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Micrathena Gracilis
''Micrathena gracilis'' is a spider in the family Araneidae (orb-weavers), commonly known as the spined micrathena or castleback orbweaver. This spider spins a moderately large (can be about 20 cm long in diameter) and very tightly coiled web. The spiders themselves are small and can be found to be anywhere from 4.2 mm to 10.8 mm long. Its venom is harmless to humans. ''M. gracilis'' is unique in appearance due to its large spiky abdomen and black and white bodies. Certain spiders of this species can also display a yellow color on the sides of their bodies. These spiders can be seen most active during the end of the summer and beginning of fall. ''M. gracilis'' is diurnal and are rarely ever seen active at night. Physical characteristics Females are 8–10 mm long. They exhibit a bulbous abdomen with spines. Males exhibit a fair amount of sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Athanase Walckenaer
Baron Charles Athanase Walckenaer (25 December 1771 – 28 April 1852) was a French civil servant and scientist. Biography Walckenaer was born in Paris and studied at the universities of University of Oxford, Oxford and University of Glasgow, Glasgow. In 1793 he was appointed head of the military transports in the Pyrenees, after which he pursued technical studies at the École Nationale des Ponts et Chaussées and the École polytechnique. He was elected member of the Institut de France in 1813, was mayor (''maire'') in the 5th arrondissement of Paris, 5th arrondissement in Paris and secretary-general of the prefect of the Seine (département), Seine 1816–1825. He was made a baron in 1823. In 1839 he was appointed conservator for the Department of Maps at the Bibliothèque Nationale, Royal Library in Paris and in 1840 secretary for life in the Académie des Inscriptions et Belles Lettres. He was one of the founders of the Société entomologique de France in 1832, and a "r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneidae
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs. The family has a cosmopolitan distribution, including many well-known large or brightly colored garden spiders. With 3,108 species in 186 genera worldwide, the Araneidae comprise the third-largest family of spiders (behind the Salticidae and Linyphiidae). Araneid webs are constructed in a stereotypical fashion, where a framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets. Orb webs are also produced by members of other spider families. The long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are closely related, being part of the superfamily Araneo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spined Micrathena (Micrathena Gracilis) Color Variant
''Micrathena gracilis'' is a spider in the family Araneidae (orb-weavers), commonly known as the spined micrathena or castleback orbweaver. This spider spins a moderately large (can be about 20 cm long in diameter) and very tightly coiled web. The spiders themselves are small and can be found to be anywhere from 4.2 mm to 10.8 mm long. Its venom is harmless to humans. ''M. gracilis'' is unique in appearance due to its large spiky abdomen and black and white bodies. Certain spiders of this species can also display a yellow color on the sides of their bodies. These spiders can be seen most active during the end of the summer and beginning of fall. ''M. gracilis'' is diurnal and are rarely ever seen active at night. Physical characteristics Females are 8–10 mm long. They exhibit a bulbous abdomen with spines. Males exhibit a fair amount of sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metepeira Incrassata
''Metepeira incrassata'', also known as the colonial orb-weaving spider, belongs to the spider family Araneidae and genus Metepeira. They are most famous for their social organization and group living behavior. They are generally found in tropical rainforest and agricultural sites in Mexico, and their habitats tend to be highly productive (high generation rate of biomass). Their group sizes are relatively larger than other colonial spiders, typically ranging from hundreds to thousands of individuals. 99% of the females are observed to participate in colonial living, generally with at least two other individuals. Because most ''M. incrassata'' females are communal, the colonies are often dominated by larger males. There is minimal sexual dimorphism observed in ''M. incrassata''. Unlike other orb-weaver spiders, ''M. incrassata'' builds a colonial web by connecting each spider's individual webs together through semi-permanent framelines. These colonial webs of ''M. incrassata'' are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enallagma Geminatum
''Enallagma geminatum'', the skimming bluet, is a species of narrow-winged damselfly in the family Coenagrionidae. It is found in North America. The IUCN conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ... of ''Enallagma geminatum'' is "LC", least concern, with no immediate threat to the species' survival. The population is stable. References Further reading * External links * Coenagrionidae Articles created by Qbugbot Insects described in 1895 {{Coenagrionidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-eyed Vireo
The white-eyed vireo (''Vireo griseus'') is a small songbird of the family Vireonidae. Distribution and habitat It breeds in the eastern United States from New England west to northern Missouri and south to Texas and Florida, and also in eastern Mexico, northern Central America, Cuba and the Bahamas. Populations on the US Gulf Coast and further south are resident, but most North American birds migrate south in winter. This vireo frequents bushes and shrubs in abandoned cultivation or overgrown pastures. Breeding The grass-lined nest is a neat cup shape, attached to a fork in a tree branch by spider webs. It lays 3–5 dark-spotted white eggs. Both the male and female incubate the eggs for 12–16 days. The young leave the nest 9–11 days after hatching. Description Measurements: * Length: 4.3-5.1 in (11-13 cm) * Weight: 0.3-0.5 oz (10-14 g) * Wingspan: 6.7 in (17 cm) Its head and back are a greyish olive, and the underparts are white with yellow flanks. The wings an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiders Of North America
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
