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Aschersonia Aleyrodis
''Aschersonia aleyrodis'' is a fungal pathogen affecting various species of insect. It has been shown to control the silverleaf whitefly (''Bemisia tabaci'') in laboratory and greenhouse conditions. Description The stroma of ''Aschersonia aleyrodis'' forms a hemispherical or cushion-shaped mass about wide and high, surrounded by a thin ring of hyphae that spreads across the leaf-surface. The conidia-forming zones consist of shallow pits in the stroma with pore-like openings. The conidia are elongated and cigar-shaped, and do not have septa. This fungus is cream, pink or pale orange, and the massed conidia are darker orange. The teleomorph of this fungus is '' Hypocrella''. Biological control of whitefly Whitefly are an increasing pest of greenhouse crops such as cucumber and tomato. The classical biological control is by the use of parasitoid wasps such as '' Encarsia formosa '', but aggressive strains of whitefly have emerged and results are unpredictable. Another approach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''true f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of extant species is estimated at between six and ten million; In: potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans, which recent research has indicated insects are nested within. Nearly all insects hatch from eggs. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silverleaf Whitefly
The silverleaf whitefly (''Bemisia tabaci'', also informally referred to as the sweet potato whitefly) is one of several species of whitefly that are currently important agricultural pests. A review in 2011 concluded that the silverleaf whitefly is actually a species complex containing at least 40 morphologically indistinguishable species. The silverleaf whitefly thrives worldwide in tropical, subtropical, and less predominately in temperate habitats. Cold temperatures kill both the adults and the nymphs of the species. The silverleaf whitefly can be confused with other insects such as the common fruitfly, but with close inspection, the whitefly is slightly smaller and has a distinct wing color that helps to differentiate it from other insects. While the silverleaf whitefly had been known in the United States since 1896, in the mid-1980s an aggressive strain appeared in poinsettia crops in Florida. For convenience that strain was referred to as (biotype B), to distinguish it f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroma (tissue)
Stroma () is the part of a tissue or organ with a structural or connective role. It is made up of all the parts without specific functions of the organ - for example, connective tissue, blood vessels, ducts, etc. The other part, the parenchyma, consists of the cells that perform the function of the tissue or organ. There are multiple ways of classifying tissues: one classification scheme is based on tissue functions and another analyzes their cellular components. Stromal tissue falls into the "functional" class that contributes to the body's support and movement. The cells which make up stroma tissues serve as a matrix in which the other cells are embedded. Stroma is made of various types of stromal cells. Examples of stroma include: * stroma of iris * stroma of cornea * stroma of ovary * stroma of thyroid gland * stroma of thymus * stroma of bone marrow * lymph node stromal cell * multipotent stromal cell (mesenchymal stem cell) Structure Stromal connective tissues are fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or more cells surrounded by a tubular cell wall. In most fungi, hyphae are divided into cells by internal cross-walls called "septa" (singular septum). Septa are usually perforated by pores large enough for ribosomes, mitochondria, and sometimes nuclei to flow between cells. The major structural polymer in fungal cell walls is typically chitin, in contrast to plants and oomycetes that have cellulosic cell walls. Some fungi have aseptate hyphae, meaning their hyphae are not partitioned by septa. Hyphae have an average diameter of 4–6 µm. Growth Hyphae grow at their tips. During tip growth, cell walls are extended by the external assembly and polymerization of cell wall components, and the internal production of new cell membrane. The S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidium
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the way they are generated through the cellular process of mitosis. The two new haploid cells are genetically identical to the haploid parent, and can develop into new organisms if conditions are favorable, and serve in biological dispersal. Asexual reproduction in ascomycetes (the phylum Ascomycota) is by the formation of conidia, which are borne on specialized stalks called conidiophores. The morphology of these specialized conidiophores is often distinctive between species and, before the development of molecular techniques at the end of the 20th century, was widely used for identification of (''e.g.'' ''Metarhizium'') species. The terms microconidia and macroconidia are sometimes used. Conidiogenesis There are two main types of co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleomorph, Anamorph And Holomorph
In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an asexual reproductive stage (morph), often mold-like. When a single fungus produces multiple morphologically distinct anamorphs, these are called synanamorphs. *Holomorph: the whole fungus, including anamorphs and teleomorph. Dual naming of fungi Fungi are classified primarily based on the structures associated with sexual reproduction, which tend to be evolutionarily conserved. However, many fungi reproduce only asexually, and cannot easily be classified based on sexual characteristics; some produce both asexual and sexual states. These problematic species are often members of the Ascomycota, but a few of them belong to the Basidiomycota. Even among fungi that reproduce both sexually and asexually, often only one method of reproduction can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypocrella
''Hypocrella''Sacc. (1878) ''Michelia'' 1(no. 3): 322. is a genus of fungi in the family Clavicipitaceae. Species The Catalogue of Life The Catalogue of Life is an online database that provides an index of known species of animals, plants, fungi, and microorganisms. It was created in 2001 as a partnership between the global Species 2000 and the American Integrated Taxonomic I ... lists: * '' Hypocrella discoidea'' (Berk. & Broome) Sacc., 1878 (type sp.) * '' Hypocrella duplex'' * '' Hypocrella turbinata'' References External links * * {{Taxonbar, from=Q10530050 Clavicipitaceae Hypocreales genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitefly
Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described. Description and taxonomy The Aleyrodidae are a family in the suborder Sternorrhyncha and at present comprise the entire superfamily Aleyrodoidea, related to the superfamily Psylloidea. The family often occurs in older literature as "Aleurodidae", but that is a junior synonym and accordingly incorrect in terms of the international standards for zoological nomenclature. Aleyrodidae are small insects, most species with a wingspan of less than 3 mm and a body length of 1 mm to 2 mm. Many are so small that their size complicates their control in greenhouses because they can only be excluded by screening with very fine mesh; in fact they can enter mesh so fine that many of their natural enemies cannot come in after them, so that unchecked whitefly populations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Pest Control
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs. There are three basic strategies for biological pest control: classical (importation), where a natural enemy of a pest is introduced in the hope of achieving control; inductive (augmentation), in which a large population of natural enemies are administered for quick pest control; and inoculative (conservation), in which measures are taken to maintain natural enemies through regular reestablishment. Natural enemies of insect pests, also known as biological control agents, include predators, parasitoids, pathogens, and competitors. Biological control agents of plant diseases are most often referred to as antagonists. Biologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encarsia Formosa
''Encarsia formosa'' is a species of chalcidoid wasp and a well known parasitoid of greenhouse whitefly, one of the first to be used commercially for biological pest control, from the 1920s. They can use at least 15 species of whitefly as a host, including ''Bemisia tabaci'' and '' Aleyrodes proletella.'' The tiny females (about 0.6 mm long) are black with a yellow abdomen and opalescent wings. This species reproduces asexually via thelytoky induced by Wolbachia infection. Males are produced only rarely. They are slightly larger than females and are completely black in coloration. Life cycle Females deposit 50-100 eggs individually inside the bodies of nymphs or pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...e of the host species. The wasp larvae develop throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhouse Whitefly
''Trialeurodes vaporariorum'', commonly known as the glasshouse whitefly or greenhouse whitefly, is an insect that inhabits the world's temperate regions. Like various other whiteflies, it is a primary insect pest of many fruit, vegetable and ornamental crops. It is frequently found in glasshouses ( greenhouses), polytunnels, and other protected horticultural environments. Adults are 1–2 mm in length, with yellowish bodies and four wax-coated wings held near parallel to the leaf surface. Life cycle Females are capable of mating less than 24 hours after emergence and most frequently lay their eggs on the undersides of leaves. Eggs are pale yellow in colour, before turning grey prior to hatching. Newly hatched nymphs, often known as crawlers, are the only mobile immature life-stage. During the first and second nymph instars, the appearance is that of a pale yellow/translucent, flat scale which can be difficult to distinguish with the naked eye. During the fourth and final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
