Orbweavers
family of suborder “Typical Spiders“
1 family, 6 species
Orb-weaving spiders are known for building flat webs with sticky silk to catch prey. They start by floating a line in the wind to another surface and then build the web’s structure. The spiders use their third claw to walk on the nonsticky parts of the web. Some orb-weavers eat and rebuild their webs daily, while others use unique methods to catch prey. The evolution of orb-weaving spiders dates back to the Jurassic period, and they are important predators in ecosystems.
Hierarchy
species of family “Orbweavers“
1 species
species of family “Orbweavers“
1 species
species of family “Orbweavers“
1 species
Description#
Generally, orb-weaving spiders are three-clawed builders of flat webs with sticky spiral capture silk. The building of a web is an engineering feat, begun when the spider floats a line on the wind to another surface. The spider secures the line and then drops another line from the center, making a “Y”. The rest of the scaffolding follows with many radii of nonsticky silk being constructed before a final spiral of sticky capture silk. The third claw is used to walk on the nonsticky part of the web. Characteristically, the prey insect that blunders into the sticky lines is stunned by a quick bite, and then wrapped in silk. If the prey is a venomous insect, such as a wasp, wrapping may precede biting and/or stinging. Much of the orb-spinning spiders’ success in capturing insects depends on the web not being visible to the prey, with the stickiness of the web increasing the visibility, thus decreasing the chances of capturing prey. This leads to a trade-off between the visibility of the web and the web’s prey-retention ability. Many orb-weavers build a new web each day. Most orb-weavers tend to be active during the evening hours; they hide for most of the day. Generally, towards evening, the spider consumes the old web, rests for about an hour, then spins a new web in the same general location. Thus, the webs of orb-weavers are generally free of the accumulation of detritus common to other species, such as black widow spiders. Some orb-weavers do not build webs at all. Members of the genera Mastophora in the Americas, Cladomelea in Africa, and Ordgarius in Australia produce sticky globules, which contain a pheromone analog. The globule is hung from a silken thread dangled by the spider from its front legs. The pheromone analog attracts male moths of only a few species. These get stuck on the globule and are reeled in to be eaten. Both genera of bolas spiders are highly camouflaged and difficult to locate. In the Araneus diadematus, variables such as wind, web support, temperatures, humidity, and silk supply all proved to be variables in web construction. When studied against the tests of nature, the spiders were able to decide what shape to make their web, how many capture spirals, or the width of their web. Though it could be expected for these spiders to just know these things, it is not well researched yet as to just how the arachnid knows how to change their web design based on their surroundings. Some scientists suggest that it could be through the spider’s spatial learning on their environmental surroundings and the knowing of what will or will not work compared to natural behavioristic rules. The spiny orb-weaving spiders in the genera Gasteracantha and Micrathena look like plant seeds or thorns hanging in their orb-webs. Some species of Gasteracantha have very long, horn-like spines protruding from their abdomens. One feature of the webs of some orb-weavers is the stabilimentum, a crisscross band of silk through the center of the web. It is found in several genera, but Argiope – the yellow and banded garden spiders of North America – is a prime example. As orb-weavers age, they tend to have less production of their silk; many adult orb-weavers can then depend on their coloration to attract more of their prey. The band may be a lure for prey, a marker to warn birds away from the web, and a camouflage for the spider when it sits in the web. The stabilimentum may decrease the visibility of the silk to insects, thus making it harder for prey to avoid the web. The orb-web consists of a frame and supporting radii overlaid with a sticky capture spiral, and the silks used by orb-weaver spiders have exceptional mechanical properties to withstand the impact of flying prey. The orb-weaving spider Zygiella x-notata produces a unique orb-web with a characteristic missing sector, similar to other species of the Zygiella genus in the Araneidae family. During the Cretaceous, a radiation of flowering plants and their insect pollinators occurred. Fossil evidence shows that the orb web was in existence at this time, which permitted a concurrent radiation of the spider predators along with their insect prey. The capacity of orb–webs to absorb the impact of flying prey led orbicularian spiders to become the dominant predators of aerial insects in many ecosystems. Insects and spiders have comparable rates of diversification, suggesting they co-radiated, and the peak of this radiation occurred 100 Mya, before the origin of angiosperms. Vollrath and Selden (2007) make the bold proposition that insect evolution was driven less by flowering plants than by spider predation – particularly through orb webs – as a major selective force. On the other hand some analyses have yielded estimates as high as 265 Mya, with a large number (including Dimitrov et al 2016) intermediate between the two. Most arachnid webs are vertical and the spiders usually hang with their heads downward. A few webs, such as those of orb-weavers in the genus Metepeira, have the orb hidden within a tangled space of web. Some Metepiera species are semisocial and live in communal webs. In Mexico, such communal webs have been cut out of trees or bushes and used for living fly paper. In 2009, workers at a Baltimore wastewater treatment plant called for help to deal with over 100 million orb-weaver spiders, living in a community that managed to spin a phenomenal web that covered some 4 acres of a building, with spider densities in some areas reaching 35,176 spiders per cubic meter.
Taxonomy#
The oldest known true orb-weaver is Mesozygiella dunlopi, from the Lower Cretaceous. Several fossils provide direct evidence that the three major orb-weaving families, namely the Araneidae, Tetragnathidae, and Uloboridae, had evolved by this time, about 140 Mya. They probably originated during the Jurassic (200 to 140 million years ago). Based on new molecular evidence in silk genes, all three families are likely to have a common origin. The two superfamilies, Deinopoidea and Araneoidea, have similar behavioral sequences and spinning apparatuses to produce architecturally similar webs. The latter weave true viscid silk with an aqueous glue property, and the former use dry fibrils and sticky silk. The Deinopoidea (including the Uloboridae), have a cribellum – a flat, complex spinning plate from which the cribellate silk is released. They also have a calamistrum – an apparatus of bristles used to comb the cribellate silk from the cribellum. The Araneoidea, or the “ecribellate” spiders, do not have these two structures. The two groups of orb-weaving spiders are morphologically very distinct, yet much similarity exists between their web forms and web construction behaviors. The cribellates retained the ancestral character, yet the cribellum was lost in the escribellates. The lack of a functional cribellum in araneoids is most likely synapomorphic. If the orb-weaver spiders are a monophyletic group, the fact that only some species in the group lost a feature adds to the controversy. The cribellates are split off as a separate taxon that retained the primitive feature, which makes the lineage paraphyletic and not synonymous with any real evolutionary lineage. The morphological and behavioral evidence surrounding orb webs led to the disagreement over a single or a dual origin. While early molecular analysis provided more support for a monophyletic origin, other evidence indicates that orb-weavers evolved earlier phylogenetically than previously thought, and were extinct at least three times during the Cretaceous.
Reproduction#
Araneid species either mate at the central hub of the web, where the male slowly traverses the web, trying not to get eaten, and when reaching the hub, mounts the female; or the male constructs a mating thread inside or outside the web to attract the female via vibratory courtship, and if successful, mating occurs on the thread. In the cannibalistic and polyandrous orb-web spider Argiope bruennichi, the much smaller males are attacked during their first copulation and are cannibalized in up to 80% of the cases. All surviving males die after their second copulation, a pattern observed in other Argiope species. Whether a male survives his first copulation depends on the duration of the genital contact; males that jump off early (before 5 seconds) have a chance of surviving, while males that copulate longer (greater than 10 seconds) invariably die. Prolonged copulation, although associated with cannibalism, enhances sperm transfer and relative paternity. When males mated with a nonsibling female, the duration of their copulation was prolonged, and consequently the males were cannibalized more frequently. When males mated with a sibling female, they copulated briefly, thus were more likely to escape cannibalism. By escaping, their chance of mating again with an unrelated female likely would be increased. These observations suggest that males can adaptively adjust their investment based on the degree of genetic relatedness of the female to avoid inbreeding depression.
Genera#
As of May 2024, the World Spider Catalog accepts the following genera:
Abba Castanheira & Framenau, 2023 – Australia (Queensland, New South Wales) Acacesia Simon, 1895 — South America, North America Acantharachne Tullgren, 1910 — Congo, Madagascar, Cameroon Acanthepeira Marx, 1883 — North America, Brazil, Cuba Acroaspis Karsch, 1878 — New Zealand, Australia Acrosomoides Simon, 1887 — Madagascar, Cameroon, Congo Actinacantha Simon, 1864 — Indonesia Actinosoma Holmberg, 1883 — Colombia, Argentina Aculepeira Chamberlin & Ivie, 1942 — North America, Central America, South America, Asia, Europe Acusilas Simon, 1895 — Asia Aethriscus Pocock, 1902 — Congo Aethrodiscus Strand, 1913 — Central Africa Aetrocantha Karsch, 1879 — Central Africa Afracantha Dahl, 1914 — Africa Agalenatea Archer, 1951 — Ethiopia, Asia Alenatea Song & Zhu, 1999 — Asia Allocyclosa Levi, 1999 — United States, Panama, Cuba Alpaida O. Pickard-Cambridge, 1889 — Central America, South America, Mexico, Caribbean Amazonepeira Levi, 1989 — South America Anepsion Strand, 1929 — Oceania, Asia Aoaraneus Tanikawa, Yamasaki & Petcharad, 2021 — China, Japan, Korea, Taiwan Arachnura Clerck, 1863 Araneus Clerck, 1757 Araniella Chamberlin & Ivie, 1942 — Asia Aranoethra Butler, 1873 — Africa Argiope Audouin, 1826 — Asia, Oceania, Africa, North America, South America, Costa Rica, Cuba, Portugal Artifex Kallal & Hormiga, 2018 — Australia Artonis Simon, 1895 — Myanmar, Ethiopia Aspidolasius Simon, 1887 — South America Augusta O. Pickard-Cambridge, 1877 — Madagascar Austracantha Dahl, 1914 — Australia Backobourkia Framenau, Dupérré, Blackledge & Vink, 2010 — Australia, New Zealand Bertrana Keyserling, 1884 — South America, Central America Bijoaraneus Tanikawa, Yamasaki & Petcharad, 2021 — Africa, Asia, Oceania Caerostris Thorell, 1868 — Africa, Asia Carepalxis L. Koch, 1872 — Oceania, South America, Mexico, Jamaica Celaenia Thorell, 1868 — Australia, New Zealand Cercidia Thorell, 1869 — Russia, Kazakhstan, India Chorizopes O. Pickard-Cambridge, 1871 — Asia, Madagascar Chorizopesoides Mi & Wang, 2018 — China, Vietnam Cladomelea Simon, 1895 — South Africa, Congo Clitaetra Simon, 1889 — Africa, Sri Lanka Cnodalia Thorell, 1890 — Indonesia, Japan Coelossia Simon, 1895 — Sierra Leone, Mauritius, Madagascar Colaranea Court & Forster, 1988 — New Zealand Collina Urquhart, 1891 — Australia Colphepeira Archer, 1941 — United States, Mexico Courtaraneus Framenau, Vink, McQuillan & Simpson, 2022 — New Zealand Cryptaranea Court & Forster, 1988 — New Zealand Cyclosa Menge, 1866 — Caribbean, Asia, Oceania, South America, North America, Central America, Africa, Europe Cyphalonotus Simon, 1895 — Asia, Africa Cyrtarachne Thorell, 1868 — Asia, Africa, Oceania Cyrtobill Framenau & Scharff, 2009 — Australia Cyrtophora Simon, 1864 — Asia, Oceania, Dominican Republic, Costa Rica, South America, Africa Deione Thorell, 1898 — Myanmar Deliochus Simon, 1894 — Australia, Papua New Guinea Dolophones Walckenaer, 1837 — Australia, Indonesia Dubiepeira Levi, 1991 — South America Edricus O. Pickard-Cambridge, 1890 — Mexico, Panama, Ecuador Enacrosoma Mello-Leitão, 1932 — South America, Central America, Mexico Encyosaccus Simon, 1895 — South America Epeiroides Keyserling, 1885 — Costa Rica, Brazil Eriophora Simon, 1864 — Oceania, United States, South America, Central America, Africa Eriovixia Archer, 1951 — Asia, Papua New Guinea, Africa Eustacesia Caporiacco, 1954 — French Guiana Eustala Simon, 1895 — South America, North America, Central America, Caribbean Exechocentrus Simon, 1889 — Madagascar Faradja Grasshoff, 1970 — Congo Friula O. Pickard-Cambridge, 1897 — Indonesia Galaporella Levi, 2009 — Ecuador Gasteracantha Sundevall, 1833 — Oceania, Asia, United States, Africa, Chile Gastroxya Benoit, 1962 — Africa Gea C. L. Koch, 1843 — Africa, Oceania, Asia, United States, Argentina Gibbaranea Archer, 1951 — Asia, Europe, Algeria Glyptogona Simon, 1884 — Sri Lanka, Italy, Israel Gnolus Simon, 1879 — Chile, Argentina Guizygiella Zhu, Kim & Song, 1997 — Asia Herennia Thorell, 1877 — Asia, Oceania Heterognatha Nicolet, 1849 — Chile Heurodes Keyserling, 1886 — Asia, Australia Hingstepeira Levi, 1995 — South America Hortophora Framenau & Castanheira, 2021 — Oceania Hypognatha Guérin, 1839 — South America, Central America, Mexico, Trinidad Hypsacantha Dahl, 1914 — Africa Hypsosinga Ausserer, 1871 — Asia, North America, Greenland, Africa Ideocaira Simon, 1903 — South Africa Indoetra Kuntner, 2006 — Sri Lanka Isoxya Simon, 1885 — Africa, Yemen Kaira O. Pickard-Cambridge, 1889 — North America, South America, Cuba, Guatemala Kangaraneus Castanheira & Framenau, 2023 — Australia Kapogea Levi, 1997 — Mexico, South America, Central America Kilima Grasshoff, 1970 — Congo, Seychelles, Yemen Larinia Simon, 1874 — Asia, Africa, South America, Europe, Oceania, North America Lariniaria Grasshoff, 1970 — Asia Larinioides Caporiacco, 1934 — Asia Lariniophora Framenau, 2011 — Australia Leviana Framenau & Kuntner, 2022 — Australia Leviaraneus Tanikawa & Petcharad, 2023 — Asia Leviellus Wunderlich, 2004 — Asia, France Lewisepeira Levi, 1993 — Panama, Mexico, Jamaica Lipocrea Thorell, 1878 — Asia, Europe Macracantha Simon, 1864 — India, China, Indonesia Madacantha Emerit, 1970 — Madagascar Mahembea Grasshoff, 1970 — Central and East Africa Mangora O. Pickard-Cambridge, 1889 — Asia, North America, South America, Central America, Caribbean Mangrovia Framenau & Castanheira, 2022 — Australia Manogea Levi, 1997 — South America, Central America, Mexico Mastophora Holmberg, 1876 — South America, North America, Central America, Cuba Mecynogea Simon, 1903 — North America, South America, Cuba Megaraneus Lawrence, 1968 — Africa Melychiopharis Simon, 1895 — Brazil Metazygia F. O. Pickard-Cambridge, 1904 — South America, Central America, North America, Caribbean Metepeira F. O. Pickard-Cambridge, 1903 — North America, Caribbean, South America, Central America Micrathena Sundevall, 1833 — South America, Caribbean, Central America, North America Micrepeira Schenkel, 1953 — South America, Costa Rica Micropoltys Kulczyński, 1911 — Papua New Guinea, Australia Milonia Thorell, 1890 — Singapore, Indonesia, Myanmar Molinaranea Mello-Leitão, 1940 — Chile, Argentina Nemoscolus Simon, 1895 — Africa Nemosinga Caporiacco, 1947 — Tanzania Nemospiza Simon, 1903 — South Africa Neogea Levi, 1983 — Papua New Guinea, India, Indonesia Neoscona Simon, 1864 — Asia, Africa, Europe, Oceania, North America, Cuba, South America Nephila Leach, 1815 — Asia, Oceania, United States, Africa, South America Nephilengys L. Koch, 1872 — Asia, Oceania Nephilingis Kuntner, 2013 — South America, Africa Nicolepeira Levi, 2001 — Chile Novakiella Court & Forster, 1993 — Australia, New Zealand Novaranea Court & Forster, 1988 — Australia, New Zealand Nuctenea Simon, 1864 — Algeria, Asia, Europe Oarces Simon, 1879 — Brazil, Chile, Argentina Ocrepeira Marx, 1883 — South America, Central America, Caribbean, North America Ordgarius Keyserling, 1886 — Asia, Oceania Paralarinia Grasshoff, 1970 — Congo, South Africa Paraplectana Brito Capello, 1867 — Asia, Africa Paraplectanoides Keyserling, 1886 — Australia Pararaneus Caporiacco, 1940 — Madagascar Paraverrucosa Mello-Leitão, 1939 — South America Parawixia F. O. Pickard-Cambridge, 1904 — Mexico, South America, Asia, Papua New Guinea, Central America, Trinidad Parmatergus Emerit, 1994 — Madagascar Pasilobus Simon, 1895 — Africa, Asia Perilla Thorell, 1895 — Myanmar, Vietnam, Malaysia Pherenice Thorell, 1899 — Cameroon Phonognatha Simon, 1894 — Australia Pitharatus Simon, 1895 — Malaysia, Indonesia Plebs Joseph & Framenau, 2012 — Oceania, Asia Poecilarcys Simon, 1895 — Tunisia Poecilopachys Simon, 1895 — Oceania Poltys C. L. Koch, 1843 — Asia, Africa, Oceania Popperaneus Cabra-García & Hormiga, 2020 — Brazil, Paraguay Porcataraneus Mi & Peng, 2011 — India, China Pozonia Schenkel, 1953 — Caribbean, Paraguay, Mexico, Panama Prasonica Simon, 1895 — Africa, Asia, Oceania Prasonicella Grasshoff, 1971 — Madagascar, Seychelles Pronoides Schenkel, 1936 — Asia Pronous Keyserling, 1881 — Malaysia, Mexico, Central America, South America, Madagascar Pseudartonis Simon, 1903 — Africa Pseudopsyllo Strand, 1916 — Cameroon Psyllo Thorell, 1899 — Cameroon, Congo Pycnacantha Blackwall, 1865 — Africa Rubrepeira Levi, 1992 — Mexico, Brazil Salsa Framenau & Castanheira, 2022 — Australia, New Caledonia, Papua New Guinea Scoloderus Simon, 1887 — Belize, North America, Argentina, Caribbean Sedasta Simon, 1894 — West Africa Singa C. L. Koch, 1836 — Africa, Asia, North America, Europe Singafrotypa Benoit, 1962 — Africa Siwa Grasshoff, 1970 — Asia Socca Framenau, Castanheira & Vink, 2022 — Australia Spilasma Simon, 1897 — South America, Honduras Spinepeira Levi, 1995 — Peru Spintharidius Simon, 1893 — South America, Cuba Taczanowskia Keyserling, 1879 — Mexico, South America Talthybia Thorell, 1898 — China, Myanmar Tatepeira Levi, 1995 — South America, Honduras Telaprocera Harmer & Framenau, 2008 — Australia Testudinaria Taczanowski, 1879 — South America, Panama Thelacantha Hasselt, 1882 — Madagascar, Asia, Australia Thorellina Berg, 1899 — Myanmar, Papua New Guinea Togacantha Dahl, 1914 — Africa Trichonephila Dahl, 1911 — Africa, Asia, Oceania, North America, South America Umbonata Grasshoff, 1971 — Tanzania Ursa Simon, 1895 — Asia, South America, South Africa Venomius Rossi, Castanheira, Baptista & Framenau, 2023 — Australia Verrucosa McCook, 1888 — North America, Panama, South America, Australia Wagneriana F. O. Pickard-Cambridge, 1904 — South America, Central America, Caribbean, North America Witica O. Pickard-Cambridge, 1895 — Cuba, Mexico, Peru Wixia O. Pickard-Cambridge, 1882 — Brazil, Guyana, Bolivia Xylethrus Simon, 1895 — South America, Mexico, Jamaica, Panama Yaginumia Archer, 1960 — Asia Zealaranea Court & Forster, 1988 — New Zealand Zilla C. L. Koch, 1834 — Azerbaijan, India, China Zygiella F. O. Pickard-Cambridge, 1902 — North America, Asia, Ukraine, South America
See also#
List of Araneidae species
External links#
Spiders of Australia Spiders of northwestern Europe Araneae, Arachnology Home Pages World Spider Catalog Orb weavers of Kentucky, University of Kentucky Pictures of Mangora species Gasteracantha cancriformis, spinybacked orbweaver on the University of Florida/Institute of Food and Agricultural Sciences Featured Creatures website Neoscona crucifera and N. domiciliorum on the University of Florida/Institute of Food and Agricultural Sciences Featured Creatures website HOE
Orb-weaving spiders are known for building flat webs with sticky silk to catch prey. They start by floating a line in the wind to another surface and then build the web’s structure. The spiders use their third claw to walk on the nonsticky parts of the web. Some orb-weavers eat and rebuild their webs daily, while others use unique methods to catch prey. The evolution of orb-weaving spiders dates back to the Jurassic period, and they are important predators in ecosystems.
Ancestry Graph
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