Tremex fuscicornis (Tremex wasp)
- 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
- Notes on Natural Enemies
- Plant Trade
- Wood Packaging
- Environmental Impact
- Detection and Inspection
- Similarities to Other Species/Conditions
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Tremex fuscicornis (Fabricius, 1787)
Preferred Common Name
- Tremex wasp
Other Scientific Names
- Sirex camelogigas Christ
- Sirex fuscicornis Fabricius
- Sirex struthiocamelus Villers
- Tremex juxicernis Walker
- Tremex simulacrum Takeuchi
- Urocerus fuscicornis Latreille
- Xyloecematium fuscicornis Heyden
- Xyloterus fuscicornis Boie
International Common Names
- Spanish: avispa taladradora de la madera
Local Common Names
- Finland: ampiaspuupistiäinen
- TREXFU (Tremex fuscicornis)
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Arthropoda
- Subphylum: Uniramia
- Class: Insecta
- Order: Hymenoptera
- Family: Siricidae
- Genus: Tremex
- Species: Tremex fuscicornis
Notes on Taxonomy and NomenclatureTop of page
DescriptionTop of page
Siricidae wasp eggs are cylindrical, creamy-white and approximately 1 mm long.
The mature larvae are on average 3 cm long. However, some individuals can reach 4 cm. They are creamy-white, with short antennae, distinct mandibles and three pairs of rudimentary legs that are approximately 0.5 mm long. The last abdominal segment has a distinct, dark spine.
The pupae are on average 3 cm long and white when they first form. They become darker prior to adult development. The pupae have distinct antennae and fully developed legs.
The adult males are completely black, including the antennae and legs. The wings are amber and much darker than the wings of the female. The females are larger than the males with a dark head and thorax. The abdomen has bands of alternating black and amber, with a long ovipositor on the last abdominal segment (Baldini, 2002; CSIRO, 2002).
DistributionTop of page
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: 15 Dec 2020
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|-Russian Far East||Present||Native|
|-New South Wales||Present||Introduced||Invasive|
Risk of IntroductionTop of page
A major concern in South America is that because Fagus spp. (beeches) are hosts within this insect's natural range, southern beeches, Nothofagus spp. are potential hosts. Several species of Nothofagus are important economic and ecological components of approximately 12 million ha of natural forests in central and southern Chile (Baldini, 2002). A similar situation exists in the Andean region of central and southern Argentina.
HabitatTop of page
Hosts/Species AffectedTop of page
T. fuscicornis was introduced in Australia after 1996 and its hosts include poplars, Populus spp. and willows, Salix spp. In Chile, where it has recently become established, T. fuscicornis attacks Populus alba (white poplar), Populus deltoides (eastern cottonwood), Populus nigra (black poplar), Salix babylonica (weeping willow), Salix humboldtiana (Humboldt willow), Acer negundo (box-elder) and Robinia pseudoacacia (black locust) (Baldini, 2002).
Host Plants and Other Plants AffectedTop of page
Growth StagesTop of page
SymptomsTop of page
List of Symptoms/SignsTop of page
|Leaves / wilting|
|Leaves / yellowed or dead|
|Stems / internal feeding|
|Stems / visible frass|
|Whole plant / plant dead; dieback|
Biology and EcologyTop of page
T. fuscicornis is a wood wasp in the family Siricidae. Wood wasp larvae bore into the wood of trees and live in a symbiotic relationship with wood-decaying fungi, which partially break down the cellulose before the larvae can use it for food. The genus Tremex contains several species of wood wasps that are indigenous to Eurasia and North America, and infest broadleaf trees. The pigeon tremex, Tremex columba, is found in North America, where it is widely distributed in Canada and the USA. It infests dead or weakened broadleaf trees. This insect is considered to be the most abundant member of the Siricidae in North America (Drooz, 1985; Smith and Schiff, 2002).
Relatively little is known about the life history and habits of T. fuscicornis in its native habitat. A report from Finland suggests that the symbiotic fungus associated with this insect may be Bjerkandera fumosa (Savela, 1998).
Some biological data are available from Chile where it has recently become established (Baldini, 2002). The females use their long ovipositor to deposit eggs in the cambium layer of host trees. The female simultaneously inoculates a phytotoxic mucus and a fungus, believed to be a species of Cerrena, into a tree. When the first-instar larvae emerge, they exclusively feed on the hyphae of the developing fungus. Later the larvae construct longitudinal, semi-circular galleries, which can run either upwards or downwards. The total length of a gallery is approximately 1 metre and it gradually increases in diameter as the larvae grow. Pupation occurs inside the wood at a depth of approximately 4 cm from the bark surface. Adult emergence occurs over an extended period from summer to autumn (October to May). Due to the prolonged period of adult emergence, it is possible to encounter all life stages during much of the growing season. The number of generations per year in Chile has not yet been established.
By comparison, the North American species, Tremex columba, which also infests broadleaf species, is believed to have one generation per year over most of its range. However, in New Brunswick, Canada, it has a minimum life cycle duration of 2 years. The fungus associated with T. columba is Daedalea unicolor [Cerrena unicolor] (Drooz, 1977; Smith and Schiff, 2002).
Natural enemiesTop of page
Notes on Natural EnemiesTop 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|
|Stems (above ground)/Shoots/Trunks/Branches||adults; eggs; larvae; nymphs; pupae||Yes||Pest or symptoms usually visible to the naked eye|
|Wood||adults; eggs; larvae; nymphs; 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||Broadleaf species: lumber, crating, pallets, dunnage||Yes|
|Solid wood packing material without bark||Broadleaf species: lumber, crating, pallets, dunnage||Yes|
|Wood Packaging not known to carry the pest in trade/transport|
|Loose wood packing material|
|Processed or treated wood|
ImpactTop of page
In Chile, weakened, damaged or recently-cut trees are preferred. However, apparently vigorous trees of some hosts, such as Acer negundo, may also suffer attack. On vigorous trees, the first attacks occur on the branches. These cause dieback and weakening of the trees. The brood adults that emerge from the branches subsequently infest the main bole. All trees that are attacked are killed (Baldini, 2002). To date, extensive damage has occurred to windbreak and shelter-belt plantings (Baldini, 2002). The attacks are typically so heavy that a single poplar can produce 2000 individual brood adults (Baldini, 2002). Therefore, the wood is impossible to use for lumber or other wood products. Moreover, the rate of decay of infested wood is accelerated because of the action of the symbiotic fungi associated with T. fuscicornis (Baldini, 2002). Another significant impact has been the loss of poplar windbreak plantings around agricultural crops and fruit orchards. This exposes the orchards to high winds and results in reduced crop yields (Baldini, 2002).
Environmental ImpactTop of page
Detection and InspectionTop of page
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.At present, direct control methods are not available for this insect. The following measures are suggested in cases where the introduction and establishment of T. fuscicornis results in the death of healthy trees. These are based on pest management measures currently in place for Sirex noctilio, in areas where this insect has been introduced in Southern Hemisphere pine plantations.
Forests, shelter-belts and ornamentals can be kept in a vigorous condition through regular scheduled thinning and proper watering. Other cultural measures include the rapid removal of freshly-cut logs of broadleaf species from forested areas during timber harvesting operations. The storage of logs under water sprays, debarking or rapid processing should be used to prevent wood wasp attacks in sawmills.
Chemical control measures have not been developed for wood wasps of the family Siricidae.
The fumigation and exposure of lumber and other wood products to high temperatures would kill all life stages of this insect.
If T. fuscicornis is introduced and established in conifer forests outside its geographic range and causes losses, the introduction of insect parasitoids in a classical biological control programme would be a potentially viable tactic.
Siricids tend to respond to host attractants and are not known to produce attractant pheromones. Consequently, pheromonal control is not a viable pest management tactic.
A trap-tree technique, used to monitor for the presence of Sirex noctilio, should also be effective for T. fuscicornis. This involves the injection of an herbicide into suppressed trees, which stresses them and makes them attractive to attack.
Integrated Pest Management
In Chile, an integrated approach that uses a combination of cutting and destroying infested trees plus the introduction of natural enemies, is under development. Low-level populations can be detected by establishing trap-trees, which are injected with a weak herbicide to make them attractive to adult T. fuscicornis. The parasitoid, Ibalia leucospoides is being evaluated as a potential biological control agent. The use of a parasitic nematode, which is an effective control for the wood wasp, Sirex noctilio, is also being considered (Baldini, 2002).
ReferencesTop of page
Baldini U-A, 2002. Tremex fuscicornis: Un factor de daño para el recurso forestal y agrícola. Agronomia y Forestal, 16:11-13.
CSIRO, 2002. 1. Common names: Tremex fuscicornis (Fabricius). CSIRO Australia and AFFA, Australia. http://www.ento.csiro.au/aicn/name_c/a_3632.htm.
EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm
Hedgren, O., 2010. Some notes on the ecology of the Tremex wasp T. fuscicornis (Hymenoptera: Siricidae). (Korthornad vedstekel Tremex fuscicornis (Hymenoptera: Siricidae) - en intressant vedinsekt på lövträd). Entomologisk Tidskrift, 131(1), 1-4. http://www.sef.nu/
Heidemaa M; Voolma K; Suda I, 1998. Species composition and distribution of the horntails (Hymenoptera, Siricoidea) of Estonia. Metsanduslikud Uurimused, 29:124-131.
Midtgaard F; Stokland JN; Sverdrup-Thygeson A, 1994. Tremex fuscicornis (Fabricius) (Hymenoptera, Siricidae) a new woodwasp for the Norwegian fauna. Fauna Norvegica Ser B, 41:97.
Midtgaard, F., Stokland, J. N., Sverdrup-Thygeson, A., 1994. Tremex fuscicornis (Fabricius) (Hymenoptera, Siricidae) a new woodwasp for the Norwegian fauna [Abstract]. Fauna Norvegica Ser B, 41(1), 97. https://eurekamag.com/research/009/675/009675168.php
Savela; M, 1998. Lepidoptera and some other life forms. Bjerkandera fumosa. FUNET, Finland. http://www.funet.fi/pub/sci/bio/life/fungi/gasteromycetes/polyporales/bjerkanderaceae/bjerkandera/index.html#fumosa.
Shamohammadi, D., Sadeghi, S. E., Melika, G., Ali, B., 2008. REPORT OF TREMEX FUSCICORNIS (HYM.: SIRICIDAE) FROM IRAN. Journal of Entomological Society of Iran, 27(2), 11-12. https://www.semanticscholar.org/paper/REPORT-OF-TREMEX-FUSCICORNIS-(HYM.%3A-SIRICIDAE)-FROM-Shamohammadi-Ebrahim/9613cb832fef5aea5077074f4c87856a77560f55
Smith DR, 1978. Pars 14, Suborder Symphyta. In: an der Vecht J, Shenefelt RD, eds. Hymenopterorum Catalogus (Nova edition). The Hague, Netherlands: Dr W Junk, BV.
Smith DR; Schiff NM, 2002. A review of the siricid woodwasps and their ibaliid parasitoids (Hymenoptera: Siricidae, Ibaliidae) in the Eastern United States, with emphasis on the mid-Atlantic region. Proceedings of the Entomological Society of Washington, 104(1):174-194; many ref.
Baldini UA, 2002. (Tremex fuscicornis: Un factor de daño para el recurso forestal y agrícola). In: Agronomia y Forestal, 16 11-13.
Blank S M, Boeve J L, Heitland W, Janicke M, Jansen E, Koch F, Kopelke J-P, Kraus M, Liston A D, Rltzau C, Schmidt S, Taeger A D, 1998. Checklist of the plant wasps in Germany (Hymenoptera: Symphyta). (Checkliste der Pflanzenwespen Deutschlands (Hymenoptera: Symphyta)). In: In A., Taeger & S. M., Blank (Eds), Pflanzenwespen Deutschlands (Hymenoptera, Symphyta). Kommentierte Bestandsaufnahme. Keltern, Goecke & Evers. Goecke & Evers, Keltern. 12-34. https://www.academia.edu/33601778/Checkliste_der_Pflanzenwespen_Hymenoptera_Symphyta_Th%C3%BCringens
CABI, Undated. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Chevin H, 1986. Note on the Hymenoptera Tenthrédoïdes (XII). - 26. Tenthrèdes rare or new for France. (Note sur les Hyménoptères Tenthrédoïdes (XII). - 26. Tenthrèdes rares ou nouvelles pour la France). Bulletin mensuel de la Société linnéenne de Lyon. 55 (10), 336-345. https://www.persee.fr/doc/linly_0366-1326_1986_num_55_10_10780
CSIRO, 2002. Common names: Tremex fuscicornis (Fabricius)., Australia: CSIRO Australia and AFFA. http://www.ento.csiro.au/aicn/name_c/a_3632.htm
Heidemaa M, Voolma K, Süda I, 1998. Species composition and distribution of the horntails (Hymenoptera, Siricoidea) of Estonia. (Puiduvaablaste (Hymenoptera, Siricoidea) liigiline koosseis ja levik Eestis.). Metsanduslikud Uurimused. 124-131.
Landi L, Braccini C, Roig Alsina A, 2011. First record of Tremex fuscicornis (Hymenoptera: Siricidae) in Argentina infesting a poplar plantation in Buenos Aires. Revista de la Sociedad Entomologica Argentina. 70 (43894), 383-387. http://www.scielo.org.ar/pdf/rsea/v70n3-4/v70n3-4a26.pdf
Lee JongWook, Ryu SungMan, Chung DongKee, 1998. Taxonomy of the genus Tremex Jurine (Hymenoptera: Siricidae) from Korea, with descriptions of one new species and one unrecorded species. Korean Journal of Biological Sciences. 2 (3), 297-302.
Midtgaard F, Stokland J N, Sverdrup-Thygeson A, 1994a. Tremex fuscicornis (Fabricius) (Hymenoptera, Siricidae) a new woodwasp for the Norwegian fauna [Abstract]. Fauna Norvegica Ser B. 41 (1), 97. https://eurekamag.com/research/009/675/009675168.php
Midtgaard F, Stokland JN, Sverdrup-Thygeson A, 1994. Tremex fuscicornis (Fabricius) (Hymenoptera, Siricidae) a new woodwasp for the Norwegian fauna. In: Fauna Norvegica Ser B, 41 97.
Palma C M A, Valenzuela E, Parra P, Gutierrez M, Torelli Silva L, 2005. Cerrena unicolor (Bull.) Murr. (Basidiomycota) isolated from mycangia of Tremex fuscicornis Fabr. (Hymenoptera Siricidae) associated to poplar decline (Populus sp.) in Chile. (Cerrena unicolor (Bull.) Murr (Basidiomycota) aislado de micangio de Tremex fuscicornis Fabr. (Hymenoptero Siricidae) asociado a decaimiento y pudricion del alamo (Populus sp.) en Chile.). Boletín Micológico. 57-61.
Pažoutová S, Šrůtka P, 2007. Symbiotic relationship between Cerrena unicolor and the horntail Tremex fuscicornis recorded in the Czech Republic. Czech Mycology. 59 (1), 83-90. http://www.natur.cuni.cz/cvsm
Pilarska D, Georgiev G, Dobreva M, Takov D, Mirchev P, Doychev D, Georgieva M, Nachev R, Dermendzhiev P, Draganova S, Linde A, Hajek A E, 2018. Pathogens and parasitoids of forest pest insects in the region of the Forest Protection Station Plovdiv (Bulgaria), during the period 1990-2017. Silva Balcanica. 19 (3), 49-59. https://silvabalcanica.files.wordpress.com/2019/01/sb_193_2018-049-059.pdf
Shamohammadi D, Sadeghi S E, Melika G, Ali B, 2008. REPORT OF TREMEX FUSCICORNIS (HYM.: SIRICIDAE) FROM IRAN. Journal of Entomological Society of Iran. 27 (2), 11-12. https://www.semanticscholar.org/paper/REPORT-OF-TREMEX-FUSCICORNIS-(HYM.%3A-SIRICIDAE)-FROM-Shamohammadi-Ebrahim/9613cb832fef5aea5077074f4c87856a77560f55
Smith DR, 1978. Pars 14, Suborder Symphyta. In: Hymenopterorum Catalogus, [ed. by an der Vecht J, Shenefelt RD]. The Hague, Netherlands: Dr W Junk, BV.
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