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Philodromus Cespitum
''Philodromus cespitum'' is a species of running crab spider in the family '' Philodromidae.'' It is found in North America, Europe, North Africa, and parts of the Middle East and Asia. ''Philodromus cespitum'' is a foliage-dweller, and is the most abundant species found in European fruit orchards. It acts as a biological control by preying on orchard pests. A diurnal ambush hunter, it preys on aphids, insects, and occasionally competitor spider species. Males court females by tapping on the females’ bodies with their forelegs. They then insert a genital plug into the female during copulation. Unlike in many other spider species, subsequent males can mate with plugged females by removing part of the plug prior to copulation. Males discriminate among females based on virginity and plug size, and can determine these factors using the females’ draglines and plug samples. Description Males of this species are approximately 3.5-5.0 mm long, and females are about 5.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philodromidae
Philodromidae, also known as philodromid crab spiders and running crab spiders, is a family of araneomorph spiders first described by Tord Tamerlan Teodor Thorell in 1870 (then known as subfamily Philodrominae within Thomisidae). It contains over 500 species in thirty genera. The most common genus is '' Philodromus'' which is widespread, similar to ''Ebo''. Other common genera include the elongate grass-dwelling '' Tibellus'' and the widespread '' Thanatus'', which includes the house crab spider that commonly captures flies on and in buildings. Description Philodromids have a crab-like shape due to the first two pairs of legs being oriented sideways (laterigrade). This is superficially similar to the "true" crab spiders (Thomisidae), such as ''Misumena vatia,'' but these families are not as closely related as previously thought. Unlike crab spiders, the legs are generally similar in size, though the second leg pair may be significantly longer than the first pair. This is most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philodromus Lividus
''Philodromus lividus'' is a spider species found in Europe (Portugal, France, Italy, Croatia) and North Africa (Morocco, Algeria). See also * List of Philodromidae species This page lists all described species of the spider family Philodromidae accepted by the World Spider Catalog : A ''Apollophanes'' '' Apollophanes'' O. Pickard-Cambridge, 1898 * '' A. aztecanus'' Dondale & Redner, 1975 — Mexico * '' A. bangal ... References lividus Spiders of Europe Spiders of Africa Fauna of Algeria Fauna of Morocco Spiders described in 1875 {{philodromidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraguild Predation
Intraguild predation, or IGP, is the killing and sometimes eating of a potential competitor of a different species. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another. Intraguild predation is common in nature and can be asymmetrical, in which one species feeds upon the other, or symmetrical, in which both species prey upon each other. Because the dominant intraguild predator gains the dual benefits of feeding and eliminating a potential competitor, IGP interactions can have considerable effects on the structure of ecological communities. Types Intraguild predation can be classified as asymmetrical or symmetrical. In asymmetrical interactions one species consistently preys upon the other, while in symmetrical interactions both species prey equally upon each other. Intraguild predation can also be age structured, in which case the vulnerability of a species to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridion
''Theridion'' is a genus of tangle-web spiders with a worldwide distribution. Notable species are the Hawaiian happy face spider (''T. grallator''), named for the iconic symbol on its abdomen, and '' T. nigroannulatum'', one of few spider species that lives in social groups, attacking prey en masse to overwhelm them as a team. Identification Spiders in this genus are about as long or longer than they are wide. Their chelicerae have two or less teeth on the front edge and none on the back edge. The front leg is the longest in both genders, but the next longest is the second leg in males and the fourth leg in females. The epigyne can vary, but the pedipalp has a median apophysis and a colulus is absent from both genders. In several species, the males have mastidia (projections) on the chelicerae. ''Theridion'' has the anterior eye row slightly curved and with a gap between it and the posterior eye row. This distinguishes it from '' Enoplognatha'', another theridiid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cacopsylla Pyri
''Cacopsylla pyri'', commonly known as the pear psylla, pear psyllid, or by its synonym ''Psylla pyri'', is an insect in the subfamily Psyllinae. Originating in Europe and Asia, it has spread to North America. It is a pest of pear trees, sucking the sap, damaging the foliage, flowers and fruit and diminishing the crop. Description Adult ''C. pyri'' are between long. The colour is variable, ranging between orange-red and black, the thorax having whitish longitudinal stripes on its upper surface. The wings are transparent, with dark veins and sometimes a smoky appearance near the base. Later instar nymphs are purplish-brown or reddish-brown, with white longitudinal stripes and black patches; the developing wing-pads each bear a single knobbed bristle. The younger nymphs are yellowish with red-purple eyes. Distribution The species is found in Europe, including Scandinavia, and in Asia. In Britain it used to be very rare, with only one record before 1969, but since then it has beco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambush Predator
Ambush predators or sit-and-wait predators are carnivorous animals that capture their prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey using sheer speed or endurance, ambush predators avoid fatigue by staying in concealment, waiting patiently for the prey to get near, before launching a sudden overwhelming attack that quickly incapacitates and captures the prey. The ambush is often opportunistic, and may be set by hiding in a burrow, by camouflage, by aggressive mimicry, or by the use of a trap (e.g. a web). The predator then uses a combination of senses to detect and assess the prey, and to time the strike. Nocturnal ambush predators such as cats and snakes have vertical slit pupils helping them to judge the distance to prey in dim light. Different ambush predators use a variety of means to capture their prey, from the long sticky tongues of chameleons to the expand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Rhythm
A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the environment (is Entrainment (chronobiology), entrained by the environment). Circadian rhythms are regulated by a circadian clock whose primary function is to rhythmically co-ordinate biological processes so they occur at the correct time to maximize the fitness of an individual. Circadian rhythms have been widely observed in animals, plants, fungi and cyanobacteria and there is evidence that they evolved independently in each of these kingdoms of life. The term ''circadian'' comes from the Latin ', meaning "around", and ', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hickmania Troglodytes
''Hickmania'' is a monotypic genus of Australian cribellate araneomorph spiders in the family Gradungulidae, containing only the Tasmanian cave spider (''Hickmania troglodytes''). The genus was first described by Willis J. Gertsch in 1958, and has been found only in Tasmania. It had been thought to be an ancient Gondwanan lineage, long since separated from its closest relatives in South America in the family Austrochilidae, but more recent data show it belongs to the Australia–New Zealand family Gradungulidae. It is an icon species for faunal conservation in Tasmania, and is named in honor of V. V. Hickman, a professor at the University of Tasmania, who specialized in spiders. The species name is derived from the Ancient Greek (''troglodytes''), meaning "cave-dweller". Description Tasmanian cave spiders have red to brown carapaces and duller, darker brown opisthosomae. They can grow up to long, and can have a legspan of up to . These primitive spiders use book lungs to br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philodromus Buchari
''Philodromus buchari'' is a spider species found in Europe. See also * List of Philodromidae species This page lists all described species of the spider family Philodromidae accepted by the World Spider Catalog : A ''Apollophanes'' '' Apollophanes'' O. Pickard-Cambridge, 1898 * '' A. aztecanus'' Dondale & Redner, 1975 — Mexico * '' A. bangal ... References buchari Spiders of Europe Spiders described in 2004 {{philodromidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niche Segregation
In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (for example, limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another ndthe relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts". See also Chapter 2: Concepts of niches, pp. 7 ''ff'' A Grinnellian niche is determined by the habitat in which a species lives and its accompanying behavioral adaptations. An Eltonian niche emphasizes that a specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trophic Level
The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a part of a wider food "web". Ecological communities with higher biodiversity form more complex trophic paths. The word ''trophic'' derives from the Ancient Greek, Greek wikt:τροφή, τροφή (trophē) referring to food or nourishment. History The concept of trophic level was developed by Raymond Lindeman (1942), based on the terminology of August Thienemann (1926): "producers", "consumers", and "reducers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philodromus Albidus
''Philodromus albidus'' is a spider species found in Europe. See also * List of Philodromidae species This page lists all described species of the spider family Philodromidae accepted by the World Spider Catalog : A ''Apollophanes'' '' Apollophanes'' O. Pickard-Cambridge, 1898 * '' A. aztecanus'' Dondale & Redner, 1975 — Mexico * '' A. bangal ... References External links albidus Spiders of Europe Spiders described in 1911 {{philodromidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
