Leptographium procerum (white pine root decline)
Index
- Pictures
- Identity
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Description
- Distribution Table
- Risk of Introduction
- Habitat
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Growth Stages
- Symptoms
- List of Symptoms/Signs
- Biology and Ecology
- Means of Movement and Dispersal
- Plant Trade
- Impact Summary
- Impact
- Environmental Impact
- Diagnosis
- Detection and Inspection
- Similarities to Other Species/Conditions
- Prevention and Control
- References
- Distribution Maps
Don't need the entire report?
Generate a print friendly version containing only the sections you need.
Generate reportIdentity
Top of pagePreferred Scientific Name
- Leptographium procerum W.B. (Kendr.) M.J. Wingf. 1985
Preferred Common Name
- white pine root decline
Other Scientific Names
- Verticicladiella procera W.B. Kendr. 1962
International Common Names
- English: Leptographium root decline; Procerum root disease; white pine root disease; white pine wilt
EPPO code
- LEPGPR (Leptographium procerum)
Summary of Invasiveness
Top of pageTaxonomic Tree
Top of page- Domain: Eukaryota
- Kingdom: Fungi
- Phylum: Ascomycota
- Subphylum: Pezizomycotina
- Class: Sordariomycetes
- Subclass: Sordariomycetidae
- Order: Ophiostomatales
- Family: Ophiostomataceae
- Genus: Leptographium
- Species: Leptographium procerum
Notes on Taxonomy and Nomenclature
Top of pageWingfield (1985) reduced Verticicladiella to synonymy with Leptographium. This synonymy was based on the fact that species in the two genera were indistinguishable under the light microscope. These findings were confirmed by Van Wyk and Wingfield (1987) and Van Wyk et al. (1988) who showed that delayed secession of the conidia that develop percurrently can lead to a false impression of sympodial development when viewed under the light microscope. Verticicladiella procera was transferred to Leptographium and renamed as Leptographium procerum (Wingfield, 1985).
Disease symptoms caused by L. procerum have been described under several different names. The first of these was white pine root decline, which occurs on Pinus strobus (Leaphart, 1960) and in Christmas tree plantations where it can reach epidemic proportions (Lackner and Alexander, 1982). This disease was also known as Leptographium root decline (Dochinger, 1967), white pine wilt and white pine root disease (Lackner and Alexander, 1982) before it was suggested that the name Procerum root disease should be used (Alexander et al., 1988). Red pine decline disease on Pinus resinosa has also been attributed to L. procerum infection (Klepzig et al., 1995).
Description
Top of pageDistribution Table
Top of pageThe 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: 17 Feb 2021Continent/Country/Region | Distribution | Last Reported | Origin | First Reported | Invasive | Reference | Notes |
---|---|---|---|---|---|---|---|
Africa |
|||||||
South Africa | Present | Introduced | |||||
Europe |
|||||||
Croatia | Present | ||||||
Italy | Present | ||||||
Norway | Present | ||||||
Poland | Present | ||||||
Serbia | Present | ||||||
Sweden | Present | ||||||
United Kingdom | Present | ||||||
North America |
|||||||
Canada | Present | Present based on regional distribution. | |||||
-Ontario | Present | Native | |||||
-Quebec | Present | Native | |||||
United States | Present | Present based on regional distribution. | |||||
-Alabama | Present | Native | |||||
-Connecticut | Present | Native | |||||
-Florida | Present | Native | |||||
-Indiana | Present | Native | |||||
-Kentucky | Present | Native | |||||
-Maryland | Present | Native | |||||
-Michigan | Present | Native | |||||
-Minnesota | Present | Native | |||||
-New Mexico | Present | Native | |||||
-New York | Present | Native | |||||
-North Carolina | Present | Native | |||||
-Ohio | Present | Native | |||||
-Oregon | Present | Native | |||||
-Pennsylvania | Present | Native | |||||
-South Carolina | Present | Native | |||||
-Tennessee | Present | Native | |||||
-Virginia | Present | Native | |||||
-Washington | Present | Native | |||||
-West Virginia | Present | Native | |||||
-Wisconsin | Present | Native | |||||
Oceania |
|||||||
New Zealand | Present | Introduced | Invasive |
Risk of Introduction
Top of pageL. procerum has also been isolated from severely diseased trees (Leaphart, 1960). Lackner and Alexander (1982) viewed the fungus as the cause of severe losses in Christmas tree plantations. In contrast to the results of Harrington and Cobb (1983) and Wingfield (1983, 1986), pathogenicity tests carried out by Halambek (1976, 1981) and Alexander et al. (1988) using isolates of L. procerum confirmed its ability to kill seedlings. Nevill and Alexander (1992a) postulated that the lack of foliar symptoms observed by Wingfield (1986) might be as a result of a long latent period of this fungus.
The debate surrounding the role of L. procerum as a conifer pathogen has not been fully resolved. The fungus is substantially less virulent than L. wageneri and a general consensus seems to be that it cannot kill trees independently. It is commonly associated with root and root collar insects (Wingfield, 1983). Symptoms associated with insects such as pine root collar weevil (Hylobius radicis) on young trees are similar to those reported for white pine root decline and this may have led to confusion relating to the role of L. procerum as a pathogen (Wingfield, 1986). It is therefore difficult to predict the impact L. procerum will have if introduced to a new area.
Habitat
Top of pageHosts/Species Affected
Top of pageHosts trees of L. procerum include: Abies fraseri (Alexander et al., 1988), A. grandis (Lane and Goheen, 1979), Picea abies (Hallaksela, 1977; Alexander et al., 1988), Pinus banksiana (Kendrick, 1962; Wingfield, 1982, 1983; Alexander et al., 1988), P. clausa (Barnard et al., 1985; Alexander et al., 1988), P. contorta (Alexander et al., 1988; Bertagnole et al., 1983), P. echinata (Horner and Alexander, 1983a; Alexander et al., 1988), P. elliotii (Horner and Alexander, 1983a; Alexander et al., 1988; Barnard et al., 1991), P. monticola (Hubert, 1953; Alexander et al., 1988), P. nigra (Lackner and Alexander, 1982; Livingston and Wingfield, 1982; Wingfield, 1982; Alexander et al., 1988), P. palustris (Otrosina et al., 1999, 2002), P. pinaster (Morelet, 1986), P. ponderosa (Wingfield, 1982; Alexander et al., 1988), P. radiata (Mackenzie and Dick, 1984; Farrell et al., 1997a, b), P. resinosa (Kendrick, 1962; Towers, 1977; Sinclair and Hudler, 1980; Halambek, 1981; Livingston and Wingfield, 1982; Wingfield, 1982; Harrington, 1988; Alexander et al., 1988), P. strobus (Kendrick, 1962; Dochinger, 1967; Halambek, 1976; Houston, 1969; Towers, 1977; Shaw and Dick, 1979; Sinclair and Hudler, 1980; Lackner and Alexander, 1982, 1984; Livingston and Wingfield, 1982; Wingfield, 1982; Horner and Alexander, 1983a, b; Mackenzie and Dick, 1984; Alexander et al., 1988; Smith, 1991), P. sylvestris (Wingfield and Gibbs, 1991; Lackner and Alexander, 1982, 1984; Wingfield, 1982; Horner and Alexander, 1983b; Rane and Tattar, 1987; Alexander et al., 1988; Harrington, 1988); P. taeda (Horner and Alexander, 1983a; Alexander et al., 1988; Nevill et al., 1995), P. thunbergii (Rane and Tattar, 1987), P. virginiana (Horner and Alexander, 1983a; Alexander et al., 1988) and Pseudotsuga menziesii (Alexander et al., 1988; Morrison and Hunt, 1988).
Host Plants and Other Plants Affected
Top of pagePlant name | Family | Context | References |
---|---|---|---|
Abies fraseri (Fraser fir) | Pinaceae | Other | |
Abies grandis (grand fir) | Pinaceae | Other | |
Picea abies (common spruce) | Pinaceae | Other | |
Pinus banksiana (jack pine) | Pinaceae | Other | |
Pinus clausa (sand pine) | Pinaceae | Other | |
Pinus contorta (lodgepole pine) | Pinaceae | Other | |
Pinus echinata (shortleaf pine) | Pinaceae | Other | |
Pinus elliottii (slash pine) | Pinaceae | Other | |
Pinus monticola (western white pine) | Pinaceae | Other | |
Pinus nigra (black pine) | Pinaceae | Other | |
Pinus palustris (longleaf pine) | Pinaceae | Other | |
Pinus pinaster (maritime pine) | Pinaceae | Other | |
Pinus ponderosa (ponderosa pine) | Pinaceae | Other | |
Pinus radiata (radiata pine) | Pinaceae | Other | |
Pinus resinosa (red pine) | Pinaceae | Other | |
Pinus strobus (eastern white pine) | Pinaceae | Main | |
Pinus sylvestris (Scots pine) | Pinaceae | Other | |
Pinus taeda (loblolly pine) | Pinaceae | Other | |
Pinus thunbergii (Japanese black pine) | Pinaceae | Other | |
Pinus virginiana (scrub pine) | Pinaceae | Other | |
Pseudotsuga menziesii (Douglas-fir) | Pinaceae | Other |
Symptoms
Top of pageIn inoculation studies using Leptographium isolated from western white pine (Pinus monticola), symptoms appeared about 25-35 days after inoculation and tree death occurred 35-40 days after inoculation (Hubert, 1953). One of the first symptoms to appear, in both inoculation studies and natural infections, is a reduction in height growth, followed by crown discoloration. A dark stain can be observed in the roots of the diseased trees, which rapidly progresses upwards in the tree (Leaphart, 1960; Alexander et al., 1988). In severe infections, marked resin exudation is observed (Alexander et al., 1988). Symptoms associated with white pine root decline include extended periods of bud break, retardation of shoot elongation, crooking of growing shoots, loss of turgour in older needles, wilting of younger needles (Hubert, 1953; Dochinger, 1967; Halambek, 1976; Pest Alert, 1977; Smith, 1991), retention of needles, needle wilt, browning of needles, and resin-soaked, black-streaked wood at the base of stems and basal cankers (Houston, 1969; Pest Alert, 1977; Towers, 1977; Anderson and Alexander, 1979; Mackenzie and Dick, 1984; Alexander et al., 1988; Smith, 1991; Otrosina et al., 1997). The basal cankers are at first circular to irregular, reddish, sunken areas, which in some cases enlarge and coalesce to form larger flattened cankers (Houston, 1969). Colonized roots are resin-soaked and cross-sections of the stems reveal prominent wedges of blue-stained wood. Discoloration of the sapwood is consistent with the patterns and physiology of blue-stain fungi (Alexander et al., 1988). In some cases the roots show diffuse black streaking (Livingston and Wingfield, 1982).
L. procerum acts in a similar way to wilt pathogens. It occurs in the vascular system, where it erodes the cell walls and travels from cell to cell through the pits (Kilbertus et al., 1980). White pine infected with L. procerum showed greater vascular occlusion, lower moisture content and reduced hydraulic conductivity than non-infected trees (Butnor et al., 2000). The water in the stem is reduced, leading to desiccation of the sapwood and foliage and ultimately premature death (Butnor et al., 2000).
Reduced water potential in symptomatic trees supports the notion that this root disease is associated with xylem dysfunction (Horner et al., 1987). Tree death occurs when the xylem is blocked by resin (Alexander et al., 1988). Symptoms were found to vary between Pinus strobus and P. sylvestris; it takes longer for symptoms to appear on P. sylvestris (Horner and Alexander, 1983b).
Red pine decline disease is characterized by circular regions of dead and dying trees that expand gradually. The root systems of these trees show high levels of mortality and several fungi (L. terebrantis, L. procerum and Ophiostoma ips) can be isolated from stained areas (Klepzig et al., 1995; Erbilgin and Raffa, 2002).
List of Symptoms/Signs
Top of pageSign | Life Stages | Type |
---|---|---|
Growing point / wilt | ||
Leaves / wilting | ||
Leaves / yellowed or dead | ||
Roots / rot of wood | ||
Stems / discoloration | ||
Stems / gummosis or resinosis | ||
Stems / internal feeding | ||
Stems / mould growth on lesion | ||
Whole plant / plant dead; dieback | ||
Whole plant / wilt |
Biology and Ecology
Top of pageJacobs et al. (2001) found that L. procerum was phylogenetically most closely related to Leptographium terebrantis. Although they share a common habitat, these species are morphologically distinct.
Physiology and Phenology
L. procerum is characterized by the presence of cellulose in its cell walls, a characteristic shared with other species of Ophiostoma (Horner et al., 1986).
Hubert (1953) showed that extracts from L. procerum could induce wilt and death in tomato seedlings, indicating that a toxin could be involved.
Environmental Requirements
White pine root decline appears to be linked to stress conditions (Alexander et al., 1988). The disease was found to be prevalent in areas with heavy soil moisture or drought conditions (Prey, 1975). It was also noticed in trees planted in poorly-drained sites and those infested by other pathogens (Towers, 1977). L. procerum, together with L. terebrantis, was isolated from symptomatic and asymptomatic trees that were stressed as a result of prescribed burning practices (Otrosina et al., 2002). The presence of L. procerum in Pinus palustris could also be seen as an indicator of stress (Otrosina et al., 1999). Trees exposed to air pollution are also more prone to infection by L. procerum and insects (Lackner and Alexander, 1983).
Red pine decline, which is also associated with the presence of L. procerum, mainly occurs on sandy soils. Stressed conditions can play a role in this disease as they create favourable conditions for attack by the insects that vector the fungus (Klepzig et al., 1991).
Associations
L. procerum has been isolated from the roots of trees infested with black stain root disease (Bertagnole et al., 1983). This disease is caused by a species in the same genus, Leptographium wageneri. Both white pine root decline and red pine decline appear to be caused by a complex of organisms, involving a number of insects and beetles, rather than by a single organism (Otrosina et al., 1999; Erbilgin and Raffa, 2002). Although L. procerum has been associated with the symptoms of white pine root decline, it does not seem to be the primary cause of the disease (Hubert, 1953).
The disease is not prevalent on healthy, unstressed trees, but readily occurs on trees that are stressed (Livingston and Wingfield, 1982). L. procerum appears to be of minor importance in tree mortality and occurs in weevil-damaged trees (Wingfield, 1982; Nevill and Alexander, 1992a). In most cases, L. procerum is isolated, together with L. terebrantis, from trees showing symptoms of insect damage (Livingston et al., 1983; Wingfield, 1983; Rane and Tattar, 1987). L. terebrantis appears to be more virulent than L. procerum (Rane and Tattar, 1987; Klepzig et al., 1996). Barnard et al. (1985) reported that in half of the cases of sand pine root disease, L. procerum was isolated together with a known root pathogen. Houston (1969) found that cankers on Pinus strobus caused by L. procerum infection were almost always associated with damage by snow, ice and the activities of ants.
Means of Movement and Dispersal
Top of pageL. procerum can spread over short distances through soil or root contact. Propagules of L. procerum can survive in the soil around infected hosts for a short period of time (Lackner and Alexander, 1984; Alexander et al., 1988). These propagules are sparsely, and not uniformly, distributed throughout the soil and are therefore unlikely to be the major source of infection (Lewis and Alexander, 1985; Lewis et al., 1987; Alexander et al., 1988). L. procerum can also be spread through root contact between infected and uninfected trees (Lackner and Alexander, 1984).
Vector Transmission
L. procerum is known to be associated with insects, especially weevils (Wingfield, 1985; Lewis and Alexander, 1986; Nevill and Alexander, 1992a, c; Lévieux et al., 1994). These insects usually feed on the roots and root collar. Wingfield et al. (1988) proposed that the association of L. procerum with these insects explains the occurrence of the fungus in trees other than those dying from white pine root decline.
Trees infected with L. procerum are usually also infested with insects that may act as vectors for the fungus (Alexander et al., 1988). Weevils are the main vectors, with bark beetles less commonly associated with the fungus (Wingfield, 1983; Lewis and Alexander, 1986; Horner et al., 1987; Alexander et al., 1988). Volatiles such as ethanol and terpenes are often released from trees infected with L. procerum and may play an important role in the association of the insects with the trees (Nevill and Alexander, 1992a).
Insects associated with L. procerum are: Dendroctonus frontalis (Otrosina et al., 1997), Dendroctonus valens (Wingfield, 1983; Rane and Tattar, 1987; Harrington, 1988; Klepzig et al., 1991), Dendroctonus terebrans (Harrington, 1988; Perry, 1991), Hylastes sp. (Lewis and Alexander, 1986; Alexander et al., 1988), Hylastes ater (Mackenzie and Dick, 1984), Hylastes opacus (Wingfield and Gibbs, 1991), Hylastes abietis (Lévieux et al., 1994), Hylastes pales (Lackner and Alexander, 1982; Wingfield, 1983; Lewis and Alexander, 1986; Alexander et al., 1988; Klepzig et al., 1991; Nevill and Alexander, 1992a, b, c, d), Hylobius radicis (Wingfield, 1982, 1983; Alexander et al., 1988; Klepzig et al., 1991), Hylobius rhizophagus [H. assimilis] (Wingfield, 1982, 1983; Alexander et al., 1988), Hylobius porculus (Klepzig et al., 1991), Hylurgus ligniperda (Mackenzie and Dick, 1984), Hylurgops palliatus (Wingfield and Gibbs, 1991), Hylurgops porosus (Wagner, 1977), Ips typographus (Harrington, 1988), Orthotomicus spp. (Lewis and Alexander, 1986; Alexander et al., 1988), Pachylobius picivorus (Wingfield, 1983; Alexander et al., 1988; Klepzig et al., 1991), Pissodes spp. (Lewis and Alexander, 1986), Pissodes nemorensis (Lackner and Alexander, 1982; Alexander et al., 1988; Nevill and Alexander, 1992a, b, c, d), Pissodes pini (Kendrick, 1962; Livingston and Wingfield, 1982), Pityokteines sp. (Lackner and Alexander, 1984; Alexander et al., 1988), Pityogenes sp. (Lackner and Alexander, 1984; Lewis and Alexander, 1986; Harrington, 1988; Alexander et al., 1988), Pityophthorus sp. (Lackner and Alexander, 1984; Alexander et al., 1988), Tomicus piniperda (Gibbs and Inman, 1991) and Xyleborus sp. (Lewis and Alexander, 1986; Alexander et al., 1988).
Three root-feeding weevils, Hylobius radicis, H. pales and Pachylobium picivorus, are implicated in the cause of red pine decline (Klepzig et al., 1991).
Silvicultural Practices
Cultural practices that can cause wounds on the roots of Pinus trees should be seen as a risk factor for increasing white pine root decline (Horner and Alexander, 1983a), as damaged roots allow entry of the fungus. This disease is prevalent in areas where roads have been cleared or trees thinned out (Shaw and Dick, 1979). L. procerum could pose a threat to the regeneration of seedlings as it can easily spread through root grafts (Otrosina et al., 1999).
Plant Trade
Top of pagePlant parts liable to carry the pest in trade/transport | Pest stages | Borne internally | Borne externally | Visibility of pest or symptoms |
---|---|---|---|---|
Bark | fungi/hyphae; fungi/spores | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Growing medium accompanying plants | fungi/spores | Yes | Pest or symptoms usually invisible | |
Roots | fungi/hyphae; fungi/spores | Yes | Pest or symptoms usually visible to the naked eye | |
Seedlings/Micropropagated plants | fungi/hyphae; fungi/spores | Yes | Pest or symptoms usually visible to the naked eye | |
Stems (above ground)/Shoots/Trunks/Branches | ||||
True seeds (inc. grain) | fungi/hyphae; fungi/spores | Yes | Pest or symptoms usually invisible | |
Wood | fungi/spores | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope |
Plant parts not known to carry the pest in trade/transport |
---|
Leaves |
Impact Summary
Top of pageCategory | Impact |
---|---|
Animal/plant collections | None |
Animal/plant products | None |
Biodiversity (generally) | None |
Crop production | None |
Environment (generally) | None |
Fisheries / aquaculture | None |
Forestry production | Negative |
Human health | None |
Livestock production | None |
Native fauna | None |
Native flora | None |
Rare/protected species | None |
Tourism | None |
Trade/international relations | None |
Transport/travel | None |
Impact
Top of pageEnvironmental Impact
Top of pageDiagnosis
Top of pageDetection and Inspection
Top of pageSimilarities to Other Species/Conditions
Top of pageKendrick (1962) considered L. procerum to be similar to L. abietinum. These species could be distinguished on the basis of the broader, uncurved conidia, longer sporogenous apparatus and primary branches of L. procerum. L. procerum is also similar to L. alethinum, L. pityophilum and L. euphyes. All three species were initially misidentified as L. procerum, but can be separated from it on the basis of clear morphological differences. The most prominent distinguishing character is probably the characteristic concentric rings formed by mycelium of L. procerum in culture (Jacobs and Wingfield, 2001; Jacobs et al. 2001).
Leptographium albopini shares a habitat with L. procerum and has been isolated from the roots of Pinus strobus and P. edulis. However, it is easily distinguished from L. procerum by the conidiophores, which occur singly in L. albopini, not arranged in groups as in L. procerum (Wingfield et al., 1994). The conidia of L. albopini are also slightly larger than those of L. procerum (Wingfield et al., 1994).
Wingfield and Marasas (1980) isolated a species of Leptographium from the roots of Pinus pinaster in South Africa and described it as Verticicladiella alacris. This species differed from L. procerum in that the conidiophores were not arranged in groups as in L. procerum (Wingfield and Marasas, 1980). L. alacris was later synonymized with L. serpens, and is characterized by serpentine hyphal growth (Wingfield and Marasas, 1981).
Prevention and Control
Top of pageDue 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.
Procerum root disease can be controlled by planting trees on sites suitable for the species, controlling weevils and bark beetles, removing slash in and around the plantation, and controlling weeds (Alexander et al., 1988). It is advisable to allow sites to lie fallow for 1 year or to consider planting non-susceptible trees (Lewis, 1985). Salmon et al. (1996) found that some natural compounds (e.g. R (-) carvone, S (-) carvone and limonin) could inhibit the germination of L. procerum conidia. However, these compounds only suppressed germination of the conidia and did not affect the growth of the fungus (Salmon et al., 1996).References
Top of pageAlexander SA; Horner WE; Lewis KJ, 1988. Leptographium procerum as a pathogen of pines. In: Harrington TC, Cobb FW Jr, eds. Leptographium Root Diseases on Conifers. St Paul, Minnesota, USA: American Phytopathological Society Press, 97-112.
Anderson RL; Alexander SA, 1979. How to identify and control white pine root decline. Forestry Bulletin, SA-FR/P6.
Dochinger LS, 1967. Leptographium root decline of eastern white pine. Phytopathology, 57:809.
Farrell RL; Hadar E; Kay; SJ; Blanchette RA; Harrington TC, 1997. Survey of sapstain organisms in New Zealand and albino anti-sapstain fungi. Proceedings: Biology and Prevention of Sapstain. British Columbia, Canada: Whistler.
Halambek M, 1976. Dieback of eastern white pine (Pinus strobus L.) in cultures. Agriculturae Conspectus Scientificus, 39:495-498.
Harrington TC, 1988. Leptographium species, their distributions, hosts and insect vectors. In: Harrington TC, Cobb FW Jr, eds. Leptographium Root Diseases on Conifers. St Paul, Minnesota, USA: American Phytopathological Society Press, 1-39.
Houston DR, 1969. Basal canker of white pine. Forest Science, 15:66-83.
Hubert EE, 1953. Studies of Leptographium isolated from western white pine. Phytopathology, 43:637-641.
Jacobs K; Wingfield MJ, 2001. Leptographium Species. Tree pathogens, insect associates and agent of bluestain. St Paul, MN, USA: APS Press.
Kendrick WB, 1962. The Leptographium complex. Verticicladiella S.Hughes. Canadian Journal of Botany, 40:771-797.
Klepzig KD; Raffa KF; Smalley EB, 1995. Dendroctonus valens and Hylastes porculus (Coleoptera: Scolytidae): vectors of pathogenic fungi (Ophiostomatales) associated with red pine decline disease. The Great Lakes Entomologist, 28:81-87.
Klepzig KD; Raffa KF; Smalley EB, 1996. Interactions of ecologically similar saprogenic fungi with healthy and abiotically stressed conifers. Forest Ecology and Management, 86:163-169.
Leaphart CD, 1956. Physiological studies of some fungi associated with pole blight of western white pine. Mycologia, 48:25-40.
Leaphart CD, 1960. A root stain disease of eastern white pine. Plant Disease Reporter, 44:704-706.
Lewis KJ, 1985. Studies on the spread of Verticicladiella procera by soil-borne and insect-borne propagules. MSc thesis. Virginia, USA: Faculty of the Virginia Polytechnic Institute and State University, 1-119.
Lewis KJ; Alexander SA, 1985. Germinability over time of Verticicladiella procera propagules in artificially infested soil and their inability to cause disease. Phytopathology, 75:1337.
Livingston WH; Wingfield MJ, 1982. First report of Verticicladiella procera on pines in Minnesota. Plant Disease, 66(3):260-261
Mackenzie M; Dick M, 1984. Verticicladiella root disease. Forest Pathology in New Zealand, 8:1-4.
Meyer GJ; Hindal DF; Quinn DO, 1983. Occurrence of white pine root decline in western Virginia. Phytopathology, 73, 967.
Morrison DJ; Hunt RS, 1988. Leptographium species associated with root disease of conifers in British Columbia. In: Harrington TC, Cobb FW Jr, eds. Leptographium Root Diseases on Conifers. St Paul, Minnesota, USA: American Phytopathological Society Press, 81-95.
Orlic S; Harapin M; Halambek M; Mayer B, 1973. Dieback of eastern white pine (Pinus strobus L.) in cultures. Prestampani iz sumarkog lista br., 9-10.
Pest Alert, 1977. White Pine root decline. USDA-Forest Service. US Government Printing Office, 1977-751-868.
Prey AJ, 1975. Forest pest conditions in Wisconsin. Annual Report. Madison, Wisconsin, USA: Department of Natural Resources, 1-21.
Salmon SM; Gray JA; Alford AR; Mulesky M; Fettig; CJ; Woods SA, 1996. Evaluation of natural products as antifeedants for the Pales weevil (Coleoptera: Curculionidae) and as fungitoxins for Leptographium procerum. Journal of Entomological Science, 31:453-465.
Van Wyk PS; Wingfield MJ, 1987. Does sympodial development occur in Leptographium spp.? Phytophylactica, 19:127.
Van Wyk PS; Wingfield; MJ; Marasas WFO, 1988. Differences in synchronisation of stages of conidial development in Leptographium species. Transactions of the British Mycological Society, 90:451-456.
Wagner RE, 1977. Verticicladiella species associated with Hylurgops porosus LeConte (Coleoptera: Scolytidae) in lodgepole pine. MSc thesis. University of Idaho, Moscow: 1-15.
Wingfield MJ, 1982. Verticicladiella procera associated with root weevil damage. Phytopathology, 72:141.
Wingfield MJ; Capretti P; Mackenzie M, 1988. Leptographium spp. as root pathogens on conifers. An international perspective. In: Harrington TC, Cobb FW Jr, eds. Leptographium Root Diseases on Conifers. St Paul, Minnesota, USA: American Phytopathological Society Press, 113-128.
Zhou XD; De Beer ZW; Wingfield D; Wingfield MJ, 2001. Ophiostomatoid fungi associated with three pine-infesting bark beetles in South Africa. Sydowia, 53:290-300.
Distribution References
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI
CABI, Undated b. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Jacobs K, Wingfield MJ, 2001. Leptographium Species. Tree pathogens, insect associates and agent of bluestain., St Paul, MN, USA: APS Press.
Kendrick WB, 1962. The Leptographium complex. Verticicladiella S.Hughes. In: Canadian Journal of Botany, 40 771-797.
Meyer GJ, Hindal DF, Quinn DO, 1983. Occurrence of white pine root decline in western Virginia. In: Phytopathology, 73 967.
Orlic S, Harapin M, Halambek M, Mayer B, 1973. Dieback of eastern white pine (Pinus strobus L.) in cultures. In: Prestampani iz sumarkog lista br, 9-10.
Prey AJ, 1975. Forest pest conditions in Wisconsin. In: Annual Report, Madison, Wisconsin, USA: Department of Natural Resources. 1-21.
Distribution Maps
Top of pageSelect a dataset
Map Legends
-
CABI Summary Records
Map Filters
Unsupported Web Browser:
One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/