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Scolopidia
A scolopidium (historically, scolopophore) is the fundamental unit of a mechanoreceptor organ in insects. It is a composition of three cells: a scolopale cap cell which caps the scolopale cell, and a bipolar sensory nerve cell. The general term of these overall sense organs is the chordotonal organs, with the scolopidia usually lying just under the exoskeleton. Scolopidia may be located within: * the subgenual organ: located in the lower part of the legs; primarily senses vibrations in underlying substrate * the crista acustica: collection of individually tuned scolopidia able to discriminate frequencies * Johnston's organ: located in the antennae; senses motion of an antenna relative to the insect's body There are many types of scolopidia, depending on the sense organ in which they belong. Mechanosensation Function Scolopidia are sensitive to mechanical disturbances, such as sound (vibrations of the air) or substrate vibrations (vibrations of surrounding solid mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgenual Organ
The subgenual organ is an organ in insects that is involved in the perception of sound. The name (Latin ''sub: "''below" and ''genus: "''knee") refers to the location of the organ just below the knee in the tibia of all legs in most insects. The function of the organ is performed by aggregations of scolopidia, the unit mechanoreceptor in invertebrates. The organ is thought to be an evolutionary artifact of ancestral insects who used their legs to detect vibrations in the underlying substrate. The anatomy and innervation of the organ is highly variable between species. However, the organ may be sensitive enough to detect less than 1 nm of displacement in the ground, and sometimes airborne sound waves. The sensitivity of the organ varies from species to species; in Orthoptera, Hymenoptera and Lepidoptera, sensitivity is on the order of one (or greater) kilohertz, while in Hemiptera sensitivity reaches only a few hundred hertz. Characteristics within orders * Lepidoptera and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordotonal Organ
Chordotonal organs are stretch receptor organs found only in insects and crustaceans. They are located at most joints and are made up of clusters of scolopidia that either directly or indirectly connect two joints and sense their movements relative to one another. They can have both Exteroception, extero- and Proprioception, proprioceptive functions, for example sensing auditory stimuli or leg movement. The word was coined by Vitus Graber in 1882, though he interpreted them as being stretched between two points like a string, sensing vibrations through resonance. Structure Chordotonal organs can be composed of a single Scolopidia, scolopidium with only a single sensory, bipolar neuron (such as the Tympanal organ, tympanal ear of a notodontid moth), or up to several thousand scolopidia, each equipped with up to four sensory neurons (as in the mosquito Johnston's organ). The bipolar sensory neurons each have an apical dendritic structure with a cilium densely packed with microtubu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johnston's Organ
Johnston's organ is a collection of sensory cells found in the pedicel (the second segment) of the antennae in the class Insecta. Johnston's organ detects motion in the flagellum (third and typically final antennal segment). It consists of scolopidia arrayed in a bowl shape, each of which contains a mechanosensory chordotonal neuron. The number of scolopidia varies between species. In homopterans, the Johnston's organs contain 25–79 scolopidia. The presence of Johnston's organ is a defining characteristic which separates the class Insecta from the other hexapods belonging to the group Entognatha. Johnston's organ was named after the physician Christopher Johnston (1822-1891) father of the physician and Assyriologist Christopher Johnston. Function In fruit flies, midges and mosquitoes In the fruit fly ''Drosophila melanogaster and Chironomus annularius'', the Johnston's organ contains almost 480 sensory neurons. In the mosquito, the Johnston's organ houses ~15 000 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crista Acustica
Crista acustica (also Siebold's organ, or crista acoustica) is a part of the hearing organ (tibial organ) in some insects (e.g. grasshoppers, crickets, katydids). It is a collection of sensory cells that form a crest (hence the name) on top of the hollow tube (the foreleg trachea) behind the hearing membrane (tympanum) on the legs of the insect. The crista acustica is a transition from the intermedia organ (from the midline to the periphery), together which compose the tibial hearing organ (as opposed to the tympanal hearing organ). The crista acustica is one of three fiddle-string-like organs or chordotonal organ in insects: the others are the intermediate organ and the supratympanal organ/subgenual organ. These chordotonal organs are actually collections of sensory cells sensitive to vibration (these cells are called scolopidia cells). Their cells are attached to the tube in the legs of the insects (the trachea, "''trah-key-ah''"). So when the tube vibrates, the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midges
A midge is any small fly, including species in several families of non-mosquito nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some midges, such as many Phlebotominae (sand fly) and Simuliidae (black fly), are vectors of various diseases. Many others play useful roles as prey for insectivores, such as various frogs and swallows. Others are important as detritivores, and form part of various nutrient cycles. The habits of midges vary greatly from species to species, though within any particular family, midges commonly have similar ecological roles. Examples of families that include species of midges include: * Blephariceridae, net-winged midges * Cecidomyiidae, gall midges * Ceratopogonidae, biting midges (also known as no-see-ums or punkies in North America and sandflies in Australia) * Chaoboridae, phantom midges * Chironomidae, non-biting midges (also known as muckl ... [...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 more than 150,000 species including horse-flies, crane flies, hoverflies, mosquitoes and others. 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 manoeuvrability 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 larval food-source and the larvae, which lack true ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemiptera
Hemiptera (; ) is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to around , and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is sometimes limited to the suborder Heteroptera. Entomologists reserve the term ''bug'' for Hemiptera or Heteroptera,Gilbert Waldbauer. ''The Handy Bug Answer Book.'' Visible Ink, 1998p. 1. which does not include other arthropods or insects of other orders such as ants, bees, beetles, or butterflies. In some varieties of English, all terrestrial arthropods (including non-insect arachnids and myriapods) also fall under the colloquial understanding of ''bug''. Many insects with "bug" in their common name, especially in American English, belong to other orders; for example, the lovebug is a fly and the Maybug and ladybug are beetles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosquitos
Mosquitoes, the Culicidae, are a family of small flies consisting of 3,600 species. The word ''mosquito'' (formed by '' mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mosquitoes have a slender segmented body, one pair of wings, three pairs of long hair-like legs, and specialized, highly elongated, piercing-sucking mouthparts. All mosquitoes drink nectar from flowers; females of some species have in addition adapted to drink blood. The group diversified during the Cretaceous period. Evolutionary biologists view mosquitoes as micropredators, small animals that parasitise larger ones by drinking their blood without immediately killing them. Medical parasitologists view mosquitoes instead as vectors of disease, carrying protozoan parasites or bacterial or viral pathogens from one host to another. The mosquito life cycle consists of four stages: egg, larva, pupa, and adult. Eggs are laid on the water surface; they hatch into motile larvae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
