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Walnut Twig Beetle
''Pityophthorus juglandis'', also known as the walnut twig beetle for feeding on several different species of walnut trees, ''Juglans'', is one of only a few species in the genus ''Pityophthorus'' that is associated with hardwoods and the only one associated with feeding on walnut trees. Description ''Pityophthorus juglandis'' can easily be distinguished from other members of its genus. Curtis Utley, a researcher at Colorado State University, elaborates on these differences stating, "Among these differences there are the 4 to 6 concentric rows of asperities on the prothorax, usually broken and overlapping at the median line. The declivity at the end of the wing covers is steep, very shallowlbisulcate and at the apex it is generally flattened with small granules." The walnut twig beetles' small size is common for its genus. Adult beetles average between 1.5 and 1.9 millimeters in length. Although little is known about the life-cycle of the walnut twig beetle, during experimentatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juglans Nigra
''Juglans nigra'', the eastern American black walnut, is a species of deciduous tree in the walnut family, Juglandaceae, native to North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central Texas. Wild trees in the upper Ottawa Valley may be an isolated native population or may have derived from planted trees. Black walnut is an important tree commercially, as the wood is a deep brown color and easily worked. Walnut seeds ( nuts) are cultivated for their distinctive and desirable taste. Walnut trees are grown both for lumber and food, and many cultivars have been developed for improved quality wood or nuts. Black walnut is susceptible to thousand cankers disease, which provoked a decline of walnut trees in some regions. Black walnut is anecdotally known for being allelopathic, which means that it releases chemicals from its roots and other tissues that may harm other organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juglans Californica
''Juglans californica'', the California black walnut, also called the California walnut, or the Southern California black walnut, is a large shrub or small tree (about 20-49 feet tall) of the walnut family, Juglandaceae, endemic to Southern California. Distribution ''Juglans californica'' is generally found in the southern California Coast Ranges, Transverse Ranges, and Peninsular Ranges. It grows as part of mixed woodlands, and also on slopes and in valleys wherever conditions are favorable. It is threatened by development and overgrazing. Some native stands remain in urban Los Angeles in the Santa Monica Mountains and Hollywood Hills. ''J. californica'' grows in riparian woodlands, either in single species stands or mixed with California's oaks (''Quercus'' spp.) and cottonwoods (''Populus fremontii''). Description ''Juglans californica'' can be either a large shrub with 1–5 trunks, or a small, single-trunked tree. The main trunk can fork close to the ground, making it loo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agar
Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar is a mixture of two components, the linear polysaccharide agarose and a heterogeneous mixture of smaller molecules called agaropectin. It forms the supporting structure in the cell walls of certain species of algae and is released on boiling. These algae are known as agarophytes, belonging to the Rhodophyta (red algae) phylum. The processing of food-grade agar removes the agaropectin, and the commercial product is essentially pure agarose. Agar has been used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture media for microbiological work. Agar can be used as a laxative; an appetite suppressant; a vegan substitute for gelatin; a thickener for soups; in fruit preserves, ice cream, and other desser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarantine
A quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been exposed to a communicable disease, yet do not have a confirmed medical diagnosis. It is distinct from medical isolation, in which those confirmed to be infected with a communicable disease are isolated from the healthy population. Quarantine considerations are often one aspect of border control. The concept of quarantine has been known since biblical times, and is known to have been practised through history in various places. Notable quarantines in modern history include the village of Eyam in 1665 during the bubonic plague outbreak in England; East Samoa during the 1918 flu pandemic; the Diphtheria outbreak during the 1925 serum run to Nome, the 1972 Yugoslav smallpox outbreak, the SARS pandemic, the Ebola pandemic and extensive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knoxville, Tennessee
Knoxville is a city in and the county seat of Knox County, Tennessee, Knox County in the U.S. state of Tennessee. As of the 2020 United States census, Knoxville's population was 190,740, making it the largest city in the East Tennessee Grand Divisions of Tennessee, Grand Division and the state's third largest city after Nashville, Tennessee, Nashville and Memphis, Tennessee, Memphis.U.S. Census Bureau2010 Census Interactive Population Search. Retrieved: December 20, 2011. Knoxville is the principal city of the Knoxville Metropolitan Area, Knoxville Metropolitan Statistical Area, which had an estimated population of 869,046 in 2019. First settled in 1786, Knoxville was the first capital of Tennessee. The city struggled with geographic isolation throughout the early 19th century. The History of rail transportation in the United States#Early period (1826–1860), arrival of the railroad in 1855 led to an economic boom. The city was bitterly Tennessee in the American Civil War#Tenne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch Elm Disease
Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America, Europe, and New Zealand. In these regions it has devastated native populations of elms that did not have resistance to the disease. The name "Dutch elm disease" refers to its identification in 1921 and later in the Netherlands by Dutch phytopathologists Marie Beatrice Schol-Schwarz, Bea Schwarz and Christine Buisman, who both worked with professor Johanna Westerdijk. The disease affects species in the genera ''Ulmus'' and ''Zelkova''; therefore it is not specific to the Ulmus × hollandica, Dutch elm hybrid. Overview Dutch elm disease (DED) is caused by ascomycete microfungi. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bark Beetles
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 spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food webfor example the purple sea urchin (''Strongylocentrotus purpuratus'') which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter (''Enhydra lutris''). Since the 20th century, invasive species have become a serious economic, social, and environmental threat. Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infectious Disease
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection. Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Specific medications used to treat infections include antibiotics, antivirals, antifungals, antiprotozoals, and antihelminthics. Infectious diseases resulted in 9.2 million deaths in 2013 (about 17% of all deaths). The branch of medicine that focuses on infections is referred to as infectious disease. Types Infections are caused by infectious agents (pathogens) including: * Bacteria (e.g. '' Mycobacterium tuberculosis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbiotic Relationship
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. The organisms, each termed a symbiont, must be of different species. In 1879, Heinrich Anton de Bary defined it as "the living together of unlike organisms". The term was subject to a century-long debate about whether it should specifically denote mutualism, as in lichens. Biologists have now abandoned that restriction. Symbiosis can be obligatory, which means that one or more of the symbionts depend on each other for survival, or facultative (optional), when they can generally live independently. Symbiosis is also classified by physical attachment. When symbionts form a single body it is called conjunctive symbiosis, while all other arrangements are called disjunctive symbiosis."symbiosis." Dorland's Illustrated Medical Dictionary. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geosmithia
''Geosmithia'' is a genus of anamorphic fungi of uncertain familial placement in the order Hypocreales. The genus, circumscribed by Australian mycologist John Pitt in 1979, is widely distributed. A 2008 estimate placed ten species in the genus, but several new species have since been described. Thousand cankers disease, which affects economically important black walnut (''Juglans nigra'') populations in North America, is caused by '' Geosmithia morbida''. Species in the genus are generally similar to those in ''Penicillium'', but can be distinguished from them by forming cylindrical conidia from rough-walled phialides. Additionally, the conidia of ''Geosmithia'' do not have a green color, in contrast to the characteristic blue-grey or green-grey conidia of ''Penicillium''. Some ''Geosmithia'' species have teleomorphic forms that are classified in the genus ''Talaromyces''. However, ''Geosmithia'' is a polyphyletic taxon with evolutionary affinities to at least three groups of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
