Theridiidae

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R G Gillespie - One of the best experts on this subject based on the ideXlab platform.

  • molecular insights into the phylogenetic structure of the spider genus theridion araneae Theridiidae and the origin of the hawaiian theridion like fauna
    Zoologica Scripta, 2007
    Co-Authors: Miquel A. Arnedo, Ingi Agnarsson, R G Gillespie
    Abstract:

    The Hawaiian happy face spider (Theridion grallator Simon, 1900), named for a remarkable abdominal colour pattern resembling a smiling face, has served as a model organism for understanding the generation of genetic diversity. Theridion grallator is one of 11 endemic Hawaiian species of the genus reported to date. Asserting the origin of island endemics informs on the evolutionary context of diversification, and how diversity has arisen on the islands. Studies on the genus Theridion in Hawaii, as elsewhere, have long been hampered by its large size (> 600 species) and poor definition. Here we report results of phylogenetic analyses based on DNA sequences of five genes conducted on five diverse species of Hawaiian Theridion, along with the most intensive sampling of Theridiinae analysed to date. Results indicate that the Hawaiian Islands were colonised by two independent Theridiinae lineages, one of which originated in the Americas. Both lineages have undergone local diversification in the archipelago and have convergently evolved similar bizarre morphs. Our findings confirm para- or polyphyletic status of the largest Theridiinae genera: Theridion, Achaearanea and Chrysso. Convergent simplification of the palpal organ has occurred in the Hawaiian Islands and in two continental lineages. The results confirm the convergent evolution of social behaviour and web structure, both already documented within the Theridiidae. Greater understanding of phylogenetic relationships within the Theridiinae is key to understanding of behavioural and morphological evolution in this highly diverse group.

  • (ARANEAE, Theridiidae) BASED ON DNA SEQUENCES
    1999
    Co-Authors: A. M. Tan, R G Gillespie, G. S. Oxford
    Abstract:

    Five species of Enoplognatha Pavesi 1880 were recently recognized as a monophyletic Enoplognatha ovata group based on morphological data. We analyzed the E. ovata clade for monophyly using four species in the E. ovata group (E. ovata (Clerck 1757), E. latimana Hippa & Oksala 1982, E. margarita Yaginuma 1964 and E. afrodite Hippa & Oksala 1983) and three other closely related taxa (E. japonica Bosenberg & Strand 1906, E. thoracica (Hahn 1833), and E. intrepida S0rensen 1898). Two species of the presumed sister genus (Steatoda Sundevall 1833) were employed as outgroups. The results indicate that the "E. ovata clade" is not monophyletic. The genus Enoplognatha Pavesi 1880 is characterized by the presence of a large col- ulus, a plesiomorphic character for the family; and accordingly, the genus is generally con? sidered one of the more primitive groups in the Theridiidae. The spiders are medium-to- large sized with a subspherical abdomen. Fe? males have a tooth on the posterior margin of the chelicerae; males usually have enlarged chelicerae, with enlarged teeth on the poste? rior margin, and have the paracymbium on the margin of the cymbium. The genus is very close to Steatoda Sundevall 1833, medium-to-

  • quantum shifts in the genetic control of a colour polymorphism in theridion grallator araneae Theridiidae the hawaiian happy face spider
    Heredity, 1996
    Co-Authors: Gerry Stephen Oxford, R G Gillespie
    Abstract:

    Quantum shifts in the genetic control of a colour polymorphism in Theridion grallator (Araneae: Theridiidae), the Hawaiian happy-face spider

  • the effects of genetic background on the island specific control of a colour polymorphism in theridion grallator araneae Theridiidae the hawaiian happy face spider
    Heredity, 1996
    Co-Authors: Gerry Stephen Oxford, R G Gillespie
    Abstract:

    The effects of genetic background on the island-specific control of a colour polymorphism in Theridion grallator (Araneae: Theridiidae), the Hawaiian happy-face spider

Hajime Yoshida - One of the best experts on this subject based on the ideXlab platform.

  • Phoroncidia, Janula and a new genus Brunepisinus (Araneae : Theridiidae) from Brunei
    Acta Arachnologica, 2011
    Co-Authors: Hajime Yoshida, Joseph K. H. Koh
    Abstract:

    Eight species of the family Theridiidae are reported from Brunei Darussalam. Phoroncidia lygeana (Walckenaer, 1842) is recorded for the first time and redescribed. Janula Strand, 1932 is revived from the synonymy of Episinus Latreille, 1809. Six new species of Janula, J. bruneiensis, J. bizona, J. bubalis, J. triangularis, J. batman and J. triocellata, are described. Monetoculus Wunderlich, 2008 is newly synonymised with Janula. A new genus, Brunepisinus, is erected based on a new species, B. selirong.

  • A revision of the genus Achaearanea (Araneae: Theridiidae)
    Acta Arachnologica, 2008
    Co-Authors: Hajime Yoshida
    Abstract:

    The genus Achaearanea Strand, 1929 (Theridiidae) is revised. Two genera, Henziectypus Archer, 1946 and Cryptachaea Archer, 1946, are revived from the synonymy of Achaearanea. Parasteatoda Archer, 1946 is recognized as an independent genus. Redefinitions and species lists of four genera, Achaearanea, Henziectypus, Cryptachaea and Parasteatoda, are given. Nine species of Henziectypus, 61 species of Cryptachaea, and 37 species and a subspecies of Parasteatoda, are respectively transferred from Achaearanea to the suitable genera.

  • a new genus of the family Theridiidae arachnida araneae
    Acta Arachnologica, 2007
    Co-Authors: Hajime Yoshida
    Abstract:

    A new genus of the family Theridiidae is described under the name of Yunohamella. Three species, Yunohamella yunohamensis (Bosenberg & Strand 1906), Y. subadulta (Bosenberg & Strand 1906) and Y. lyrica (Walckenaer 1842), are newly transferred from Takayus Yoshida 2001.

  • A new genus and three new species of the family Theridiidae (Arachnida: Araneae) from North Borneo
    Acta Arachnologica, 2003
    Co-Authors: Hajime Yoshida
    Abstract:

    A new genus, Deelemanella, and three new species, D. borneo, Molione christae and M. kinabalu, belonging to the family Theridiidae are described from North Borneo.

  • A revision of the Japanese genera and species of the subfamily Theridiinae (Araneae: Theridiidae)
    Acta Arachnologica, 2001
    Co-Authors: Hajime Yoshida
    Abstract:

    A revision of the Japanese genera and species of the subfamily Theridiinae Sundevall 1833 (Araneae: Theridiidae) is given. Hooded paracymbium of male palpus and absence of colulus characterize Theridiinae. Monetinae Simon 1894 and Spintharinae Simon 1894 are newly synonymized with Theridiinae. Keys to the subfamilies of Theridiidae and the genera of Theridiinae are given.Two genera, Paidiscura Archer 1950 and Rugathodes Archer 1950, are newly recorded from Japan and three new genera, Nipponidion, Takayus and Kejia, are described. Eleven species are newly transferred from Theridion to those genera: P. subpallens (Bosenberg & Strand 1906), R. nigrolimbata (Yaginuma 1972), N. yaeyamense (Yoshida 1993), Ta. takayensis (S. Saito 1939), Ta. chikunii (Yaginuma 1960), Ta. latifolius (Yaginuma 1960), Ta. yunohamensis (Bosenberg & Strand 1906), Ta. subadultus (Bosenberg & Strand 1906), Ta. lyricus (Walckenaer 1842), K. sterninotata (Bosenberg & Strand 1906) and K. mneon (Bosenberg & Strand 1906).Three new species are described: Nipponidion okinawense, Keijia maculata and Theridula iriomotensis. Theridula albipes S. Saito 1935 described from Sakhalin is newly transferred to Chrysso. Three species names, Chrysso venusta (Yaginuma 1957), C. rapula (Yaginuma 1960) and Theridion adamsoni Berland 1934, are newly synonymized with C. scintillans (Thorell 1895), C. albipes and Keijia mneon, respectively. Neotype of Takayus takayensis (S. Saito 1939) is designated.Fifteen Chinese or American species of Theridion are newly transferred to the other genera as follows: Takayus kunmingicus (Zhu 1998), Ta. naevius (Zhu 1998), Ta. lushanensis (Zhu 1998), Ta. xui (Zhu 1998), Ta. linimaculatus (Zhu 1998), Ta. wangi (Zhu 1998), Ta. sublatifolius (Zhu 1998), Ta. lunulatus (Guan & Zhu 1993), Ta. huanrenensis(Zhu & Gao 1993), Ta. quadrimaculatus (Song & Kim 1991), Keijia qionghaiensis (Zhu 1998), K. tincta (Walkenaer 1802), K. antoni (Keyserling 1884), K. alabamensis (Gertsch & Archer 1942) and K. punctosparsa (Emerton 1882), .Three species names, Theridion argyrodiforme Bosenberg & Strand 1906, Th. indicis Bosenberg & Strand 1906 and Th. sagaphilum Strand 1916, are treated as nomina dubia.

Gerry Stephen Oxford - One of the best experts on this subject based on the ideXlab platform.

Ingi Agnarsson - One of the best experts on this subject based on the ideXlab platform.

  • A revised and dated phylogeny of cobweb spiders (Araneae, Araneoidea, Theridiidae): A predatory Cretaceous lineage diversifying in the era of the ants (Hymenoptera, Formicidae).
    Molecular phylogenetics and evolution, 2015
    Co-Authors: Jie Liu, Laura J. May-collado, Stano Pekár, Ingi Agnarsson
    Abstract:

    Cobweb spiders (Theridiidae) are highly diverse from the perspective of species richness, morphological diversity, variety of web architecture, and behavioral repertoires. The family includes over 50% of social spiders, a behavioral rarity among the order, and members of the family are furthermore the subject of research on venom, silk biomechanics, kleptoparasitism and web building, among other traits. Theridiidae is one of the most abundant groups of spiders, and thus key insect predators in many different ecosystems and is among relatively few spider families that show high degree of myrmecophagy. Modern comparative studies on all these fronts are best buttressed on a phylogenetic foundation. Our goal here is to offer a revised, dated, phylogenetic hypothesis for the family by summarizing previously published data from multiple molecular and morphological studies through data-mining, and adding novel data from several genera. We also test the hypothesis that the origin and diversification of cobweb spiders coincides with that of ants on which many species specialize as prey. The new phylogeny is largely congruent with prior studies and current taxonomy and should provide a useful tool for theridiid classification and for comparative analyses. Nevertheless, we also highlight the limitations of currently available data-the state of the art in Theridiidae phylogenetics-offering weak support for most of the deeper nodes in the phylogeny. Thus the need is clear for modern phylogenomic approaches to obtain a more solid understanding, especially of relationships among subfamilies. We recover the monophyly of currently recognized theridiid subfamilies with the exception of some enigmatic 'pholcommatines' (Styposis, Phoroncidia) and putative 'hadrotarsines' (Audifia, Tekellina) whose placement is uncertain in our analyses. Theridiidae dates back some 100 mya to the Cretaceous, a period of diversification in flowering plants and many groups of insects, including ants. The origin of cobweb spiders, and hence the cobweb-a speciallized trap for pedestrian prey-coincides with a major diversification shift in ants. The family becomes abundant in fossil record 50-40 mya as ants also diversify and reach dominance and contemporary patterns of abundances of theridiids and ants show the same trends, with increasing relative abundance towards the equator and at lower altitudes. We find that among orbiculariae, lineages that specialize on ant prey are non-randomly clustered within Theridiidae. Given these findings we hypothesize that the origin of the gumfoot web was a stepping stone that facilitated the capture of ants and resulted in specialized myrmecophagy in a number of 'basal' theridiids. We also document a subsequent loss in myrmecophagy, and associated increase in speciation rates, as 'recent' theridiid groups evolve diverse web forms and many return to the capture of aerial prey.

  • molecular insights into the phylogenetic structure of the spider genus theridion araneae Theridiidae and the origin of the hawaiian theridion like fauna
    Zoologica Scripta, 2007
    Co-Authors: Miquel A. Arnedo, Ingi Agnarsson, R G Gillespie
    Abstract:

    The Hawaiian happy face spider (Theridion grallator Simon, 1900), named for a remarkable abdominal colour pattern resembling a smiling face, has served as a model organism for understanding the generation of genetic diversity. Theridion grallator is one of 11 endemic Hawaiian species of the genus reported to date. Asserting the origin of island endemics informs on the evolutionary context of diversification, and how diversity has arisen on the islands. Studies on the genus Theridion in Hawaii, as elsewhere, have long been hampered by its large size (> 600 species) and poor definition. Here we report results of phylogenetic analyses based on DNA sequences of five genes conducted on five diverse species of Hawaiian Theridion, along with the most intensive sampling of Theridiinae analysed to date. Results indicate that the Hawaiian Islands were colonised by two independent Theridiinae lineages, one of which originated in the Americas. Both lineages have undergone local diversification in the archipelago and have convergently evolved similar bizarre morphs. Our findings confirm para- or polyphyletic status of the largest Theridiinae genera: Theridion, Achaearanea and Chrysso. Convergent simplification of the palpal organ has occurred in the Hawaiian Islands and in two continental lineages. The results confirm the convergent evolution of social behaviour and web structure, both already documented within the Theridiidae. Greater understanding of phylogenetic relationships within the Theridiinae is key to understanding of behavioural and morphological evolution in this highly diverse group.

  • SUBSOCIALITY IN HELVIBIS THORELLI KEYSERLING 1884 (ARANEAE, Theridiidae, THERIDIINAE) FROM FRENCH GUIANA
    Journal of Arachnology, 2006
    Co-Authors: Jonathan A Coddington, Ingi Agnarsson
    Abstract:

    Abstract Preliminary observations on Helvibis thorelli (Theridiidae) in French Guiana suggest a typical subsocial behavior in this species, with nests consisting of a mother and her offspring who collaborate in prey capture. Communal feeding occurs over several juvenile instars. Subsociality has previously been described in three theridiid genera (Achaearanea, Anelosimus, Theridion) and predicted to occur in further genera of the subfamily Theridiinae. Our findings support this prediction and have important implications for comparative studies as they add another independent observation of social behavior: current phylogenetic knowledge implies subsociality evolved independently in each of these genera.

  • phylogenetic placement of echinotheridion araneae Theridiidae do male sexual organ removal emasculation and sexual cannibalism in echinotheridion and tidarren represent evolutionary replicas
    Invertebrate Systematics, 2006
    Co-Authors: Ingi Agnarsson
    Abstract:

    Uniquely among spiders, males of two cobweb spider (Theridiidae) genera, Tidarren Chamberlin & Ivie, 1934 and Echinotheridion Levi, 1963, voluntarily amputate one of their secondary sexual organs (the pedipalpi, modified as sperm transfer organs) before their last molt and thus have only one palp as adults. This is the first step in a fascinating sexual biology observed in both genera, which is marked by sexual dimorphism – males are tiny compared with females – and usually involves both emasculation and sexual cannibalism. To study the evolution of these striking traits it is essential to understand the phylogenetic relationship of these genera. Both morphological and molecular data place Tidarren in the subfamily Theridiinae. However, Echinotheridion has not been placed phylogenetically to date owing to rarity of specimens, and difficulty of interpreting the highly autapomorphic palpal organ, the main source of morphological characters. Here, the phylogenetic position of Echinotheridion is inferred using fragments of three nuclear (Histone 3, 18S rDNA, and 28S rDNA) and two mitochondrial (16S rDNA and COI) loci. Each matrix separately, and a combined matrix, were analysed using parsimony with gaps either treated as missing data, or as 5th state, and with Bayesian methods. Although all genes agree that Tidarren and Echinotheridion are closely related, perhaps surprisingly, none of the analyses supported their sister relationship. The sister relationship was ambiguously supported in a preliminary morphological analysis, whereas combined molecular and morphological data refuted it. This implies a more complex evolutionary history of male sexual organ removal and other bizarre sexual biology of Tidarren and Echinotheridion than previously envisioned. Many of the analyses are equally consistent with two hypotheses: a single origin, followed by a secondary loss; or independent evolution of this behaviour in the two genera. However, based on the combined molecular Bayesian phylogeny, and some of the preliminary ‘total evidence’ analyses, the latter hypothesis is better supported.

  • NOTES ON WEB AND WEB PLASTICITY AND DESCRIPTION OF THE MALE OF ACHAEARANEA HIEROGLYPHICA (MELLO-LEITÃO) (ARANEAE, Theridiidae)
    Journal of Arachnology, 2006
    Co-Authors: Ingi Agnarsson, Jonathan A Coddington
    Abstract:

    Abstract Cobweb spiders (Theridiidae) exhibit a rich variety of web designs. Current knowledge of theridiid web architecture and evolution indicates that theridiid web design shows high within-taxon diversity and frequent convergence. Here we redescribe Achaearanea hieroglyphica (Mello-Leitao 1940), including the first description of the male, and document in this species (1) an unusual web design and (2) two dramatically different type of webs.

Xianjin Peng - One of the best experts on this subject based on the ideXlab platform.

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