia
- Class: Insecta
- Order: Coleoptera
- Family: Scolytidae
- Genus: Ips
- Species: Ips subelongatus
Notes on Taxonomy and NomenclatureTop of page
DescriptionTop of page
No information available.
Typical Ips larva; see Kalina (1969).
The beetle has an elongated body, 4.5-6.0 mm long. It is brown or dark brown and covered with thick, long, yellow-grey hairs. Frons is covered with small grains, which change into dots on the vertex. Prothorax is not narrower than the elytra. The elytra are about one fifth longer than they are wide. The first half is covered with small denticles, the back half is covered with small dots. There are thick hairs on the front part and sides of the pronotum. The hairs are thin or absent in the middle of the back side. There is no middle strip along the back side of the pronotum. Elytra are characterized by parallel side edges. Their width is equal to the space between the base of the pronotum and the upper edge of the cavity situated on the slope of the elytra (area of thick hairs). Intervals between striae are wide and covered with a number of small thin dots and unclear cross-wrinkles. Sides of elytra and edges of the cavity on their posterior slope are covered with thick long hairs. Hairs of the front and middle parts of elytra are thinner and form small rows on intervals. The cavity is bright and covered with small dots and hairs. There are two hardly visible and isolated small rows formed by hairs close to the suture within the cavity. During the life of the beetles, hairs situated on the cavity break off. There are four well-developed teeth on the edges of each side of the cavity. They are situated the same distance from each other. The third tooth is larger than the others (Stark, 1952).
I. subelongatus is variable morphologically. It is possible to find specimens in the same stand that differ in the length and width ratio of the elytra, in degree of hairiness, in size, and also in the location and number of teeth situated on cavity edges of elytra.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.Last updated: 12 May 2022
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Estonia||Absent, Intercepted only|
|Finland||Absent, Intercepted only|
|-Eastern Siberia||Present, Widespread|
|-Northern Russia||Present, Localized|
|-Russian Far East||Present, Widespread|
|-Western Siberia||Present, Widespread|
|Ukraine||Absent, Formerly present|
Risk of IntroductionTop of page
I. subelongatus also presents a risk to other continents where Larix plantations are exploited, particularly North America.
Appropriate measures would be to require treatment (debarking or kiln-drying) or "pest-free area" for wood, and treatment or "pest-free area" for bark. For plants for planting, which present little risk, only very large plants (above 3 m) might considered ("pest-free place of production"). It may be appropriate to extend the requirement to other, less important hosts (Picea, Pinus).
Fumigation schedules for sulfuryl fluoride and phosphine have been worked out in Japan (Soma et al., 1998). Methyl isothiocyanate has also been tested (Naito et al., 1999).
Hosts/Species AffectedTop of page
Host Plants and Other Plants AffectedTop of page
|Larix gmelinii (Dahurian larch)||Pinaceae||Main|
|Larix kaempferi (Japanese larch)||Pinaceae||Main|
|Larix sibirica (Siberian larch)||Pinaceae||Main|
|Pinus koraiensis (fruit pine)||Pinaceae||Other|
|Pinus sibirica (Siberian stone pine)||Pinaceae||Other|
|Pinus sylvestris (Scots pine)||Pinaceae||Other|
Growth StagesTop of page
SymptomsTop of page
List of Symptoms/SignsTop of page
|Leaves / yellowed or dead|
|Stems / internal feeding|
|Whole plant / internal feeding|
Biology and EcologyTop of page
When attcking impaired but viable trees, I. subelongatus invades the middle and apical parts of the stem first. For larch trees that are dying it prefers to invade the lower stem, which retains the sappy bast for the longest time.
Beetles start to leave winter asylums in the middle of May. Their mass emergence takes place either at the end of this month or in the first 10 days of June. Mass emergence does not exceed three to five days, although some specimens fly to the end of June. The first copulation cells appear at the end of May, the first gallery systems with finished female galleries appear at the beginning of June.
The gallery system of I. subelongatus resembles that of I. sexdentalis, but is smaller in size. Usually, three maternal galleries extend away from the copulation cell in the longitudinal direction. Two of them go in the same direction (up or down).
It is sometimes possible to find gallery systems with two or four maternal galleries. The length of the maternal galleries is usually 13-17 cm, but they sometimes exceed 25 cm.
Females gnaw egg notches on each side of the gallery. They can make over 50 notches in one gallery. Females do not lay eggs in every notch, and a number of the eggs perish; this is why the number of egg notches does not always agree with the number of larval galleries. Nevertheless the number of larval galleries can be very large, so they get entangled or run into a common weaving cavity at a short distance from the female gallery. Isolated larval galleries do not normally exceed 5 cm. Their width close to the egg notch is around 0.7-1.2 mm. Their width at the end part is around 2.5-6 mm.
The first larvae appear in galleries at the end of May. The first pupae appear in the last 10 days of June; the first young beetles appear in pupa cradles at the beginning of July. The second oviposition of hibernated beetles takes place in the first half of July. Then some females of a new second generation start to lay eggs. Pupae of the summer oviposition are found until the beginning of September. I. subelongatus apparently hibernates in the Baikal region and Kazakhstan in the imago stage (Kostin, 1964). In some northern areas of the Amur Region some of the larvae hibernate (Isaev, 1963; Utkin, 1963). In Central Yakutia young beetles which emerged at the end of July or at the beginning of August start to make maternal galleries and lay single eggs. However, emerged larvae perish in the winter (Petrenko, 1965).
Additional feeding by young beetles occurs in places of their development or in isolated single or group galleries. They are found on tops and branches of dead or dying trees, as well as on stems of young growth. These feeding galleries created by the young adult beetles are 3-7 cm long. They extend away from the common entry like a fan, are crowded and almost always penetrate the alburnum.
Some of the adults hibernate in pupa cradles or in the adult feeding galleries. In most cases hibernation takes place in forest litter under the moss cover 4-5 cm thick and in soil (Florov, 1949). Hibernating beetles are found in the soil at the end of August, although at the same time pupae can still be found in the tree.
Natural enemiesTop of page
|Natural enemy||Type||Life stages||Specificity||References||Biological control in||Biological control on|
|Bacillus thuringiensis thuringiensis||Pathogen|
|Cryptaphelenchus diversispicularis||Parasite||Russia; Russian Far East||Larix|
Means of Movement and DispersalTop of page
Pathway VectorsTop of page
Plant TradeTop of page
|Plant parts liable to carry the pest in trade/transport||Pest stages||Borne internally||Borne externally||Visibility of pest or symptoms|
|Bark||arthropods/adults; arthropods/eggs; arthropods/larvae; arthropods/pupae||Yes||Pest or symptoms usually visible to the naked eye|
|Stems (above ground)/Shoots/Trunks/Branches||arthropods/adults; arthropods/eggs; arthropods/larvae; arthropods/pupae||Yes||Pest or symptoms usually visible to the naked eye|
|Plant parts not known to carry the pest in trade/transport|
|Fruits (inc. pods)|
|Growing medium accompanying plants|
|True seeds (inc. grain)|
Wood PackagingTop of page
|Wood Packaging liable to carry the pest in trade/transport||Timber type||Used as packing|
|Solid wood packing material with bark||Yes|
Impact SummaryTop of page
|Fisheries / aquaculture||None|
ImpactTop of page
In Japan (Yamaoka et al., 1998) I. subelongatus has been shown to be associated with several ophiostomatoid fungi, of which Ceratocystis laricicola can weaken and kill larch trees, as in the case of I. cembrae (Redfern et al., 1987).
Similarities to Other Species/ConditionsTop of page
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Control measures include forest management and sanitation: improving the resistance of forests, cutting and elimination of infested trees. Insecticides such as phoxim can be applied to felled "trap trees" on which the beetles have aggregated.
ReferencesTop of page
EPPO, 2004. PQR EPPO plant quarantine information retrieval system. Version 4.3. Paris, France: EPPO.
EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm
Florov DN, 1949. Koroedy chvojnych derebiev Vostochnoi Sibiri. Irkutsk (in Russian).
Gao ChangQi, Sun ShouHui, Ren XiaoGuang, Niu YanZhang, Song LiWen, Zhang YunSheng, 2000. Study on biological and ecological characteristics of Ips subelongatus Motsch. Journal of Forestry Research, 11(2), 114-118.
Gao CQ, Ren XG, Wang DS, Zhang HY, Sun SH, Sun JB, Niu YZ, 1998. Occurrence, regulation and forecasting technique of Ips subelongatus. Journal of Northeast Forestry University, 16:24-28.
Gao CQ, Sun SH, Ren XG, Niu YZ, Song LW, Zhang YS, 2000. Study of biological and ecological characteristics of Ips subelongatus. Journal of Forestry Research, 11:114-118.
Grechkin VP, 1962. Bolshoj listvennychnyi koroed. Zoolo. Zhurna, (4):374-379 (in Russian).
Grüne S, 1979. Handbuch zur bestimmung der Europäischen Borkenkäfer (Brief illustrated key to European bark beetles). Hannover, Germany: Verlag M & H Schapfer.
Gusteleva LA, 1982. Prospects of using microbial preparations against Ips subelongatus. Lesnoe Khozyaistvo, No 9, 67 (in Russian).
Issaev AS, 1966. Borer Pests of Larix dahurica. Moscow, Russia: Nauka.
Issaev AS, Utkin AI, 1963. Nizovye pozhary v listvennichnyh lessah vostochnoi Sibiri i znachenie stvolovyh vreditelei v poslepozharnyom sostoyanii drevostoya. Zashtita lesov ot nasekomyh-vreditelei., Moscow, AN SSSR (in Russian).
Kalina V, 1969. Larvae of European bark beetles (Coleoptera, Scolytidae). Studia Entomologica Forestalia, 1:13-22, 2:41-61.
Kolomiets NG, Bogdanova DA, 1980. Parazity i chishchniki ksilofagov Sibiri. Novosibirsk, USSR: Izdatelstvo "Nauka", Sibirskoe Otdelenie.
Kostin IA, 1964. Stvolovye vrediteli khvoinyh lesov Kazakhstana. Alma-Ata, AN raz.SSR, (in Russian).
Liu ZF, Zhang QH, Chu D, Sun YJ, Sheng MN, Xu SB, Zhang XD, Shao CH, Han SC, 1990. Analysis of the incidence of stem borers in burned forests in Danxinganling Mountains. Forest Pest and Disease, No. 1:38-40
Mamaev BM, 1985. Borer Pests of Forests of Siberia and the Far East. Moscow, Russia: Agropromizdat.
Mamaev BM, 1985. Stvolovye vrediteli lesov Sibiri i Dalnego Vostoka, Moscow, Nauka (in Russian).
Mamaev YuB, 1990. Foci of stem pests in larch forests of the Tuva ASSR damaged by Dendrolimus sibiricus. Izvestiya Vysshikh Uchebnykh Zavedenii Lesnoi Zhurnal, No. 2, 16-19.
Maslov AD, 1988. Guide on Forest Protection against Pests and Diseases. Moscow, "Agropromizdat" (in Russian).
Mozolevskaya EG, Belova NK, Lebedeva GS, 1991. Practical Manual on Forest Entomology. Moscow, Russia: Ekologiya.
Naito H, Soma Y, Matsuoka I, Misumi T, Akagawa T, Mizobuchi M, Kawakami F, 1999. Effects of methyl isothiocyanate on forest insect pests. Research Bulletin of the Plant Protection Service, Japan, No. 35:1-4; 3 ref.
Pavlovskii EN, Shtakelberg AA, et al. , 1955. Forest pests. Guide. Moscow - Leningrad, Edition of Academy of sciences of the USSR, V(2):422-1097 (in Russian).
Qiu HG, Fu WJ, Qi YT, He LF, Ling XD, 1988. Studies on the aggregation pheromone of Ips subelongatus. II. The relationship between aggregation behaviour and its host plant tree. Contributions from Shanghai Institute of Entomology, 8:67-72; 9 ref.
Rozhkov AS, ed. , 1966. Vrediteli listvennitsy sibirskoi. Moscow, "Nauka" (in Russian).
Schneider HJ, 1977. Experience in the control of the large larch bark beetle in stands of low vitality. Allgemeine Forst Zeitschrift, 32:1115-1116.
Shamaev AV, 1994. Guide for Identification of Pests of Forest Tree Trunks, subject to phytosanitary requirements at import in other countries. Syktyvkar, Russia: Viktoriya.
Smith IM, McNamara DG, Scott PR, Holderness M, 1997. Quarantine pests for Europe. Second Edition. Data sheets on quarantine pests for the European Union and for the European and Mediterranean Plant Protection Organization. Quarantine pests for Europe. Second Edition. Data sheets on quarantine pests for the European Union and for the European and Mediterranean Plant Protection Organization., Ed. 2:vii + 1425 pp.; many ref.
Soma Y, Oogita T, Misumi T, Kawakami F, 1998. Effect of gas mixtures of sulfuryl fluoride and phosphine on forest insect pests. Research Bulletin of the Plant Protection Service, Japan, No. 34:11-14; 7 ref.
Stark VN, 1952. Korojedi (bark beetles). In: Fauna SSSR. Moskow, Leningrad, SSSR: Public. Acad. Sc. USSR, 31:95-461.
Vorontsov AI, 1975. Lesnaya entomologiya. Moscow. pp. 312.
Vorontsov AI, 1995. Forest Entomology. Manual for Universities. Moscow, Ecologia (in Russian).
Yamaoka, Y., Chung WenHsin, Masuya, H., Hizai, M., 2009. Constant association of ophiostomatoid fungi with the bark beetle Ips subelongatus invading Japanese larch logs. Mycoscience, 50(3), 165-172. doi: 10.1007/s10267-008-0468-7
Yanovskii, V. M., Kiselev, V. V., 1975. The role of biotic factors in regulating the numbers of the large larch bark-beetle. Izvestiya Sibirskogo Otdeleniya Akademii Nauk SSSR, Biologicheskikh Nauk, (No.5 (1)), 48-54.
Yuan Fei, Luo YouQing, Shi Juan, Keliövaara, K., Qi GuoXin, Li XiangJun, Han YongShi, Chen Chao, 2008. Invasive sequence and ecological niche of main insect borers of Larix gmelinii forest in Aershan, Inner Mongolia. Forestry Studies in China, 10(1), 9-13. doi: 10.1007/s11632-008-0014-x
Zhang QH, Birgersson G, Schlyter F, Chen GF, 2000. Pheromone components in the larch bark beetle Ips cembrae from China: quantitative variation among attack phases and individuals. Journal of Chemical Ecology, 26:841-858.
Zhang QingHe, Schlyter, F., Chen GuoFa, Wang YanJun, 2007. Electrophysiological and behavioral responses of Ips subelongatus to semiochemicals from its hosts, non-hosts, and conspecifics in China. Journal of Chemical Ecology, 33(2), 391-404. doi: 10.1007/s10886-006-9231-8
Zhang QingHe, Tolasch, T., Schlyter, F., Francke, W., 2002. Enantiospecific antennal response of bark beetles to spiroacetal (E)-conophthorin. Journal of Chemical Ecology, 28(9), 1839-1852. doi: 10.1023/A:1020569303433
Zhou XiuHua, Song RuiQing, Cao Cui, Cui Lei, Liang XiaoDong, Pan JianZhong, Zhu YuanJin, Hu ZhenYu, 2011. Identification and biological and physiological characteristics of 3 fungus strains associated with Ips subelongatus. Scientia Silvae Sinicae, 47(5):82-86. http://lyke.chinajournal.net.cn
Zhou XiuHua, Song RuiQing, Zhou XuDong, Cui Lei, Cao Cui, 2011. Fungal population in the inside and outside of Ips subelongatus body and the gallary of insect-bored larch logs. Mycosystema, 30(3):400-407. http://journals.im.ac.cn/jwxtcn
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Gao ChangQi, Sun ShouHui, Ren XiaoGuang, Niu YanZhang, Song LiWen, Zhang YunSheng, 2000. Study on biological and ecological characteristics of Ips subelongatus Motsch. Journal of Forestry Research. 11 (2), 114-118.
Liu Z F, Zhang Q H, Chu D, Sun Y J, Sheng M N, Xu S B, Zhang X D, Shao C H, Han S C, 1990. Analysis of the incidence of stem borers in burned forests in Danxinganling Mountains. Forest Pest and Disease. 38-40.
Liu Z F, Zhao B Y, Zhao S F, Sheng M L, Zhang Q H, Cui Z Q, Chu D, Sun Y J, Xu S B, Zhang X D, 1989. A report on monitoring stem borers in burned areas in Daxinganling Mountain. Forest Science and Technology. 12-15.
Paciura D, Beer Z W de, Jacobs K, Zhou X D, Ye H, Wingfield M J, 2010. Eight new Leptographium species associated with tree-infesting bark beetles in China. Persoonia. 94-108. DOI:10.3767/003158510X551097
Seebens H, Blackburn T M, Dyer E E, Genovesi P, Hulme P E, Jeschke J M, Pagad S, Pyšek P, Winter M, Arianoutsou M, Bacher S, Blasius B, Brundu G, Capinha C, Celesti-Grapow L, Dawson W, Dullinger S, Fuentes N, Jäger H, Kartesz J, Kenis M, Kreft H, Kühn I, Lenzner B, Liebhold A, Mosena A (et al), 2017. No saturation in the accumulation of alien species worldwide. Nature Communications. 8 (2), 14435. http://www.nature.com/articles/ncomms14435
Song LiWen, Zhang QingHe, Chen YueQu, Zuo TongTong, Ren BingZhong, 2011. Field responses of the Asian larch bark beetle, Ips subelongatus, to potential aggregation pheromone components: disparity between two populations in northeastern China. Insect Science. 18 (3), 311-319. DOI:10.1111/j.1744-7917.2010.01375.x
Yamaoka Y, Chung WenHsin, Masuya H, Hizai M, 2009. Constant association of ophiostomatoid fungi with the bark beetle Ips subelongatus invading Japanese larch logs. Mycoscience. 50 (3), 165-172. DOI:10.1007/s10267-008-0468-7
Yang Z, Gu Y, Song Y, 2003. A new species in the genus Ropalophorus Curtis (Hymenoptera: Braconidae) from China, parasitizing adults of the bark beetle Ips subelongatus (Coleoptera: Scolytidae), with a key to world species of the genus. Zoologische Mededelingen. 77 (15-36), 631-636.
Yuan Fei, Luo YouQing, Shi Juan, Keliövaara K, Qi GuoXin, Li XiangJun, Han YongShi, Chen Chao, 2008. Invasive sequence and ecological niche of main insect borers of Larix gmelinii forest in Aershan, Inner Mongolia. Forestry Studies in China. 10 (1), 9-13. DOI:10.1007/s11632-008-0014-x
Zhang QingHe, Schlyter F, Chen GuoFa, Wang YanJun, 2007. Electrophysiological and behavioral responses of Ips subelongatus to semiochemicals from its hosts, non-hosts, and conspecifics in China. Journal of Chemical Ecology. 33 (2), 391-404. DOI:10.1007/s10886-006-9231-8
Zhang QingHe, Tolasch T, Schlyter F, Francke W, 2002. Enantiospecific antennal response of bark beetles to spiroacetal (E)-conophthorin. Journal of Chemical Ecology. 28 (9), 1839-1852. DOI:10.1023/A:1020569303433
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