Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Amylostereum areolatum



Amylostereum areolatum


  • Last modified
  • 27 September 2018
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Natural Enemy
  • Preferred Scientific Name
  • Amylostereum areolatum
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Fungi
  •     Phylum: Basidiomycota
  •       Subphylum: Agaricomycotina
  •         Class: Agaricomycetes
  • Summary of Invasiveness
  • A. areolatum is a basidiomycete that causes a white rot of a broad range of conifers. Its invasiveness arises from a symbiotic association with woodwasps of the genus Sirex. The species Sirexnoct...

  • There are no pictures available for this datasheet

    If you can supply pictures for this datasheet please contact:

    CAB International
    OX10 8DE
  • Distribution map More information

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report


Top of page

Preferred Scientific Name

  • Amylostereum areolatum (Chaillet ex Fr.) Boidin 1958

Other Scientific Names

  • Lloydellopsis areolata (Chaillet ex Fr.) Pouzar 1959
  • Stereum areolatum (Chaillet ex Fr.) Fr. 1838
  • Thelephora areolata Chaillet ex Fr. 1828
  • Xylobolus areolatus (Chaillet ex Fr.) P. Karst 1881

Summary of Invasiveness

Top of page

A. areolatum is a basidiomycete that causes a white rot of a broad range of conifers. Its invasiveness arises from a symbiotic association with woodwasps of the genus Sirex. The species Sirexnoctilio is listed as “highly invasive” on the ISSG/IUCN website (ISSG, 2008) and is a Regulated Pest for the USA (APHIS, 2009a). The wasp and the fungus are native to Europe, North Africa and western Asia where their damage is considered secondary (Spradbery and Kirk, 1978). Introduced to areas of the Southern Hemisphere where exotic pine species are grown in plantations, these organisms have caused major losses. The insect invaded New Zealand by at least 1900, but did not cause serious concern until the 1940s (Talbot, 1977). It later spread to Tasmania and the southern parts of Australia and the wasp/fungus association was introduced into southern South America, beginning in Uruguay in 1980 (Ciesla, 2003). Invasion of South Africa occurred in 1994 (Tribe, 1995). Woodwasps are repeatedly detected in material imported to the USA, but were successfully excluded until 2004 (Wilson et al., 2009). The wasp and fungus were later found in nearby Canada (Ontario), although apparently due to a separate introduction (Bergeron et al., 2008; Wilson et al., 2009). Recent surveys found the wasp in four states of the USA (Evans-Goldner and Bunce, 2009) and 25 counties of Ontario in Canada (Shields, 2009).

Schiff (2008) summarizes differences in complexity of the ecological situations in the Southern Hemisphere countries and North America that could affect spread and impact of the fungus and wasp.

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Fungi
  •         Phylum: Basidiomycota
  •             Subphylum: Agaricomycotina
  •                 Class: Agaricomycetes
  •                     Subclass: Agaricomycetidae
  •                         Order: Russulales
  •                             Family: Amylostereaceae
  •                                 Genus: Amylostereum
  •                                     Species: Amylostereum areolatum

Notes on Taxonomy and Nomenclature

Top of page

The genus Amylostereum, including A. areolatum, was separated by Boidin (1958) from Stereum on the basis of the encrusted cystidia in the hymenium. Lloydellopsis is a redundant later genus, based on the same type species. Xylobolus is another group of Stereum-like fungi having smooth amyloid basidiospores that is distinguished from Stereum and Amylostereum principally by the presence of acanthophyses in the hymenium (Boidin, 1958).

Amylostereum currently contains four species (Kirk et al., 2008). A. areolatum, Amylostereum chailletii (Pers.) Boidin and Amylostereum laevigatum (Fr.) Boidin have symbiotic relationships with woodwasps in the family Siricidae (Gilbertson, 1984; Tabata and Abe, 1997).
Tabata et al. (2000) examined relationships of Amylostereum and Echinodontium species using sequences of ITS and manganese peroxidase regions of DNA. Their results confirm relationships within Amylostereum (Vasiliauskas et al., 1999; Slippers et al., 2000), grouping the other three species together at some distance from A. amylostereum. With respect to the genus as a whole, they proposed placing it in the Echinodontiaceae rather than in its own family, although that is not accepted here.


Top of page

Basidiomata perennial on conifers, corky or leathery, partly resupinate, flattened on bark or wood with hymenium exposed, partly reflexed, with shield-shaped or broad areas projected 1-3 cm upwards/outwards. Upper/outer surface rust-brown to black, matted-hairy, undulating, with furrows or grooves. Hymenial surface generally smooth, sometimes cracked or uneven, grey to brown with a violet or lilac tint, margin thin, white. Basidia in hymenium narrowly clavate, 20-30 x 4-5 µm; basidiospores smooth, colourless, ellipsoidal to cylindrical, amyloid (staining blue in iodine). Context dimitic; cystidia encrusted, 40-60 x 6-9 mm. Thomsen (1998) found the hymenium of a limited sample of basidiocarps to be brown-violet, with a white margin; basidiospores were 3.5-5.5 x 2.0-3.0 mm.

Colony in culture relatively fast-growing, white, cottony, becoming more appressed and dark, cream, buff or brownish, with age, darker on reverse. Mycelium dimitic: generative hyphae thin-walled, with clamp connections, skeletal hyphae thick-walled, generally unbranched, ending in thick-walled, brownish, encrusted cystidia. Arthrospores cylindrical, hyaline, generated from certain hyphae by fragmentation. Optimum growth in culture occurred at 20-25°C (King, 1966).
Fungus in hypopleural organs of siricid larvae consists of coiled hyphae surrounded by a wax-like material. In the intersegmental sacs, or mycangia, of adult females, arthrospores are unicellular or multicellular (Gilmour, 1965).
See Boidin and Lanquetin (1984), Breitenbach and Kranzlin (1988), Chamuris (1988), and Gadgil (2005) for more detailed descriptions. Stalpers (1978) provides a description of the asexual state.


Top of page

Due to the mutualistic relationship between the fungus and the wasp Sirex noctilio, an identical distribution is presumed. The wasp is considered native to Europe, North Africa and western Asia (Spradbery and Kirk, 1978), but records of the fungus only represent Europe. A. areolatum is more commonly seen in central Europe than in the northern countries (Eriksson et al., 1978; Jahn, 1979). On the other hand, the fungus has been identified as a pathogen of native tree species in Japan where it has a mutualistic relationship with at least one other wasp, Sirex nitobei (Fukuda and Hijii, 1996). Sirex juvencus is also a vector of A. areolatum in the Northern Hemisphere (Spradbery and Kirk, 1978).

Carnegie et al. (2006) have made predictions of the ability of S. noctilio to establish in invaded areas that necessarily entails the presence of A. areolatum, or, at least, the particular genotype that the insect has carried with it to parts of the Southern Hemisphere (Slippers et al., 2001, 2002). They predict that establishment is likely to occur in southern South America, eastern Australia and South Africa, but suggest that extension to other parts of those continents would require human mediation. The wasp has recently invaded parts of the northern USA and adjacent Canada (Bergeron et al., 2008; Wilson et al., 2009); other parts of the continent are suitable for its establishment (Carnegie et al., 2006). Plantings of susceptible host species in China could lead to potential invasion by the wasp-fungus, although Carnegie et al. (2006) suggest that some other factor besides climate and host availability are restricting S. noctilio in that country. Reports exist of A. areolatum in northwestern China (Zhang, 2005) and the Russian Far East (Boidin and Lanquetin, 1984); the relationship of those reports to the fungus-wasp association in Japan is not clear (Kobayashi et al., 1978).

Distribution Table

Top 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.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


ChinaPresentPresent based on regional distribution.
-GansuPresentZhang, 2005Herbarium specimens
-NingxiaPresentZhang, 2005Herbarium specimen
Georgia (Republic of)PresentUK CAB International, 2009Wasp present
JapanPresentPresent based on regional distribution.
-HonshuPresentKobayashi, 2007
MongoliaPresentUK CAB International, 2009Wasp present


South AfricaPresentIntroduced Invasive Baxter et al., 1995; Tribe, 1995; Croft, 2007On Pinus radiata
-Canary IslandsPresentUK CAB International, 2009

North America

CanadaPresentPresent based on regional distribution.
-OntarioLocalisedIntroduced Invasive Bergeron et al., 2008; Shields, 2009On Pinus sylvestris
USAPresentPresent based on regional distribution.
-MichiganLocalisedIntroduced Invasive Evans-Goldner and Bunce, 2009Wasp survey result
-New YorkLocalisedIntroduced Invasive Evans-Goldner and Bunce, 2009; Wilson et al., 2009
-PennsylvaniaLocalisedIntroduced Invasive Evans-Goldner and Bunce, 2009Wasp survey result
-VermontLocalisedIntroduced Invasive Evans-Goldner and Bunce, 2009Wasp survey result

South America

ArgentinaPresentIntroduced Invasive Echeverría, 1991Wasp introduced 1985-86
BrazilPresentPresent based on regional distribution.
-ParanaPresentIntroduced Invasive Iede et al., 1988Wasp introduced
-Rio Grande do SulPresentIntroduced Invasive Iede et al., 1988Wasp introduced
-Santa CatarinaPresentIntroduced Invasive Iede et al., 1988Wasp introuced
ChileLocalisedIntroduced2001 Invasive Ciesla, 2003Wasp introduced 2001
UruguayPresentIntroduced1980 Invasive Rebuffo, 1990Wasp introduced 1980


AustriaPresentNativeBreitenbach and Kranzlin, 1988
BelgiumPresentNativeUK CAB International, 2009
CyprusPresentUK CAB International, 2009Wasp distribution
Czech RepublicPresentNativeBPI, US National Fungus Collections1975
Czechoslovakia (former)PresentNativeUK CAB International, 2009Wasp distribution
DenmarkPresentNativeThomsen, 1998
EstoniaPresentNativeUK CAB International, 2009Wasp distribution
FinlandPresentNativeHansen and Knudsen, 1997
FrancePresentNativeBoidin and Lanquetin, 1984
GermanyPresentNativeJahn, 1979; Boidin and Lanquetin, 1984
GreecePresentNativeUK CAB International, 2009Wasp distribution
HungaryPresentNativeUK CAB International, 2009Wasp distribution
ItalyPresentNativeUK CAB International, 2009Wasp distribution
LithuaniaPresentNativeVasiliauskas and Stenlid, 1999
NorwayPresentNativeUK CAB International, 2009Wasp distribution
PolandPresentNativeLuszczynski, 1997
PortugalPresentNativeUK CAB International, 2009Wasp distribution
-AzoresPresentUK CAB International, 2009
RomaniaPresentNativeUK CAB International, 2009Wasp distribution
Russian FederationPresentPresent based on regional distribution.
-Eastern SiberiaPresentUK CAB International, 2009Wasp distribution
-Russian Far EastPresentBoidin and Lanquetin, 1984
-Western SiberiaPresentUK CAB International, 2009Wasp distribution
SerbiaPresentNativeUK CAB International, 2009Wasp distribution
SpainPresentNativeUK CAB International, 2009Wasp distribution
SwedenPresentVasiliauskas and Stenlid, 1999
SwitzerlandWidespreadNativeBreitenbach and Kranzlin, 1988
UKPresentNativeUK CAB International, 2009Wasp distribution
Yugoslavia (Serbia and Montenegro)PresentNativeUK CAB International, 2009Wasp distribution


AustraliaPresentPresent based on regional distribution.
-New South WalesPresentIntroduced Invasive UK CAB International, 2009Wasp distribution
-QueenslandPresentIntroduced Invasive Carnegie et al., 2005Wasp distribution
-South AustraliaPresentIntroduced Invasive UK CAB International, 2009Wasp distribution
-TasmaniaPresentIntroduced Invasive Wasp distribution
-VictoriaWidespreadIntroduced Invasive Neumann and Marks, 1990Wasp distribution
New ZealandWidespreadIntroduced Invasive Gaut, 1969; Gadgil, 2005

History of Introduction and Spread

Top of page

The fungus and wasp larvae were introduced into New Zealand before 1900, apparently in shipments of logs from Europe (Gilmour, 1965). This was not of great concern until damage to exotic tree plantations appeared in the drought years of the late 1940s (Rawlings, 1955). In 1950-51, the wasp/fungus appeared in Tasmania (Gilbert and Miller, 1952). By 1961, they had arrived in Victoria eventually reaching New South Wales and Southern Australia (Carnegie et al., 2005). Despite the awareness of its threat, the wasp/fungus was introduced into South America, beginning in Uruguay in 1980, spreading to Argentina, Brazil, and Chile (Ciesla, 2003). Invasion of South Africa occurred in 1994 (Tribe, 1995). Woodwasps are repeatedly detected in material imported to the USA, but Sirex noctilio was successfully excluded until 2004 (Ciesla, 2003; Wilson et al., 2009). The wasp and fungus were later found in nearby Canada (Ontario) although apparently due to a separate introduction (Bergeron et al., 2008; Wilson et al., 2009). Recent surveys found the wasp in four states of the USA (Evans-Goldner and Bunce, 2009) and 25 counties of Ontario in Canada (Shields, 2009).


Top of page
Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Argentina 1985-1986 Self-propelled (pathway cause) Yes Echeverria (1991); Echeverría (1991) Thought to be introduced from Uruguay
Australia New Zealand 1950-1961 Yes Talbot (1977) Tasmania - 1950, Victoria by 1961
Brazil 1988 Self-propelled (pathway cause) Yes Iede et al. (1988) Thought to be introduced from Uruguay
Canada 2006 Bergeron et al. (2008)
Chile 2001 No Ciesla (2003) Limited areas
New Zealand Europe <1900 Timber trade (pathway cause) Yes Talbot (1977)
South Africa Europe 1994 Yes Tribe (1995)
Uruguay 1980 Yes Rebuffo (1990)
USA 2004 Yes Wilson et al. (2009)

Risk of Introduction

Top of page

The most recent introductions into the USA and Canada indicate the level of risk for this pest/pathogen threat. Despite a high level of awareness and frequent interceptions of woodwasps by plant protection personnel (Ciesla, 2003), the wasp and fungus have arrived in North America. The likely routes and means were not identified (Bergeron et al., 2008; Wilson et al, 2009). Ciesla (2003) cites a number of consumer goods that incorporate logs or wood products as potential carriers. Bark-bearing and debarked logs, as well as untreated lumber, might carry the fungus, but the wasp appears necessary for its inoculation into trees. Once introduced, the wasp, a strong flier seeking out suitable tree hosts (Ciesla, 2003), can transport the fungus over land and possibly across narrow seas. Northwestern South America, eastern Africa, and Western Australia are areas for which accidental introduction by humans would be required (Carnegie et al., 2006). Likewise, afforestation in China with introduced Pinus species suggests that Sirex/Amylostereum is of quarantine concern for China (Bi et al., 2008).

Habitat List

Top of page
Terrestrial – ManagedManaged forests, plantations and orchards Principal habitat Harmful (pest or invasive)
Terrestrial ‑ Natural / Semi-naturalNatural forests Principal habitat Harmful (pest or invasive)
Natural forests Principal habitat Natural

Hosts/Species Affected

Top of page

In Europe, the fungus is reported on Abies, Picea (Hansen and Knudsen, 1997) and Cryptomeria species (Cardosa et al., 1992). Gadgil (2005) considers the introduced species of Abies,Larix, and Picea to be relatively resistant in New Zealand, but the numerous Pinus species, also introduced, are generally susceptible. Abies holophylla is a susceptible native species in the Russian Far East (Boidin and Lanquetin, 1984). In Japan, Pinus densiflora and Pinus thunbergii are hosts (Kobayashi, 2007); the fungusis reported from China on a Picea sp. (Zhang, 2005). Pseudotsugamenziesii (Gilmour, 1965) and Cedrus atlantica are also hosts in New Zealand (Burnip et al., 2008). The tree species known to be attacked by Sirex noctilio, thus are also hosts for this fungus, are listed by CABI (2009).

King (1966) reported that the fungus also grew well, although more slowly, in laboratory-inoculated freshly cut branches of pine species: Pinus radiata, Pinus canariensis, Pinus pinaster and Pinus halepensis, and of other conifers: Araucaria cunninghamii, Araucaria excelsa, and Cedrus deodara.

Growth Stages

Top of page Vegetative growing stage


Top of page

Symptoms on infected trees are a combination of those caused by the fungus and wasp vector. Resin droplets appear at sites of wasp oviposition (King, 1966; Kobayashi et al., 1978). On Pinus radiata, yellowing of needles occurs on older parts of the tree within several weeks, followed by yellowing and loss of needles on younger parts, or death of the tree with foliage remaining green or turning red-brown. The yellowing of younger needles is sometimes accompanied by wilting of the youngest ones at branch tips, the whole fascicle drooping, particularly in periods of active growth and adequate moisture (Coutts, 1969). However, these symptoms are due to a mucus material produced by the wasp and not the fungus (Coutts, 1969; Talbot, 1977).

Interior symptoms begin with a white discoloration of the wood, extending more longitudinally than laterally, produced beyond the growth of the fungus near the oviposition site. A brown-stained area of similar shape develops later in the bark around the site; a strip of dead bark develops above and below the wasp puncture. A. areolatum causes a dry white rot of the wood before and after the death of the tree (King, 1966).
No fructification of the fungus has been observed in New Zealand or Australia (Hood, 1992), but the emerging wasp adults bore distinctive round holes through the bark (Talbot, 1977; Schiff, 2008).

List of Symptoms/Signs

Top of page
SignLife StagesType
Growing point / dieback
Leaves / wilting
Leaves / yellowed or dead
Stems / dieback
Stems / discoloration
Stems / gummosis or resinosis
Stems / internal feeding
Stems / mycelium present
Stems / rot
Whole plant / plant dead; dieback
Whole plant / wilt

Biology and Ecology

Top of page

A. areolatum has a tetrapolar outcrossing mating system (Vasiliauskas and Stenlid, 1999). The species also exhibits vegetative compatibility groups in culture (Vasiliauskas and Stenlid, 1999), which appear to represent genetic clones (Vasiliauskas et al., 1998).

The fungus is not known to fruit in Australia or New Zealand (King, 1966; Hood, 1992), although isolates from infected trees were able to fruit on wood blocks in culture (Gaut, 1969). Arthrospores carried by adult female wasps are injected into trees during oviposition. Neither arthrospores nor basidiospores were able to grow beyond germination in pure culture, but Gaut (1969) was able to obtain cultures from arthrospores by starting them on a tissue culture of Pinus radiata. The sexual state is observed in nature in central Europe (Breitenbach and Kranzin, 1988), although it is rare in northern Europe (Eriksson et al., 1978). Based on the low number and wide distribution of vegetative compatibility groups around the Baltic Sea, Vasiliauskas and Stenlid (1999) and Thomsen and Koch (1999) considered distribution of the pathogen in that region more likely to have occurred through the insect vector than by aerial dispersal of the basidiospores.

Based on cultural tests, King (1966) suggested that A. areolatum is a poor competitor for growth in Sirex-infested trees; poor competition with saprobes in dead trees may explain the low frequency of fruiting. A. areolatum grows slowly in the tree and only in dry wood (70% moisture content) (Gaut, 1969; Webber and Gibbs, 1989) The fungus colonies are limited to areas around the oviposition site and larval tunnels while the tree is alive (King, 1966) and do not grow much beyond the inoculation site in resistant trees (Coutts, 1969). Nevertheless, Klepzig et al. (2009) found that in culture, A. areolatum can exclude the Ophiostoma species associated with the southern pine beetle, indicating that it might be successful in early competition in infected trees.

Strains of the fungus may differ. Williams and Mastro (2009) report a significant growth rate difference between a North American isolate and one used in Australian biological control work. The Australian isolate is different from the single clone, which was introduced with the wasp into South Africa and South America (Slippers et al., 2001).


The fungus has a mutualistic association with Sirex spp.: Sirex noctilio, Sirex juvencus, Sirexnotobei (Gilbertson, 1984). It is carried in specific structures (mycangia) on the female woodwasp body at the base of the ovipositor, and is introduced into the holes drilled by the wasp when it is laying eggs, although, in some cases, only the spores will be deposited (Gaut, 1969; Fukuda and Hijii, 1996).

The fungus grows in a limited area around the hole, rotting the sapwood, and providing a dry, resin-free habitat for the wasp larvae, which tunnel in the wood and feed on the mycelium (Madden, 1981; Webber and Gibbs, 1989). When fungal growth results from wasp deposits of spores alone in relatively healthy trees, this may weaken the trees sufficiently to provide additional breeding sites for the wasp (Gilbertson, 1984; Fukuda and Hijii, 1996).

Wasp larvae carry hyphae encased in a wax-like material inside hypopleural organs on the exoskeleton, but these are absent in the pupae (Gilmour, 1965). The adult female then must acquire quantities of hyphae as it is emerging from pupation and out of the tree (Webber and Gibbs, 1989). Male larvae and adults do not carry the fungus.

Tabata et al. (2000) have reported the isolation of A. areolatum from another siricid species, Xoanon matsumurae in Japan, but the details of the association were not explored.


Top of page
Cf - Warm temperate climate, wet all year Preferred Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year
Cs - Warm temperate climate with dry summer Preferred Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers
Df - Continental climate, wet all year Preferred Continental climate, wet all year (Warm average temp. > 10°C, coldest month < 0°C, wet all year)
Dw - Continental climate with dry winter Preferred Continental climate with dry winter (Warm average temp. > 10°C, coldest month < 0°C, dry winters)

Notes on Natural Enemies

Top of page

CABI (2009) presents information on natural enemies used for the biological control of Sirex noctilio.

Means of Movement and Dispersal

Top of page


Basidiospores are distributed by the wind from the fruiting bodies produced on the outside surface of erect or fallen trees (Breitenbach and Kranzlin, 1988). Basidiocarps are rare in northern Europe (Eriksson et al., 1978). Vasiliauskas and Stenlid (1999) and Thomsen and Koch (1999) suggest that this means of dispersal is unlikely to account for trans-Baltic occurrence of clones of this species. Instead, the fungus is likely to be wasp-transmitted across significant distances, but probably carried across international boundaries in imported wood. Basidiocarps have not been observed in overseas areas of introduction (King, 1966; Hood, 1992), thus basidiospores are not a significant means of spread there.

Vector Transmission
The siricid wasps are strong fliers, capable of flying several kilometers in search of suitable trees (Ciesla, 2003). A natural spread rate of 20-50 km per year has been reported for Sirex noctilio (CABI, 2009). The wasp generally attacks weakened, damaged or poorly growing trees (Talbot, 1977). Fukuda and Hijii (1996) report that the species Sirex nitobei also oviposits on weakened trees, apparently detecting these by volatile compounds. Weakened trees produce a greater quantity of volatiles (Borockzy et al., 2009).
The fungus is considered to have been introduced into New Zealand with Sirex noctilio in a shipment of logs (Gilmour, 1965), and with the wasp into South Africa in wooden packing crate material (Tribe and Cilllie, 2004). Siricid wasps in wood products have been intercepted by APHIS in the USA (Ciesla, 2003) and by phytosanitary agencies in other countries (CABI, 2009).

Plant Trade

Top of page
Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
Bark hyphae Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
Stems (above ground)/Shoots/Trunks/Branches hyphae Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
Wood hyphae Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope

Impact Summary

Top of page
Economic/livelihood Negative
Environment (generally) Negative


Top of page

Talbot (1977) notes that the impact of the Sirex/Amylostereum association can vary depending on the silvicultural situation. The fungus is relatively rare in Europe, where the several Amylostereum species/siricid wasp associations are presumably in balance in the natural woodland. However, in plantations of exotic species this balance may be disrupted. Vasiliauskas et al. (1996) report A. areolatum as one of the primary parasites on wounded trees in Swedish plantations. The large outbreak of Sirex noctilio in 1946-1949 in New Zealand, despite the significant number of trees killed, may have had a beneficial effect by reducing the density of the long-unthinned plantations of Pinus radiata (Rawlings, 1955). Eliminating the more susceptible smaller and weaker trees through thinning is a tactic to reduce the severity and impact of the fungus/wasp association on plantations in Australia (Neumann and Marks, 1990). In the USA and Canada, a number of native species, some of which are attacked as exotics in overseas plantations, may be threatened (Wilson et al., 2009), particularly where they occur in denser stands or are grown in plantations in southern states (Dodds, 2009). The existing complex ecological situation that is more similar to that of the fungus native range may reduce or complicate the impact (Schiff, 2008).

Economic Impact

Top of page

Economic effects of the introduction of the Sirex noctilio/A. areolatum complex in countries of the Southern Hemisphere are summarized by CABI (2009). Haugen (2006) reports some projections of possible impacts on forests of the USA, and Yemshanov et al. (2009) have presented models of possible impacts on the forest industry in eastern Canada. The total harvest losses over 28 years in Canada could equal as much as $2.1 billion depending on model assumptions.

Environmental Impact

Top of page

Attention on the effects in the southern hemisphere has focused primarily on introduced tree species. No data are available on the impacts on the native species in forests in Japan (Kobayashi et al., 1978; Fukuda and Hijii, 1996). Haugen (2006) identified possible impacts in the USA through changes in forest composition, reduction in native siricid wasp populations, and increases in other insect pests and fungal pathogens that attack weakened or dying trees.

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Has a broad native range
  • Has high reproductive potential
  • Reproduces asexually
Impact outcomes
  • Host damage
  • Increases vulnerability to invasions
  • Modification of fire regime
  • Negatively impacts forestry
  • Threat to/ loss of native species
Impact mechanisms
  • Pathogenic
Likelihood of entry/control
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field
  • Difficult/costly to control


Top of page

The production of arthrospores in culture is necessary to identify A. areolatum (Gaut, 1969). These appear in cultures grown on standard fungal media, including 2% malt extract agar and cornmeal agar (King, 1966; Stalpers, 1978). Gaut (1969) utilized matings of homokaryotic cultures, observation of hyphal anastomosis, and electrophoretic protein profiles to identify the pathogen in Australia. Bergeron et al. (2008) compared the ITS sequences of rDNA extracted from cultured isolates with those of standard strains of A. areolatum. The Canadian isolates matched European and Asian isolates at the 99% level; they matched Amylostereum chailletii at about 97%. Slippers et al. (2002) found that RFLP analysis of DNA easily distinguished the two species.

Detection and Inspection

Top of page

In Europe, the fungus may eventually produce fruiting bodies on infected trees. Elsewhere, observation of holes made by emerging siricid wasps are a clue to the presence of the fungus associated with larval tunnels (Spradbery and Kirk, 1978; Schiff, 2008). Due to the fact that there may be more than one species of woodwasp in a given area, examination of culture characteristics or DNA sequence data is required to establish the identity of the fungus.

Similarities to Other Species/Conditions

Top of page

Amylostereum chailletii, also a woodwasp-vectored fungus in Northern Hemisphere forests, is reported to be distinguished by larger basidiospores, 6.2-8 x 3-4 mm, according to Boidin and Lanquetin (1984), although Thomsen (1998) found a range of 4.8-8 x 2.4-4 mm and Chamuris (1988) reports 5-8 x 3-5 mm. Thomsen (1998) describes the hymenium colour of fruiting bodies as varying in pale to darker brown shades (cream, orange-grey, reddish-brown, greyish-brown or brick-red) without the purple or lilac tint of A. areolatum; the paler colours are most common. Cultures on 5% MEA or 4% PDA are paler than those of A. areolatum (pale-yellow or yellowish-white vs. yellow-brown to rust-brown) and do not produce arthrospores (Thomsen, 1998). King (1966) reported that many basidiospores of A. chailletii germinated and produced mycelium on agar, whereas those of A. areolatum seldom germinated and, if so, did not produce mycelium.

Prevention and Control

Top 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.


Despite the history of accidental introduction of the fungus/wasp association to widely separated continents, phytosanitary measures may prevent, or at least slow, their spread by intercepting infested logs, packing materials, and other bark-bearing tree products (Ciesla, 2003; Evans-Goldner and Bunce, 2009). Human-assisted transport of these organisms is required for movement to other parts of those continents where climatic conditions and tree species permit their establishment (Carnegie et al., 2006). Efforts to prevent that transport are conducted by phytosanitary agencies such as APHIS (2009b) and the CFIA (2009).
Cultural Control and Sanitary Measures
Silvicultural practices, including selection of suitable tree species and phenotypes, choice of proper plantation sites, appropriate and timely thinning of stands, prevention of wounds caused by fire or harvesting, removal of cut, damaged and wind-thrown trees and sufficient fertilization, will reduce or prevent the accumulation of weakened or dying trees that are the preferred breeding sites for siricid wasps (Neumann and Marks, 1990; CABI, 2009).
Biological Control
UK CAB International (2009) [CABI] lists parasitic and predatory insects that attack Sirex noctilio, most of which have been deployed in Australia and New Zealand. One parasitoid moves toward fungus-produced volatiles to locate the larvae on which its own young feed (Martinez et al., 2006). Parasitoids provide limited control of wasp populations because they depend on a certain level of siricid population for their own survival and multiplication (Carnegie et al., 2005).
The tylenchid nematode Beddingia (= Deladenus) siricidicola, discovered in New Zealand and later found in Europe (Bedding, 1995), lives in and feeds on A. areolatum colonies in trees and also infects Sirex larvae and female wasps. Because it has a separate cycle of growth and reproduction based on fungus feeding, it can cause a greater reduction in wasp numbers. The nematode can be raised in cultures of the fungus and injected into trees for effective control of the wasp (Bedding, 1995). B. siricidicola is currently under evaluation for use in the USA (Williams and Mastro, 2009); it is already present in infected trees in Canada (Shields, 2009).
Monitoring and Surveillance
CABI (2009) outlines the use of trap trees, in combination with remote sensing surveys, for identifying the areas of infestation by S. noctilio and monitoring its activity. Carnegie et al. (2005) discuss their use in Australia.

Gaps in Knowledge/Research Needs

Top of page

Ciesla (2003) notes the lack of knowledge about possible subspecies of the insect or strains of fungus with differing levels of aggressiveness and host specificity. The pest/pathogen/host situation in China remains to be examined (Carnegie et al., 2006).


Top of page

APHIS, 2009. Plant Health: Animal and Plant Health Inspection Service. Washington DC, USA: USDA.

APHIS, 2009. Plant Import: Animal and Plant Health Inspection Service. Washington DC, USA: USDA.

Baxter AP; Rong IH; Schutte AL, 1995. Amylostereum areolatum (Aphyllophorales: Stereaceae) in South Africa. South African Journal of Botany, 61(6):352-354.

Bedding RA, 1995. Biological control of Sirex noctilio using the nematode Deladenus siricidicola. In: Nematodes and Biological Control of Insect Pests [ed. by Bedding, R. A. \Akhurst, R. J. \Kaya, H.]. Melbourne, Australia: CSIRO, 11-20.

Bergeron MJ; Hamelin RC; Leal I; Davis C; Groot Pde, 2008. First report of Amylostereum areolatum, the fungal symbiont of Sirex noctilio, on Pinus spp. in Canada. Plant Disease, 92(7):1138. HTTP://

Bi HuiQuan; Simpson J; Eldridge R; Sullivan S; Li RongWei; Xiao YuGui; Zhou JianHua; Wu ZhongXing; Yan Hong; Huang Quan; Liu QianLi, 2008. Survey of damaging pests and preliminary assessment of forest health risks to the long term success of Pinus radiata introduction in Sichuan, southwest China. Journal of Forestry Research, 19(2):85-100.

Boidin J, 1958. [English title not available]. (Heterobasidiomycetes saprophytes et Homobasidiomycetes resupines: V. Essai sur le genre Stereum Pers. ex SF Gray.) Revue de Mycologie, 23:318-334.

Boidin J; Lanquetin P, 1984. [English title not available]. (Le genre Amylostereum (Basidiomycetes). Intercompatibilites partielles entre especes allopatriques.) Bulletin Trimestriel de la Societe Mycologique de France, 100:211-236.

Boroczky K; Crook DJ; Francese JA; Mastro VC; Tumlinson JH, 2009. Chemical ecology of Sirex noctilio. Proceedings of the 19th Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.]. Pennsylvania, USA: USDA Forest Service, 8-9.

BPI (US National Fungus Collections), 2009. Fungal Databases - Specimens. Beltsville, USA: Systematic Mycology and Microbiology Laboratory, Agricultural Research Service, USDA.

Breitenbach J; Kranzlin F, 1988. Fungi of Switzerland. Vol. 2. Non-gilled Fungi. Lucerne, Switzerland: Verlag Mykologia.

Burnip CM; Harvey IC; Voice D; Braithwaite M, 2008. New host association for Sirex noctilio and Amylostereum areolatum on Cedrus atlantica. New Zealand Plant Protection, 61:391.

Cardoso J; Melo I; Telleria MT, 1992. Aphyllophorales of Peneda-Geres National Park (Portugal). Cryptogamic Botany, 2:395-404.

Carnegie AJ; Eldridge RH; Waterson DG, 2005. History and management of sirex wood wasp in pine plantations in New South Wales, Australia. New Zealand Journal of Forestry Science, 35(1):3-24.

Carnegie AJ; Matsuki M; Haugen DA; Hurley BP; Ahumada R; Klasmer P; Sun JiangHua; Iede ET, 2006. Predicting the potential distribution of Sirex noctilio (Hymenoptera: Siricidae), a significant exotic pest of Pinus plantations. Annals of Forest Science, 63(2):119-128.

CFIA, 2009. Invasive Species. Ottawa, Canada: Government of Canada.

Chamuris GP, 1988. The non-stipitate stereoid fungi in the northeastern United States and adjacent Canada. Mycologia Memoir, 14:1-247.

Ciesla WM, 2003. European woodwasp: a potential threat to North America's conifer forests. Journal of Forestry, 101(2):18-23.

Coutts MP, 1969. The mechanism of pathogenicity of Sirex noctilio on Pinus radiata. I. Effects of the symbiotic fungus Amylostereum sp. (Thelephoraceae). Australian Journal of Biological Sciences, 22(4):915-24.

Croft P, 2007. Monitoring the introduction, development and damage of Sirex infestations in KwaZulu-Natal. The Sirex Woodwasp: Expanding Frontiers. Programme, International Sirex Symposium, Pretoria and Pietermaritzburg, South Africa, 9-16 May 2007., South Africa: Forestry and Agricultural Biotechnology Institute, 37.

Dodds KJ, 2009. Sirex noctilio impacts on native and exotic pine stands in the northeastern United States. Proceedings of the 19th Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.]. Pennsylvania, USA: USDA Forest Service, 17-18.

Echeverria NE, 1991. The pine borer wasp, Sirex noctilio (Hymenoptera, Siricidae). IFONA Reporter, No. 2:22-23

Eriksson J; Hjortstam K; Ryvarden L, 1978. The Corticiaceae of North Europe. Vol. 5 Mycoaciella-Phanerochaete. Oslo, Norway: Fungiflora, 889-1407.

Evans-Goldner L; Bunce LK, 2009. United States Sirex woodwasp program update. Proceedings of the 19th Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.]. Pennsylvania, USA: USDA Forest Service.

Farr DF; Rossman AY; Palm ME; McCray EB, 2009. Fungal Databases, Systematic Botany & Mycology Laboratory, ARS, USDA. USA: ARS, USDA.

Fukuda H; Hijii N, 1996. Host-tree conditions affecting the oviposition activities of the woodwasp, Sirex nitobei Matsumura (Hymenoptera: Siricidae). Journal of Forest Research, 1:177-181.

Gadgil PD, 2005. Fungi of New Zealand. Vol. 4 Fungi on Trees and Shrubs in New Zealand. Hong Kong, China: Fungal Diversity Press, 437 pp.

Gaut IPC, 1969. Identity of the fungal symbiont of Sirex noctilio. Australian Journal of Biological Sciences, 22(4):905-14.

Gilbert JM; Miller LW, 1952. An outbreak of Sirex noctilio (F.) in Tasmania. Australian Forestry, 16:63-69.

Gilbertson RL, 1984. Relationships between insects and wood-rotting Basidiomycetes. In: Fungus-Insect Relationships. Perspectives in Ecology and Evolution [ed. by Wheeler, Q. \Blackwell, M.]. New York, USA: Columbia University Press, 514 pp.

GILMOUR JW, 1965. The life cycle of the fungal symbiont of Sirex noctilio. New Zealand Journal of Forestry, 10(1):80-89.

Hansen L; Knudsen H, 1997. Nordic Macromycetes. Vol. 3 Heterobasidioid, aphyllophoroid and gastromycetoid basidiomycetes. Copenhagen, Denmark: Nordsvamp, 444 pp.

Haugen DA, 2006. Sirex noctilio. Exotic Forest Pest Information System for North America. Pennsylvania, USA: USDA Forest Service.

Hood IA, 1992. An illustrated guide to fungi on wood in New Zealand. Auckland, New Zealand; Auckland University Press, 424 pp.

Iede ET; Penteado S do RC; Bisol JC, 1988. First record of Sirex noctilio attacking Pinus tpda in Brazil. Circular Tecnica - Centro Nacional de Pesquisa de Florestas Curitiba, Parana, Brazil, No. 20:ii + 12 pp.

ISSG, 2005. Global Invasive Species Database (GISD). Auckland, New Zealand: University of Auckland.

Jahn H, 1979. Pilze die an Holz wachsen ([English title not available]). Herford, Germany: Bussesche Verlagshandlung, 268 pp.

King JM, 1966. Some aspects of the biology of the fungal symbiont of Sirex noctilio. Australian Journal of Botany, 14(1):25-30.

Kirk P; Cannon P; Minter D; Stalpers J, 2008. Ainsworth and Bisby’s Dictionary of the Fungi, Ed.10 [ed. by Kirk, P.\Cannon, P.\Minter, D.\Stalpers, J.]. Wallingford, UK: CABI, xii + 771 pp.

Klepzig KD; Slippers B; Wingfield MJ, 2009. Competition between fungi associated with Sirex woodwasp and Southern Pine Beetle. Proceedings of the 19th Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.]. Pennsylvania, USA: USDA Forest Service.

Kobayashi T, 2007. Index of Fungi Inhabiting Woody Plants in Japan. Host, Distribution and Literature. Tokyo, Japan: Zenkoku-Noson-Kyiku Kyokai Publishing Co., 1227 pp.

Kobayashi T; Sasaki K; Enda N, 1978. Correlation between Sirex nitobei and Amylostereum areolatum, associated with the death of Japanese pine trees during winter season. Journal of the Japanese Forestry Society, 60(11):405-411.

Luszczynski J, 1997. Interesting macromycetes found in Kielce town (Central Poland). Acta Mycologica, 32:207-228.

Madden JL, 1981. Egg and larval development in the woodwasp, Sirex noctilio F. Australian Journal of Zoology, 29(4):493-506.

Martínez AS; Fernández-Arhex V; Corley JC, 2006. Chemical information from the fungus Amylostereum areolatum and host-foraging behaviour in the parasitoid Ibalia leucospoides. Physiological Entomology, 31(4):336-340.

Neumann FG; Marks GC, 1990. Status and management of insect pests and diseases in Victorian softwood plantations. Australian Forestry, 53(2):131-144; 49 ref.

Rawlings GB, 1955. Epidemics in Pinus radiata forests in New Zealand. New Zealand Journal of Forestry, 7:53-55.

Rebuffo S, 1990. La "Avispa de la Madera" Sirex noctilio F. en el Uruguay. Montevideo: Dir. For:1-17.

Schiff NM, 2008. Sirex noctilio: overview of biology and control. Washington DC, USA: USDA.

Shields L, 2009. Update on Sirex noctilio in Canada. Proceedings of the 19th Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.]. Pennsylvania, USA: USDA Forest Service, 69.

Slippers B; Wingfield BD; Coutinho TA; Wingfield MJ, 2002. DNA sequence and RFLP data reflect geographical spread and relationships of Amylostereum areolatum and its insect vectors. Molecular Ecology, 11(9):1845-1854.

Slippers B; Wingfield MJ; Coutinho TA; Wingfield BD, 2001. Population structure and possible origin of Amylostereum areolatum in South Africa. Plant Pathology, 50(2):206-210.

Slippers B; Wingfield MJ; Wingfield BD; Coutinho TA, 2000. Relationships among Amylostereum species associated with siricid woodwasps inferred from mitochondrial ribosomal DNA sequences. Mycologia, 92:955-963.

Spradbery JP; Kirk AA, 1978. Aspects of the ecology of siricid woodwasps (Hymenoptera: Siricidae) in Europe, North Africa and Turkey with special reference to the biological control of Sirex noctilio F. in Australia. Bulletin of Entomological Research, 68(2):341-359.

Stalpers JA, 1978. Identification of wood-inhabiting fungi in pure culture. Studies in Mycology, No. 16:248 pp.

Tabata M; Abe Y, 1997. Amylostereum laevigatum associated with the Japanese horntail, Urocerus japonicus. Mycoscience, 38(4):421-427.

Tabata M; Harrington TC; Chen Wei; Abe Y, 2000. Molecular phylogeny of species in the genera Amylostereum and Echinodontium. Mycoscience, 41(6):585-593; 39 ref.

Talbot PHB, 1977. The Sirex-Amylostereum-Pinus association. Annual Review of Phytopathology, 15:41-54.

Thomsen IM, 1998. Characters of fruitbodies, basidiospores and cultures useful for recognizing Amylostereum areolatum and A. chailletii. Mycotaxon, 69:419-428.

Thomsen IM; Koch J, 1999. Somatic compatibility in Amylostereum areolatum and A. chailletii as a consequence of symbiosis with siricid woodwasps. Mycological Research, 103(7):817-823.

Tribe GD, 1995. The woodwasp Sirex noctilio Fabricius (Hymenoptera: Siricidae), a pest of Pinus species, now established in South Africa. African Entomology, 3(2):215-217

Tribe GD; Cillié JJ, 2004. The spread of Sirex noctilio Fabricius (Hymenoptera: Siricidae) in South African pine plantations and the introduction and establishment of its biological control agents. African Entomology, 12(1):9-17.

UK CAB International, 2009. Sirex noctilio (Fabricius, 1793), woodwasp. [pest/pathogen]. Crop Protection Compendium, AQB CPC record:Sheet 2268.

Vasiliauskas R; Johannesson H; Stenlid J, 1999. Molecular relationships within the genus Amylostereum as determined by internal transcribed spacer sequences of the ribosomal DNA. Mycotaxon, 71:155-161.

Vasiliauskas R; Stenlid J, 1999. Vegetative compatibility groups of Amylostereum areolatum and A. chailletii from Sweden and Lithuania. Mycological Research, 103(7):824-829.

Vasiliauskas R; Stenlid J; Johansson M, 1996. Fungi in bark peeling wounds of Picea abies in central Sweden. European Journal of Forest Pathology, 26(6):285-296.

Vasiliauskas R; Stenlid J; Thomsen IM, 1998. Clonality and genetic variation in Amylostereum areolatum and A. chailletii from northern Europe. New Phytologist, 139:751-758.

Webber JF; Gibbs JN, 1989. Insect dissemination of fungal pathogens of trees. Insect-fungus interactions. 14th Symposium of the Royal Entomological Society of London in collaboration with the British Mycological Society [edited by Wilding, N.; Collins, N.M.; Hammond, P.M.; Webber, J.F.] London, UK; Academic Press, 161-193

Williams DW; Mastro V, 2009. Evaluation of Beddingia siricidicola as a biological control agent of Sirex noctilio in North America. Proceedings of the 19th Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.].

Wilson AD; Schiff NM; Haugen DA; Hoebeke ER, 2009. First report of Amylostereum areolatum in pines in the United States. Plant Disease, 93(1):108. HTTP://

Yemshanov D; McKenney DW; deGroot P; Haugen D; Sidders D; Joss B, 2009. An assessment of Sirex noctilio spread and potential impacts on pine wood supply and harvests in eastern Canada. Proceedings of the Interagency Research Forum on Invasive Species 2008 [ed. by U. S. D. A.]. Pennsylvania, USA: USDA Forest Service.

Zhang XQ, 2005. Basidiomycetes. I. Cantharellales, Hymenochaetales, Polyporales, Thelephorales and other aphyllophoralean fungi. In: Fungi of Northwestern China [ed. by Zhuang, W.]. Ithaca, USA: Mycotaxon Ltd, 305-321.

Links to Websites

Top of page
Exotic forest Pest Information System for North America
International Sirex Symposium, South Africa, May 2007
IUCN-ISSG Invasive Species Group
US Dept of Agriculture - APHIS


Top of page

10/09/09 Original text by:

Systematic Mycology & Microbiology Laboratory, USDA-ARS, 10300 Baltimore Ave., Beltsville, MD 20705, USA


Distribution Maps

Top of page
You can pan and zoom the map
Save map