|
Poekilocerus Pictus
''Poekilocerus pictus'', the painted grasshopper, aak grasshopper or ak grasshopper, is a fairly large and brightly coloured species of grasshopper found in India, Pakistan and Afghanistan, especially in drier regions. Both adults and nymphs are toxic; the nymphs are notorious for being able to squirt a jet of noxious liquid at up to around away when grasped. ''P. pictus'' was long regarded as the only ''Poekilocerus'' of the Indian subcontinent (other species are found in Southwest Asia and Africa), but in 2016 a new species, the overall yellowish-brown '' P. geniplanus'', was described from Chhattisgarh. Description Adults of ''P. pictus'' typically are long. The nymphs are greenish-yellow with fine black markings and small crimson spots. The mature grasshopper has canary yellow and turquoise or blue stripes on its body, green tegmina with yellow spots, and pale red hind wings. Feeding and toxicity Both adults and nymphs of ''P. pictus'' feed extensively on poisonous ''C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johan Christian Fabricius
Johan Christian Fabricius (7 January 1745 – 3 March 1808) was a Danish zoologist, specialising in "Insecta", which at that time included all arthropods: insects, arachnids, crustaceans and others. He was a student of Carl Linnaeus, and is considered one of the most important entomologists of the 18th century, having named nearly 10,000 species of animals, and established the basis for the modern insect classification. Biography Johan Christian Fabricius was born on 7 January 1745 at Tønder in the Duchy of Schleswig, where his father was a doctor. He studied at the gymnasium at Altona and entered the University of Copenhagen in 1762. Later the same year he travelled together with his friend and relative Johan Zoëga to Uppsala, where he studied under Carl Linnaeus for two years. On his return, he started work on his , which was finally published in 1775. Throughout this time, he remained dependent on subsidies from his father, who worked as a consultant at Frederiks Hospita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pest (organism)
A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry or cause a nuisance to people, especially in their homes. Humans have modified the environment for their own purposes and are intolerant of other creatures occupying the same space when their activities impact adversely on human objectives. Thus, an elephant is unobjectionable in its natural habitat but a pest when it tramples crops. Some animals are disliked because they bite or sting; snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...s, wasps, ants, bed bugs, fleas and ticks belong in this category. Others enter the home; these include houseflies, which land on and contaminate food, beetles, which tunnel into the woodwor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrgomorphidae
Pyrgomorphidae is a family of grasshoppers in the order Orthoptera; it is the only family in the superfamily Pyrgomorphoidea, with a pan-tropical distribution. Their name is probably derived from ''pyrgos'' (Greek: ''Πύργος'') meaning "tower": a reference to the form (''morph'') of the head in the type genus ''Pyrgomorpha'' and other genera. They may sometimes be known as "gaudy grasshoppers", due to the striking, often aposematic colouration of a number of genera; however many others are camouflaged or cryptic, including the genus ''Pyrgomorpha''. Subfamilies and tribes Incomplete list of genera and species: Subfamily Orthacridinae All tribes and selected genera only are shown here: * Tribe Brunniellini Kevan, 1963 - Philippines * Tribe Chapmanacridini Kevan & Akbar, 1964 - W. Africa * Tribe Fijipyrgini Kevan, 1966 - Fiji * Tribe Geloiini Bolívar, 1905 - Madagascar * Tribe Gymnohippini Kevan & Akbar, 1964 - Madagascar * Tribe Ichthiacridini Kevan, Singh & Akbar, 1964 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome ( haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and female will fuse to create a cell with two copies of each chromosome again, the zygote. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metathorax
The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites ( exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral), and the metapleuron (lateral) on each side. The metathorax is the segment that bears the hindwings in most winged insects, though sometimes these may be reduced or modified, as in the flies (Diptera), in which they are reduced to form halteres, or flightless, as in beetles (Coleoptera), in which they may be completely absent even though forewings are still present. All adult insects possess legs on the metathorax. In most groups of insects, the metanotum is reduced relative to the mesonotum. In the suborder Apocrita of the Hymenoptera, the first abdominal segment is fused to the metathorax, and is then called the propodeum. See also *Glossary of entomology terms *Insect morphology *Mesothorax *Prothorax *Thorax (insect anatomy) The thorax is the midsection ( tagma) of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Pheromone
Sex pheromones are pheromones released by an organism to attract an individual of the same species, encourage them to mate with them, or perform some other function closely related with sexual reproduction. Sex pheromones specifically focus on indicating females for breeding, attracting the opposite sex, and conveying information on species, age, sex and genotype. Non-volatile pheromones, or cuticular contact pheromones, are more closely related to social insects as they are usually detected by direct contact with chemoreceptors on the antennae or feet of insects. Insect sex pheromones have found uses in pheromone trap , monitoring and trapping of pest insects. Evolution Sex pheromones have evolved in many species. The many types of pheromones (i.e. alarm, aggregation, defense, sexual attraction) all have a common cause acting as chemical cues to trigger a response. However, sex pheromones are particularly associated with signaling mating behaviors or dominance. The odors release ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Glycoside
Cardiac glycosides are a class of organic compounds that increase the output force of the heart and decrease its rate of contractions by inhibiting the cellular sodium-potassium ATPase pump. Their beneficial medical uses are as treatments for congestive heart failure and cardiac arrhythmias; however, their relative toxicity prevents them from being widely used. Most commonly found as secondary metabolites in several plants such as foxglove plants, these compounds nevertheless have a diverse range of biochemical effects regarding cardiac cell function and have also been suggested for use in cancer treatment. Classification General structure The general structure of a cardiac glycoside consists of a steroid molecule attached to a sugar (glycoside) and an R group. The steroid nucleus consists of four fused rings to which other functional groups such as methyl, hydroxyl, and aldehyde groups can be attached to influence the overall molecule's biological activity. Cardiac glycosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscosity
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] |
Segment (biology)
Segmentation in biology is the division of some animal and plant body plans into a series of repetitive segments. This article focuses on the segmentation of animal body plans, specifically using the examples of the taxa Arthropoda, Chordata, and Annelida. These three groups form segments by using a "growth zone" to direct and define the segments. While all three have a generally segmented body plan and use a growth zone, they use different mechanisms for generating this patterning. Even within these groups, different organisms have different mechanisms for segmenting the body. Segmentation of the body plan is important for allowing free movement and development of certain body parts. It also allows for regeneration in specific individuals. Definition Segmentation is a difficult process to satisfactorily define. Many taxa (for example the molluscs) have some form of serial repetition in their units but are not conventionally thought of as segmented. Segmented animals are thos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsum (anatomy)
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. The area occupied by the abdomen is called the abdominal cavity. In arthropods it is the posterior (anatomy), posterior tagma (biology), tagma of the body; it follows the thorax or cephalothorax. In humans, the abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint (the intervertebral disc between Lumbar vertebrae, L5 and Vertebra#Sacrum, S1) to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear. In vertebrates, the abdomen is a large body c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
