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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] |
Arthur Burton Gahan
Arthur Burton Gahan (9 December 1880 — 23 May 1960) was an American entomologist who was a specialist on parasitic Hymenoptera particularly the Chalcidoidea Chalcid wasps (, , for their metallic colour) are insects within the superfamily Chalcidoidea, part of the order Hymenoptera. The superfamily contains some 22,500 known species, and an estimated total diversity of more than 500,000 species, me .... Gahan was born in Kansas and went to Kansas State College where he graduated in 1903. He then studied entomology at the Maryland Agricultural College and received an M.S. in 1906 and then worked there as an entomologist. In 1913 he moved to the US Department of Agriculture and worked at the US National Museum and became a specialist on the Chalcidoidea. He was also a coach for the University of Maryland basketball team. See also * :Taxa named by Arthur Burton Gahan References External links Gahan fellowship* Gahan Family papers at the University of Maryland Libraries. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual 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). In addition, while a nymph moults, it never enters a pupal stage. Instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called instars. This is the case, for example, in Orthoptera (crickets, grasshoppers and locusts), Hemiptera (cicadas, shield bugs, whiteflies, aphids, leafhoppers, froghoppers, treehoppers etc.), mayflies, termites, cockroaches, mantises, stoneflies and Odonata (dragonflies and damselflies). Nymphs of aquatic insects, as in the Odonata, Ephemeroptera, and Plecoptera, are also called naiads, an Ancient Greek name for mythological water nymphs. Usage of the term 'naiad' is no longer popular among entomologists, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insects Used As Insect Pest Control Agents
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. Insect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Pest Control Wasps
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments. Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations.Based on definition from: Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use the scientific metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphelinidae
The Aphelinidae are a moderate-sized family of tiny parasitic wasps, with about 1100 described species in some 28 genera. These minute insects are challenging to study, as they deteriorate rapidly after death unless extreme care is taken (e.g., preservation in ethanol), making identification of most museum specimens difficult. The larvae of the majority are primary parasitoids on Hemiptera, though other hosts are attacked, and details of the life history can be variable (e.g., some attack eggs, some attack pupae, and others are hyperparasites). Males and females may have different hosts and different life historie They are found throughout the world in virtually all habitats, and are extremely important as biological control agents. The oldest fossils are known from the Eocene aged Baltic Amber. They are difficult to separate from other Chalcidoidea except by subtle features of the wing venation and other difficult characters, and the family appears to be paraphyletic, so is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circulation (fluid Dynamics)
In physics, circulation is the line integral of a vector field around a closed curve. In fluid dynamics, the field is the fluid velocity field. In electrodynamics, it can be the electric or the magnetic field. Circulation was first used independently by Frederick Lanchester, Martin Kutta and Nikolay Zhukovsky. It is usually denoted Γ (Greek uppercase gamma). Definition and properties If V is a vector field and dl is a vector representing the differential length of a small element of a defined curve, the contribution of that differential length to circulation is dΓ: :\mathrm\Gamma=\mathbf\cdot \mathrm\mathbf=, \mathbf, , \mathrm\mathbf, \cos \theta. Here, ''θ'' is the angle between the vectors V and dl. The circulation Γ of a vector field V around a closed curve ''C'' is the line integral: :\Gamma=\oint_\mathbf\cdot \mathrm d \mathbf. In a conservative vector field this integral evaluates to zero for every closed curve. That means that a line integral between any two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starting Vortex
In fluid dynamics, the starting vortex is a vortex which forms in the air adjacent to the trailing edge of an airfoil as it is accelerated from rest. It leaves the airfoil (which now has an equal but opposite "bound vortex" around it), and remains (nearly) stationary in the flow. It rapidly decays through the action of viscosity. The initial (and quite brief) presence of a starting vortex as an airfoil begins to move was predicted by early aerodynamicists, and eventually photographed. Whenever the speed or angle of attack of an airfoil changes there is a corresponding amount of vorticity deposited in the wake behind the airfoil, joining the two trailing vortices. This vorticity is a continuum of mini-starting-vortexes. The wake behind an aircraft is a continuous sheet of weak vorticity, between the two trailing vortices, and this accounts for the changes in strength of the trailing vortices as the airspeed of the aircraft and angle of attack on the wing change during fli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inviscid
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the internal frictional force between adjacent layers of fluid that are in relative motion. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls. Experiments show that some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. For a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity. In general, viscosity depends on a fluid's state, such as its temperature, pressure, and rate of deformation. However, the dependence on some of these properties is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reynolds Number
In fluid mechanics, the Reynolds number () is a dimensionless quantity that helps predict fluid flow patterns in different situations by measuring the ratio between inertial and viscous forces. At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers flows tend to be turbulent. The turbulence results from differences in the fluid's speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow ( eddy currents). These eddy currents begin to churn the flow, using up energy in the process, which for liquids increases the chances of cavitation. The Reynolds number has wide applications, ranging from liquid flow in a pipe to the passage of air over an aircraft wing. It is used to predict the transition from laminar to turbulent flow and is used in the scaling of similar but different-sized flow situations, such as between an aircraft model in a wind tunnel and the full-size ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encarsia Formosa, An Endoparasitic Wasp, Is Used For Whitefly Control
''Encarsia'' is a large genus of minute parasitic wasps of the family Aphelinidae. The genus is very diverse with currently about 400 described species and worldwide distribution. Noyes, J. S. 2003Universal Chalcidoidea database/ref> The number of existing species is expected to be several times higher because many species are still undescribed.Heraty, J. M., et al. (2008) Systematics and Biology of ''Encarsia''. Chapter 4, pp. 71-87 In: Gould, J., et al. (Eds), In: Classical Biological Control of ''Bemisia tabaci'' in the United States. A review of interagency research and implementation. Progress in Biological Control 4. Springer Science and Business Media B. V. 1-343. ''Encarsia'' is a very complex genus, with specimens showing both inter- and intra-specific variations, making morphological classification difficult. The adult wasps, tiny insects about 1 or 2 millimeters in size, are primarily parasitoids of sessile stages of Sternorrhyncha, in particular whiteflies (Aleyrodidae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 their life cycle, the stages thereof being egg, larva, pupa, and imago. The processes of entering and completing the pupal stage are controlled by the insect's hormones, especially juvenile hormone, prothoracicotropic hormone, and ecdysone. The act of becoming a pupa is called pupation, and the act of emerging from the pupal case is called eclosion or emergence. The pupae of different groups of insects have different names such as ''chrysalis'' for the pupae of butterflies and ''tumbler'' for those of the mosquito family. Pupae may further be enclosed in other structures such as cocoons, nests, or shells. Position in life cycle The pupal stage follows the larval stage and precedes adulthood (''imago'') in insects with complete metamorphosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomate Blatt Eier Weiße Fliege Parasitiert
Kid Abelha was a pop band from Rio de Janeiro, Brazil, formed by Paula Toller (lead vocals), George Israel (sax, guitar and vocals) and Bruno Fortunato (acoustic and electric guitar). The group has recorded 13 studio albums, 3 live albums and 2 live DVDs. They have created many songs which have entered into Brazilian pop-rock history. The group sold more than 8 million albums worldwide. History A precursor group was formed by drummer Carlos Beni, Pedro Farah and Leoni, called "Chrisma". In 1981, Paula Toller meets Leoni in college, PUC-Rio, they start dating and then she used to visit the band rehearsals. The boys always asked her to join the band, but she denied a lot of times, saying she was too shy, but her constant visits to the rehearsals motivated her to sing. George Israel, otherwise, was seen playing saxophone in Búzios and invited by a friend of Leoni to meet the band. In 1982, with guitarist Beto Martins and American keyboardist Richard Owens they recorded a demo tap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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