Scorias spongiosa is a sooty mould fungus that grows on aphid honeydew. It is a member of the Capnodiaceae family of ascomycete fungi. It is found only on American beech trees, Fagus grandifolia.
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The aphids accumulate in late summer and autumn, forming large colonies. Spores of Scorias spongiosa are borne by wind and rain and fall on the honeydew secretions found below the aphids. The first hyphal growth is straw coloured and unpigmented. The hyphae adhere to each other for short distances, diverging and re-adhering to form a loose stranded structure.
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Pigmentation begins to occur on the surfaces of outer strands and the stroma begins to darken. The hyphae coalesce and form mycelial strands which radiate outward and upward from the supporting structure.Reynolds DR. 1978. Foliicolous ascomycetes 1: The capnodiaceous genus Scorias, reproduction Flask-shaped, spore-bearing pycnidia appear on the mycelia, which have a waxlike appearance: the matrix turns from brittle to soft as it absorbs moisture.
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Below these colonies, deposits of sooty mold develop caused by the fungus Scorias spongiosa growing saprophytically on the honeydew the insects exude. This is also harmless to the trees. Beech leaf disease, first discovered in Ohio in 2012, is thought to be caused by nematodes. It has spread to several other states as well as Canada and has the potential to kill millions of trees throughout North America and may threaten the beeches of Europe as well.
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One of its tephras overlies an older formation that was erupted 1400 BP. Lavas from this cone form a peninsula in Lake Epulafquen and modified the local hydrography. Another cinder cone La Angostura formed a peninsula separating the lakes Epulafquen and Huechulafquen. This cone has three craters. A tephra layer of black trachyandesite has been linked to Huanquihue and is dated 4028-4212 BP. Varve count dating has indicated that tephras in Lake Villarrica and Lake Calafquen erupted presumably in 1591 are compositionally similar to Huanquihue scorias.
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UMass: The Beech Blight Aphid Beech blight aphids moving in unison - doing the Boogie Woogie Deposits of sooty mold caused by the fungus Scorias spongiosa build up below the colonies growing on the copious amounts of honeydew the insects exude.Tom Volk's Fungus of the Month The aphids do not usually cause much damage to overall tree health, but dieback is occasionally seen on very heavily infested branches. If infestations are heavy, twigs may die, but damage to the tree is usually minor. The aphids can be blasted off with a jet of water or can be controlled with any insecticides labeled for aphids.
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Blocks of red, cemented scoria within the Painted Dunes lava flows (photo) are pieces of this earlier cone, which were carried away by the flowing lava. When Cinder Cone formed, the magma feeding the eruption changed composition, shifting from basaltic andesite to andesite before returning to basaltic andesite with increased titanium content. While basaltic andesites are volcanic rocks containing 53 to 57% silica, andesites are those containing 57 to 63% silica. The lava flows and scorias at the volcano closely resemble each other despite distinct chemical compositions, forming dark, fine-grained rocks, with a few visible crystals of the minerals olivine, plagioclase, and quartz.
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The ecology of the different species, their interactions, relationship to the host have been little understood. A chance observation of a Microcyclospora tardicrescens inhibiting the growth of the fruit pathogen Colletotrichum fioriniae in dual culture tests, yielded trichothecolone acetate and its (S)-7-hydroxy derivative as active principles for the interaction between M. tardicrescens and C. fioriniae. Genera causing sooty molds are Alternaria, Cladosporium, Aureobasidium, Antennariella, Limacinula, Scorias, Meliola, and Capnodium. Sooty mold grows particularly well on plants that produce a sugary exudate, if they are infested by honeydew secreting insects such as aphids, scales and the whitefly, or when infested by insects that suck sap from the host plant.
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Scorias spongiosa is a specialist and grows exclusively on the honeydew formed by colonies of the beech blight aphid, Grylloprociphilus imbricator. This aphid is found only on one host plant, the American beech tree, Fagus grandifolia, where it congregates on branches and twigs, creating copious amounts of honeydew that drip onto vegetation below.UMass Extension: The Beech Blight Aphid The large quantity of honeydew enables this fungus to grow to a large size, much bigger than other sooty mould fungi, which produce only a thin black layer on the surface of leaves. On tree trunks this fungus has been known to grow into a mass of hyphae as big as a football, but it is more usual for the agglomeration on branches or twigs to reach a diameter of about fifteen centimetres.
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