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Plebeia Quadripunctata
''Schwarziana quadripunctata'' is a small, stingless bee found in a stretch of the South American Amazon from Goiás, Brazil, through Paraguay, to Misiones, Argentina.Michener, C.D. (2007). ''The Bees of the World''. Baltimore: Johns Hopkins University Press. This highly eusocial insect constructs earthen nests in the subterranean level of the subtropical environment, an unusual feature among other stingless bees. The species ranges in sizes from and feeds on a diverse diet of flowering plants found abundantly on the forest floor, including guacatonga (''Casearia sylvestris'') and the mistletoe species '' Struthanthus concinnus''. Taxonomy and phylogeny ''Schwarziana quadripunctata'' was first described by the French entomologist and former president of the French Entomologist Society Amédéé Louis Michel le Peletier in 1836. Although originally placed in the genus ''Trigona'', more recent taxonomic evaluations have since placed it under its current genus, following the 194 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amédée Louis Michel Le Peletier, Comte De Saint-Fargeau
Amédée Louis Michel le Peletier, comte de Saint-Fargeau (9 October 1770 – 23 August 1845), also spelled Lepeletier or Lepelletier, was a French entomologist, and specialist in the Hymenoptera. In 1833, he served as president of the Société entomologique de France. Works *with Gaspard Auguste Brullé '' Histoire naturelle des insectes. Hyménoptères''. Roret, Paris 1836–46 p.m. *''Memoires sur le G. Gorytes Latr. Arpactus Jur''. Paris 1832. *''Monographia tenthredinetarum, synonimia extricata''. Levrault, Paris 1823–25. *''Mémoire sur quelques espéces nouvelles d’Insectes de la section des hyménoptères appelés les portetuyaux et sur les caractères de cette famille et des genres qui la composent''. Paris 1806. *''Défense de Félix Lepeletier''. Vatar, Paris 1796/97. *with Jean Guillaume Audinet-Serville a treatise on Hemiptera to Guillaume-Antoine Olivier's Histoire naturelle. ''Entomologie, ou histoire naturelle des Crustacés, des Arachnides et des Insectes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meliponini
Stingless bees, sometimes called stingless honey bees or simply meliponines, are a large group of bees (about 550 described species), comprising the tribe Meliponini (or subtribe Meliponina according to other authors). They belong in the family Apidae, and are closely related to common honey bees, carpenter bees, orchid bees, and bumblebees. Meliponines have stingers, but they are highly reduced and cannot be used for defense, though these bees exhibit other defensive behaviors and mechanisms. Meliponines are not the only type of bee incapable of stinging: all male bees and many female bees of several other families, such as Andrenidae, also cannot sting. Some stingless bees have powerful mandibles and can inflict painful bites. Geographical distribution Stingless bees can be found in most tropical or subtropical regions of the world, such as Australia, Africa, Southeast Asia, and tropical America.Michener, C D. ''The bees of the World''. Johns Hopkins University Press, 972 pp. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physogastric
Physogastrism or physogastry is a characteristic of certain arthropods (mostly insects and mites), where the abdomen is greatly enlarged and membranous. The most common examples are the "queens" of certain species of eusocial insects such as termites, bees and ants, in which the abdomen swells in order to hold enlarged ovaries, thus increasing fecundity. This means that the queen has the ability to hold more and produce more eggs at one time. Physogastric queens produce an enormous number of eggs which can account for a significant amount of their body weight. In the termite species '' Macrotermes subhyalinus'', eggs can make up a third of their body weight, and a 15-gram queen can produce up to 30 eggs per minute. The physogastric queens' egg production is supported by oocyte proteins supplied by the "queen body fat." In termites Physogastrism in termites presents itself in quite an unusual manner. Unlike most physogastric insects, the queen termite is able to increase its size ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensillum
A sensillum (plural ''sensilla'') is an arthropod sensory organ protruding from the cuticle of exoskeleton, or sometimes lying within or beneath it. Sensilla appear as small hairs or pegs over an individual's body. Inside each sensillum there are two to four sensory neurons. These neurons, or receptors, gather information about environment the arthropod is in: * Chemoreceptors (i.e. trichoid, basionic, coeloconic, placodea) * Mechanoreceptors (e.g.: bristle sensilla, campaniform sensilla, hair plates, chordotonal neurons) * Thermoreceptors * Hygroreceptors Most sensilla are specially shaped according to the type of information they are gathering. In spiders, slit sensilla are used to detect substrate vibrations, while trichobothria are used to detect air-borne vibrations. Chemoreceptors Chemo-reception is one of the most dominant senses in the insect kingdom. Many arthropods use chemical signals to locate food, shelter and mates. Other invertebrates have similar sensory o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paramagnetic
Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, diamagnetic materials are repelled by magnetic fields and form induced magnetic fields in the direction opposite to that of the applied magnetic field. Paramagnetic materials include most chemical elements and some compounds; they have a relative magnetic permeability slightly greater than 1 (i.e., a small positive magnetic susceptibility) and hence are attracted to magnetic fields. The magnetic moment induced by the applied field is linear in the field strength and rather weak. It typically requires a sensitive analytical balance to detect the effect and modern measurements on paramagnetic materials are often conducted with a SQUID magnetometer. Paramagnetism is due to the presence of unpaired electrons in the material, so most atoms wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamagnetic
Diamagnetic materials are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted by a magnetic field. Diamagnetism is a quantum mechanical effect that occurs in all materials; when it is the only contribution to the magnetism, the material is called diamagnetic. In paramagnetic and ferromagnetic substances, the weak diamagnetic force is overcome by the attractive force of magnetic dipoles in the material. The magnetic permeability of diamagnetic materials is less than the permeability of vacuum, ''μ''0. In most materials, diamagnetism is a weak effect which can be detected only by sensitive laboratory instruments, but a superconductor acts as a strong diamagnet because it repels a magnetic field entirely from its interior. Diamagnetism was first discovered when Anton Brugmans observed in 1778 that bismuth was repel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Magnetic Field
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo. The magnitude of Earth's magnetic field at its surface ranges from . As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11° with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of Earth. The North geomagnetic pole actually represents the South pole of Earth's magnetic field, and conversely the South geomagnetic pole corresponds to the north pole of Earth's magnetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetoreception
Magnetoreception is a sense which allows an organism to detect the Earth's magnetic field. Animals with this sense include some arthropods, molluscs, and vertebrates (fish, amphibians, reptiles, birds, and mammals, though not humans). The sense is mainly used for orientation and navigation, but it may help some animals to form regional maps. Experiments on migratory birds provide evidence that they make use of a cryptochrome protein in the eye, relying on the quantum radical pair mechanism to perceive magnetic fields. This effect is extremely sensitive to weak magnetic fields, and readily disturbed by radio-frequency interference, unlike a conventional iron compass. Birds have iron-containing materials in their upper beaks. There is some evidence that this provides a magnetic sense, mediated by the trigeminal nerve, but the mechanism is unknown. Cartilaginous fish including sharks and stingrays can detect small variations in electric potential with their electroreceptive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or exemplified by the odors of gasoline and lighter fluid. They occur in a diverse range of molecular structures and phases: they can be gases (such as methane and propane), liquids (such as hexane and benzene), low melting solids (such as paraffin wax and naphthalene) or polymers (such as polyethylene and polystyrene). In the fossil fuel industries, ''hydrocarbon'' refers to the naturally occurring petroleum, natural gas and coal, and to their hydrocarbon derivatives and purified forms. Combustion of hydrocarbons is the main source of the world's energy. Petroleum is the dominant raw-material source for organic commodity chemicals such as solvents and polymers. Most anthropogenic (human-generated) emissions of greenhouse gases are carbon di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honeybee
A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmopolitan distribution of honey bees, introducing multiple subspecies into South America (early 16th century), North America (early 17th century), and Australia (early 19th century). Honey bees are known for their construction of perennial colonial nests from wax, the large size of their colonies, and surplus production and storage of honey, distinguishing their hives as a prized foraging target of many animals, including honey badgers, bears and human hunter-gatherers. Only eight surviving species of honey bee are recognized, with a total of 43 subspecies, though historically 7 to 11 species are recognized. Honey bees represent only a small fraction of the roughly 20,000 known species of bees. The best known honey bee is the western honey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyne
The gyne (, from Greek γυνή, "woman") is the primary reproductive female caste of social insects (especially ants, wasps, and bees of order Hymenoptera, as well as termites). Gynes are those destined to become queens, whereas female workers are typically barren and cannot become queens. Having a queen is what makes a "queenright" hive, nest, or colony of eusocial insects. A colony with multiple queens is said to be a polygyne form, whereas one with only one is a monogyne form. The red imported fire ant is known to have colonies in both polygyne and monogyne forms. The small red ant, ''Leptothorax acervorum'', has colonies that switch from monogyny to polygyny as a result of seasonal fluctuations. The little fire ant ''Wasmannia auropunctata'' produces unique kinds of meiotic oocytes with a drastic reduction in recombination. These oocytes may either fuse together for gyne production ( automictic parthenogenesis with central fusion) or be fertilized by male gametes for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, a half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute. The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses (regardless of whether it is human-induced). "Deforestation" and "forest area net change" are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
