|
Laboulbeniales Genera
The Laboulbeniales is an order of Fungi within the class Laboulbeniomycetes. They are also known by the colloquial name beetle hangers or labouls. The order includes around 2,325 species of obligate insect ectoparasites that produce cellular thalli from two-celled ascospores. Of the described Laboulbeniales, Weir and Hammond 1997 find 80% to be from Coleoptera and the next largest group to be the 10% from Diptera. Recently, the genus ''Herpomyces'', traditionally considered a basal member of Laboulbeniales, was transferred to the order Herpomycetales based on molecular phylogenetic data. Laboulbeniales typically do not kill their hosts, although they may impair host fitness if the parasite density is high. Laboulbeniales form individual thalli, and lack vegetative hyphae. A thallus is attached to its host by a simple dark-colored foot cell, or a rhizoidal haustorium through which the fungus penetrates the exoskeleton of its host to draw nutrients from the hemolymph. The external ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperomyces Virescens
''Hesperomyces'' is a genus of fungi in the family Laboulbeniaceae. The genus contains ten species, including the type species, the Green Beetle Hanger ('' Hesperomyces virescens''). ''H. virescens'' is a complex of species. It is an ecoparasite of an invasive species to Europe and the Americas, the harlequin ladybird (''Harmonia axyridis''). Laboratory bioassays pointed out that ''Hesperomyces''-infected ladybirds suffered increased mortality rates. The fungus completes its entire life cycle on the tough outer layer or integument of a living host where individual fruiting bodies or thalli are formed directly from ascospores. The thalli can form on any part of the insect, but spore germination likely only occurs once the host cuticle has hardened. The spores are believed to have a short life span. Due to the spores' sticky nature, they are not transmitted by contact with substrate or the air. Instead they are spread directly by host activities and it is suggested that trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diptera
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing an estimated 1,000,000 species including horse-flies, crane flies, hoverflies and others, although only about 125,000 species have been described. Flies have a mobile head, with a pair of large compound eyes, and mouthparts designed for piercing and sucking (mosquitoes, black flies and robber flies), or for lapping and sucking in the other groups. Their wing arrangement gives them great maneuverability in flight, and claws and pads on their feet enable them to cling to smooth surfaces. Flies undergo complete metamorphosis; the eggs are often laid on the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyly
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. ource for pronunciation./ref> It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthetic plants, and edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major revisions of the classification schemes. Researchers concerned more with ecology than with syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each other, further blurring any distinctions. Terms that are sometimes used synonymously but have more precise meanings are cryptic species for two or more species hidden under one species name, sibling species for two (or more) species that are each other's closest relative, and species flock for a group of closely related species that live in the same habitat. As informal taxonomic ranks, species group, species aggregate, macrospecies, and superspecies are also in use. Two or more taxa that were once considered conspecific (of the same species) may later be subdivided into infraspecific taxa (taxa within a species, such as bacterial strains or plant varieties), that is complex but it is not a species complex. A species complex is in most ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roland Thaxter
Roland Thaxter (August 28, 1858 – April 22, 1932) was an American mycologist, plant pathologist, botanist, and entomologist, renowned for his contribution to the insect parasitic fungi—Laboulbeniales. His college education was completed at Harvard, where he dedicated forty years to mycological and botanical research. His five-volume series on fungi in the order Laboulbeniales laid a solid foundation of research on these insect ectoparasites. He also contributed to the field of Plant Pathology. Biography Roland Thaxter was born in Newtonville, Massachusetts, 1858, the third and youngest child in the family. His parents were Levi Thaxter and Celia (née Laighton) Thaxter. He married Mabel Gray Thaxter in 1887. Thaxter's personality was influenced greatly by his literary family. His father was a lawyer and an authority who brought the works of the poet Robert Browning to the American public. His mother, Celia Thaxter, was a distinguished poet, most well known for her book '' An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perithecia
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemolymph
Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which hemolymph cells called hemocytes are suspended. In addition to hemocytes, the plasma also contains many chemicals. It is the major tissue type of the open circulatory system characteristic of arthropods (e.g. arachnids, crustaceans and insects). In addition, some non-arthropods such as molluscs possess a hemolymphatic circulatory system. Oxygen-transport systems were long thought unnecessary in insects, but ancestral and functional hemocyanin has been found in the hemolymph. Insect "blood" generally does not carry hemoglobin, although hemoglobin may be present in the tracheal system instead and play some role in respiration. Method of transport In the grasshopper, the closed portion of the system consists of tubular hearts and an a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haustorium
In botany and mycology, a haustorium (plural haustoria) is a rootlike structure that grows into or around another structure to absorb water or nutrients. For example, in mistletoe or members of the broomrape family, the structure penetrates the host's tissue and draws nutrients from it. In mycology, it refers to the appendage or portion of a parasitic fungus (the hyphal tip), which performs a similar function. Microscopic haustoria penetrate the host plant's cell wall and siphon nutrients from the space between the cell wall and plasma membrane but do not penetrate the membrane itself. Larger (usually botanical, not fungal) haustoria do this at the tissue level. The etymology of the name corresponds to the Latin word '' haustor'' meaning ''the one who draws, drains or drinks'', and refers to the action performed by the outgrowth. In fungi Fungi in all major divisions form haustoria. Haustoria take several forms. Generally, on penetration, the fungus increases the surface ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyphae
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. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thallus
Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or " twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms were previously known as the thallophytes, a polyphyletic group of distantly related organisms. An organism or structure resembling a thallus is called thalloid, thallodal, thalliform, thalline, or thallose. A thallus usually names the entire body of a multicellular non-moving organism in which there is no organization of the tissues into organs. Even though thalli do not have organized and distinct parts ( leaves, roots, and stems) as do the vascular plants, they may have analogous structures that resemble their vascular "equivalents". The analogous structures have similar function or macroscopic structure, but different microscopic structure; for example, no thallus has vascular tissue. In exceptional cases such as the Lemnoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpomycetales
The Herpomycetales is an order of fungi within the class Laboulbeniomycetes. The order includes a single dioecious genus, '' Herpomyces'', with 27 accepted species of obligate ectoparasites that are associated exclusively with cockroaches. Like the Laboulbeniales order, they produce cellular thalli. However, the thalli of ''Herpomyces'' are developmentally and morphologically unique. The order was described in 2019 based on the phylogenetic analysis of three gene regions. A more recent phylogeny found that Herpomycetales and Laboulbeniales are not sister clades, which provides evidence for the idea that the thallus originated at least twice in the class Laboulbeniomycetes. This is in line with the fact that thalli of both orders are developmentally and morphologically different. The draft genome of '' Herpomyces periplanetae'' has been sequenced and assembled—the only one in the class thus far. ''Herpomyces periplanetae'' is a very widespread parasite on the antennae of adul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_(10144905255).jpg "Click for more on -> Diptera")
