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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. ''P. cespitum'' is a foliage-dweller, and is the most abundant species found in European fruit orchards. It acts as a Biological pest control, biological control by preying on orchard pests. ''P. cespitum'' is a Diurnality, diurnal ambush hunter and preys on Aphid, 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 ... [...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 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatry
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation. Such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation may, but need not, arise through secondary contact, which refers to speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may or may not interbreed. Types of populations Four main types of population pairs exist in nature. Sympatric populations (or species) contrast with parapatric populations, which contact one another in adjacent but not shared ranges and do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocoon (silk)
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 metamorphos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Darwin ... [...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 (biology), 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 vulner ... [...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 then 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 ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cacopsylla Pyri
''Psylla pyri'', commonly known as the pear psylla or pear psyllid, is an insect in the family Psyllidae. 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 The adult ''Psylla pyri'' is 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 become much more common, especially i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambush Predator
Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap 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 expandin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Rhythm
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the environment (Entrainment (chronobiology), entrained by the environment). These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in animals, plants, fungi and cyanobacteria. The term ''circadian'' comes from the Latin ''wikt:circa#Latin, circa'', meaning "approximately", and ''dies'', 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 circadian rhythms are endogenous, they are adjusted to the local environment by external cues called zeitgebers (German for "time givers"), which include light, temperature and redox cy ... [...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 is the last of an old Gondwanan lineage, long since separated from its closest relatives in South America. 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 breathe, seen as four light patches beneath the abdomen. Males are smaller than females, and have a distinct kink-like curve near th ... [...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 (spider), Apollophanes'' O. Pickard-Cambridge, 1898 * ''Apollophanes aztecanus, A. aztecanus'' Don ... References External links buchari Spiders of Europe Spiders described in 2004 {{philodromidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niche Segregation
Species use restricted ecological niches, and the niches of all species are segregated, often with much overlap, by the use of different habitats, different geographic areas and seasons, and different food resources, to mention only a few of the many niche dimensions. The causes of niche restriction and segregation are important problems in evolutionary ecology. Background Two ecological paradigms deal with the problem. The first paradigm predominates in what may be called “classical” ecology. It assumes that niche space is largely saturated with individuals and species, leading to strong competition. Niches are restricted because “neighbouring” species, i.e., species with similar ecological characteristics such as similar habitats or food preferences, prevent expansion into other niches or even narrow niches down. This continual struggle for existence is an important assumption of natural selection introduced by Darwin as an explanation for evolution. The other paradigm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
