Blue stain fungi (also known as sap stain fungi) is a vague term including various fungi that cause dark staining in sapwood. [1] The staining is most often blue, but could also be grey or black. Because the grouping is based solely on symptomatics, it is not a monophyletic grouping.
Depending on the author, the group can include between 100 and 250 species of ascomycetes and so-called deuteromycetes. They are usually divided into three different groups: [1]
Importance of the symbiotic relationship between blue stain fungi and bark beetles.
Symbiotic association between bark beetles and species of blue stain fungi is a well-known and studied phenomenon in the forestry pathology. Some bark beetle species like Mountain Pine Beetle (Dendroctonus ponderosae) feed on phloem layer just underneath the bark of a lodgepole pines when they are developing from larval to adult stage. Mountain Pine Beetle carry the spores of at least 2 known blue stain fungi species, Ophiostoma clavigerum and Ophiostoma montium. [2] These spores are carried on the exoskeleton of the beetles from one tree to another and aid the insects in overcoming defence mechanisms of different pine species. After the beetles initiate their attack and bore through the bark spores are released. These spores immediately start to multiply and block important conductive vessels within the tree tissues. The tree loses its ability to produce resin and to defend itself. [3]
Trade and pulp production problems associated with blue stain fungi
Developing spores of the blue stain fungi are a concern in packaging materials used for shipping from Canada to Australia due to the potential risk of introducing invasive species of fungi. [4]
According to Pulp and Paper Research Institute of Canada the wood infected with the blue stain fungus have a high proportion of fines that are not suitable for pulp production. [2]
The major economic damage caused by the blue stain fungi is aesthetic because of the usually undesirable discoloration of wood. Blue stain fungi do not affect the strength of wood. [5] In some cases the staining is desirable in fine wood crafting applications where it is called spalting.
Ascomycota or Endomycopsis, is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of Ascomycota are asexual and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewers' and bakers' yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.
Ambrosia beetles are beetles of the weevil subfamilies Scolytinae and Platypodinae, which live in nutritional symbiosis with ambrosia fungi. The beetles excavate tunnels in dead or stressed trees into which they introduce fungal gardens, their sole source of nutrition. After landing on a suitable tree, an ambrosia beetle excavates a tunnel in which it releases its fungal symbiont. The fungus penetrates the plant's xylem tissue, extracts nutrients from it, and concentrates the nutrients on and near the surface of the beetle gallery. Ambrosia fungi are typically poor wood degraders, and instead utilize less demanding nutrients. Symbiotic fungi produce and detoxify ethanol, which is an attractant for ambrosia beetles and likely prevents growth of antagonistic pathogens and selects for other beneficial symbionts. The majority of ambrosia beetles colonize xylem of recently dead trees, but some colonize stressed trees that are still alive, and a few species attack healthy trees. Species differ in their preference for different parts of trees, different stages of deterioration, and in the shape of their tunnels ("galleries"). However, the majority of ambrosia beetles are not specialized to any taxonomic group of hosts, unlike most phytophagous organisms including the closely related bark beetles. One species of ambrosia beetle, Austroplatypus incompertus exhibits eusociality, one of the few organisms outside of Hymenoptera and Isoptera to do so.
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.
The mountain pine beetle is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton, and measures approximately 5 millimetres, about the size of a grain of rice.
Resin acid refers to mixtures of several related carboxylic acids, primarily abietic acid, found in tree resins. Nearly all resin acids have the same basic skeleton: three fused rings having the empirical formula C19H29COOH. Resin acids are tacky, yellowish gums that are water-insoluble. They are used to produce soaps for diverse applications, but their use is being displaced increasingly by synthetic acids such as 2-ethylhexanoic acid or petroleum-derived naphthenic acids.
The term mycangium is used in biology for special structures on the body of an animal that are adapted for the transport of symbiotic fungi. This is seen in many xylophagous insects, which apparently derive much of their nutrition from the digestion of various fungi that are growing amidst the wood fibers. In some cases, as in ambrosia beetles, the fungi are the sole food, and the excavations in the wood are simply to make a suitable microenvironment for the fungus to grow. In other cases, wood tissue is the main food, and fungi weaken the defense response from the host plant.
Ophiostoma ulmi is a species of fungus in the family Ophiostomataceae. It is one of the causative agents of Dutch elm disease. It was first described under the name Graphium ulmi, and later transferred to the genus Ophiostoma.
Ophiostoma novo-ulmi is a species of fungus in the family Ophiostomataceae. It is one of the key causative agents associated with Dutch Elm Disease (DED), along with Ophiostoma ulmi and Ophiostoma himal-ulmi.
Porodaedalea pini, commonly known as the pine conk, is a species of fungus in the family Hymenochaetaceae. It is a plant pathogen that causes tree disease commonly known as "red ring rot" or "white speck". This disease, extremely common in the conifers of North America, decays tree trunks, rendering them useless for lumber. It is a rot of the heartwood. Signs of the fungus include shelf-shaped conks protruding from the trunks of trees. Spores produced on these conks are blown by the wind and infect other trees. Formal management of this disease is limited, and the disease is controlled primarily by cultural practices. Red ring rot is an important forest disturbance agent and plays a key role in habitat formation for several forest animals.
The mountain pine beetle has killed large numbers of the lodgepole pine trees in the northern mountains of the US state of Colorado. The more recent outbreak of another bark beetle pest, the spruce beetle, is threatening higher-elevation forests of Engelmann spruce. Chemical prevention is effective but too costly for large-scale use. Dead trees increase the incidence of wildfires. Uses have been found for the dead wood including composting and in construction, and potentially to make biochar.
Armillaria ostoyae is a species of fungus (mushroom), pathogenic to trees, in the family Physalacriaceae. In the western United States, it is the most common variant of the group of species under the name Armillaria mellea. A. ostoyae is common on both hardwood and conifer wood in forests west of the Cascade Range in Oregon, United States. It has decurrent gills and the stipe has a ring. The mycelium invades the sapwood and is able to disseminate over great distances under the bark or between trees in the form of black rhizomorphs ("shoestrings"). In most areas of North America, Armillaria ostoyae can be separated from other species by its physical features: cream-brown colors, prominent cap scales, and a well-developed stem ring distinguish it from other Armillaria. Like several other Armillaria, the mycelium of Armillaria ostoyae can display bioluminescence, resulting in foxfire.
The European spruce bark beetle, is a species of beetle in the weevil subfamily Scolytinae, the bark beetles, and is found from Europe to Asia Minor and some parts of Africa.
The sirex woodwasp is a species of horntail, native to Europe, Asia, and northern Africa. Adults vary in length from 9 to 36 mm.
Amylostereum is the single genus in the fungal family Amylostereaceae. The genus currently comprises four saprotrophic and parasitic species, which live off living or dead wood. The Amylostereaceae cause white rot in the wood by disintegrating the tissue component lignin. They produce crust-like, partially wavy fruit bodies on the surface of infested trees, which are similar to those produced by Stereum species.
The Canadian forestry industry is a major contributor to the Canadian economy. With 39% of Canada's land acreage covered by forests, the country contains 9% of the world's forested land. The forests are made up primarily of spruce, poplar and pine. The Canadian forestry industry is composed of three main sectors: solid wood manufacturing, pulp and paper and logging. Forests, as well as forestry are managed by The Department of Natural Resources Canada and the Canadian Forest Service, in cooperation with several organizations which represent government groups, officials, policy experts, and numerous other stakeholders. Extensive deforestation by European settlers during the 18th and 19th centuries has been halted by more modern policies. Today, less than 1% of Canada's forests are affected by logging each year. Canada is the 2nd largest exporter of wood products, and produces 12.3% of the global market share. Economic concerns related to forestry include greenhouse gas emissions, biotechnology, biological diversity, and infestation by pests such as the mountain pine beetle.
Hylastes ater is a species of beetle in the family Curculionidae, the true weevils. It is a bark beetle, a member of the subfamily Scolytinae. Its common name is the black pine bark beetle. It is native to Europe and parts of Asia, including China and Korea. It is known as an introduced species in many other regions, including Australia, New Zealand, the Americas, and South Africa. It is a pest of pines and other trees, and it is widespread in areas where pine trees are cultivated. The species "is an important threat to the biosecurity of all forested countries."
Ips is a genus of beetles in the family Curculionidae, the true weevils. They are bark beetles, members of the subfamily Scolytinae. Species are distributed throughout the Northern Hemisphere. Some are known as introduced species in Australia and Africa. Many species are pests of forest trees, especially pines and spruces. They are known commonly as engraver beetles, ips engraver beetles, and pine engravers.
Platypus apicalis, known by its common name the New Zealand pinhole boring beetle, is a wood-boring beetle endemic to New Zealand and found throughout the North and South Island in a range of environments.
Platypus cylindrus, commonly known as the oak pinhole borer, is a species of ambrosia beetle in the weevil family Scolytinae. The adults and larvae burrow under the bark of mature oak trees. It is native to Europe.
Dendroctonus valens, also known as the red turpentine beetle, is a species of bark beetle characterized by a dark-reddish brown hue. It is native to forests across North and Central America. In its adult form, these beetles range from six to ten millimeters in length. A notable characteristic about them is their use of acoustic signals and chemical cues when engaging in what is a very complex mating process.