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Ornithodoros Capensis
''Ornithodoros'' is a genus in the soft-bodied tick family, Argasidae. It is distinguished from other genera in the family by the absence of a lateral 'suture' line. It is the largest genus within Argasidae, consisting of approximately 130 species. ''Ornithodoros'' ticks are parasitic associates of shelter-seeking vertebrates, such as mammals, birds and reptiles. Prior to its reclassification in 1844, the genus ''Ornithodoros'' was described under the genus ''Argas''. Physiology The opening between the midgut and hindgut has been lost, preventing these ticks from excreting digestive waste products from their bodies. Habitat The genus ''Ornithodoros'' have been documented worldwide, with the highest occurrence in the Paleartic realm. Life Cycle The life cycle of all species of ''Ornithodoros'' is parasitic and relies on one or multiple hosts, most of which are shelter-seeking vertebrates, and can also parasitize humans. Mating and moulting occur in close proximity to site ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithodoros Savignyi
''Ornithodoros savignyi'', known as sand tampan, African eyed tampan or Kalahari sand tampan, is one of some 37 species in the genus ''Ornithodoros'' and is a Argasidae, soft tick with a leathery, mammillated integument, causing paralysis and tampan toxicosis, two unrelated conditions. The sand tampan is an ectoparasite on humans, their livestock and wild animals, including birds and bats. Occurring in semi-desert areas of Africa, Saudi Arabia and other parts of the Persian Gulf, India, Sri Lanka and into Asia, it is able to survive for lengthy periods without feeding, spending most of its life burrowed under sand or loose soil, often in wait for animals that rest or sleep under trees or in the lee of rocks, but also in places where people or their animals congregate such as marketplaces, places of worship, cattle kraals and village squares. The timing of its activity is geared to coincide with that of potential hosts, but hot sunny conditions are usually avoided. Because of its ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hindgut
The hindgut (or epigaster) is the posterior ( caudal) part of the alimentary canal. In mammals, it includes the distal one third of the transverse colon and the splenic flexure, the descending colon, sigmoid colon and up to the ano-rectal junction. In zoology, the term ''hindgut'' refers also to the cecum and ascending colon. Structure Blood supply Arterial supply is by the inferior mesenteric artery, and venous drainage is to the portal venous system. Lymphatic drainage is to the chyle cistern. Nerve supply The hindgut is innervated via the inferior mesenteric plexus. Sympathetic innervation is from the lumbar splanchnic nerves (L1-L2), parasympathetic innervation is from S2-S4. Development Additional images File:Gray985.png, Abdominal part of digestive tube and its attachment to the primitive or common mesentery. Human embryo of six weeks. File:Gray1115.png, Tail end of human embryo twenty-five to twenty-nine days old. File:Illacme plenipes female with 170 segments a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Swine Fever Virus
African swine fever virus (ASFV) is a large, double-stranded DNA virus in the ''Asfarviridae'' family. It is the causative agent of African swine fever (ASF). The virus causes a haemorrhagic fever, hemorrhagic fever with high mortality rates in domestic pigs; some isolates can cause death of animals as quickly as a week after infection. It persistently infects its natural hosts, warthogs, bushpigs, and soft ticks of the genus ''Ornithodoros'', which likely act as a vector (epidemiology), vector, with no disease signs. It does not cause disease in humans. ASFV is endemic to sub-Saharan Africa and exists in the wild through a cycle of infection between ticks and wild pigs, bushpigs, and warthogs. The disease was first described after European settlers brought pigs into areas endemic with ASFV, and as such, is an example of an emerging infectious disease. ASFV replicates in the cytoplasm of infected cells. It is the only virus with a double-stranded DNA genome known to be transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relapsing Fever
Relapsing fever is a vector-borne disease caused by infection with certain bacteria in the genus '' Borrelia'', which is transmitted through the bites of lice, soft-bodied ticks (genus '' Ornithodoros''), or hard-bodied ticks (Genus Ixodes). Signs and symptoms Most infected people develop sickness between 5 and 15 days after they are bitten. The symptoms may include a sudden fever, chills, headaches, muscle or joint aches, and nausea. A rash may also occur. These symptoms usually continue for 2 to 9 days, then disappear. This cycle may continue for several weeks if the person is not treated. Causes Louse-borne relapsing fever Along with '' Rickettsia prowazekii'' and '' Bartonella quintana'', '' Borrelia recurrentis'' is one of three pathogens of which the body louse ('' Pediculus humanus humanus'') is a vector. Louse-borne relapsing fever is more severe than the tick-borne variety. Louse-borne relapsing fever occurs in epidemics amid poor living conditions, famine, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia
''Borrelia'' is a genus of bacteria of the spirochete phylum. Several species cause Lyme disease, also called Lyme borreliosis, a zoonotic, vector-borne disease transmitted by ticks. Other species of ''Borrelia'' cause relapsing fever, and are transmitted by ticks or lice, depending on the species of bacteria. The genus is named after French biologist Amédée Borrel (1867–1936), who first documented the distinction between a species of ''Borrelia anserina'' and the other known type of spirochete at the time, ''Treponema pallidum''. This bacterium must be viewed using dark-field microscopy, which make the cells appear white against a dark background. ''Borrelia'' species are grown in Barbour-Stoenner-Kelly medium. Of 52 known species of ''Borrelia'', 20 are members of the Lyme disease group (with an additional 3 proposed), 29 belong to the relapsing fever group, and two are members of a genetically distinct third group typically found in reptiles. A proposal has been made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tick-borne Relapsing Fever
Relapsing fever is a vector-borne disease caused by infection with certain bacteria in the genus '' Borrelia'', which is transmitted through the bites of lice, soft-bodied ticks (genus ''Ornithodoros''), or hard-bodied ticks (Genus Ixodes). Signs and symptoms Most infected people develop sickness between 5 and 15 days after they are bitten. The symptoms may include a sudden fever, chills, headaches, muscle or joint aches, and nausea. A rash may also occur. These symptoms usually continue for 2 to 9 days, then disappear. This cycle may continue for several weeks if the person is not treated. Causes Louse-borne relapsing fever Along with '' Rickettsia prowazekii'' and '' Bartonella quintana'', '' Borrelia recurrentis'' is one of three pathogens of which the body louse ('' Pediculus humanus humanus'') is a vector. Louse-borne relapsing fever is more severe than the tick-borne variety. Louse-borne relapsing fever occurs in epidemics amid poor living conditions, famine, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood-borne Disease
A blood-borne disease is a disease that can be spread through contamination by blood and other body fluids. Blood can contain pathogens of various types, chief among which are microorganisms, like bacteria and parasites, and non-living infectious agents such as viruses. Three blood-borne pathogens in particular, all viruses, are cited as of primary concern to health workers by the CDC-NIOSH: human immunodeficiency virus, hepatitis B, and hepatitis C. Diseases that are not usually transmitted directly by blood contact, but rather by insect or other vector, are more usefully classified as vector-borne disease, even though the causative agent can be found in blood. Vector-borne diseases include West Nile virus, zika fever and malaria. Many blood-borne diseases can also be contracted by other means, including high-risk sexual behavior or intravenous drug use. These diseases have also been identified in sports medicine. Since it is difficult to determine what pathogens any given sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematophagy
Hematophagy (sometimes spelled haematophagy or hematophagia) is the practice by certain animals of feeding on blood (from the Greek words αἷμα ' "blood" and φαγεῖν ' "to eat"). Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy is a preferred form of feeding for many small animals, such as worms and arthropods. Some intestinal nematodes, such as Ancylostomatids, feed on blood extracted from the capillaries of the gut, and about 75 percent of all species of leeches (e.g., '' Hirudo medicinalis'') are hematophagous. The spider '' Evarcha culicivora'' feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey. Some fish, such as lampreys and candirus; mammals, especially vampire bats; and birds, including the vampire finch, Hood mockingbird, Tristan thrush, and oxpeckers, also practise hematophagy. Mechanism and evolution Hematop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autogeny
In entomology, anautogeny is a reproductive strategy in which an adult female insect must eat a particular sort of meal (generally vertebrate blood) before laying eggs in order for her eggs to mature. This behavior is most common among dipteran insects, such as mosquitoes. Anautogenous animals often serve as vectors for infectious disease in their hosts because of their contact with hosts' blood. The opposite trait (needing no special food as an adult to successfully reproduce) is known as autogeny. Factors governing anautogeny Anautogenous insects generally reach adulthood without sufficient reserves of nutrients (particularly protein) to produce viable eggs, necessitating additional feeding as adults. A high-protein meal, usually of blood, allows the production of yolk to nourish the eggs and makes reproduction possible. This blood is typically obtained through ectoparasitism on large vertebrates. However, even individuals who do have the reserves needed to produce viable egg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instar
An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After shedding their exoskeleton (moulting), the juvenile arthropods continue in their life cycle until they either pupate or moult again. The instar period of growth is fixed; however, in some insects, like the salvinia stem-borer moth, the number of instars depends on early larval nutrition. Some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars. For most insect species, an ''instar'' is the developmental stage of the larval forms of holometabolous (complete metamorphism) or ny ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nymph (biology)
In biology, a nymph (from Ancient Greek wikt:νύμφα, νύμφα ''nūmphē'' meaning "bride") is the juvenile (organism), juvenile form of some invertebrates, particularly insects, which undergoes gradual metamorphosis (biology), metamorphosis (hemimetabolism) before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult, except for a lack of wings (in winged species) and the emergence of genitalia. In addition, while a nymph ecdysis, moults, it never enters a pupal stage. Instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called instars. Taxa with nymph stages Many species of Arthropod, arthropods have nymph stages. This includes the insect orders such as Orthoptera (cricket (insect), crickets, grasshoppers and locusts), Hemiptera (cicadas, shield bugs, Whitefly, whiteflies, aphids, leafhoppers, froghoppers, treehoppers), mayfly, mayflies, termites, cockroaches, mantises, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moulting
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at specific times of the year, or at specific points in its life cycle. In medieval times, it was also known as "mewing" (from the French verb "muer", to moult), a term that lives on in the name of Britain's Royal Mews where the King's hawks used to be kept during moulting time before becoming horse stables after Tudor times. Moulting can involve shedding the Epidermis (skin), epidermis (skin), pelage (hair, feathers, fur, wool), or other external layer. In some groups, other body parts may be shed, for example, the entire exoskeleton in arthropods, including the wings in some insects. Examples In birds In birds, moulting is the periodic replacement of feathers by shedding old feathers while producing new ones. Feathers are dead struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
