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Sample records for australian funnel-web spiders

  1. Funnel-web spider bite

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    ... page: //medlineplus.gov/ency/article/002844.htm Funnel-web spider bite To use the sharing features on ... the effects of a bite from the funnel-web spider. Male funnel-web spiders are more poisonous ...

  2. The Lethal Toxin from Australian Funnel-Web Spiders Is Encoded by an Intronless Gene

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    Pineda, Sandy Steffany; Wilson, David; Mattick, John S.; King, Glenn F.

    2012-01-01

    Australian funnel-web spiders are generally considered the most dangerous spiders in the world, with envenomations from the Sydney funnel-web spider Atrax robustus resulting in at least 14 human fatalities prior to the introduction of an effective anti-venom in 1980. The clinical envenomation syndrome resulting from bites by Australian funnel-web spiders is due to a single 42-residue peptide known as δ-hexatoxin. This peptide delays the inactivation of voltage-gated sodium channels, which results in spontaneous repetitive firing and prolongation of action potentials, thereby causing massive neurotransmitter release from both somatic and autonomic nerve endings. Here we show that δ-hexatoxin from the Australian funnel-web spider Hadronyche versuta is produced from an intronless gene that encodes a prepropeptide that is post-translationally processed to yield the mature toxin. A limited sampling of genes encoding unrelated venom peptides from this spider indicated that they are all intronless. Thus, in distinct contrast to cone snails and scorpions, whose toxin genes contain introns, spiders may have developed a quite different genetic strategy for evolving their venom peptidome. PMID:22928020

  3. The lethal toxin from Australian funnel-web spiders is encoded by an intronless gene.

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    Sandy Steffany Pineda

    Full Text Available Australian funnel-web spiders are generally considered the most dangerous spiders in the world, with envenomations from the Sydney funnel-web spider Atrax robustus resulting in at least 14 human fatalities prior to the introduction of an effective anti-venom in 1980. The clinical envenomation syndrome resulting from bites by Australian funnel-web spiders is due to a single 42-residue peptide known as δ-hexatoxin. This peptide delays the inactivation of voltage-gated sodium channels, which results in spontaneous repetitive firing and prolongation of action potentials, thereby causing massive neurotransmitter release from both somatic and autonomic nerve endings. Here we show that δ-hexatoxin from the Australian funnel-web spider Hadronyche versuta is produced from an intronless gene that encodes a prepropeptide that is post-translationally processed to yield the mature toxin. A limited sampling of genes encoding unrelated venom peptides from this spider indicated that they are all intronless. Thus, in distinct contrast to cone snails and scorpions, whose toxin genes contain introns, spiders may have developed a quite different genetic strategy for evolving their venom peptidome.

  4. Characterization of insecticidal peptides from venom Australian funnel-web spiders

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    E. J. Vonorax

    2006-04-01

    Full Text Available Australian funnel-web spiders are relatively large primitive hunting spiders. Male Atrax robustus spiders have been responsible for a number of human deaths. Venom was collected from the species Hadronyche infensa (Hickman [female], H. formidabilis [male and female], H. versuta [female], and A. robustus (Cambridge [male] and was fractionated by high performance liquid chromatography. This resulted in the isolation and purification of a homologous series of 7 insecticidal peptides of relatively low molecular mass (approximately 4kDa. The amino acid sequences of these toxins consisted of 36 or 37 amino acids and were named atracotoxins. For the major bioassay of these toxins, we used the cotton bollworm, Helicoverpa armigera (Hubner, due to the great damage it causes to crops worldwide. These toxins, when injected subcutaneously into fifth or sixth instar larvae of Helicoverpa armigera,were lethal or caused an apparently irreversible writhing. The toxin from H. versuta venom showed no significant toxicity when subcutaneously injected into newborn mice. One of the toxins was found to have a free acid carboxyl terminus. These toxins have great potential as lead compounds for insecticide design or for incorporation in recombinant baculovirus insecticides.

  5. Short-range phenotypic divergence among genetically distinct parapatric populations of an Australian funnel-web spider.

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    Wong, Mark K L; Woodman, James D; Rowell, David M

    2017-07-01

    Speciation involves divergence at genetic and phenotypic levels. Where substantial genetic differentiation exists among populations, examining variation in multiple phenotypic characters may elucidate the mechanisms by which divergence and speciation unfold. Previous work on the Australian funnel-web spider Atrax sutherlandi Gray (2010; Records of the Australian Museum 62 , 285-392; Mygalomorphae: Hexathelidae: Atracinae) has revealed a marked genetic structure along a 110-kilometer transect, with six genetically distinct, parapatric populations attributable to past glacial cycles. In the present study, we explore variation in three classes of phenotypic characters (metabolic rate, water loss, and morphological traits) within the context of this phylogeographic structuring. Variation in metabolic and water loss rates shows no detectable association with genetic structure; the little variation observed in these rates may be due to the spiders' behavioral adaptations (i.e., burrowing), which buffer the effects of climatic gradients across the landscape. However, of 17 morphological traits measured, 10 show significant variation among genetic populations, in a disjunct manner that is clearly not latitudinal. Moreover, patterns of variation observed for morphological traits serving different organismic functions (e.g., prey capture, burrowing, and locomotion) are dissimilar. In contrast, a previous study of an ecologically similar sympatric spider with little genetic structure indicated a strong latitudinal response in 10 traits over the same range. The congruence of morphological variation with deep phylogeographic structure in Tallaganda's A. sutherlandi populations, as well as the inconsistent patterns of variation across separate functional traits, suggest that the spiders are likely in early stages of speciation, with parapatric populations independently responding to local selective forces.

  6. Unravelling the complex venom landscapes of lethal Australian funnel-web spiders (Hexathelidae: Atracinae) using LC-MALDI-TOF mass spectrometry.

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    Palagi, Alexandre; Koh, Jennifer M S; Leblanc, Mathieu; Wilson, David; Dutertre, Sébastien; King, Glenn F; Nicholson, Graham M; Escoubas, Pierre

    2013-03-27

    Spider venoms represent vast sources of bioactive molecules whose diversity remains largely unknown. Indeed, only a small subset of species have been studied out of the ~43,000 extant spider species. The present study investigated inter- and intra-species venom complexity in 18 samples collected from a variety of lethal Australian funnel-web spiders (Mygalomorphae: Hexathelidae: Atracinae) using C4 reversed-phase separation coupled to offline MALDI-TOF mass spectrometry (LC-MALDI-TOF MS). An in-depth investigation focusing on four atracine venoms (male Illawarra wisharti, male and female Hadronyche cerberea, and female Hadronyche infensa Toowoomba) revealed, on average, ~800 peptides in female venoms while male venoms contained ~400 peptides, distributed across most HPLC fractions. This is significantly higher than previous estimates of peptide expression in mygalomorph venoms. These venoms also showed distinct intersexual as well as intra- and inter-species variation in peptide masses. Construction of both 3D and 2D contour plots revealed that peptide mass distributions in all 18 venoms were centered around the 3200-5400m/z range and to a lesser extent the 6600-8200m/z range, consistent with previously described hexatoxins. These findings highlight the extensive diversity of peptide toxins in Australian funnel-web spider venoms that that can be exploited as novel therapeutic and biopesticide lead molecules. In the present study we describe the complexity of 18 venoms from lethal Australian funnel-web spiders using LC-MALDI-TOF MS. The study includes an in-depth investigation, focusing on four venoms, that revealed the presence of ~800 peptides in female venoms and ~400 peptides in male venoms. This is significantly higher than previous estimates of peptide expression in spider venoms. By constructing both 3D and 2D contour plots we were also able to reveal the distinct intersexual as well as intra- and inter-species variation in venom peptide masses. We show that

  7. delta-Atracotoxins from australian funnel-web spiders compete with scorpion alpha-toxin binding but differentially modulate alkaloid toxin activation of voltage-gated sodium channels.

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    Little, M J; Zappia, C; Gilles, N; Connor, M; Tyler, M I; Martin-Eauclaire, M F; Gordon, D; Nicholson, G M

    1998-10-16

    delta-Atracotoxins from the venom of Australian funnel-web spiders are a unique group of peptide toxins that slow sodium current inactivation in a manner similar to scorpion alpha-toxins. To analyze their interaction with known sodium channel neurotoxin receptor sites, we studied their effect on [3H]batrachotoxin and 125I-Lqh II (where Lqh is alpha-toxin II from the venom of the scorpion Leiurus quinquestriatus hebraeus) binding and on alkaloid toxin-stimulated 22Na+ uptake in rat brain synaptosomes. delta-Atracotoxins significantly increased [3H]batrachotoxin binding yet decreased maximal batrachotoxin-activated 22Na+ uptake by 70-80%, the latter in marked contrast to the effect of scorpion alpha-toxins. Unlike the inhibition of batrachotoxin-activated 22Na+ uptake, delta-atracotoxins increased veratridine-stimulated 22Na+ uptake by converting veratridine from a partial to a full agonist, analogous to scorpion alpha-toxins. Hence, delta-atracotoxins are able to differentiate between the open state of the sodium channel stabilized by batrachotoxin and veratridine and suggest a distinct sub-conductance state stabilized by delta-atracotoxins. Despite these actions, low concentrations of delta-atracotoxins completely inhibited the binding of the scorpion alpha-toxin, 125I-Lqh II, indicating that they bind to similar, or partially overlapping, receptor sites. The apparent uncoupling between the increase in binding but inhibition of the effect of batrachotoxin induced by delta-atracotoxins suggests that the binding and action of certain alkaloid toxins may represent at least two distinguishable steps. These results further contribute to the understanding of the complex dynamic interactions between neurotoxin receptor site areas related to sodium channel gating.

  8. Towards rationalisation of antivenom use in funnel-web spider envenoming: enzyme immunoassays for venom concentrations.

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    Miller, Mark; O'Leary, Margaret A; Isbister, Geoffrey K

    2016-03-01

    Funnel-web spider (Atrax and Hadronyche spp.) envenoming is rare but causes severe neuromuscular, autonomic, and cardiac effects. A rabbit-derived IgG antivenom is available, but venom detection in patients has not been reported. To use serial venom and antivenom concentrations to better define envenoming and antivenom effectiveness. Serum was collected from nine patients with suspected funnel-web spider bites and clinical effects were recorded. Venom-specific enzyme immunoassays were developed to measure funnel-web spider venom and antivenom concentrations. Goat anti-rabbit whole serum was coupled to UltraLink resin and added to samples to remove bound venom and measure free venom. Antivenom efficacy was defined as antivenom binding all free venom and antivenom effectiveness as resolution of clinical features. Venom was detectable in samples from six of nine patients. In three patients without venom detected, there were only moderate effects, which did not completely respond to antivenom in all cases and no spider was identified. In five of six cases, a male Atrax spp. (Sydney funnel-web) spider was identified. Three patients had moderate envenoming which responded to antivenom. Three patients had severe envenoming and developed catecholamine-induced myocarditis and acute pulmonary oedema. Although cholinergic and non-specific clinical features appeared to respond to antivenom, myocarditis and pulmonary oedema lasted 2-4 days. Median venom concentration pre-antivenom in five patients with samples was 5.6 ng/ml (3-35 ng/ml), and immediately post-antivenom decreased to a median of 0 ng/ml (0-1.8 ng/ml). Post-antivenom venom concentrations decreased when bound venom was removed; median, 0 ng/ml (0-0.9 ng/ml), indicating that most venom detected post-antivenom was bound. There was recurrence of venom and clinical features in one patient when a pressure bandage was removed. Detection of venom in suspected funnel-web spider bites identified definite cases with

  9. Review of the Australian wolf spider genus Venator (Araneae, Lycosidae).

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    Framenau, Volker W

    2015-09-11

    Species of the Australian wolf spider genus Venator are reviewed including the type species, V. spenceri Hogg, 1900, from south-eastern Australia and V. immansuetus (Simon, 1909) comb. nov., a common species in south-west Western Australia. Venator marginatus Hogg, 1900 is only known from two female specimens and the genital morphology of this species does not conform to the diagnosis of genus as presented here. Therefore V. marginatus is considered incerta sedis. Venator includes medium-sized (9.0-22 mm body length) wolf spiders of overall brownish colouration, and with a black patch covering the anterior three quarters of the venter. They differ from all other wolf spiders in particular by genitalic characters, namely an elevated atrium of the female epigyne that forms a raised edged against the inverted T-shaped median septum. This edge often corresponds to a retrolateral incision on the tegular apophysis of the male pedipalp. The genus is mainly a representative of the Bassian fauna of the Australian continent where it occurs predominantly in dry sclerophyll forests.

  10. The Aromatic Head Group of Spider Toxin Polyamines Influences Toxicity to Cancer Cells

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    David Wilson

    2017-10-01

    Full Text Available Spider venoms constitute incredibly diverse libraries of compounds, many of which are involved in prey capture and defence. Polyamines are often prevalent in the venom and target ionotropic glutamate receptors. Here we show that a novel spider polyamine, PA366, containing a hydroxyphenyl-based structure is present in the venom of several species of tarantula, and has selective toxicity against MCF-7 breast cancer cells. By contrast, a polyamine from an Australian funnel-web spider venom, which contains an identical polyamine tail to PA366 but an indole-based head-group, is only cytotoxic at high concentrations. Our results suggest that the ring structure plays a role in the cytotoxicity and that modification to the polyamine head group might lead to more potent and selective compounds with potential as novel cancer treatments.

  11. Revision of the funnel-web spider genus Novalena (Araneae: Agelenidae).

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    Maya-Morales, Julieta; Jiménez, María Luisa

    2017-05-05

    The Western Hemisphere genus Novalena Chamberlin & Ivie 1942 (Araneae: Agelenidae) is revised. The genus now includes a total of 53 species, of which 40 are new species from USA, Mexico, Guatemala, and Costa Rica: N. ajusco sp. nov. (♀), N. alamo sp. nov. (♂), N. alvarezi sp. nov. (♀), N. atzimbo sp. nov. (♀), N. bosencheve sp. nov. (♂), N. chamberlini sp. nov. (♂ ♀), N. cieneguilla sp. nov. (♀), N. cintalapa sp. nov. (♂ ♀), N. clara sp. nov. (♂ ♀), N. comaltepec sp. nov. (♀), N. creel sp. nov. (♂ ♀), N. dentata sp. nov. (♂ ♀), N. divisadero sp. nov. (♀), N. durango sp. nov. (♀), N. franckei sp. nov. (♂ ♀), N. garnica sp. nov. (♂ ♀), N. gibarrai sp. nov. (♂ ♀), N. irazu sp. nov. (♀), N. iviei sp. nov. (♂), N. ixtlan sp. nov. (♂), N. jiquilpan sp. nov. (♀), N. leonensis sp. nov. (♂ ♀), N. mexiquensis sp. nov. (♂ ♀), N. oaxaca sp. nov. (♂ ♀), N. paricutin sp. nov. (♀), N. perote sp. nov. (♂ ♀), N. plata sp. nov. (♀), N. poncei sp. nov. (♂ ♀), N. popoca sp. nov. (♀), N. prieta sp. nov. (♀), N. puebla sp. nov. (♂ ♀), N. punta sp. nov. (♂ ♀), N. rothi sp. nov. (♂ ♀), N. saltoensis sp. nov. (♀), N. sinaloa sp. nov. (♀), N. tacana sp. nov. (♂ ♀), N. triunfo sp. nov. (♀), N. valdezi sp. nov. (♂ ♀), N. victoria sp. nov. (♀), and N. volcanes sp. nov. (♀). Nine are previously described species: N. annamae (Gertsch & Davis 1940), N. attenuata (F.O. Pickard-Cambridge 1902), N. bipartita (Kraus 1955), N. calavera Chamberlin & Ivie 1942, N. costata (F.O. Pickard-Cambridge 1902), N. laticava (Kraus 1955), N. orizaba (Banks 1898), N. shlomitae (García-Villafuerte 2009), and N. simplex (F.O. Pickard-Cambridge 1902). Four new synonyms are proposed: N. pina Chamberlin & Ivie 1942 = N. intermedia (Chamberlin & Gertsch 1930); N. idahoana (Gertsch 1934) and N. wawona Chamberlin & Ivie 1942 = N. lutzi (Gertsch 1933); N. tolucana (Gertsch & Davis 1940) = N. approximata (Gertsch & Ivie 1936). One species is transferred from Melpomene back to Novalena: N. bipunctata Roth 1967 stat. rev. One species is transferred to Hoffmannilena Maya-Morales & Jiménez 2016: H. nova (O. Pickard-Cambridge 1896) comb. nov.

  12. Antibacterial activity of venom from funnel web spider Agelena labyrinthica (Araneae: Agelenidae

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    M Benli

    2008-01-01

    Full Text Available Since the number of microorganisms that are resistant to antibiotics has been increasing steadily, the need for combating these pathogens requires new pharmaceutical agents. To produce these substances, new models have been developed in recent decades. In our study, the venom of Agelena labyrinthica (Clerck, 1757 (Araneae: Agelenidae was tested against ten bacterial strains, specifically, testing 1/100, 1/10 and 1/1 fractions of diluted venom against these bacteria. While the 1/100 dilution was successful in only one of ten bacterial strains, the 1/10 and the 1/1 were effective on six of ten bacterial strains. The most effective results, among these three different concentrations, were observed on Bacillus subtilis. The other five strains that were also sensitive to the dilutions showed similar inhibition zones. Morphological alterations on bacterial cells and comparison with normal cells were accomplished by scanning electron microscopy (SEM. The venom-treated cells, due to their loss of cytoplasm, shrank and presented cell wall depression.

  13. Revision of the Australian Union-Jack wolf spiders, genus Tasmanicosa (Araneae, Lycosidae, Lycosinae).

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    Framenau, Volker W; Baehr, Barbara C

    2016-12-23

    The Australian wolf spider (Lycosidae Sundevall, 1833) genus Tasmanicosa Roewer, 1959 with Lycosa tasmanica Hogg, 1905 as type species is revised to include 14 species: T. godeffroyi (L. Koch, 1865), comb. nov. (= Lycosa tasmanica Hogg, 1905, syn. nov.; = Lycosa zualella Strand, 1907, syn. nov.; = Lycosa woodwardi Simon, 1909, syn. nov.); T. fulgor sp. nov.; T. gilberta (Hogg, 1905) comb. nov.; T. harmsi sp. nov.; T. hughjackmani sp. nov.; T. kochorum sp. nov.; T. leuckartii (Thorell, 1870), comb. nov. (= Lycosa molyneuxi Hogg, 1905, syn. nov.); T. musgravei (McKay, 1974) comb. nov.; T. phyllis (Hogg, 1905) comb. nov. (= Lycosa stirlingae Hogg, 1905, syn. nov.); T. ramosa (L. Koch, 1877), comb. nov.; T. salmo sp. nov.; T. semicincta (L. Koch, 1877) comb. nov.; T. stella sp. nov.; and T. subrufa (Karsch, 1878) comb. nov. Within the Australian wolf spider fauna, the genus Tasmanicosa can be diagnosed by the distinct pattern of radiating light and dark lines forming a "Union-Jack" pattern on the carapace. Male pedipalp morphology identifies the genus as part of the subfamily Lycosinae Sundevall, 1833 due to the presence of a transverse tegular apophysis with dorsal groove guiding the embolus during copulation. However, genital morphology is variable and a synapomorphy based on male pedipalp or female epigyne morphology could not be identified. Members of Tasmanicosa are comparatively large spiders (body length ca. 12-30 mm), that build a shallow burrow, which is sometimes covered with a flimsy trapdoor. Species of Tasmanicosa are largely a Bassian faunal element with preference for open woodlands and/or floodplains, although some species can be found into the semi-arid Australian interior. Two Australian wolf spider species may represent Tasmanicosa based on their original descriptions, but due to immature types in combination with the somatic similarities of all Tasmanicosa species, cannot be identified with certainty. They are therefore considered nomina dubia

  14. SVM-based prediction of propeptide cleavage sites in spider toxins identifies toxin innovation in an Australian tarantula.

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    Emily S W Wong

    Full Text Available Spider neurotoxins are commonly used as pharmacological tools and are a popular source of novel compounds with therapeutic and agrochemical potential. Since venom peptides are inherently toxic, the host spider must employ strategies to avoid adverse effects prior to venom use. It is partly for this reason that most spider toxins encode a protective proregion that upon enzymatic cleavage is excised from the mature peptide. In order to identify the mature toxin sequence directly from toxin transcripts, without resorting to protein sequencing, the propeptide cleavage site in the toxin precursor must be predicted bioinformatically. We evaluated different machine learning strategies (support vector machines, hidden Markov model and decision tree and developed an algorithm (SpiderP for prediction of propeptide cleavage sites in spider toxins. Our strategy uses a support vector machine (SVM framework that combines both local and global sequence information. Our method is superior or comparable to current tools for prediction of propeptide sequences in spider toxins. Evaluation of the SVM method on an independent test set of known toxin sequences yielded 96% sensitivity and 100% specificity. Furthermore, we sequenced five novel peptides (not used to train the final predictor from the venom of the Australian tarantula Selenotypus plumipes to test the accuracy of the predictor and found 80% sensitivity and 99.6% 8-mer specificity. Finally, we used the predictor together with homology information to predict and characterize seven groups of novel toxins from the deeply sequenced venom gland transcriptome of S. plumipes, which revealed structural complexity and innovations in the evolution of the toxins. The precursor prediction tool (SpiderP is freely available on ArachnoServer (http://www.arachnoserver.org/spiderP.html, a web portal to a comprehensive relational database of spider toxins. All training data, test data, and scripts used are available from

  15. Influence of Crop Management and Environmental Factors on Wolf Spider Assemblages (Araneae: Lycosidae) in an Australian Cotton Cropping System.

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    Rendon, Dalila; Whitehouse, Mary E A; Hulugalle, Nilantha R; Taylor, Phillip W

    2015-02-01

    Wolf spiders (Lycosidae) are the most abundant ground-hunting spiders in the Australian cotton (Gossypium hirsutum L.) agroecosystems. These spiders have potential in controlling pest bollworms, Helicoverpa spp. (Lepidoptera: Noctuidae) in minimum-tilled fields. A study was carried out during a wet growing season (2011-2012) in Narrabri, New South Wales, Australia, to determine how different crop rotations and tillage affect wolf spider assemblages in cotton fields. Spider abundance and species richness did not differ significantly between simple plots (no winter crop) and complex plots (cotton-wheat Triticum aestivum L.-vetch Vicia benghalensis L. rotation). However, the wolf spider biodiversity, as expressed by the Shannon-Weaver and Simpson's indices, was significantly higher in complex plots. Higher biodiversity reflected a more even distribution of the most dominant species (Venatrix konei Berland, Hogna crispipes Koch, and Tasmanicosa leuckartii Thorell) and the presence of more rare species in complex plots. T. leuckartii was more abundant in complex plots and appears to be sensitive to farming disturbances, whereas V. konei and H. crispipes were similarly abundant in the two plot types, suggesting higher resilience or recolonizing abilities. The demographic structure of these three species varied through the season, but not between plot types. Environmental variables had a significant effect on spider assemblage, but effects of environment and plot treatment were overshadowed by the seasonal progression of cotton stages. Maintaining a high density and even distribution of wolf spiders that prey on Helicoverpa spp. should be considered as a conservation biological control element when implementing agronomic and pest management strategies. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Poisonous Spiders: Bites, Symptoms, and Treatment; an Educational Review.

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    Rahmani, Farzad; Banan Khojasteh, Seyed Mahdi; Ebrahimi Bakhtavar, Hanieh; Rahmani, Farnaz; Shahsavari Nia, Kavous; Faridaalaee, Gholamreza

    2014-01-01

    More than 40,000 species of spiders have been identified in the world. Spider bites is a common problem among people, however few of them are harmful but delay in treatment can cause death. Since the spider bites are risk full to human, they should be taken seriously, especially in endemic areas. Our objective in this review was to study about poisonous spiders and find out treatments of them. Therefore, we collected related articles from PubMed database and Google Scholar. Three important syndromes caused by spider bites are loxoscelism, latrodectism and funnel web spider syndrome. Many treatments are used but much more studies should have done to decrease the mortality. In this review, we describes different venomous spiders according to their appearance, symptoms after their bites and available treatments.

  17. Poisonous Spiders: Bites, Symptoms, and Treatment; an Educational Review

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    Farzad Rahmani

    2014-03-01

    Full Text Available More than 40,000 species of spiders have been identified in the world. Spider bites is a common problem among people, however few of them are harmful but delay in treatment can cause death. Since the spider bites are risk full to human, they should be taken seriously, especially in endemic areas. Our objective in this review was to study about poisonous spiders and find out treatments of them. Therefore we collected related articles from PubMed database and Google Scholar. Three important syndromes caused by spider bites are loxoscelism, latrodectism and funnel web spider syndrome. Many treatments are used but much more studies should have done to decrease the mortality. In this review, we describes different venomous spiders according to their appearance, symptoms after their bites and available treatments. 

  18. Taxonomy, systematics and biology of the Australian halotolerant wolf spider genus Tetralycosa (Araneae: Lycosidae: Artoriinae

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    Volker W. Framenau

    2017-07-01

    Full Text Available The Australian wolf spider genus Tftralycosa Roewer, 1960, with Lycosa meracula Simon, 1909 (junior synonym of Lycosa oraria L. Koch, 1877 as type species, is revised to include 13 species, eight of which are described as new here: Tetralycosa adarca sp. nov., T. alteripa (McKay, 1976, T. arabanae Framenau, Gotch & Austin, 2006, T. baudinettei sp. nov., T. caudex sp. nov., T. eyrei (Hickman, 1944, T. floundersi sp. nov., T. halophila sp. nov., T. oraria (L. Koch, 1876, T. orariola sp. nov., T. williamsi sp. nov., T. wundurra (McKay, 1979 comb. nov. and T. rebecca sp. nov. Members of Tetralycosa are halotolerant, exclusively inhabiting saline environments such as coastal beaches, and mound springs, clay pans and salt lakes in the Australian interior. A phylogenetic analysis of the genus identified a monophyletic clade of eight species that live permanently on the barren surface of salt lakes suggesting a single radiation into this extremely inhospitable habitat. Some of these Tetralycosa species are currently known from single salt lakes only and with increasing disturbances of these systems by mining, agriculture and recreational use, research effort should be increased to study their ecology and conservation status.

  19. Efficacy of Australian red-back spider (Latrodectus hasselti) antivenom in the treatment of clinical envenomation by the cupboard spider Steatoda capensis (Theridiidae).

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    Atakuziev, Bakhadir U; Wright, Christine E; Graudins, Andis; Nicholson, Graham M; Winkel, Kenneth D

    2014-08-01

    We describe the first Steatoda capensis envenomation treated with CSL red-back spider antivenom (RBSAV). The patient, a 51-year-old female, developed acute local pain, swelling, redness, and diaphoresis in association with tender lymphadenopathy and hypertension. These features responded, in a dose-dependent manner, to RBSAV. In vitro studies confirmed that RBSAV could neutralize S. capensis venom at equivalent concentrations required to neutralize red-back spider (Latrodectus hasselti) venom. Similar data were obtained using Mexican Latrodectus mactans antivenom (Aracmyn®). Although S. capensis yielded similar quantities of venom protein as L. hasselti, pooled S. capensis and Steatoda grossa venom was more rapidly toxic to insects than either L. hasselti or Latrodectus tredecimguttatus venom. By contrast, both Latrodectus venoms were more potent than S. capensis venom in contracting rat isolated mesenteric arteries. Size-exclusion and anion-exchange chromatography was used to purify a 130 kDa fraction from S. capensis venom that induced contracture and loss of twitch tension in chick isolated biventer cervicis nerve-muscle preparations in a manner similar to α-latrotoxin. This activity was abolished by pre-incubation with RBSAV. We conclude that 'steatodism' may overlap more closely with latrodectism than previously recognized and that this bite should be managed in the same way as for Australian red-back envenomation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Vth Pan American Symposium on Animal, Plant and Microbial Toxins

    National Research Council Canada - National Science Library

    Ownby, Charlotte

    1996-01-01

    .... Presentations on arthropod toxins included work on scorpion neurotoxins, K+ channel-blocking peptides, lice and wasp proteins, stinging insect venom allergens and Australian funnel-web spider toxins...

  1. A Tank Bromeliad Favors Spider Presence in a Neotropical Inundated Forest.

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    Yann Hénaut

    Full Text Available Tank bromeliads are good models for understanding how climate change may affect biotic associations. We studied the relationships between spiders, the epiphytic tank bromeliad, Aechmea bracteata, and its associated ants in an inundated forest in Quintana Roo, Mexico, during a drought period while, exceptionally, this forest was dry and then during the flooding that followed. We compared spider abundance and diversity between 'Aechmea-areas' and 'control-areas' of the same surface area. We recorded six spider families: the Dipluridae, Ctenidae, Salticidae, Araneidae, Tetragnathidae and Linyphiidae among which the funnel-web tarantula, Ischnothele caudata, the only Dipluridae noted, was the most abundant. During the drought period, the spiders were more numerous in the Aechmea-areas than in the control-areas, but they were not obligatorily associated with the Aechmea. During the subsequent flooding, the spiders were concentrated in the A. bracteata patches, particularly those sheltering an ant colony. Also, a kind of specificity existed between certain spider taxa and ant species, but varied between the drought period and subsequent flooding. We conclude that climatic events modulate the relationship between A. bracteata patches and their associated fauna. Tank bromeliads, previously considered only for their ecological importance in supplying food and water during drought, may also be considered refuges for spiders during flooding. More generally, tank bromeliads have an important role in preserving non-specialized fauna in inundated forests.

  2. Australian Assassins, Part I: A review of the Assassin Spiders (Araneae, Archaeidae) of mid-eastern Australia

    Science.gov (United States)

    Rix, Michael G.; Harvey, Mark S.

    2011-01-01

    Abstract The Assassin Spiders of the family Archaeidae are an ancient and iconic lineage of basal araneomorph spiders, characterised by a specialised araneophagic ecology and unique, ‘pelican-like’ cephalic morphology. Found throughout the rainforests, wet sclerophyll forests and mesic heathlands of south-western, south-eastern and north-eastern Australia, the genus Austrarchaea Forster & Platnick, 1984 includes a diverse assemblage of relictual, largely short-range endemic species. With recent dedicated field surveys and significant advances in our understanding of archaeid biology and ecology, numerous new species of assassin spiders have been discovered in the montane sub-tropical and warm-temperate closed forests of mid-eastern Australia, including several rare or enigmatic taxa and species of conservation concern. This fauna is revised and 17 new species are described from south-eastern Queensland and eastern New South Wales: Austrarchaea alani sp. n., Austrarchaea aleenae sp. n., Austrarchaea binfordae sp. n., Austrarchaea christopheri sp. n., Austrarchaea clyneae sp. n., Austrarchaea cunninghami sp. n., Austrarchaea dianneae sp. n., Austrarchaea harmsi sp. n., Austrarchaea helenae sp. n., Austrarchaea judyae sp. n., Austrarchaea mascordi sp. n., Austrarchaea mcguiganae sp. n., Austrarchaea milledgei sp. n., Austrarchaea monteithi sp. n., Austrarchaea platnickorum sp. n., Austrarchaea raveni sp. n. and Austrarchaea smithae sp. n. Adult specimens of the type species, Austrarchaea nodosa (Forster, 1956) are redescribed from the Lamington Plateau, south-eastern Queensland, and distinguished from the sympatric species Austrarchaea dianneae sp. n. A key to species and a molecular phylogenetic analysis of COI and COII mtDNA sequences complement the species-level taxonomy, with maps, habitat photos, natural history information and conservation assessments provided for all species. PMID:21998529

  3. Australian Assassins, Part I: A review of the Assassin Spiders (Araneae: Archaeidae of mid-eastern Australia

    Directory of Open Access Journals (Sweden)

    Michael Rix

    2011-08-01

    Full Text Available The Assassin Spiders of the family Archaeidae are an ancient and iconic lineage of basal araneomorph spiders, characterised by a specialised araneophagic ecology and unique, ‘pelican-like’ cephalic morphology. Found throughout the rainforests, wet sclerophyll forests and mesic heathlands of south-western, south-eastern and north-eastern Australia, the genus Austrarchaea Forster & Platnick, 1984 includes a diverse assemblage of relictual, largely short-range endemic species. With recent dedicated field surveys and significant advances in our understanding of archaeid biology and ecology, numerous new species of assassin spiders have been discovered in the montane sub-tropical and warm-temperate closed forests of mid-eastern Australia, including several rare or enigmatic taxa and species of conservation concern. This fauna is revised and 17 new species are described from south-eastern Queensland and eastern New South Wales: A. alani sp. n., A. aleenae sp. n., A. binfordae sp. n., A. christopheri sp. n., A. clyneae sp. n., A. cunninghami sp. n., A. dianneae sp. n., A. harmsi sp. n., A. helenae sp. n., A. judyae sp. n., A. mascordi sp. n., A. mcguiganae sp. n., A. milledgei sp. n., A. monteithi sp. n., A. platnickorum sp. n., A. raveni sp. n. and A. smithae sp. n. Adult specimens of the type species, A. nodosa (Forster, 1956 are redescribed from the Lamington Plateau, south-eastern Queensland, and distinguished from the sympatric species A. dianneae sp. n. A key to species and a molecular phylogenetic analysis of COI and COII mtDNA sequences complement the species-level taxonomy, with maps, habitat photos, natural history information and conservation assessments provided for all species.

  4. Deer herbivory reduces web-building spider abundance by simplifying forest vegetation structure

    Directory of Open Access Journals (Sweden)

    Elizabeth J. Roberson

    2016-09-01

    Full Text Available Indirect ecological effects are a common feature of ecological systems, arising when one species affects interactions among two or more other species. We examined how browsing by white-tailed deer (Odocoileus virginianus indirectly affected the abundance and composition of a web-building spider guild through their effects on the structure of the ground and shrub layers of northern hardwood forests. We examined paired plots consisting of deer-free and control plots in the Allegheny Plateau region Pennsylvania and Northern Highlands region of Wisconsin. We recorded the abundance of seven types of webs, each corresponding to a family of web-building spiders. We quantified vegetation structure and habitat suitability for the spiders by computing a web scaffold availability index (WSAI at 0.5 m and 1.0 m above the ground. At Northern Highlands sites, we recorded prey availability. Spider webs were twice as abundant in deer-free plots compared to control plots, while WSAI was 7–12 times greater in deerfree plots. Prey availability was lower in deer-free plots. With the exception of funnel web-builders, all spider web types were significantly more abundant in deer-free plots. Both deer exclusion and the geographic region of plots were significant predictors of spider community structure. In closed canopy forests with high browsing pressure, the low density of tree saplings and shrubs provides few locations for web-building spiders to anchor webs. Recruitment of these spiders may become coupled with forest disturbance events that increase tree and shrub recruitment. By modifying habitat structure, deer appear to indirectly modify arthropod food web interactions. As deer populations have increased in eastern North America over the past several decades, the effects of deer on web-building spiders may be widespread.

  5. SPIDER SILK

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2014-05-01

    Full Text Available The strengthness and toughness of spider fiber and its multifunctional nature is only surpassed in some cases by synthetic high performance fibers. In the world of natural fibers, spider silk has been long time recognized as a wonder fiber for its unique combination of high strength and rupture elongation. Scientists in civil military engineering reveal that the power of biological material (spider silk lies in the geometric configuration of structural protein, and the small cluster of week hydrogen bonds that works together to resist force and dissipate energy. Each spider and each type of silk has a set of mechanical properties optimized for their biological function. Most silks, in particular deagline silk, have exceptional mechanical properties. They exhibit a unique combination of high tensile strength and extensibility (ductility. This enables a silk fiber to absorb a lot of energy before breaking (toughness, the area under a stress- strain curve. A frequent mistake made in the mainstream media is to confuse strength and toughness when comparing silk to other materials. As shown below in detail, weight for weight, silk is stronger than steel, but not as strong as Kevlar. Silk is,however, tougher than both.This paper inform about overview on the today trend in the world of spider silk.

  6. Fish Predation by Semi-Aquatic Spiders: A Global Pattern

    Science.gov (United States)

    Nyffeler, Martin; Pusey, Bradley J.

    2014-01-01

    More than 80 incidences of fish predation by semi-aquatic spiders – observed at the fringes of shallow freshwater streams, rivers, lakes, ponds, swamps, and fens – are reviewed. We provide evidence that fish predation by semi-aquatic spiders is geographically widespread, occurring on all continents except Antarctica. Fish predation by spiders appears to be more common in warmer areas between 40° S and 40° N. The fish captured by spiders, usually ranging from 2–6 cm in length, are among the most common fish taxa occurring in their respective geographic area (e.g., mosquitofish [Gambusia spp.] in the southeastern USA, fish of the order Characiformes in the Neotropics, killifish [Aphyosemion spp.] in Central and West Africa, as well as Australian native fish of the genera Galaxias, Melanotaenia, and Pseudomugil). Naturally occurring fish predation has been witnessed in more than a dozen spider species from the superfamily Lycosoidea (families Pisauridae, Trechaleidae, and Lycosidae), in two species of the superfamily Ctenoidea (family Ctenidae), and in one species of the superfamily Corinnoidea (family Liocranidae). The majority of reports on fish predation by spiders referred to pisaurid spiders of the genera Dolomedes and Nilus (>75% of observed incidences). There is laboratory evidence that spiders from several more families (e.g., the water spider Argyroneta aquatica [Cybaeidae], the intertidal spider Desis marina [Desidae], and the ‘swimming’ huntsman spider Heteropoda natans [Sparassidae]) predate fish as well. Our finding of such a large diversity of spider families being engaged in fish predation is novel. Semi-aquatic spiders captured fish whose body length exceeded the spiders’ body length (the captured fish being, on average, 2.2 times as long as the spiders). Evidence suggests that fish prey might be an occasional prey item of substantial nutritional importance. PMID:24940885

  7. Brown Recluse Spider

    Science.gov (United States)

    ... to a group of spiders commonly known as violin spiders or fiddlebacks. The characteristic fiddle-shaped pattern ... 4-19.1mm) • Color: Golden brown • A dark violin/fiddle shape (see top photo) is located on ...

  8. Spider Bites (For Parents)

    Science.gov (United States)

    ... body rash fever and chills fatigue Of a black widow spider bite: rigid, painful muscles within 8 hours no ... child was bitten by a brown recluse or black widow spider Think Prevention! Make sure garages, attics, and woodpiles ...

  9. Ontogenesis, gender, and molting influence the venom yield in the spider Coremiocnemis tropix (Araneae, Theraphosidae)

    OpenAIRE

    Herzig, Volker

    2010-01-01

    The demand for spider venom increases along with the growing popularity of venoms-based research. A deeper understanding of factors that influence the venom yield in spiders would therefore be of interest to both commercial venom suppliers and research facilities. The present study addresses the influence of several factors on the venom yield by systematically analyzing the data obtained from 1773 electrical milkings of the Australian theraphosid spider Coremiocnemis tropix. Gender and ontoge...

  10. Spider Bites: First Aid

    Science.gov (United States)

    ... t had one in the last five years. Black widow spider You can usually identify a black widow spider by the hourglass marking on its belly. In ... in the South. Signs and symptoms of a black widow spider bite may include: At first, slight swelling and ...

  11. A reconsideration of the classification of the spider infraorder Mygalomorphae (Arachnida: Araneae based on three nuclear genes and morphology.

    Directory of Open Access Journals (Sweden)

    Jason E Bond

    Full Text Available BACKGROUND: The infraorder Mygalomorphae (i.e., trapdoor spiders, tarantulas, funnel web spiders, etc. is one of three main lineages of spiders. Comprising 15 families, 325 genera, and over 2,600 species, the group is a diverse assemblage that has retained a number of features considered primitive for spiders. Despite an evolutionary history dating back to the lower Triassic, the group has received comparatively little attention with respect to its phylogeny and higher classification. The few phylogenies published all share the common thread that a stable classification scheme for the group remains unresolved. METHODS AND FINDINGS: We report here a reevaluation of mygalomorph phylogeny using the rRNA genes 18S and 28S, the nuclear protein-coding gene EF-1γ, and a morphological character matrix. Taxon sampling includes members of all 15 families representing 58 genera. The following results are supported in our phylogenetic analyses of the data: (1 the Atypoidea (i.e., antrodiaetids, atypids, and mecicobothriids is a monophyletic group sister to all other mygalomorphs; and (2 the families Mecicobothriidae, Hexathelidae, Cyrtaucheniidae, Nemesiidae, Ctenizidae, and Dipluridae are not monophyletic. The Microstigmatidae is likely to be subsumed into Nemesiidae. Nearly half of all mygalomorph families require reevaluation of generic composition and placement. The polyphyletic family Cyrtaucheniidae is most problematic, representing no fewer than four unrelated lineages. CONCLUSIONS: Based on these analyses we propose the following nomenclatural changes: (1 the establishment of the family Euctenizidae (NEW RANK; (2 establishment of the subfamily Apomastinae within the Euctenizidae; and (3 the transfer of the cyrtaucheniid genus Kiama to Nemesiidae. Additional changes include relimitation of Domiothelina and Theraphosoidea, and the establishment of the Euctenizoidina clade (Idiopidae + Euctenizidae. In addition to these changes, we propose a "road map

  12. Latrodectism: case report of a katipo spider (Latrodectus katipo) bite and review of the literature.

    Science.gov (United States)

    Thatcher, Lucinda; Janes, Ron

    2012-03-09

    We describe the case of a 29-year-old man who was bitten on the leg by a katipo spider, a relative of the Australian redback and American black widow spiders, while camping in sand dunes at Mahanga Beach, Mahia (North Island of New Zealand). Symptoms of latrodectism developed within hours, and were not diminished until two doses of the antivenom had been administered. This is only the second case report of a katipo spider bite in the recent literature. The katipo spider bite produces significant symptoms, however an antivenom is available in some hospital pharmacies.

  13. Spiders in caves.

    Science.gov (United States)

    Mammola, Stefano; Isaia, Marco

    2017-04-26

    World experts of different disciplines, from molecular biology to macro-ecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance. As the description of the first eyeless spider ( Stalita taenaria ), an array of papers on subterranean spider biology, ecology and evolution has been published, but a comprehensive review on these topics is still lacking. We provide a general overview of the spider families recorded in hypogean habitats worldwide, we review the different adaptations of hypogean spiders to subterranean life, and we summarize the information gathered so far about their origin, population structure, ecology and conservation status. Finally, we point out the limits of the knowledge we currently have regarding hypogean spiders, aiming to stimulate future research. © 2017 The Author(s).

  14. Bat Predation by Spiders

    Science.gov (United States)

    Nyffeler, Martin; Knörnschild, Mirjam

    2013-01-01

    In this paper more than 50 incidences of bats being captured by spiders are reviewed. Bat-catching spiders have been reported from virtually every continent with the exception of Antarctica (∼90% of the incidences occurring in the warmer areas of the globe between latitude 30° N and 30° S). Most reports refer to the Neotropics (42% of observed incidences), Asia (28.8%), and Australia-Papua New Guinea (13.5%). Bat-catching spiders belong to the mygalomorph family Theraphosidae and the araneomorph families Nephilidae, Araneidae, and Sparassidae. In addition to this, an attack attempt by a large araneomorph hunting spider of the family Pisauridae on an immature bat was witnessed. Eighty-eight percent of the reported incidences of bat catches were attributable to web-building spiders and 12% to hunting spiders. Large tropical orb-weavers of the genera Nephila and Eriophora in particular have been observed catching bats in their huge, strong orb-webs (of up to 1.5 m diameter). The majority of identifiable captured bats were small aerial insectivorous bats, belonging to the families Vespertilionidae (64%) and Emballonuridae (22%) and usually being among the most common bat species in their respective geographic area. While in some instances bats entangled in spider webs may have died of exhaustion, starvation, dehydration, and/or hyperthermia (i.e., non-predation death), there were numerous other instances where spiders were seen actively attacking, killing, and eating the captured bats (i.e., predation). This evidence suggests that spider predation on flying vertebrates is more widespread than previously assumed. PMID:23516436

  15. Tarantula spider bite

    Science.gov (United States)

    ... spider belongs, contains the largest number of venomous species known. This article is for information only. DO ... Wash the area with soap and water. Place ice (wrapped in a clean cloth or other covering) ...

  16. Black widow spider

    Science.gov (United States)

    ... spider belongs, contains the largest number of venomous species known. This article is for information only. DO ... Clean the area with soap and water. Wrap ice in a clean cloth and place it on ...

  17. Space spider crane

    Science.gov (United States)

    Macconochie, Ian O. (Inventor); Mikulas, Martin M., Jr. (Inventor); Pennington, Jack E. (Inventor); Kinkead, Rebecca L. (Inventor); Bryan, Charles F., Jr. (Inventor)

    1988-01-01

    A space spider crane for the movement, placement, and or assembly of various components on or in the vicinity of a space structure is described. As permanent space structures are utilized by the space program, a means will be required to transport cargo and perform various repair tasks. A space spider crane comprising a small central body with attached manipulators and legs fulfills this requirement. The manipulators may be equipped with constant pressure gripping end effectors or tools to accomplish various repair tasks. The legs are also equipped with constant pressure gripping end effectors to grip the space structure. Control of the space spider crane may be achieved either by computer software or a remotely situated human operator, who maintains visual contact via television cameras mounted on the space spider crane. One possible walking program consists of a parallel motion walking program whereby the small central body alternatively leans forward and backward relative to end effectors.

  18. Spider Spinning for Dummies

    Science.gov (United States)

    Bird, Richard S.

    Spider spinning is a snappy name for the problem of listing the ideals of a totally acyclic poset in such a way that each ideal is computed from its predecessor in constant time. Such an algorithm is said to be loopless. Our aim in these lectures is to show how to calculate a loopless algorithm for spider spinning. The calculation makes use of the fundamental laws of functional programming and the real purpose of the exercise is to show these laws in action.

  19. Pre-Deployment Handbook: Solomon Islands

    Science.gov (United States)

    2014-06-01

    Australian Funnel Web Spider can also be found. Blacktip Reef Sharks are common to the Pacific and are generally timid and skittish, seldom...lagoon people also believe the spirits of their deceased live in the sharks around the island’s waters. Guadalcanal and Malaita have people that...are known for drunken assaults. House and vehicle break-ins occur, including against expatriates from other nations. Attacks on vehicles, such as

  20. Company profile: Spider stories.

    Science.gov (United States)

    Giuliani, Andrea

    2008-06-01

    SpiderBiotech is a biotech company that has carried out extensive research and development on peptide-based anti-infectives, with five people involved in R&D activities and a strong network of industrial and academic partners experienced in the field of anti-infectives. SpiderBiotech has also created a proprietary library of bioactive peptides and lipopeptides (both linear and dendrimeric) active against bacterial and viral infections. At the moment they have two ongoing projects: the most advanced is focused on the development of a panel of peptide based antibiotics. The second project is related to novel antiviral drugs to treat acyclovir resistant Herpes virus infections.

  1. Spider Invasion Across the Galaxy

    Directory of Open Access Journals (Sweden)

    Chung-Yue Hui

    2014-06-01

    Full Text Available The nature of the exotic stellar corpses which reincarnate by consuming their companion is reviewed. Apart from sucking life from their partners, they are actually eating the doomed companions away by their deadly and powerful particle/radiation beams. Such situation resembles that a female “black widow” spider that eats its mate after mating. These celestial zombies are called - Millisecond pulsars (MSPs. In this review article, I will focus on the effort of Fermi Asian Network (FAN in exploring these intricating objects over the last five years. Two special classes of MSPs are particularly striking. Since Fermi Gamma-ray Space Telescope has started surveying the gamma−ray sky, the population of “black widows” has been boosted. Another dramatic class is so-called “redbacks” (Australian cousin of “black widows” which has just emerged in the last few years. These MSPs provide us with a long-sought missing link in understanding the transition between accretion-powered and rotation-powered systems. The strategy of hunting MSPs through mulitwavelength observations of the unidentified Fermi objects is also reviewed.

  2. Spider Invasion Across the Galaxy

    Science.gov (United States)

    Hui, Chung-Yue

    2014-06-01

    The nature of the exotic stellar corpses which reincarnate by consuming their companion is reviewed. Apart from sucking life from their partners, they are actually eating the doomed companions away by their deadly and powerful particle/radiation beams. Such situation resembles that a female ¡°black widow¡± spider that eats its mate after mating. These celestial zombies are called - Millisecond pulsars (MSPs). In this review article, I will focus on the effort of Fermi Asian Network (FAN) in exploring these intricating objects over the last five years. Two special classes of MSPs are particularly striking. Since Fermi Gamma-ray Space Telescope has started surveying the gamma?ray sky, the population of ¡°black widows¡± has been boosted. Another dramatic class is so-called ¡°redbacks¡± (Australian cousin of ¡°black widows¡±) which has just emerged in the last few years. These MSPs provide us with a long-sought missing link in understanding the transition between accretion-powered and rotation-powered systems. The strategy of hunting MSPs through mulitwavelength observations of the unidentified Fermi objects is also reviewed.

  3. Black widow spider envenomation.

    Science.gov (United States)

    Peterson, Michael E

    2006-11-01

    Black widow spiders are found throughout the continental United States and north into the southern Canadian provinces. Male black widow spiders are of little medical importance. Female black widow spiders can be 20 times larger than males. The female can be identified by the hourglass pattern, red or orange in color, on the ventral aspect of her shiny, globose black abdomen. Black widow spiders control the amount of venom they inject; an estimated 15% of bites to humans are non-envenomating. Cats are very sensitive to the venom and deaths are common. Dogs have severe clinical signs but are considered more resistant than cats. A single bite is capable of delivering a lethal dose of venom to companion animals. There are several toxic components consisting of five or six biologically active proteins. These include a potent mammalian neurotoxin called alpha-latrotoxin, which induces neurotransmitter release from nerve terminals. Acetylcholine, noradrenalin, dopamine, glutamate, and enkephalin systems are all susceptible to the toxin. Onset of clinical signs usually occurs during the first 8 hours post envenomation. The condition is extremely painful in moderate to severe envenomations. Abdominal rigidity without tenderness is a hallmark sign of Latrodectus envenomation. In cats, paralytic signs may occur early and are particularly marked. Hypertension is a significant threat. First aid is of no value in the treatment. The primary treatment for black widow spider envenomation is the administration of specific antivenin, which provides the most permanent and quickest relief of the envenomation syndrome, usually within 30 minutes of infusion. The prognosis of Latrodectus envenomation is uncertain of several days, and complete recovery may take weeks.

  4. Temporal Patterns in the Abundance and Species Composition of Spiders on Host Plants of the Invasive Moth Epiphyas postvittana (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Hogg, Brian N; Mills, Nicholas J; Daane, Kent M

    2017-06-01

    Generalist predators such as spiders may help mitigate the spread and impact of exotic herbivores. The lack of prey specificity and long generation times of spiders may allow them to persist when pests are scarce, and to limit the growth of pest populations before they reach damaging levels. We examined whether resident spiders are likely to play a role in maintaining populations of the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), below outbreak levels in California. We surveyed the spider community on two E. postvittana host plants, the ornamental Australian tea tree, Leptospermum laevigatum, and the weed French broom, Genista monspessulana, to characterize spider and larval E. postvittana abundance and spider species composition throughout the year. Spider densities and species composition showed slight seasonal changes. Spiders were present during periods of high and low E. postvittana abundance. Anyphaenid hunting spiders, Anyphaena aperta Banks in Australian tea tree and Anyphaena pacifica Banks in French broom, dominated spider species composition at four of five sampled sites, and underwent only slight seasonal variation in abundance. Adult A. aperta were rare at all times of the year, suggesting that high mortality among juvenile A. aperta limits the potential of this species as a predator of E. postvittana. Nevertheless, the continued presence of spiders throughout the year indicates that the resident spider community is likely to play a key role in reducing E. postvittana populations in California. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  5. Reversible myocarditis after spider bite.

    Science.gov (United States)

    Kara, Hasan; Ak, Ahmet; Bayir, Aysegul; Avci, Ahmet

    2013-04-08

    Black widow spiders (Latrodectus tredecimguttatus) are poisonous spiders endemic in Turkey. Latrodectus bites may cause myocarditis with increased cardiac enzymes. We treated two men (aged 20 and 33 years) who had myocarditis after black spider bites with leucocytosis and elevated levels of troponin I, creatine kinase and creatine kinase-MB fraction. Both patients had normal results on an ECG, and one patient had abnormal echocardiography with minimal left ventricular wall movement disorder. Both patients were hospitalised in the intensive care unit and treated with intravenous fluids, analgesics, spasmolytic drugs, tetanus prophylaxis and cardiac monitoring. The levels of troponin I, creatine kinase and creatine kinase-MB fraction improved, and the patients were discharged home on the third and fifth hospital day without complications. Myocarditis after a Latrodectus bite is rare, but may be associated with serious complications. Therefore, in regions endemic with Latrodectus spiders, prudent treatment of spider bites may include cardiac evaluation and monitoring.

  6. Black widow spider and brown recluse spider bites in Texas from 1998 through 2002.

    Science.gov (United States)

    Forrester, Mathias B; Stanley, Sharilyn K

    2003-10-01

    Black widow spiders and brown recluse spiders are of medical importance to humans in the US. However, these spiders differ in their habits, habitat, and the clinical effects and treatment of their bite. This study used data from human exposure calls to poison centers in Texas to compare the epidemioloy of bites from these 2 spiders. During 1998-2002, 760 black widow spider bites and 1,369 brown recluse spider bites were reported. Black widow spider bite penetrance demonstrated no secular trend during this time period while the penetrance of brown recluse spider bites increased. A higher percentage of black widow spider bites occurred among males, while a higher proportion of brown recluse spider bites were reported for females. Black widow spider bites most frequently had mild outcomes while brown recluse spider bites most often had moderate outcomes. The majority of reported bites for both types of spider occurred at the patient's own residence, although the percentage was lower for black widow spiders. Seasonal trends were noted for both black widow and brown recluse spiders. The highest penetrance of black widow spider bites was observed in western Texas while the highest penetrance of brown recluse spider bites was observed in central Texas. This information is useful for identifying those populations at greatest risk for the respective spider bites.

  7. Black widow spider bite.

    Science.gov (United States)

    Kobernick, M

    1984-05-01

    Latrodectus mactans has now invaded towns and cities. The spider's venom is a neurotoxin that causes little local reaction but produces pain and spasm in large skeletal muscle groups within 30 minutes to three hours after the bite. Severe envenomation may result in respiratory failure and coma. First aid is of no value. Muscle relaxants are useful in treatment, as is calcium gluconate. Antivenin is indicated for high-risk victims, such as those with hypertension and persons younger than 16 or older than 60 years of age.

  8. Application of 3 kinds of practical electromagnetic spiders in electromagnetic spider web

    Directory of Open Access Journals (Sweden)

    Jiang Min

    2016-01-01

    Full Text Available Electromagnetic spider web the launch circuit has introduced a lot, but in the center position of the utility of the spider generally have 3 kinds of circuits respectively, the use of single-chip microcomputer circuit of the low energy consumption spider by multi-channel transmission, single circuit receiver circuit. Direct use of the 3 channels of the spider and the use of PLC circuit spider, depending on the actual situation were placed.

  9. Spider phylogenomics: untangling the Spider Tree of Life

    Directory of Open Access Journals (Sweden)

    Nicole L. Garrison

    2016-02-01

    Full Text Available Spiders (Order Araneae are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the “usual suspect” genes have been unable to produce a well-supported phylogenetic framework for the entire order. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125–90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results

  10. Summary statistics for fossil spider species taxonomy

    OpenAIRE

    Penney, David; Dunlop, Jason; Marusik, Yuri

    2012-01-01

    Abstract Spiders (Araneae) are one of the most species-rich orders on Earth today, and also have one of the longest geological records of any terrestrial animal groups, as demonstrated by their extensive fossil record. There are currently around 1150 described fossil spider species, representing 2.6% of all described spiders (i.e. extinct and extant). Data for numbers of fossil and living spider taxa described annually (and various other metrics for the fossil taxa) were compiled from current...

  11. Spider and burnable poison rod combinations

    International Nuclear Information System (INIS)

    Edwards, G.T.; Schluderberg, D.C.

    1980-01-01

    An improved design of burnable poison rods and associated spiders used in fuel assemblies of pressurized water power reactor cores, is described. The rods are joined to the spider arms in a manner which is proof against the reactor core environment and yet allows the removal of the rods from the spider simply, swiftly and delicately. (U.K.)

  12. Approach and avoidance in fear of spiders

    NARCIS (Netherlands)

    Rinck, M.; Becker, E.S.

    2007-01-01

    We examined attitudes towards spiders by employing an Approach-Avoidance Task, in which participants respond to pictures by pulling a joystick towards themselves or by pushing it away from themselves. For spider fearfuls, this stimulus–response assignment is either compatible (push spiders away) or

  13. New unidentate jumping spider genera (Araneae: Salticidae) from Australia.

    Science.gov (United States)

    Richardson, Barry J

    2013-01-01

    The Australian fauna includes large numbers of undescribed, tiny, litter-living, jumping spiders. In this paper four monotypic new genera (Ananeon howardensis n. g. n. sp., Barraina anfracta n. g. n.sp., Frewena maculata n.g. n.s., and Pungalina weiri n.g, n.sp.) are described. Two species (Neon taylori n.sp. and Neon australis n. sp.) representing the two distinctive morphological patterns found in Australian species of this genus are also described. The former, similar in the morphology of the palp and genitalia to that found in many species from eastern Australia, is most similar in morphology to N. sumatranus Logunov 1998 from Indonesia and N. kovblyuki Logunov 2004 from the Crimea. The latter, and other similar species from South Australia and Western Australia, has palp morphology and fringing on L1 very similar to that seen in N. nojimai Ikeda 1995 from Japan.

  14. Biphasic activity of a jumping spider

    Science.gov (United States)

    Okuyama, Toshinori

    2011-01-01

    Individual variation is a ubiquitous and important factor that affects ecological dynamics. This study examined individual variation in the nest-use pattern of the jumping spider Phidippus audax. Although the jumping spider is a diurnal species, field observations in this study revealed that the majority of individuals remained in their nests during the day. An accompanying examination of the hunger level of the spiders revealed that spiders that remained in nests were more starved than those observed outside nests. If spiders actively forage when they are starved, as has been suggested by previous studies, one would expect to see the opposite trend (i.e., spiders that remained in nests are more satiated). Thus, the pattern observed in the field contradicts the known behavioral pattern of the spiders. An individual-based model was used to investigate the behavioral mechanism of the spider and the discrepancy found in the observations. A basic assumption of the model is that spiders possess distinct inactive and active phases (biphasic activity pattern), and transitions between the two phases are regulated by the hunger level of the spider. Data from a laboratory experiment were used to examine the assumptions of the model partially. The model was able to capture patterns observed in the data, suggesting that the pattern of transitions in biphasic activity is an important trait of the foraging behavior of the jumping spider.

  15. The toxicology of Latrodectus tredecimguttatus: the Mediterranean Black Widow spider.

    Science.gov (United States)

    Bonnet, M S

    2004-01-01

    The symptomatology of envenomation by the Mediterranean Black Widow Spider, Latrodectus tredecimguttatus, is reviewed. The results confirm the hypothesis that the homeopathic remedy, Tarentula hispanica, is derived from this spider, not from the Wolf spider, Lycosa tarentula.

  16. The Legs That Rock the Cradle: Spider Mothers

    Indian Academy of Sciences (India)

    Abstract. Spiders are excellent models to study behavioural diversityand evolutionary adaptations in the animal world. This articleexplores the strategies used by spiders to maximise thesurvival of their offspring.

  17. The evolution of sociality in spiders

    DEFF Research Database (Denmark)

    Lubin, Yael; Bilde, T.

    2007-01-01

    . Anelosimus (Theridiidae) C. Sociality in Spiders: An Evolutionary Dead End? V. Evolution and Maintenance of Sociality in Spiders: Relevant Models A. Kin Selection 1. Kin Recognition 2. Inbreeding and Kin Selection B. Multilevel Selection (Group Selection) C. Ecological Benefits D. Ecological Constraints E......I. Introducing Social Spiders II. Social and Subsocial Species: A Survey of Behavioral Traits III. Inbred Sociality in Spiders A. Cooperation Versus Competition: A Balancing Act B. Do Social Spiders Have Division of Labor? C. Colony Foundation: Propagule Dispersal Versus Fission D. Female......-Biased Colony Sex Ratios: Primary and Operational Sex Ratios E. Mating System: Inbreeding and Its Population-Genetic Consequences F. "Boom and Bust" Colony Dynamics IV. Phylogenetic Relationships Among Social Spider Species A. Common Features of Social Evolution B. Case Studies 1. Stegodyphus (Eresidae) 2...

  18. Australian Government Information Resources

    OpenAIRE

    Chapman, Bert

    2017-01-01

    Provides an overview of Australian Government information resources. Features content from Australian Government agency websites such as the Department of Environment and Energy, Department of Defence, Australian National Maritime Museum, ANZAC Memorial in Sydney, Department of Immigration & Border Protection, Australian Bureau of Statistics, Australian Dept. of Agriculture and Water Resources, Australian Parliament, Australian Treasury, Australian Transport Safety Board, and Australian Parl...

  19. Tangled in a sparse spider web

    DEFF Research Database (Denmark)

    Dimitrov, Dimitar Stefanov; Lopardo, Lara; Giribet, Gonzalo

    2012-01-01

    In order to study the tempo and the mode of spider orb web evolution and diversification, we conducted a phylogenetic analysis using six genetic markers along with a comprehensive taxon sample. The present analyses are the first to recover the monophyly of orb-weaving spiders based solely on DNA ...

  20. Spider phobics more easily see a spider in morphed schematic pictures

    Directory of Open Access Journals (Sweden)

    Partchev Ivailo

    2007-11-01

    Full Text Available Abstract Background Individuals with social phobia are more likely to misinterpret ambiguous social situations as more threatening, i.e. they show an interpretive bias. This study investigated whether such a bias also exists in specific phobia. Methods Individuals with spider phobia or social phobia, spider aficionados and non-phobic controls saw morphed stimuli that gradually transformed from a schematic picture of a flower into a schematic picture of a spider by shifting the outlines of the petals until they turned into spider legs. Participants' task was to decide whether each stimulus was more similar to a spider, a flower or to neither object while EEG was recorded. Results An interpretive bias was found in spider phobia on a behavioral level: with the first opening of the petals of the flower anchor, spider phobics rated the stimuli as more unpleasant and arousing than the control groups and showed an elevated latent trait to classify a stimulus as a spider and a response-time advantage for spider-like stimuli. No cortical correlates on the level of ERPs of this interpretive bias could be identified. However, consistent with previous studies, social and spider phobic persons exhibited generally enhanced visual P1 amplitudes indicative of hypervigilance in phobia. Conclusion Results suggest an interpretive bias and generalization of phobia-specific responses in specific phobia. Similar effects have been observed in other anxiety disorders, such as social phobia and posttraumatic stress disorder.

  1. Mating system does not predict permanent sperm depletion in black widow spiders.

    Science.gov (United States)

    Modanu, Maria; Michalik, Peter; Andrade, Maydianne C B

    2013-05-01

    Variation in sperm production is strongly influenced by mating system across taxa. Recent work in spiders suggests that males of some species show termination of spermatogenesis before their adult molt and thus an inability to produce sperm after maturation. This permanent sperm depletion (PSD) has been hypothesized to co-occur with monogyny, genital mutilation, or sexual cannibalism because the maintenance of continual sperm supplies is not necessary for species where males can expect only one mating opportunity. Here we test this hypothesis in two congeners exhibiting genital mutilation: the sexually cannibalistic, monogynous Australian redback spider Latrodectus hasselti and the polygynous Western black widow Latrodectus hesperus. We report that PSD does not occur in adult males of either species, and show that males transfer sperm into their copulatory organs multiple times as adults. These data suggest evolutionary links between mating system and investment in sperm production may be more complex than currently appreciated. © 2013 Wiley Periodicals, Inc.

  2. Learned predation risk management by spider mites

    Directory of Open Access Journals (Sweden)

    Thomas eHackl

    2014-09-01

    Full Text Available Predation is a prime selective force shaping prey behavior. Investment in anti-predator behavior is traded-off against time and energy for other fitness-enhancing activities such as foraging or reproduction. To optimize this benefit/cost trade-off, prey should be able to innately and/or by experience modulate their behavior to the level of predation risk. Here, we assessed learned predation risk management in the herbivorous two-spotted spider mite Tetranychus urticae. We exposed spider mites coming from benign (naïve or high immediate predation risk (experienced environments to latent and/or no risk and assessed their site choice, activity and oviposition. Benign environments were characterized by the absence of any predator cues, high immediate risk environments by killed spider mites, physical presence of the predatory mite Phytoseiulus persimilis and associated chemosensory traces left on the surface, and latent risk environments by only predator traces. In the no-choice experiment both naïve and experienced spider mites laid their first egg later on leaves with than without predator traces. Irrespective of predator traces presence/absence, experienced mites laid their first egg earlier than naïve ones did. Naïve spider mites were more active, indicating higher restlessness, and laid fewer eggs on leaves with predator traces, whereas experienced mites were less active and laid similar numbers of eggs on leaves with and without predator traces. In the choice experiment both naïve and experienced spider mites preferentially resided and oviposited on leaves without predator traces but experienced mites were less active than naïve ones. Overall, our study suggests that spider mites experienced with high predation risk behave bolder under latent risk than naïve spider mites. Since predator traces alone do not indicate immediate risk, we argue that the attenuated anti-predator response of experienced spider mites represents adaptive learned

  3. Understanding Spider-Man: Your Everyday Superhero

    OpenAIRE

    Falk, Nicklas; Blomsterberg, Sofie Amalie; Suciu, Alice Sabrina; Pedersen, Mads Peter; Lucas, Vilhelm

    2014-01-01

    This project focuses on the understanding of Spider-Man, and the morals and ethics that lie behind the choices he makes. Through the Dimensions Philosophy & Science/Text & Sign, this understanding is concluded by looking at ethical theories and comic book analysis. Based on the Ultimate Spider-Man comic book series, the aim is to clarify who Spider-Man is and what causes him to act in certain ways; before and after his realization of power. Some theories used to investigate these area...

  4. Almost a spider: a 305-million-year-old fossil arachnid and spider origins.

    Science.gov (United States)

    Garwood, Russell J; Dunlop, Jason A; Selden, Paul A; Spencer, Alan R T; Atwood, Robert C; Vo, Nghia T; Drakopoulos, Michael

    2016-03-30

    Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasierigen. et sp. nov. from the Late Carboniferous (Stephanian,ca 305-299 Ma) of Montceau-les-Mines, France. It is three-dimensionally preserved within a siderite concretion, allowing both laboratory- and synchrotron-based phase-contrast computed tomography reconstruction. The latter is a first for siderite-hosted fossils and has allowed us to investigate fine anatomical details. Although distinctly spider-like in habitus, this remarkable fossil lacks a key diagnostic character of Araneae: spinnerets on the underside of the opisthosoma. It also lacks a flagelliform telson found in the recently recognized, spider-related, Devonian-Permian Uraraneida. Cladistic analysis resolves our new fossil as sister group to the spiders: the spider stem-group comprises the uraraneids and I. brasieri While we are unable to demonstrate the presence of spigots in this fossil, the recovered phylogeny suggests the earliest character to evolve on the spider stem-group is the secretion of silk. This would have been followed by the loss of a flagelliform telson, and then the ability to spin silk using spinnerets. This last innovation defines the true spiders, significantly post-dates the origins of silk, and may be a key to the group's success. The Montceau-les-Mines locality has previously yielded a mesothele spider (with spinnerets). Evidently, Late Palaeozoic spiders lived alongside Palaeozoic arachnid grades which approached the spider condition, but did not express the full suite of crown-group autapomorphies. © 2016 The Authors.

  5. Modelling Crop Biocontrol by Wanderer Spiders

    Science.gov (United States)

    Venturino, Ezio; Ghersi, Andrea

    2008-09-01

    We study mathematically the effects some spiders populations have on insects living in and near agroecosystems, where woods and vineyards alternate in the landscape as in the Alta Langa, Piemonte, NW Italy.

  6. Spider's web inspires fibres for industry

    Science.gov (United States)

    Dacey, James

    2010-03-01

    Spiders may not be everybody's idea of natural beauty, but nobody can deny the artistry in the webs that they spin, especially when decorated with water baubles in the morning dew. Inspired by this spectacle, a group of researchers in China has mimicked the structural properties of the spider's web to create a fibre for industry that can manipulate water with the same skill and efficiency, writes James Dacey.

  7. Reversible Myocarditis after Black Widow Spider Envenomation

    OpenAIRE

    Tarek Dendane; Khalid Abidi; Naoufel Madani; Asmae Benthami; Fatima-Zohra Gueddari; Redoune Abouqal; Amine-Ali Zeggwagh

    2012-01-01

    Black widow spiders can cause variable clinical scenarios from local damage to very serious conditions including death. Acute myocardial damage is rarely observed and its prognostic significance is not known. We report a rare case of a 35-year-old man who developed an acute myocarditis with cardiogenic pulmonary edema requiring mechanical ventilation caused by black widow spider's envenomation. The patient was previously healthy. The clinical course was associated with systemic and cardiovasc...

  8. Edge effect on weevils and spiders

    OpenAIRE

    R. Horváth; T. Magura; G. Péter; B. Tóthmérész

    2002-01-01

    The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest...

  9. Anaphylaxis to black widow spider antivenom.

    Science.gov (United States)

    Hoyte, Christopher O; Cushing, Tracy A; Heard, Kennon J

    2012-06-01

    Black widow spider envenomation is commonly reported to poison centers. Black widow spider envenomation produces a clinical syndrome, known as latrodectism, characterized by headache, nausea, vomiting, several muscle cramping and pain, joint stiffness, hypertension, and regional diaphoresis. Black widow spider antivenom (Merck & Co, Inc, West Point, PA USA) is an effective and relatively safe treatment option. There is 1 clear case of anaphylaxis secondary to black widow spider antivenom reported in the medical literature. Here, we report a case of anaphylaxis to antivenom. A 12-year-old boy presented to the emergency department (ED) with diffuse, severe pain 2 1/2 hours after being bitten by a black widow spider on the right lower extremity. In the ED, the patient failed analgesic therapy with fentanyl and was given black widow spider antivenom. Within 45 minutes, he exhibited signs and symptoms consistent with anaphylaxis, including wheezing, chest tightness, pruritus, and urticarial rash. The patient was given standard therapy for anaphylaxis, and all of his signs and symptoms (including the pain secondary to the black widow envenomation) resolved over 6 hours of observation. Leading experts agree that the use of antivenom is indicated in cases of severe envenomation not responsive to standard therapy. Despite concern that the antivenom is an equine-derived whole IgG and can precipitate early hypersensitivity reactions, there is only 1 other reported case of anaphylaxis to the antivenom in the medical literature.

  10. Cognitive bias in spider-phobic children: Comparison of a pictorial and a linguistic spider Stroop.

    NARCIS (Netherlands)

    Kindt, M.; Brosschot, J.F.

    1999-01-01

    Examined the relation between spider fear in children and cognitive processing bias toward threatening information. It was investigated whether spider fear in children is related to a cognitive bias for threatening pictures and words. Pictorial and linguistic Stroop stimuli were administered to 28

  11. Discovery of fossil spider remains in Tertiary soft brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Manewald, U.; Heimer, S.; Volkman, N.

    1986-11-01

    A fossil spring spider (Salticidae) is described, discovered in a 1 cm/sup 3/ void of a lower Miocene brown coal seam in Bitterfeld (GDR). The spider's hair, chelicerae and legs are well preserved. A photograph of the cephalothorax is provided. In the same coal seam egg cocoons of other spiders were also found and are shown in two further microscopic photographs. Conclusions are drawn on spider fossilization, sedimentation and paleoenvironment of the Miocene coal seam 8 references.

  12. SPIDER OR NO SPIDER? NEURAL CORRELATES OF SUSTAINED AND PHASIC FEAR IN SPIDER PHOBIA.

    Science.gov (United States)

    Münsterkötter, Anna Luisa; Notzon, Swantje; Redlich, Ronny; Grotegerd, Dominik; Dohm, Katharina; Arolt, Volker; Kugel, Harald; Zwanzger, Peter; Dannlowski, Udo

    2015-09-01

    Processes of phasic fear responses to threatening stimuli are thought to be distinct from sustained, anticipatory anxiety toward an unpredicted, potential threat. There is evidence for dissociable neural correlates of phasic fear and sustained anxiety. Whereas increased amygdala activity has been associated with phasic fear, sustained anxiety has been linked with activation of the bed nucleus of stria terminalis (BNST), anterior cingulate cortex (ACC), and the insula. So far, only a few studies have focused on the dissociation of neural processes related to both phasic and sustained fear in specific phobia. We suggested that first, conditions of phasic and sustained fear would involve different neural networks and, second, that overall neural activity would be enhanced in a sample of phobic compared to nonphobic participants. Pictures of spiders and neutral stimuli under conditions of either predicted (phasic) or unpredicted (sustained) fear were presented to 28 subjects with spider phobia and 28 nonphobic control subjects during functional magnetic resonance imaging (fMRI) scanning. Phobic patients revealed significantly higher amygdala activation than controls under conditions of phasic fear. Sustained fear processing was significantly related to activation in the insula and ACC, and phobic patients showed a stronger activation than controls of the BNST and the right ACC under conditions of sustained fear. Functional connectivity analysis revealed enhanced connectivity of the BNST and the amygdala in phobic subjects. Our findings support the idea of distinct neural correlates of phasic and sustained fear processes. Increased neural activity and functional connectivity in these networks might be crucial for the development and maintenance of anxiety disorders. © 2015 Wiley Periodicals, Inc.

  13. Sex-specific kleptoparasitic foraging in ant-eating spiders

    DEFF Research Database (Denmark)

    Martisová, Martina; Bilde, T.; Pekar, Stano

    2009-01-01

    . To investigate this hypothesis, we studied the effect of sex and life history stage on the frequency of kleptoparasitism in ant-eating spiders of the genus Zodarion in the field. These spiders use a special capture technique involving a quick attack on an ant that is left unguarded by spiders for several minutes...

  14. Acute Generalized Exanthematous Pustulosis (AGEP Triggered by a Spider Bite

    Directory of Open Access Journals (Sweden)

    Michael Makris

    2009-01-01

    Discussion: A spider bite may represent a possible causative factor of AGEP. A spider's venom contains sphingomyelinase that stimulates the release of IL8 and GM-CSF, which are involved in AGEP pathogenesis. Whether or not the con-current use of antibiotics has an effect in AGEP appearance when combined with a spider's venom, cannot be excluded.

  15. Edge effect on weevils and spiders

    Directory of Open Access Journals (Sweden)

    R. Horváth

    2002-05-01

    Full Text Available The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest interior was significantly lower than that of the forest edge and the meadow. The composition of the spider assemblage of the edge was more similar to the forest, while the composition of weevils in the edge was more similar to the meadow. Our results based on two invertebrate groups operating on different trophic levels suggest that there is a significant edge effect for the studied taxa resulting in higher species richness in the edge.

  16. Disentangling the phylogenetic and ecological components of spider phenotypic variation.

    Science.gov (United States)

    Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

    2014-01-01

    An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

  17. Checklist of spider fauna of FR Peshawar, FATA, Pakistan

    Directory of Open Access Journals (Sweden)

    F. Perveen

    2012-03-01

    Full Text Available The spiders are known as poisonous arthropods, but they also act as the predator or biological pests control agent. Their 23 species belonging to 15 genera and 09 families were reported during 2009-2010 from FR Peshawar, FATA, Pakistan. The reported families Clubionidae, Scytodidae and Sprassidae covered each 4%, Araneidae, Gnaphosidae, Pholicidae and Salticidae each 9%, Thomisidae 13% and Lycosidae 43% biodiversity of spiders of FATA. However, the largest spider collected was huntsman, Isopoda tuhodnigra (Barrion with total body length 15.80+-0.83 mm. Moreover, the smallest spider was wolf spider, Pardosa birmanica (Simon with total body length 4.20+-1.30 mm. Further, the crab spiders, Thomisus pugilis (Stoliczka, T. spectabilis (Doleschall and Diaea evanida (Thorell were the most colorful species belonging to family Thomisidae. A detail study is required for further exploration of spider fauna of FATA.

  18. Uncovering the structure-function relationship in spider silk

    Science.gov (United States)

    Yarger, Jeffery L.; Cherry, Brian R.; van der Vaart, Arjan

    2018-03-01

    All spiders produce protein-based biopolymer fibres that we call silk. The most studied of these silks is spider dragline silk, which is very tough and relatively abundant compared with other types of spider silks. Considerable research has been devoted to understanding the relationship between the molecular structure and mechanical properties of spider dragline silks. In this Review, we overview experimental and computational studies that have provided a wealth of detail at the molecular level on the highly conserved repetitive core and terminal regions of spider dragline silk. We also discuss the role of the nanocrystalline β-sheets and amorphous regions in determining the properties of spider silk fibres, endowing them with strength and elasticity. Additionally, we outline imaging techniques and modelling studies that elucidate the importance of the hierarchical structure of silk fibres at the molecular level. These insights into structure-function relationships can guide the reverse engineering of spider silk to enable the production of superior synthetic fibres.

  19. Black widow spider bite: a case study.

    Science.gov (United States)

    Gaisford, Kristine; Kautz, Donald D

    2011-01-01

    This article is a case study of a patient cared for in the hours before her death. After the patient's death, we learned the patient died of a black widow spider bite. This article sheds light on the potential seriousness of this venom and allows for more rapid detection and treatment of those who are unfortunate enough to be bitten. The authors have documented the sequence of events for the patient, outlined the care the patient received, examined the pathophysiology of the body to a spider bite, and then made a passionate appeal for other nurses who work in critical care to do the same with patients in similar situations.

  20. Programming spiders, bots, and aggregators in Java

    CERN Document Server

    Heaton, Jeff

    2006-01-01

    The content and services available on the web continue to be accessed mostly through direct human control. But this is changing. Increasingly, users rely on automated agents that save them time and effort by programmatically retrieving content, performing complex interactions, and aggregating data from diverse sources. Programming Spiders, Bots, and Aggregators in Java teaches you how to build and deploy a wide variety of these agents-from single-purpose bots to exploratory spiders to aggregators that present a unified view of information from multiple user accounts. You will quickly build on

  1. Reversible Myocarditis after Black Widow Spider Envenomation

    Directory of Open Access Journals (Sweden)

    Tarek Dendane

    2012-01-01

    Full Text Available Black widow spiders can cause variable clinical scenarios from local damage to very serious conditions including death. Acute myocardial damage is rarely observed and its prognostic significance is not known. We report a rare case of a 35-year-old man who developed an acute myocarditis with cardiogenic pulmonary edema requiring mechanical ventilation caused by black widow spider's envenomation. The patient was previously healthy. The clinical course was associated with systemic and cardiovascular complaints. His electrocardiogram revealed ST-segment elevation with T-wave amplitude. The plasma concentrations of cardiac enzymes were elevated. His first echocardiography showed hypokinesis of the left ventricle (left ventricle ejection fraction 48%. Magnetic resonance imaging showed also focal myocardial injury of the LV. There was progressive improvement in cardiac traces, biochemical and echocardiographical values (second left ventricle ejection fraction increased to 50%. Myocardial involvement after a spider bite is rare and can cause death. The exact mechanism of this myocarditis is unknown. We report a rare case of acute myocarditis with cardiogenic pulmonary edema requiring mechanical ventilation caused by black widow spider's envenomation. We objectively documented progressive clinical and electrical improvement.

  2. Reversible myocarditis after black widow spider envenomation.

    Science.gov (United States)

    Dendane, Tarek; Abidi, Khalid; Madani, Naoufel; Benthami, Asmae; Gueddari, Fatima-Zohra; Abouqal, Redoune; Zeggwagh, Amine-Ali

    2012-01-01

    Black widow spiders can cause variable clinical scenarios from local damage to very serious conditions including death. Acute myocardial damage is rarely observed and its prognostic significance is not known. We report a rare case of a 35-year-old man who developed an acute myocarditis with cardiogenic pulmonary edema requiring mechanical ventilation caused by black widow spider's envenomation. The patient was previously healthy. The clinical course was associated with systemic and cardiovascular complaints. His electrocardiogram revealed ST-segment elevation with T-wave amplitude. The plasma concentrations of cardiac enzymes were elevated. His first echocardiography showed hypokinesis of the left ventricle (left ventricle ejection fraction 48%). Magnetic resonance imaging showed also focal myocardial injury of the LV. There was progressive improvement in cardiac traces, biochemical and echocardiographical values (second left ventricle ejection fraction increased to 50%). Myocardial involvement after a spider bite is rare and can cause death. The exact mechanism of this myocarditis is unknown. We report a rare case of acute myocarditis with cardiogenic pulmonary edema requiring mechanical ventilation caused by black widow spider's envenomation. We objectively documented progressive clinical and electrical improvement.

  3. Spiders Tune Glue Viscosity to Maximize Adhesion.

    Science.gov (United States)

    Amarpuri, Gaurav; Zhang, Ci; Diaz, Candido; Opell, Brent D; Blackledge, Todd A; Dhinojwala, Ali

    2015-11-24

    Adhesion in humid conditions is a fundamental challenge to both natural and synthetic adhesives. Yet, glue from most spider species becomes stickier as humidity increases. We find the adhesion of spider glue, from five diverse spider species, maximizes at very different humidities that matches their foraging habitats. By using high-speed imaging and spreading power law, we find that the glue viscosity varies over 5 orders of magnitude with humidity for each species, yet the viscosity at maximal adhesion for each species is nearly identical, 10(5)-10(6) cP. Many natural systems take advantage of viscosity to improve functional response, but spider glue's humidity responsiveness is a novel adaptation that makes the glue stickiest in each species' preferred habitat. This tuning is achieved by a combination of proteins and hygroscopic organic salts that determines water uptake in the glue. We therefore anticipate that manipulation of polymer-salts interaction to control viscosity can provide a simple mechanism to design humidity responsive smart adhesives.

  4. Hey! A Black Widow Spider Bit Me!

    Science.gov (United States)

    ... as soon as you can because they can make you very sick. With an adult's help, wash the bite well with soap and water. Then apply an ice pack to the bite, and try to elevate the area and keep it still to help prevent the ... black widows, you'll want to make sure that's the kind of spider that bit ...

  5. The aerodynamic signature of running spiders.

    Directory of Open Access Journals (Sweden)

    Jérôme Casas

    Full Text Available Many predators display two foraging modes, an ambush strategy and a cruising mode. These foraging strategies have been classically studied in energetic, biomechanical and ecological terms, without considering the role of signals produced by predators and perceived by prey. Wolf spiders are a typical example; they hunt in leaf litter either using an ambush strategy or by moving at high speed, taking over unwary prey. Air flow upstream of running spiders is a source of information for escaping prey, such as crickets and cockroaches. However, air displacement by running arthropods has not been previously examined. Here we show, using digital particle image velocimetry, that running spiders are highly conspicuous aerodynamically, due to substantial air displacement detectable up to several centimetres in front of them. This study explains the bimodal distribution of spider's foraging modes in terms of sensory ecology and is consistent with the escape distances and speeds of cricket prey. These findings may be relevant to the large and diverse array of arthropod prey-predator interactions in leaf litter.

  6. A novel neurotoxin from venom of the spider, Brachypelma albopilosum.

    Science.gov (United States)

    Zhong, Yunhua; Song, Bo; Mo, Guoxiang; Yuan, Mingwei; Li, Hongli; Wang, Ping; Yuan, Minglong; Lu, Qiumin

    2014-01-01

    Spiders have evolved highly selective toxins for insects. There are many insecticidal neurotoxins in spider venoms. Although a large amount of work has been done to focus on neurotoxicity of spider components, little information, which is related with effects of spider toxins on tumor cell proliferation and cytotoxicity, is available for Brachypelma albopilosum venom. In this work, a novel spider neurotoxin (brachyin) was identified and characterized from venoms of the spider, Brachypelma albopilosum. Brachyin is composed of 41 amino acid residues with the sequence of CLGENVPCDKDRPNCCSRYECLEPTGYGWWYASYYCYKKRS. There are six cysteines in this sequence, which form three disulfided bridges. The serine residue at the C-terminus is amidated. Brachyin showed strong lethal effects on American cockroaches (Periplaneta americana) and Tenebrio molitor (common mealbeetle). This neurotoxin also showed significant analgesic effects in mice models including abdominal writhing induced by acetic acid and formalin-induced paw licking tests. It was interesting that brachyin exerted marked inhibition on tumor cell proliferation.

  7. A novel neurotoxin from venom of the spider, Brachypelma albopilosum.

    Directory of Open Access Journals (Sweden)

    Yunhua Zhong

    Full Text Available Spiders have evolved highly selective toxins for insects. There are many insecticidal neurotoxins in spider venoms. Although a large amount of work has been done to focus on neurotoxicity of spider components, little information, which is related with effects of spider toxins on tumor cell proliferation and cytotoxicity, is available for Brachypelma albopilosum venom. In this work, a novel spider neurotoxin (brachyin was identified and characterized from venoms of the spider, Brachypelma albopilosum. Brachyin is composed of 41 amino acid residues with the sequence of CLGENVPCDKDRPNCCSRYECLEPTGYGWWYASYYCYKKRS. There are six cysteines in this sequence, which form three disulfided bridges. The serine residue at the C-terminus is amidated. Brachyin showed strong lethal effects on American cockroaches (Periplaneta americana and Tenebrio molitor (common mealbeetle. This neurotoxin also showed significant analgesic effects in mice models including abdominal writhing induced by acetic acid and formalin-induced paw licking tests. It was interesting that brachyin exerted marked inhibition on tumor cell proliferation.

  8. Stress/Strain Characteristics and Biochemical Correlates of Spider Silks

    Science.gov (United States)

    1999-10-18

    do aminoacid analysis on silk samples measured and collected from the same spiders. Background to reports 1 and 2: Dr Kaplan left Natick during the...properties (shown by us) as well as measurable effects on silk aminoacid compositions (C Craig pers. comm). Thus after initial samples of silks from a...variability could be the state of nutrition of the spider. Starvation has been shown to have an effect on the web- geometry in orb-weaving spiders 2; and

  9. Spider silk: a novel optical fibre for biochemical sensing

    OpenAIRE

    Hey Tow, Kenny; Chow, Desmond; Vollrath, Fritz; Dicaire, Isabelle; Gheysens, Tom; Thévenaz, Luc

    2015-01-01

    Whilst being thoroughly used in the textile industry and biomedical sector, silk has not yet been exploited for fibre optics-based sensing although silk fibres directly obtained from spiders can guide light and have shown early promises to being sensitive to some solvents. In this communication, a pioneering optical fibre sensor based on spider silk is reported, demonstrating for the first time the use of spider silk as an optical fibre sensor to detect polar solvents such as water, ammonia a...

  10. Reconstructing web evolution and spider diversification in the molecular era.

    Science.gov (United States)

    Blackledge, Todd A; Scharff, Nikolaj; Coddington, Jonathan A; Szüts, Tamas; Wenzel, John W; Hayashi, Cheryl Y; Agnarsson, Ingi

    2009-03-31

    The evolutionary diversification of spiders is attributed to spectacular innovations in silk. Spiders are unique in synthesizing many different kinds of silk, and using silk for a variety of ecological functions throughout their lives, particularly to make prey-catching webs. Here, we construct a broad higher-level phylogeny of spiders combining molecular data with traditional morphological and behavioral characters. We use this phylogeny to test the hypothesis that the spider orb web evolved only once. We then examine spider diversification in relation to different web architectures and silk use. We find strong support for a single origin of orb webs, implying a major shift in the spinning of capture silk and repeated loss or transformation of orb webs. We show that abandonment of costly cribellate capture silk correlates with the 2 major diversification events in spiders (1). Replacement of cribellate silk by aqueous silk glue may explain the greater diversity of modern orb-weaving spiders (Araneoidea) compared with cribellate orb-weaving spiders (Deinopoidea) (2). Within the "RTA clade," which is the sister group to orb-weaving spiders and contains half of all spider diversity, >90% of species richness is associated with repeated loss of cribellate silk and abandonment of prey capture webs. Accompanying cribellum loss in both groups is a release from substrate-constrained webs, whether by aerially suspended webs, or by abandoning webs altogether. These behavioral shifts in silk and web production by spiders thus likely played a key role in the dramatic evolutionary success and ecological dominance of spiders as predators of insects.

  11. The canopy spiders (Araneae of the floodplain forest in Leipzig

    Directory of Open Access Journals (Sweden)

    Otto, Stefan

    2010-10-01

    Full Text Available The canopy spiders of the floodplain forest in Leipzig have become a focus of ecological studies in recent years. In 2006 we sampled 30 tree canopies in the ‘Burgaue’ nature reserve with pyrethrum knock-down fogging, recording 502 adult spiders belonging to 48 species and 11 families. Based on these data and the results of a previous fogging study, the studied spider community was dominated by forest and forest-edge species with a preference for the shrub and canopy strata as well as by spiders of the web spider feeding guild. The community structure was typical for arboreal spider communities from northern temperate forests but very different from communities in the tropics. Species richness and evenness were similar to the old growth near-primary Białowieża Forest in Poland. The checklist of 96 canopy spider species of the floodplain forest of Leipzig includes 54 additions to the spider fauna of Leipzig and vicinity by recent canopy studies and eight first canopy records for Leipzig from our field work. The theridiid Dipoena torva (Thorell, 1875 was recorded for the first time in Saxony. The floodplain forest of Leipzig sustains a large and species-rich arboreal spider community and is thus a valuable habitat for a large proportion of endangered species (12%.

  12. Araneae Sloveniae: a national spider species checklist

    Science.gov (United States)

    Kostanjšek, Rok; Kuntner, Matjaž

    2015-01-01

    Abstract The research of the spider fauna of Slovenia dates back to the very beginning of binomial nomenclature, and has gone through more and less prolific phases with authors concentrating on taxonomy, faunistics, ecology and zoogeographic reviews. Although the body of published works is remarkable for a small nation, the faunistic data has remained too scattered for a thorough understanding of regional biotic diversity, for comparative and ecological research, and for informed conservation purposes. A national checklist is long overdue. Here, a critical review of all published records in any language is provided. The species list currently comprises 738 species, is published online at http://www.bioportal.si/katalog/araneae.php under the title Araneae Sloveniae, and will be updated in due course. This tool will fill the void in cataloguing regional spider faunas and will facilitate further araneological research in central and southern Europe. PMID:25632258

  13. Araneae Sloveniae: a national spider species checklist

    Directory of Open Access Journals (Sweden)

    Rok Kostanjšek

    2015-01-01

    Full Text Available The research of the spider fauna of Slovenia dates back to the very beginning of binomial nomenclature, and has gone through more and less prolific phases with authors concentrating on taxonomy, faunistics, ecology and zoogeographic reviews. Although the body of published works is remarkable for a small nation, the faunistic data has remained too scattered for a thorough understanding of regional biotic diversity, for comparative and ecological research, and for informed conservation purposes. A national checklist is long overdue. Here, a critical review of all published records in any language is provided. The species list currently comprises 738 species, is published online at http://www.bioportal.si/katalog/araneae.php under the title Araneae Sloveniae, and will be updated in due course. This tool will fill the void in cataloguing regional spider faunas and will facilitate further araneological research in central and southern Europe.

  14. Red-back spider (Latrodectus hasselti) antivenom prevents the toxicity of widow spider venoms.

    Science.gov (United States)

    Graudins, A; Padula, M; Broady, K; Nicholson, G M

    2001-02-01

    Widow spiders of the genus Latrodectus are found worldwide and produce similar clinical envenomation syndromes. In Australia, red-back spider antivenom (RBS-AV) is effective therapy for Latrodectus hasselti envenomation and it has been reported to reverse envenomation by other widow spiders. This study assessed the efficacy of RBS-AV in preventing in vitro and in vivo toxicity of widow spider venoms of North America and Europe. The binding of RBS-AV to alpha-latrotoxin and Latrodectus venoms (Latrodectus spp mactans, hesperus, lugubris, tredecimguttatus, hasselti) was assayed using Western blotting. Prevention of in vitro toxicity to alpha-latrotoxin and the same venoms was tested by pretreating an isolated chick biventer cervicis nerve-muscle preparation with RBS-AV. Prevention of in vivo toxicity was determined by a lethality study in male Balb/c mice (2.5 to 5x median lethal dose [LD50]) or alpha-latrotoxin (10x LD50) preincubated with antivenom or without RBS-AV (control). In Western blots, RBS-AV bound to alpha-latrotoxin and similar widow spider proteins in all venoms tested, indicating antigenic similarity with proteins found in RBS venom. Antivenom prevented the typical in vitro muscle contracture and loss of twitch tension seen with alpha-latrotoxin and the venoms tested. Control mice rapidly developed signs of envenomation, but mice treated with RBS-AV remained free of signs of envenomation. RBS-AV prevented both in vitro and in vivo toxicity from Latrodectus venoms and alpha-latrotoxin in mice. These data suggest that RBS-AV may be clinically effective in the treatment of envenomation resulting from the bite of other widow spiders.

  15. Disentangling the phylogenetic and ecological components of spider phenotypic variation.

    Directory of Open Access Journals (Sweden)

    Thiago Gonçalves-Souza

    Full Text Available An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables to the variation in spider body size and shape by comparing spiders at different scales: (i between bromeliads and dicot plants (i.e., habitat scale and (ii among bromeliads with distinct architectural features (i.e., microhabitat scale. We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species and ecological components (that express trait values independent of phylogenetic relationships. At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

  16. Black widow spider envenomation in pregnancy.

    Science.gov (United States)

    Wolfe, Michael D; Myers, Orrin; Caravati, E Martin; Rayburn, William F; Seifert, Steven A

    2011-01-01

    Little data exist regarding the optimal treatment and outcomes of pregnancies complicated by black widow spider envenomation. Our objective is to evaluate the clinical effects, medical outcomes, and treatment differences between pregnant and nonpregnant women. This observational study is based on a review of the database maintained by the American Association of Poison Control Centers from 2003 to 2007. Of the 12,640 human black widow spider envenomations reported at 61 poison centers in the United States, 3194 (25.3%) involved women of reproductive age, defined as age 15-45 years of age, with 97 (3.0% of reproductive-age women) being pregnant. Comparing pregnant and nonpregnant women, there were no significant differences in recommended or administered treatments. Pregnant women were more likely than nonpregnant women (OR: 1.84, 95% CI: 1.20-2.83) to have outcomes coded as minor, moderate, or major rather than no effect. Significantly higher percentages of pregnant patients were treated at a healthcare facility where they were either released (36.1% vs. 19.9%, p  Black widow spider envenomation is a rare occurrence in pregnant women and the short-term outcomes appear to be favorable.

  17. Host selection by a kleptobiotic spider

    Science.gov (United States)

    Hénaut, Yann; Delme, Juliette; Legal, Luc; Williams, Trevor

    2005-02-01

    Why do kleptobiotic spiders of the genus Argyrodes seem to be associated with spiders of the genus Nephila worldwide? Observations following introduction of experimental insect prey of different sizes and weights on to host webs revealed that: (1) small prey are more effectively retained on the web of Nephila clavipes than on the web of another common host, Leucauge venusta. (2) N. clavipes did not consume small prey that accumulated on the web whereas larger, heavier prey were enveloped and stored. (3) We observed clear partitioning of prey items between N. clavipes and Argyrodes spp.; diet selection by Argyrodes did not overlap with that of N. clavipes but closely overlapped with that of L. venusta. (4) L. venusta responds very quickly to prey impact whereas N. clavipes is slower, offering a temporal window of opportunity for Argyrodes foraging. (5) The ability of L. venusta to detect and respond to small items also means that it acts aggressively to Argyrodes spp., whereas N. clavipes does not. Consequently, food-acquisition behaviours of Argyrodes were clearly less risky with N. clavipes compared with L. venusta. We conclude that when a kleptobiotic organism has a choice of various host species, it will opt for the least risky host that presents the highest rate of availability of food items. The fact that Nephila species present such characteristics explains the worldwide association with Argyrodes kleptobiotic spiders.

  18. Troponin elevation after black widow spider envenomation.

    Science.gov (United States)

    Bush, Sean P; Davy, J Veeran

    2015-09-01

    Black widow spider envenomation generally results in self-limiting pain that can be treated in the emergency department (ED) with analgesics and benzodiazepines, usually with no further intervention. Occasionally, a patient has to be admitted or treated with antivenom for refractory pain or a venom-induced complication. We present the case of an 84-year-old man who presented to our ED with chest pain and dyspnea after being bitten on the foot by a western black widow spider (Lactrodectus hesperus). His initial cardiac troponin I (cTnI) was elevated at 0.07 ng/ml and continued to rise to a peak of 0.17 ng/ml. He also had rhabdomyolysis, another uncommon complication of black widow envenomation. An elevated cTnI generally signifies myocardial injury and is rarely seen after black widow envenomation. We discuss the possible etiologies for an elevated cardiac biomarker, in this context, and review potentially serious complications of widow spider envenomation presenting with chest symptoms and an elevated cardiac biomarker.

  19. Nanofibre production in spiders without electric charge.

    Science.gov (United States)

    Joel, Anna-Christin; Baumgartner, Werner

    2017-06-15

    Technical nanofibre production is linked to high voltage, because nanofibres are typically produced by electrospinning. In contrast, spiders have evolved a way to produce nanofibres without high voltage. These spiders are called cribellate spiders and produce nanofibres within their capture thread production. It is suggested that their nanofibres become frictionally charged when brushed over a continuous area on the calamistrum, a comb-like structure at the metatarsus of the fourth leg. Although there are indications that electrostatic charges are involved in the formation of the thread structure, final proof is missing. We proposed three requirements to validate this hypothesis: (1) the removal of any charge during or after thread production has an influence on the structure of the thread; (2) the characteristic structure of the thread can be regenerated by charging; and (3) the thread is attracted to or repelled from differently charged objects. None of these three requirements were proven true. Furthermore, mathematical calculations reveal that even at low charges, the calculated structural assembly of the thread does not match the observed reality. Electrostatic forces are therefore not involved in the production of cribellate capture threads. © 2017. Published by The Company of Biologists Ltd.

  20. Structure–Activity Relationship Study of Spider Polyamine Toxins as Inhibitors of Ionotropic Glutamate Receptors

    DEFF Research Database (Denmark)

    Xiong, Xiaofeng; Poulsen, Mette H; Hussein, Rama A

    2014-01-01

    The spider polyamine toxins Joro spider toxin-3 (JSTX-3) and Nephila polyamine toxins-1 and -8 (NPTX-1 and NPTX-8) are isolated from the venom of the orb-weaver spider Nephila clavata (Joro spider). They share a high degree of structural resemblance, their aromatic head groups being the only...

  1. Fear of spiders: The effect of real threat on the interference caused by symbolic threat

    NARCIS (Netherlands)

    Kwakkenbos, C.M.C.; Becker, E.S.; Rinck, M.

    2010-01-01

    The effect of the presence of a real spider on attentional biases for symbolic spider stimuli was examined in 42 low-fearful and 26 high-spider-fearful participants. They completed a word colour-naming task as well as a picture orientation-judgement task, both with versus without a spider present in

  2. Three newly recorded Linyphiid spiders (Araneae: Linyphiidae from Korea

    Directory of Open Access Journals (Sweden)

    Sue Yeon Lee

    2018-03-01

    Full Text Available Three Linyphiid spiders, Caviphantes pseudosaxetorum Wunderlich, 1979, Erigone edentata Saito and Ono, 2001, and Savignia kawachiensis Oi, 1960, are reported for the first time from Korea with taxonomic illustrations and redescription. In this study, the genus Caviphantes Oi, 1960 is also newly recorded to Korean spider fauna.

  3. Spider diversity in relation to habitat heterogeneity and an altitudinal ...

    African Journals Online (AJOL)

    Using pitfall traps, wandering spiders (Arachnida: Araneae) were sampled in a nested design from three different localities in the mountainous arid ecosystem of South Sinai at low, middle, and high altitudes. Habitat type and altitude were clearly different among the three localities. Spider diversity per trap varied spatially ...

  4. Forest floor spiders of woodlots in an agricultural landscape

    NARCIS (Netherlands)

    Mabelis, A.

    1996-01-01

    An inventory of spiders was made in woodlots, which are situated in an agricultural landscape in the eastern part of the Netherlands. Aim of the study was to test the hypotheses that good dispersers, like spiders, will be distributed randomly over habitat patches and consequently, that there will be

  5. Alleviation of oxidative stress induced by spider mite invasion ...

    African Journals Online (AJOL)

    Spider mite invasion induces oxidative stress on bean plants and increased soluble sugars, phenole, proline and peroxidase activity, but decreased catalase activity and ascorbic acid and carotenoid concentration. Application of elicitors significantly enhanced spider mite tolerance by decreasing hydrogen peroxide, ...

  6. Who is afraid of a black Spider(-Man)?

    OpenAIRE

    Ora C. McWilliams

    2013-01-01

    An Internet post asking about Spider-Man's race in a film turned into an Internet campaign about an actor that led fans to interact with each other as well as with the actor, which in turn led to the attention of media producers, which resulted in a change in Spider-Man's race in a print comic book.

  7. Who is afraid of a black Spider(-Man?

    Directory of Open Access Journals (Sweden)

    Ora C. McWilliams

    2013-06-01

    Full Text Available An Internet post asking about Spider-Man's race in a film turned into an Internet campaign about an actor that led fans to interact with each other as well as with the actor, which in turn led to the attention of media producers, which resulted in a change in Spider-Man's race in a print comic book.

  8. Using Spider-Web Patterns To Determine Toxicity

    Science.gov (United States)

    Noever, David A.; Cronise, Raymond J.; Relwani, Rachna A.

    1995-01-01

    Method of determining toxicities of chemicals involves recording and analysis of spider-web patterns. Based on observation spiders exposed to various chemicals spin webs that differ, in various ways, from normal webs. Potential alternative to toxicity testing on higher animals.

  9. Brain systems underlying encounter expectancy bias in spider phobia.

    Science.gov (United States)

    Aue, Tatjana; Hoeppli, Marie-Eve; Piguet, Camille; Hofstetter, Christoph; Rieger, Sebastian W; Vuilleumier, Patrik

    2015-06-01

    Spider-phobic individuals are characterized by exaggerated expectancies to be faced with spiders (so-called encounter expectancy bias). Whereas phobic responses have been linked to brain systems mediating fear, little is known about how the recruitment of these systems relates to exaggerated expectancies of threat. We used fMRI to examine spider-phobic and control participants while they imagined visiting different locations in a forest after having received background information about the likelihood of encountering different animals (spiders, snakes, and birds) at these locations. Critically, imagined encounter expectancies modulated brain responses differently in phobics as compared with controls. Phobics displayed stronger negative modulation of activity in the lateral prefrontal cortex, precuneus, and visual cortex by encounter expectancies for spiders, relative to snakes or birds (within-participants analysis); these effects were not seen in controls. Between-participants correlation analyses within the phobic group further corroborated the hypothesis that these phobia-specific modulations may underlie irrationality in encounter expectancies (deviations of encounter expectancies from objective background information) in spider phobia; the greater the negative modulation a phobic participant displayed in the lateral prefrontal cortex, precuneus, and visual cortex, the stronger was her bias in encounter expectancies for spiders. Interestingly, irrationality in expectancies reflected in frontal areas relied on right rather than left hemispheric deactivations. Our data accord with the idea that expectancy biases in spider phobia may reflect deficiencies in cognitive control and contextual integration that are mediated by right frontal and parietal areas.

  10. Time-dependent motor properties of multipedal molecular spiders.

    Science.gov (United States)

    Samii, Laleh; Blab, Gerhard A; Bromley, Elizabeth H C; Linke, Heiner; Curmi, Paul M G; Zuckermann, Martin J; Forde, Nancy R

    2011-09-01

    Molecular spiders are synthetic biomolecular walkers that use the asymmetry resulting from cleavage of their tracks to bias the direction of their stepping motion. Using Monte Carlo simulations that implement the Gillespie algorithm, we investigate the dependence of the biased motion of molecular spiders, along with binding time and processivity, on tunable experimental parameters, such as number of legs, span between the legs, and unbinding rate of a leg from a substrate site. We find that an increase in the number of legs increases the spiders' processivity and binding time but not their mean velocity. However, we can increase the mean velocity of spiders with simultaneous tuning of the span and the unbinding rate of a spider leg from a substrate site. To study the efficiency of molecular spiders, we introduce a time-dependent expression for the thermodynamic efficiency of a molecular motor, allowing us to account for the behavior of spider populations as a function of time. Based on this definition, we find that spiders exhibit transient motor function over time scales of many hours and have a maximum efficiency on the order of 1%, weak compared to other types of molecular motors.

  11. Evidence for competition between carnivorous plants and spiders.

    Science.gov (United States)

    Jennings, David E; Krupa, James J; Raffel, Thomas R; Rohr, Jason R

    2010-10-07

    Several studies have demonstrated that competition between disparate taxa can be important in determining community structure, yet surprisingly, to our knowledge, no quantitative studies have been conducted on competition between carnivorous plants and animals. To examine potential competition between these taxa, we studied dietary and microhabitat overlap between pink sundews (Drosera capillaris) and wolf spiders (Lycosidae) in the field, and conducted a laboratory experiment examining the effects of wolf spiders on sundew fitness. In the field, we found that sundews and spiders had a high dietary overlap with each other and with the available arthropod prey. Associations between sundews and spiders depended on spatial scale: both sundews and spiders were found more frequently in quadrats with more abundant prey, but within quadrats, spiders constructed larger webs and located them further away from sundews as the total sundew trapping area increased, presumably to reduce competition. Spiders also constructed larger webs when fewer prey were available. In the laboratory, our experiment revealed that spiders can significantly reduce sundew fitness. Our findings suggest that members of the plant and animal kingdoms can and do compete.

  12. Spiders of Kerala Agricultural University Campus, Thrissur, Kerala, India

    Directory of Open Access Journals (Sweden)

    C. K. Adarsh

    2015-12-01

    Full Text Available A total of 86 species of spiders belonging to 56 genera of 20 families have been recorded from the Kerala Agricultural University (KAU campus, Thrissur, Kerala, southern India.  This represents 5.1% of the total spiders’ species and 33.33% of the total families of spiders recorded in India.  The dominant spider family at KAU campus is Araneidae with 18 species of nine genera. Salticidae is represented by 14 species of 13 genera.  Out of 252 endemic spiders of India, 16 have been reported from KAU campus.  Guild structure analysis shows spiders belonging to seven types of feeding guilds present in KAU campus.  Orb-web builders are the dominant feeding guild accounting for 34%, followed by stalkers (22%, ground runners (20%, ambushers (8%, scattered line weavers (8%, foliage runners (7% and sheet-web builders (1%. 

  13. Nutrient regulation in a predator, the wolf spider Pardosa prativaga

    DEFF Research Database (Denmark)

    Jensen, Kim; Mayntz, David; Toft, Søren

    2011-01-01

    Nutrient balancing is well known in herbivores and omnivores, but has only recently been demonstrated in predators. To test how a predator might regulate nutrients when the prey varies in nutrient composition, we restricted juvenile Pardosa prativaga wolf spiders to diets of one of six fruit fly......, Drosophila melanogaster, prey types varying in lipid:protein composition during their second instar. We collected all fly remnants to estimate food and nutrient intake over each meal. The spiders adjusted their capture rate and nutrient extraction in response to prey mass and nutrient composition...... irrespective of energy intake. Intake was initially regulated to a constant lipid plus protein mass, but later spiders fed on prey with high proportions of protein increased consumption relative to spiders fed on other prey types. This pattern indicates that the spiders were prepared to overconsume vast...

  14. SPIDER: CMB Polarimetry from the Edge of Space

    Energy Technology Data Exchange (ETDEWEB)

    Gualtieri, R.; et al.

    2017-11-28

    SPIDER is a balloon-borne instrument designed to map the polarization of the millimeter-wave sky at large angular scales. SPIDER targets the B-mode signature of primordial gravitational waves in the cosmic microwave background (CMB), with a focus on mapping a large sky area with high fidelity at multiple frequencies. SPIDER's first longduration balloon (LDB) flight in January 2015 deployed a total of 2400 antenna-coupled Transition Edge Sensors (TESs) at 90 GHz and 150 GHz. In this work we review the design and in-flight performance of the SPIDER instrument, with a particular focus on the measured performance of the detectors and instrument in a space-like loading and radiation environment. SPIDER's second flight in December 2018 will incorporate payload upgrades and new receivers to map the sky at 285 GHz, providing valuable information for cleaning polarized dust emission from CMB maps.

  15. Morphological evolution of spiders predicted by pendulum mechanics.

    Directory of Open Access Journals (Sweden)

    Jordi Moya-Laraño

    Full Text Available BACKGROUND: Animals have been hypothesized to benefit from pendulum mechanics during suspensory locomotion, in which the potential energy of gravity is converted into kinetic energy according to the energy-conservation principle. However, no convincing evidence has been found so far. Demonstrating that morphological evolution follows pendulum mechanics is important from a biomechanical point of view because during suspensory locomotion some morphological traits could be decoupled from gravity, thus allowing independent adaptive morphological evolution of these two traits when compared to animals that move standing on their legs; i.e., as inverted pendulums. If the evolution of body shape matches simple pendulum mechanics, animals that move suspending their bodies should evolve relatively longer legs which must confer high moving capabilities. METHODOLOGY/PRINCIPAL FINDINGS: We tested this hypothesis in spiders, a group of diverse terrestrial generalist predators in which suspensory locomotion has been lost and gained a few times independently during their evolutionary history. In spiders that hang upside-down from their webs, their legs have evolved disproportionately longer relative to their body sizes when compared to spiders that move standing on their legs. In addition, we show how disproportionately longer legs allow spiders to run faster during suspensory locomotion and how these same spiders run at a slower speed on the ground (i.e., as inverted pendulums. Finally, when suspensory spiders are induced to run on the ground, there is a clear trend in which larger suspensory spiders tend to run much more slowly than similar-size spiders that normally move as inverted pendulums (i.e., wandering spiders. CONCLUSIONS/SIGNIFICANCE: Several lines of evidence support the hypothesis that spiders have evolved according to the predictions of pendulum mechanics. These findings have potentially important ecological and evolutionary implications since

  16. Cloning and activity of a novel α-latrotoxin from red-back spider venom.

    Science.gov (United States)

    Graudins, Andis; Little, Michelle J; Pineda, Sandy S; Hains, Peter G; King, Glenn F; Broady, Kevin W; Nicholson, Graham M

    2012-01-01

    The venom of the European black widow spider Latrodectus tredecimguttatus (Theridiidae) contains several high molecular mass (110-140 kDa) neurotoxins that induce neurotransmitter exocytosis. These include a vertebrate-specific α-latrotoxin (α-LTX-Lt1a) responsible for the clinical symptoms of latrodectism and numerous insect-specific latroinsectoxins (LITs). In contrast, little is known about the expression of these toxins in other Latrodectus species despite the fact that envenomation by these spiders induces a similar clinical syndrome. Here we report highly conserved α-LTX, α-LIT and δ-LIT sequence tags in Latrodectus mactans, Latrodectus hesperus and Latrodectus hasselti venoms using tandem mass spectrometry, following bioassay-guided separation of venoms by liquid chromatography. Despite this sequence similarity, we show that the anti-α-LTX monoclonal antibody 4C4.1, raised against α-LTX-Lt1a, fails to neutralize the neurotoxicity of all other Latrodectus venoms tested in an isolated chick biventer cervicis nerve-muscle bioassay. This suggests that there are important structural differences between α-LTXs in theridiid spider venoms. We therefore cloned and sequenced the α-LTX from the Australian red-back spider L. hasselti (α-LTX-Lh1a). The deduced amino acid sequence of the mature α-LTX-Lh1a comprises 1180 residues (∼132kDa) with ∼93% sequence identity with α-LTX-Lt1a. α-LTX-Lh1a is composed of an N-terminal domain and a central region containing 22 ankyrin-like repeats. The presence of two furin cleavage sites, conserved with α-LTX-Lt1a, indicates that α-LTX-Lh1a is derived from the proteolytic cleavage of an N-terminal signal peptide and C-terminal propeptide region. However, we show that α-LTX-Lh1a has key substitutions in the 4C4.1 epitope that explains the lack of binding of the monoclonal antibody. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Brown spider dermonecrotic toxin directly induces nephrotoxicity

    International Nuclear Information System (INIS)

    Chaim, Olga Meiri; Sade, Youssef Bacila; Bertoni da Silveira, Rafael; Toma, Leny; Kalapothakis, Evanguedes; Chavez-Olortegui, Carlos; Mangili, Oldemir Carlos; Gremski, Waldemiro; Dietrich, Carl Peter von; Nader, Helena B.; Sanches Veiga, Silvio

    2006-01-01

    Brown spider (Loxosceles genus) venom can induce dermonecrotic lesions at the bite site and systemic manifestations including fever, vomiting, convulsions, disseminated intravascular coagulation, hemolytic anemia and acute renal failure. The venom is composed of a mixture of proteins with several molecules biochemically and biologically well characterized. The mechanism by which the venom induces renal damage is unknown. By using mice exposed to Loxosceles intermedia recombinant dermonecrotic toxin (LiRecDT), we showed direct induction of renal injuries. Microscopic analysis of renal biopsies from dermonecrotic toxin-treated mice showed histological alterations including glomerular edema and tubular necrosis. Hyalinization of tubules with deposition of proteinaceous material in the tubule lumen, tubule epithelial cell vacuoles, tubular edema and epithelial cell lysis was also observed. Leukocytic infiltration was neither observed in the glomerulus nor the tubules. Renal vessels showed no sign of inflammatory response. Additionally, biochemical analyses showed such toxin-induced changes in renal function as urine alkalinization, hematuria and azotemia with elevation of blood urea nitrogen levels. Immunofluorescence with dermonecrotic toxin antibodies and confocal microscopy analysis showed deposition and direct binding of this toxin to renal intrinsic structures. By immunoblotting with a hyperimmune dermonecrotic toxin antiserum on renal lysates from toxin-treated mice, we detected a positive signal at the region of 33-35 kDa, which strengthens the idea that renal failure is directly induced by dermonecrotic toxin. Immunofluorescence reaction with dermonecrotic toxin antibodies revealed deposition and binding of this toxin directly in MDCK epithelial cells in culture. Similarly, dermonecrotic toxin treatment caused morphological alterations of MDCK cells including cytoplasmic vacuoles, blebs, evoked impaired spreading and detached cells from each other and from

  18. Checklist of the spiders (Araneae) of Israel.

    Science.gov (United States)

    Zonstein, Sergei; Marusik, Yuri M

    2013-01-01

    This checklist records 631 spider species and subspecies belonging to 49 families in Israel. Species distributions are given in both generalised (by main geographic areas of the country) and detailed (by localities) form. Twenty-seven records are considered as doubtful and another ten are based on misidentifications. A historical survey is provided. Each record is presented in its original combination. The list is dominated by members of the families Gnaphosidae and Salticidae (20.0% and 17.1% of total species, respectively). The level of regional endemism exceeds 37.0%.

  19. Cuticular antifungals in spiders: density- and condition dependence.

    Directory of Open Access Journals (Sweden)

    Daniel González-Tokman

    Full Text Available Animals living in groups face a high risk of disease contagion. In many arthropod species, cuticular antimicrobials constitute the first protective barrier that prevents infections. Here we report that group-living spiders produce cuticular chemicals which inhibit fungal growth. Given that cuticular antifungals may be costly to produce, we explored whether they can be modulated according to the risk of contagion (i.e. under high densities. For this purpose, we quantified cuticular antifungal activity in the subsocial crab spider Diaea ergandros in both natural nests and experimentally manipulated nests of varying density. We quantified the body-condition of spiders to test whether antifungal activity is condition dependent, as well as the effect of spider density on body-condition. We predicted cuticular antifungal activity to increase and body-condition to decrease with high spider densities, and that antifungal activity would be inversely related to body-condition. Contrary to our predictions, antifungal activity was neither density- nor condition-dependent. However, body-condition decreased with density in natural nests, but increased in experimental nests. We suggest that pathogen pressure is so important in nature that it maintains high levels of cuticular antifungal activity in spiders, impacting negatively on individual energetic condition. Future studies should identify the chemical structure of the isolated antifungal compounds in order to understand the physiological basis of a trade-off between disease prevention and energetic condition caused by group living, and its consequences in the evolution of sociality in spiders.

  20. Probing the Impact of Acidification on Spider Silk Assembly Kinetics.

    Science.gov (United States)

    Xu, Dian; Guo, Chengchen; Holland, Gregory P

    2015-07-13

    Spiders utilize fine adjustment of the physicochemical conditions within its silk spinning system to regulate spidroin assembly into solid silk fibers with outstanding mechanical properties. However, the exact mechanism about which this occurs remains elusive and is still hotly debated. In this study, the effect of acidification on spider silk assembly was investigated on native spidroins from the major ampullate (MA) gland fluid excised from Latrodectus hesperus (Black Widow) spiders. Incubating the protein-rich MA silk gland fluid at acidic pH conditions results in the formation of silk fibers that are 10-100 μm in length and ∼2 μm in diameter as judged by optical and electron microscope methods. The in vitro spider silk assembly kinetics were monitored as a function of pH with a (13)C solid-state MAS NMR approach. The results confirm the importance of acidic pH in the spider silk self-assembly process with observation of a sigmoidal nucleation-elongation kinetic profile. The rates of nucleation and elongation as well as the percentage of β-sheet structure in the grown fibers depend on the pH. These results confirm the importance of an acidic pH gradient along the spinning duct for spider silk formation and provide a powerful spectroscopic approach to probe the kinetics of spider silk formation under various biochemical conditions.

  1. Mermithid parasitism of Hawaiian Tetragnatha spiders in a fragmented landscape

    Science.gov (United States)

    Vandergast, Amy; Roderick, George K.

    2003-01-01

    Hawaiian Tetragnatha spiders inhabiting small forest fragments on the Big Island of Hawaii are parasitized by mermithid nematodes. This is the first report of mermithid nematodes infecting spiders in Hawaii, and an initial attempt to characterize this host–parasite interaction. Because immature mermithids were not morphologically identifiable, a molecular identification was performed. A phylogenetic analysis based on 18S small ribosomal subunit nuclear gene sequences suggested that Hawaiian spider mermithids are more closely related to a mainland presumptive Aranimemis species that infects spiders, than to an insect-infecting mermithid collected on Oahu, HI, or to Mermis nigrescens, also a parasite of insects. Measured infection prevalence was low (ranging from 0 to 4%) but differed significantly among forest fragments. Infection prevalence was associated significantly with fragment area, but not with spider density nor spider species richness. Results suggest that mermithid populations are sensitive to habitat fragmentation, but that changes in infection prevalence do not appear to affect spider community structure.

  2. Spider Silk-CBD-Cellulose Nanocrystal Composites: Mechanism of Assembly.

    Science.gov (United States)

    Meirovitch, Sigal; Shtein, Zvi; Ben-Shalom, Tal; Lapidot, Shaul; Tamburu, Carmen; Hu, Xiao; Kluge, Jonathan A; Raviv, Uri; Kaplan, David L; Shoseyov, Oded

    2016-09-18

    The fabrication of cellulose-spider silk bio-nanocomposites comprised of cellulose nanocrystals (CNCs) and recombinant spider silk protein fused to a cellulose binding domain (CBD) is described. Silk-CBD successfully binds cellulose, and unlike recombinant silk alone, silk-CBD self-assembles into microfibrils even in the absence of CNCs. Silk-CBD-CNC composite sponges and films show changes in internal structure and CNC alignment related to the addition of silk-CBD. The silk-CBD sponges exhibit improved thermal and structural characteristics in comparison to control recombinant spider silk sponges. The glass transition temperature (Tg) of the silk-CBD sponge was higher than the control silk sponge and similar to native dragline spider silk fibers. Gel filtration analysis, dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and cryo-transmission electron microscopy (TEM) indicated that silk-CBD, but not the recombinant silk control, formed a nematic liquid crystalline phase similar to that observed in native spider silk during the silk spinning process. Silk-CBD microfibrils spontaneously formed in solution upon ultrasonication. We suggest a model for silk-CBD assembly that implicates CBD in the central role of driving the dimerization of spider silk monomers, a process essential to the molecular assembly of spider-silk nanofibers and silk-CNC composites.

  3. Spider Communities and Biological Control in Native Habitats Surrounding Greenhouses

    Directory of Open Access Journals (Sweden)

    Belén Cotes

    2018-03-01

    Full Text Available The promotion of native vegetation as a habitat for natural enemies, which could increase their abundance and fitness, is especially useful in highly simplified settings such as Mediterranean greenhouse landscapes. Spiders as generalist predators may also be involved in intra-guild predation. However, the niche complementarity provided by spiders as a group means that increased spider diversity may facilitate complementary control actions. In this study, the interactions between spiders, the two major horticultural pests, Bemisia tabaci and Frankliniella occidentalis, and their naturally occurring predators and parasitoids were evaluated in a mix of 21 newly planted shrubs selected for habitat management in a highly disturbed horticultural system. The effects of all factors were evaluated using redundancy analysis (RDA and the generalized additive model (GAM to assess the statistical significance of abundance of spiders and pests. The GAM showed that the abundance of both pests had a significant effect on hunter spider’s abundance, whereas the abundance of B. tabaci, but not F. occidentalis, affected web-weavers’ abundance. Ordination analysis showed that spider abundance closely correlated with that of B. tabaci but not with that of F. occidentalis, suggesting that complementarity occurs, and thereby probability of biocontrol, with respect to the targeted pest B. tabaci, although the temporal patterns of the spiders differed from those of F. occidentalis. Conservation strategies involving the establishment of these native plants around greenhouses could be an effective way to reduce pest populations outdoors.

  4. Inhibition of the spider heartbeat by gravity and vibration

    Science.gov (United States)

    Finck, A.

    1984-01-01

    The rate and vigor of the spider heartbeat is controlled by an external pacemaker. A mechanical feature of the spider cardio-vascular system is the production of high serum pressure in the prosoma and the legs. This appears to be the source for leg extension. The lyriform organ on the patella of the leg is sensitive to vibratory and kinesthetic stimuli. This sensitivity depends upon the degree of leg extension. Thus the activity of the heart and the response characteristics of the sense receptor are related. The effect of a supra-threshold vibratory or gravitational stimulus is to produce an inhibition and a tachycardia of the spider heartbeat.

  5. Spider silk reinforced by graphene or carbon nanotubes

    Science.gov (United States)

    Lepore, Emiliano; Bosia, Federico; Bonaccorso, Francesco; Bruna, Matteo; Taioli, Simone; Garberoglio, Giovanni; Ferrari, Andrea C.; Pugno, Nicola Maria

    2017-09-01

    Spider silk has promising mechanical properties, since it conjugates high strength (~1.5 GPa) and toughness (~150 J g-1). Here, we report the production of silk incorporating graphene and carbon nanotubes by spider spinning, after feeding spiders with the corresponding aqueous dispersions. We observe an increment of the mechanical properties with respect to pristine silk, up to a fracture strength ~5.4 GPa and a toughness modulus ~1570 J g-1. This approach could be extended to other biological systems and lead to a new class of artificially modified biological, or ‘bionic’, materials.

  6. Biotechnological Trends in Spider and Scorpion Antivenom Development

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard; Solà, Mireia; Jappe, Emma Christine

    2016-01-01

    Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest...... at an increasingly faster pace. In this review, the current knowledge of spider and scorpion venoms is presented, followed by a discussion of all published biotechnological efforts within development of spider and scorpion antitoxins based on small molecules, antibodies and fragments thereof, and next generation...

  7. Myocarditis after black widow spider envenomation.

    Science.gov (United States)

    Sari, Ibrahim; Zengin, Suat; Davutoglu, Vedat; Yildirim, Cuma; Gunay, Nurullah

    2008-06-01

    The black widow spider (BWS), which is a member of the arthropod family, is widely distributed on earth. Black widow spider bites can cause a wide variety of signs or symptoms in humans, but the cardiovascular manifestations are relatively rare except hypertension/hypotension and bradycardia/tachycardia. We report on a 65-year-old man who experienced myocarditis after BWS envenomation, which is extremely rare. He complained of chest pain after the BWS bite, and electrocardiography (ECG) was consistent with a 0.5-mm ST-segment elevation in leads II, aVF, and V3 through V6 and accompanying augmentation in T-wave amplitude in leads V3 through V6 without reciprocal changes. Creatine kinase-MB, troponin-I, and aspartate aminotransferase levels peaked at 98 IU/L, 6.1 ng/mL, and 62 U/L, respectively. His ECG readings and cardiac enzymes returned to normal with supportive treatment, and he was discharged with complete recovery. To the best of our knowledge, the present case is the third in the literature reporting myocarditis and the first reporting ST-segment elevation and accompanying augmentation in T-wave amplitude after BWS envenomation. In addition to usual measures, we recommend ECG and cardiac-specific enzyme followup for every patient envenomated by BWS for potentially fatal cardiac involvement.

  8. Intracellular recording from a spider vibration receptor.

    Science.gov (United States)

    Gingl, Ewald; Burger, Anna-M; Barth, Friedrich G

    2006-05-01

    The present study introduces a new preparation of a spider vibration receptor that allows intracellular recording of responses to natural mechanical or electrical stimulation of the associated mechanoreceptor cells. The spider vibration receptor is a lyriform slit sense organ made up of 21 cuticular slits located on the distal end of the metatarsus of each walking leg. The organ is stimulated when the tarsus receives substrate vibrations, which it transmits to the organ's cuticular structures, reducing the displacement to about one tenth due to geometrical reasons. Current clamp recording was used to record action potentials generated by electrical or mechanical stimuli. Square pulse stimulation identified two groups of sensory cells, the first being single-spike cells which generated only one or two action potentials and the second being multi-spike cells which produced bursts of action potentials. When the more natural mechanical sinusoidal stimulation was applied, differences in adaptation rate between the two cell types remained. In agreement with prior extracellular recordings, both cell types showed a decrease in the threshold tarsus deflection with increasing stimulus frequency. Off-responses to mechanical stimuli have also been seen in the metatarsal organ for the first time.

  9. Microcirculation abnormalities provoked by Loxosceles spiders' envenomation.

    Science.gov (United States)

    Cristina de Oliveira-Lima, Kátia; Farsky, Sandra Helena P; Lopes, Priscila Hess; de Andrade, Rute Maria Gonçalves; van den Berg, Carmen W; Tambourgi, Denise V

    2016-06-15

    Loxoscelism is caused by envenomation by spiders from Loxosceles genus. Clinical symptoms only appear a few hours after envenomation and can evolve in local reactions, such as dermonecrosis, and systemic reactions, including intravascular haemolysis, intravascular coagulation and renal failure. Considering that alterations in the microcirculatory network are involved in the pathogenesis of different diseases, including the inflammatory process, the aim of this study was to investigate the action of venoms of males and females of Loxosceles intermedia and Loxosceles laeta on the microcirculatory network and examine the systemic production of inflammatory mediators in a murine model of loxoscelism. We observed that during systemic envenomation, the alterations in the microcirculation include increase in the number of rolling cells, which was more intense in animals injected with female Loxosceles spider venoms. This positively correlated with increase in TNF-α and NO serum levels, induction of which was higher by female venoms when compared with male venoms. The increase of leukocytes rolling was not accompanied by increase of cell adhesion. The absence of leukocyte extravasation may explain why in mice, in contrast to humans, no cutaneous loxoscelism occurs. Thus, targeting the neutrophil adhesion and extravasation in Loxosceles envenomed patients may prevent cutaneous pathology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Phylogenomics resolves a spider backbone phylogeny and rejects a prevailing paradigm for orb web evolution.

    Science.gov (United States)

    Bond, Jason E; Garrison, Nicole L; Hamilton, Chris A; Godwin, Rebecca L; Hedin, Marshal; Agnarsson, Ingi

    2014-08-04

    Spiders represent an ancient predatory lineage known for their extraordinary biomaterials, including venoms and silks. These adaptations make spiders key arthropod predators in most terrestrial ecosystems. Despite ecological, biomedical, and biomaterial importance, relationships among major spider lineages remain unresolved or poorly supported. Current working hypotheses for a spider "backbone" phylogeny are largely based on morphological evidence, as most molecular markers currently employed are generally inadequate for resolving deeper-level relationships. We present here a phylogenomic analysis of spiders including taxa representing all major spider lineages. Our robust phylogenetic hypothesis recovers some fundamental and uncontroversial spider clades, but rejects the prevailing paradigm of a monophyletic Orbiculariae, the most diverse lineage, containing orb-weaving spiders. Based on our results, the orb web either evolved much earlier than previously hypothesized and is ancestral for a majority of spiders or else it has multiple independent origins, as hypothesized by precladistic authors. Cribellate deinopoid orb weavers that use mechanically adhesive silk are more closely related to a diverse clade of mostly webless spiders than to the araneoid orb-weaving spiders that use adhesive droplet silks. The fundamental shift in our understanding of spider phylogeny proposed here has broad implications for interpreting the evolution of spiders, their remarkable biomaterials, and a key extended phenotype--the spider web. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Evolution of stenophagy in spiders (Araneae): evidence based on the comparative analysis of spider diets.

    Science.gov (United States)

    Pekár, Stano; Coddington, Jonathan A; Blackledge, Todd A

    2012-03-01

    Stenophagy (narrow diet breadth) represents an extreme of trophic specialization in carnivores, but little is known about the forces driving its evolution. We used spiders, the most diversified group of terrestrial predators, to investigate whether stenophagy (1) promoted diversification; (2) was phylogenetically conserved and evolutionarily derived state; and (3) was determined either by geographical distribution and foraging guild. We used published data on the prey of almost 600 species. Six categories of stenophagy were found: myrmecophagy, araneophagy, lepidopterophagy, termitophagy, dipterophagy, and crustaceophagy. We found that the species diversity of euryphagous genera and families was similar to stenophagous genera and families. At the family level, stenophagy evolved repeatedly and independently. Within families, the basal condition was oligophagy or euryphagy. Most types of stenophagy were clearly derived: myrmecophagy in Zodariidae; lepidopterophagy in Araneidae; dipterophagy in Theridiidae. In contrast, araneophagy was confined to basal and intermediate lineages, suggesting its ancestral condition. The diet breadth of species from the tropics and subtropics was less diverse than species from the temperate zone. Diet breadth was lower in cursorial spiders compared to web-building species. Thus, the evolution of stenophagy in spiders appears to be complex and governed by phylogeny as well as by ecological determinants. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  12. Biomimetic calcium phosphate coatings on recombinant spider silk fibres

    NARCIS (Netherlands)

    Yang, Liang; Hedhammar, My; Blom, Tobias; Leifer, Klaus; Johansson, Jan; Habibovic, Pamela; van Blitterswijk, Clemens

    2010-01-01

    Calcium phosphate ceramic coatings, applied on surfaces of metallic and polymeric biomaterials, can improve their performance in bone repair and regeneration. Spider silk is biocompatible, strong and elastic, and hence an attractive biomaterial for applications in connective tissue repair. Recently,

  13. Peculiar torsion dynamical response of spider dragline silk

    Science.gov (United States)

    Liu, Dabiao; Yu, Longteng; He, Yuming; Peng, Kai; Liu, Jie; Guan, Juan; Dunstan, D. J.

    2017-07-01

    The torsional properties of spider dragline silks from Nephila edulis and Nephila pilipes spiders are investigated by using a torsion pendulum technique. A permanent torsional deformation is observed after even small torsional strain. This behaviour is quite different from that of the other materials tested here, i.e., carbon fiber, thin metallic wires, Kevlar fiber, and human hair. The spider dragline thus displays a strong energy dissipation upon the initial excitation (around 75% for small strains and more for a larger strain), which correspondingly reduces the amplitude of subsequent oscillations around the new equilibrium position. The variation of torsional stiffness in relaxation dynamics of spider draglines for different excitations is also determined. The experimental result is interpreted in the light of the hierarchical structure of dragline silk.

  14. [Effectiveness of a repellent paint against the spider Loxosceles laeta].

    Science.gov (United States)

    Catalán, Alejandro; Araya, Jorge E; Varela, Héctor; Cortés, William; Sagua, Hernán; González Cortés, Jorge

    2009-02-01

    Loxoscelism is a severe reaction to the bite of the spider Loxosceles laeta. In recent years, a paint with repellent properties has been promoted in the commerce. However, there are no reports of experiments evaluating its effectiveness. To evaluate experimentally the repellent properties of a paint against Loxosceles laeta. Males, females and nymphs of L laeta were deposited in cockpits that allow the free displacement of the spider. Half of the cockpit was covered with repellent paint. Daily observations during one week, determined how frequently the spiders occupied the space covered with repellent paint. The experiments were run in triplicate. No statistical differences in the occupancy of spaces covered with repellent paint or not covered with it were observed for nymphs (87% and 67%, respectively), males (72% and 77%, respectively) or females (91% and 84%, respectively). The tested paint does not have a repellent action against the spider Loxosceles laeta.

  15. SPIDERS (ARANEI) OF VOLGOGRAD SITY AND ITS ENVIRONS

    OpenAIRE

    A. V. Ponomarev; A. S. Khnykin

    2013-01-01

    Abstract. Aim. Fauna of spiders of Volgograd Region is researched uncompletely. Only 149 species of 19 families were listed in previous references. Complete listing of spiders of this large region was the aim of our investigation.Location. Volgograd Region, Russia.Methods. Material was collected in Volgograd City with environs and Volga-Don area in 2009–2013. Areas with minimum of anthropogenic influence within the city, artificial ecosystem of park type, plots of native vegetation along the ...

  16. Benefits of cooperation with genetic kin in a subsocial spider

    DEFF Research Database (Denmark)

    Schneider, J.M.; Bilde, T.

    2008-01-01

    used a cross-fostering design to control for genetic relatedness and group membership. Our study animal was the periodic social spider Stegodyphus lineatus, a transitional species that belongs to a genus containing both permanent social and periodic social species. In S. lineatus, the young cooperate....... Hence, in communally feeding spiders, nepotism favors group retention and reduces the conflict between selfish interests and the interests of the group....

  17. Early events in the evolution of spider silk genes.

    Directory of Open Access Journals (Sweden)

    James Starrett

    Full Text Available Silk spinning is essential to spider ecology and has had a key role in the expansive diversification of spiders. Silk is composed primarily of proteins called spidroins, which are encoded by a multi-gene family. Spidroins have been studied extensively in the derived clade, Orbiculariae (orb-weavers, from the suborder Araneomorphae ('true spiders'. Orbicularians produce a suite of different silks, and underlying this repertoire is a history of duplication and spidroin gene divergence. A second class of silk proteins, Egg Case Proteins (ECPs, is known only from the orbicularian species, Lactrodectus hesperus (Western black widow. In L. hesperus, ECPs bond with tubuliform spidroins to form egg case silk fibers. Because most of the phylogenetic diversity of spiders has not been sampled for their silk genes, there is limited understanding of spidroin gene family history and the prevalence of ECPs. Silk genes have not been reported from the suborder Mesothelae (segmented spiders, which diverged from all other spiders >380 million years ago, and sampling from Mygalomorphae (tarantulas, trapdoor spiders and basal araneomorph lineages is sparse. In comparison to orbicularians, mesotheles and mygalomorphs have a simpler silk biology and thus are hypothesized to have less diversity of silk genes. Here, we present cDNAs synthesized from the silk glands of six mygalomorph species, a mesothele, and a non-orbicularian araneomorph, and uncover a surprisingly rich silk gene diversity. In particular, we find ECP homologs in the mesothele, suggesting that ECPs were present in the common ancestor of extant spiders, and originally were not specialized to complex with tubuliform spidroins. Furthermore, gene-tree/species-tree reconciliation analysis reveals that numerous spidroin gene duplications occurred after the split between Mesothelae and Opisthothelae (Mygalomorphae plus Araneomorphae. We use the spidroin gene tree to reconstruct the evolution of amino acid

  18. Spiders of the Vine Plants in Southern Moravia

    OpenAIRE

    Lucie Havlová; Vladimír Hula; Jana Niedobová

    2015-01-01

    Araneofauna of vineyards is relatively known in Central Europe but we have a lack of knowledge about araneofauna which occur directly on the vine plants. Our investigation was focused on spiders which live on vine plants, especially on the vine plants trunks. We investigated spiders in six vineyards in southern Moravia (Šatov, Mikulov, Popice, Morkůvky, Nosislav and Blučina). Vineyards were under different soil management, traps were placed on different parts of particular locality (terraced ...

  19. Rapid Characterization of Spider Silk Genes via Exon Capture

    Science.gov (United States)

    2015-03-28

    argentata (silver garden spider ), Latrodectus hesperus (Western black widow ), and Nephila clavipes (golden silk orb- weaver). A. diadematus and N...in light of sequence divergence, we also studied Parasteatoda tepidariorum (common house spider ) and Steatoda grossa (false black widow ). P...could determine the minimum number of spidroin gene copies in a black widow genome. In less well-characterized species, such as A. diadematus, our data

  20. Early events in the evolution of spider silk genes.

    Science.gov (United States)

    Starrett, James; Garb, Jessica E; Kuelbs, Amanda; Azubuike, Ugochi O; Hayashi, Cheryl Y

    2012-01-01

    Silk spinning is essential to spider ecology and has had a key role in the expansive diversification of spiders. Silk is composed primarily of proteins called spidroins, which are encoded by a multi-gene family. Spidroins have been studied extensively in the derived clade, Orbiculariae (orb-weavers), from the suborder Araneomorphae ('true spiders'). Orbicularians produce a suite of different silks, and underlying this repertoire is a history of duplication and spidroin gene divergence. A second class of silk proteins, Egg Case Proteins (ECPs), is known only from the orbicularian species, Lactrodectus hesperus (Western black widow). In L. hesperus, ECPs bond with tubuliform spidroins to form egg case silk fibers. Because most of the phylogenetic diversity of spiders has not been sampled for their silk genes, there is limited understanding of spidroin gene family history and the prevalence of ECPs. Silk genes have not been reported from the suborder Mesothelae (segmented spiders), which diverged from all other spiders >380 million years ago, and sampling from Mygalomorphae (tarantulas, trapdoor spiders) and basal araneomorph lineages is sparse. In comparison to orbicularians, mesotheles and mygalomorphs have a simpler silk biology and thus are hypothesized to have less diversity of silk genes. Here, we present cDNAs synthesized from the silk glands of six mygalomorph species, a mesothele, and a non-orbicularian araneomorph, and uncover a surprisingly rich silk gene diversity. In particular, we find ECP homologs in the mesothele, suggesting that ECPs were present in the common ancestor of extant spiders, and originally were not specialized to complex with tubuliform spidroins. Furthermore, gene-tree/species-tree reconciliation analysis reveals that numerous spidroin gene duplications occurred after the split between Mesothelae and Opisthothelae (Mygalomorphae plus Araneomorphae). We use the spidroin gene tree to reconstruct the evolution of amino acid compositions of

  1. Latrodectism—Effects of the Black Widow Spider Bite

    OpenAIRE

    Timms, Patrick K.; Gibbons, Robert B.

    1986-01-01

    Latrodectism—envenomation by the black widow spider, Latrodectus mactans—has been reported in virtually every state. The spider is particularly prevalent in the Southwest, Southeast and California, and symptoms from its bite are painful and may be confusing to clinicians. Prompt improvement can be expected in most cases with administration of calcium and muscle relaxant, but some patients may require treatment with antivenin. No deaths occurred in our series of 11 patients, although one case ...

  2. Spider silk as a blueprint for greener materials : a review

    OpenAIRE

    Lefèvre, Thierry; Auger, Michèle

    2016-01-01

    Spider silk exhibits remarkable properties, especially its well-known tensile performances. They rely on a complex nanostructured hierarchical organisation that studies progressively elucidate. Spider silk encompasses a vast range of fibres that exhibit diverse and captivating physical and biological characteristics. The full understanding of the relation between structure and properties may lead in the future to the design of a variety of high-performance, tailored materials and ...

  3. Small Molecules from Spiders Used as Chemical Probes

    DEFF Research Database (Denmark)

    Olsen, Christian Adam; Kristensen, Anders S.; Strømgaard, Kristian

    2011-01-01

    Spiders are important species in ecological systems and as major predators of insects they are endowed with a plethora of low‐molecular‐weight natural products having intriguing biological activities. The isolation and biological characterization of these entities are well established, however, o...... the area of pheromones and allomones from spiders. Herein, we recapitulate these recent results, put them into perspective with previous findings, and provide an outlook for future studies of these chemotypes....

  4. Visual Discrimination Learning in the Jumping Spider Phidippus regius

    Directory of Open Access Journals (Sweden)

    Massimo De Agrò

    2017-11-01

    Full Text Available Over the past decade, research in comparative psychology has increasingly focused on non-vertebrate models of cognition. Jumping spiders provide excellent models for the study of visually mediated behaviors, such as associative learning or the navigation of complex environments. Here, we tested visual and memory abilities of Phidippus regius to discriminate between artificial geometrical stimuli and to generalize the learned discrimination to illusory stimuli, using the amodal completion mechanism. Spiders were first trained to associate one shape (‘X’ or ‘O’ with a reward (sugar water, whilst the other shape was associated with an aversive taste (acidic water. Spiders were then asked to choose between the two shapes in the absence of any reward or punishment. They were then presented with an occluded version of the previously rewarded shape to test for the presence of amodal completion. Spiders were able to learn the discrimination task, although the association was not transferred to the illusory stimulus. This study provides the first demonstration of shape discrimination learning in a jumping spider. The results of the test on the illusory shape are discussed considering that either the spiders' visual system may not require amodal completion or they could have the tendency to learn the shape associated with the aversive taste rather than that associated with the reward.

  5. Australian uranium mining policy

    International Nuclear Information System (INIS)

    Fisk, B.

    1985-01-01

    Australian government policy is explained in terms of adherence to the Non-Proliferation Treaty. Two alleged uncertainties are discussed: the future of Australian mining industry as a whole -on which it is said that Australian uranium mines will continue to be developed; and detailed commercial policy of the Australian government - on which it is suggested that the three-mines policy of limited expansion of the industry would continue. Various aspects of policy, applying the principles of the NPT, are listed. (U.K.)

  6. The phylogeny of fossil whip spiders.

    Science.gov (United States)

    Garwood, Russell J; Dunlop, Jason A; Knecht, Brian J; Hegna, Thomas A

    2017-04-21

    Arachnids are a highly successful group of land-dwelling arthropods. They are major contributors to modern terrestrial ecosystems, and have a deep evolutionary history. Whip spiders (Arachnida, Amblypygi), are one of the smaller arachnid orders with ca. 190 living species. Here we restudy one of the oldest fossil representatives of the group, Graeophonus anglicus Pocock, 1911 from the Late Carboniferous (Duckmantian, ca. 315 Ma) British Middle Coal Measures of the West Midlands, UK. Using X-ray microtomography, our principal aim was to resolve details of the limbs and mouthparts which would allow us to test whether this fossil belongs in the extant, relict family Paracharontidae; represented today by a single, blind species Paracharon caecus Hansen, 1921. Tomography reveals several novel and significant character states for G. anglicus; most notably in the chelicerae, pedipalps and walking legs. These allowed it to be scored into a phylogenetic analysis together with the recently described Paracharonopsis cambayensis Engel & Grimaldi, 2014 from the Eocene (ca. 52 Ma) Cambay amber, and Kronocharon prendinii Engel & Grimaldi, 2014 from Cretaceous (ca. 99 Ma) Burmese amber. We recovered relationships of the form ((Graeophonus (Paracharonopsis + Paracharon)) + (Charinus (Stygophrynus (Kronocharon (Charon (Musicodamon + Paraphrynus)))))). This tree largely reflects Peter Weygoldt's 1996 classification with its basic split into Paleoamblypygi and Euamblypygi lineages; we were able to score several of his characters for the first time in fossils. Our analysis draws into question the monophyly of the family Charontidae. Our data suggest that Graeophonus is a crown group amblypygid, and falls within a monophyletic Paleoamblypgi clade, but outside the family Paracharontidae (= Paracharonopsis + Paracharon). Our results also suggest a new placement for the Burmese amber genus Kronocharon, a node further down from its original position. Overall, we offer a

  7. Microdissection of black widow spider silk-producing glands.

    Science.gov (United States)

    Jeffery, Felicia; La Mattina, Coby; Tuton-Blasingame, Tiffany; Hsia, Yang; Gnesa, Eric; Zhao, Liang; Franz, Andreas; Vierra, Craig

    2011-01-11

    Modern spiders spin high-performance silk fibers with a broad range of biological functions, including locomotion, prey capture and protection of developing offspring. Spiders accomplish these tasks by spinning several distinct fiber types that have diverse mechanical properties. Such specialization of fiber types has occurred through the evolution of different silk-producing glands, which function as small biofactories. These biofactories manufacture and store large quantities of silk proteins for fiber production. Through a complex series of biochemical events, these silk proteins are converted from a liquid into a solid material upon extrusion. Mechanical studies have demonstrated that spider silks are stronger than high-tensile steel. Analyses to understand the relationship between the structure and function of spider silk threads have revealed that spider silk consists largely of proteins, or fibroins, that have block repeats within their protein sequences. Common molecular signatures that contribute to the incredible tensile strength and extensibility of spider silks are being unraveled through the analyses of translated silk cDNAs. Given the extraordinary material properties of spider silks, research labs across the globe are racing to understand and mimic the spinning process to produce synthetic silk fibers for commercial, military and industrial applications. One of the main challenges to spinning artificial spider silk in the research lab involves a complete understanding of the biochemical processes that occur during extrusion of the fibers from the silk-producing glands. Here we present a method for the isolation of the seven different silk-producing glands from the cobweaving black widow spider, which includes the major and minor ampullate glands [manufactures dragline and scaffolding silk], tubuliform [synthesizes egg case silk], flagelliform [unknown function in cob-weavers], aggregate [makes glue silk], aciniform [synthesizes prey wrapping and egg

  8. Molecular cloning and expression of the C-terminus of spider ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    . Among the types of spider silks, draglines from Nephila clavipes and Araneus diadematus have been the most intensely studied. However, the entirety of a spider silk gene has not been cloned yet, and sequence data from. Molecular cloning ...

  9. Spider Web DNA: A New Spin on Noninvasive Genetics of Predator and Prey.

    Directory of Open Access Journals (Sweden)

    Charles C Y Xu

    Full Text Available Noninvasive genetic sampling enables biomonitoring without the need to directly observe or disturb target organisms. This paper describes a novel and promising source of noninvasive spider and insect DNA from spider webs. Using black widow spiders (Latrodectus spp. fed with house crickets (Acheta domesticus, we successfully extracted, amplified, and sequenced mitochondrial DNA from spider web samples that identified both spider and prey to species. Detectability of spider DNA did not differ between assays with amplicon sizes from 135 to 497 base pairs. Spider and prey DNA remained detectable at least 88 days after living organisms were no longer present on the web. Spider web DNA as a proof-of-concept may open doors to other practical applications in conservation research, pest management, biogeography studies, and biodiversity assessments.

  10. Spider Web DNA: A New Spin on Noninvasive Genetics of Predator and Prey.

    Science.gov (United States)

    Xu, Charles C Y; Yen, Ivy J; Bowman, Dean; Turner, Cameron R

    2015-01-01

    Noninvasive genetic sampling enables biomonitoring without the need to directly observe or disturb target organisms. This paper describes a novel and promising source of noninvasive spider and insect DNA from spider webs. Using black widow spiders (Latrodectus spp.) fed with house crickets (Acheta domesticus), we successfully extracted, amplified, and sequenced mitochondrial DNA from spider web samples that identified both spider and prey to species. Detectability of spider DNA did not differ between assays with amplicon sizes from 135 to 497 base pairs. Spider and prey DNA remained detectable at least 88 days after living organisms were no longer present on the web. Spider web DNA as a proof-of-concept may open doors to other practical applications in conservation research, pest management, biogeography studies, and biodiversity assessments.

  11. Riparian spiders as sentinels of PCB contamination across heterogeneous aquatic ecosystems

    Science.gov (United States)

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the ...

  12. Spider Web DNA: A New Spin on Noninvasive Genetics of Predator and Prey

    Science.gov (United States)

    Xu, Charles C. Y.; Yen, Ivy J.; Bowman, Dean; Turner, Cameron R.

    2015-01-01

    Noninvasive genetic sampling enables biomonitoring without the need to directly observe or disturb target organisms. This paper describes a novel and promising source of noninvasive spider and insect DNA from spider webs. Using black widow spiders (Latrodectus spp.) fed with house crickets (Acheta domesticus), we successfully extracted, amplified, and sequenced mitochondrial DNA from spider web samples that identified both spider and prey to species. Detectability of spider DNA did not differ between assays with amplicon sizes from 135 to 497 base pairs. Spider and prey DNA remained detectable at least 88 days after living organisms were no longer present on the web. Spider web DNA as a proof-of-concept may open doors to other practical applications in conservation research, pest management, biogeography studies, and biodiversity assessments. PMID:26606730

  13. Early Australian Pronunciation.

    Science.gov (United States)

    Gunn, John S.

    Comparative research indicates that almost without exception, late eighteenth century non-standard English pronunciation was very close to what is called Broad Australian. Present Australian English is closely akin to the blended, popular colloquial London English, spoken by the largest group of Australia's first settlers. This pronunciation…

  14. Australian Asian Options

    OpenAIRE

    Manuel Moreno; Javier F. Navas

    2003-01-01

    We study European options on the ratio of the stock price to its average and viceversa. Some of these options are traded in the Australian Stock Exchange since 1992, thus we call them Australian Asian options. For geometric averages, we obtain closed-form expressions for option prices. For arithmetic means, we use different approximations that produce very similar results.

  15. First report of clinical presentation of a bite by a running spider ...

    African Journals Online (AJOL)

    This article describes the clinical progression of symptoms over a period of 5 days of a bite inflicted by a Philodromus sp. spider. Commonly known as 'running spiders', these are not considered to be harmful to humans. This report, however, is the first description of an actual bite by a member of this group of spiders ...

  16. Radiation Safety System for SPIDER Neutral Beam Accelerator

    Science.gov (United States)

    Sandri, S.; Coniglio, A.; D'Arienzo, M.; Poggi, C.

    2011-12-01

    SPIDER (Source for Production of Ion of Deuterium Extracted from RF Plasma only) and MITICA (Megavolt ITER Injector Concept Advanced) are the ITER neutral beam injector (NBI) testing facilities of the PRIMA (Padova Research Injector Megavolt Accelerated) Center. Both injectors accelerate negative deuterium ions with a maximum energy of 1 MeV for MITICA and 100 keV for SPIDER with a maximum beam current of 40 A for both experiments. The SPIDER facility is classified in Italy as a particle accelerator. At present, the design of the radiation safety system for the facility has been completed and the relevant reports have been presented to the Italian regulatory authorities. Before SPIDER can operate, approval must be obtained from the Italian Regulatory Authority Board (IRAB) following a detailed licensing process. In the present work, the main project information and criteria for the SPIDER injector source are reported together with the analysis of hypothetical accidental situations and safety issues considerations. Neutron and photon nuclear analysis is presented, along with special shielding solutions designed to meet Italian regulatory dose limits. The contribution of activated corrosion products (ACP) to external exposure of workers has also been assessed. Nuclear analysis indicates that the photon contribution to worker external exposure is negligible, and the neutron dose can be considered by far the main radiation protection issue. Our results confirm that the injector has no important radiological impact on the population living around the facility.

  17. SPIDER: Probing the Early Universe with a Suborbital Polarimeter

    Science.gov (United States)

    Fraisse, Aurélien A.; SPIDER Collaboration

    2012-01-01

    SPIDER is a balloon-borne polarimeter designed to detect a divergence-free polarization pattern ("B-modes") in the Cosmic Microwave Background (CMB). In the inflationary scenario, the spectrum of the tensor perturbations that generate this signal is proportional to that of the primordial scalar perturbations through the tensor-to-scalar ratio r. The expected level of systematic error in the SPIDER instrument is significantly below the amplitude of an interesting cosmological B-mode signal with r=0.03. An optimized scanning strategy enables us to minimize uncertainty in the reconstruction of the Stokes parameters used to characterize the CMB, while providing access to a relatively wide range of angular scales. In the SPIDER field, the polarized emission from interstellar dust is as bright or brighter than the cosmological r=0.03 B-mode signal at all SPIDER frequencies (90, 150, and 280 GHz), a situation similar to that found in the "Southern Hole." Despite this foreground contamination, two 20-day flights of the SPIDER instrument will constrain the amplitude of the B-mode signal to rAPRA-NNX07AL64G), the National Science Foundation (ANT-1043515), the Gordon and Betty Moore Foundation, and the David and Lucile Packard Foundation. Support in Canada is provided by NSERC, the Canadian Space Agency, the Canada Foundation for Innovation, and CIFAR.

  18. Recent Advances in Research on Widow Spider Venoms and Toxins

    Directory of Open Access Journals (Sweden)

    Shuai Yan

    2015-11-01

    Full Text Available Widow spiders have received much attention due to the frequently reported human and animal injures caused by them. Elucidation of the molecular composition and action mechanism of the venoms and toxins has vast implications in the treatment of latrodectism and in the neurobiology and pharmaceutical research. In recent years, the studies of the widow spider venoms and the venom toxins, particularly the α-latrotoxin, have achieved many new advances; however, the mechanism of action of the venom toxins has not been completely clear. The widow spider is different from many other venomous animals in that it has toxic components not only in the venom glands but also in other parts of the adult spider body, newborn spiderlings, and even the eggs. More recently, the molecular basis for the toxicity outside the venom glands has been systematically investigated, with four proteinaceous toxic components being purified and preliminarily characterized, which has expanded our understanding of the widow spider toxins. This review presents a glance at the recent advances in the study on the venoms and toxins from the Latrodectus species.

  19. Endemic harvestmen and spiders of Austria (Arachnida: Opiliones, Araneae

    Directory of Open Access Journals (Sweden)

    Komposch, Christian

    2011-01-01

    Full Text Available A comprehensive overview of plant, fungus and animal species of Austria revealed a total of 748 endemic and subendemic species, including, 11 harvestman and 46 spider species. Altogether two endemic harvestmen (Nemastoma bidentatum relictum, Nemastoma schuelleri and 8 endemic spiders (Abacoproeces molestus, Collinsia (caliginosa nemenziana, Mughiphantes severus, Mughiphantes styriacus, Pelecopsis alpica, Scotophaeus nanus, Troglohyphantes novicordis, Troglohyphantes tauriscus, beside 9 subendemic harvestman and 38 subendemic spider species have been recorded from Austria. Hot-spots of endemism in the Eastern Alps are the north-eastern (Ennstaler Alps and southern Calcareous Alps (Karawanken, Karnische Alps and the Central Alps (Hohe Tauern, Gurktaler Alps, Ötztaler and Stubaier Alps. Most of the endemic arachnid species occur from the nival down to the montane zone. Important habitats are rocky areas, caves and woodlands. High absolute numbers and percentages of endemics can be found within the harvestman families Cladonychiidae, Ischyropsalididae and Nemastomatidae and in the spider genera Lepthyphantes s. l. and Troglohyphantes. The conservation status of these highly endangered taxa – 85 % of the spider species and 100 % of the harvestman taxa are endangered in Austria – is poor.

  20. Treatment effect on biases in size estimation in spider phobia.

    Science.gov (United States)

    Shiban, Youssef; Fruth, Martina B; Pauli, Paul; Kinateder, Max; Reichenberger, Jonas; Mühlberger, Andreas

    2016-12-01

    The current study investigates biases in size estimations made by spider-phobic and healthy participants before and after treatment. Forty-one spider-phobic and 20 healthy participants received virtual reality (VR) exposure treatment and were then asked to rate the size of a real spider immediately before and, on average, 15days after the treatment. During the VR exposure treatment skin conductance response was assessed. Prior to the treatment, both groups tended to overestimate the size of the spider, but this size estimation bias was significantly larger in the phobic group than in the control group. The VR exposure treatment reduced this bias, which was reflected in a significantly smaller size rating post treatment. However, the size estimation bias was unrelated to the skin conductance response. Our results confirm the hypothesis that size estimation by spider-phobic patients is biased. This bias is not stable over time and can be decreased with adequate treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The Australian National Seismograph Network

    OpenAIRE

    Jepsen, D.

    1994-01-01

    The Australian Seismological Centre of the Australian Geological Survey Organisation, operates and co-operates a national seismograph network consisting of 24 analogue and 8 digitally telemetred (3 broadband) stations (see fig. 1 and table 1). The network covers the Australian continent and the Australian Antarctic Territory.

  2. The Australian National Seismograph Network

    Directory of Open Access Journals (Sweden)

    D. Jepsen

    1994-06-01

    Full Text Available The Australian Seismological Centre of the Australian Geological Survey Organisation, operates and co-operates a national seismograph network consisting of 24 analogue and 8 digitally telemetred (3 broadband stations (see fig. 1 and table 1. The network covers the Australian continent and the Australian Antarctic Territory.

  3. Interactions Between the Chilean Recluse Spider (Araneae: Sicariidae) and an Araneophagic Spitting Spider (Araneae: Scytodidae).

    Science.gov (United States)

    Canals, Mauricio; Arriagada, Nicolás; Solís, Rigoberto

    2015-03-01

    In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider, Loxosceles laeta Nicolet, a species that shares the microenvironmental habitats with the spitting spider Scytodes globula Nicolet. The latter species has been proposed as a potential predator of L. laeta. For this research, we studied the interaction between both species during individual encounters to assess the possibility of population regulation of L. laeta cohorts exposed to this potential predator. We found that in most encounters S. globula prevailed. Also, S. globula preys on spiderlings of L. laeta, with a population effect on cohorts of this species. These findings suggest that S. globula may be influencing L. laeta populations in central Chile. The population regulation of L. laeta by predation would be important because this species, in the absence of predators, has a high reproductive rate, and it can maintain populations of large size. However according to our results, although S. globula may aid in the reduction of both spiderling and adult L. laeta populations, and perhaps other Loxosceles species, it is insufficient for biological control of Loxosceles species. Its presence together with other control measures such as hygiene of the rooms can help to decrease loxoscelism incidence. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Prey interception drives web invasion and spider size determines successful web takeover in nocturnal orb-web spiders

    Directory of Open Access Journals (Sweden)

    Wenjin Gan

    2015-10-01

    Full Text Available A striking feature of web-building spiders is the use of silk to make webs, mainly for prey capture. However, building a web is energetically expensive and increases the risk of predation. To reduce such costs and still have access to abundant prey, some web-building spiders have evolved web invasion behaviour. In general, no consistent patterns of web invasion have emerged and the factors determining web invasion remain largely unexplored. Here we report web invasion among conspecifics in seven nocturnal species of orb-web spiders, and examined the factors determining the probability of webs that could be invaded and taken over by conspecifics. About 36% of webs were invaded by conspecifics, and 25% of invaded webs were taken over by the invaders. A web that was built higher and intercepted more prey was more likely to be invaded. Once a web was invaded, the smaller the size of the resident spider, the more likely its web would be taken over by the invader. This study suggests that web invasion, as a possible way of reducing costs, may be widespread in nocturnal orb-web spiders.

  5. Influence of spider silk on refugia preferences of the recluse spiders Loxosceles reclusa and Loxosceles laeta (Araneae: Sicariidae).

    Science.gov (United States)

    Vetter, Richard S; Rust, Michael K

    2010-06-01

    In a previous experimental study, recluse spiders Loxosceles reclusa Gertsch and Mulaik and Loxosceles laeta (Nicolet) (Araneae: Sicariidae) preferred small cardboard refugia covered with conspecific silk compared with never-occupied refugia. Herein, we investigated some factors that might be responsible for this preference using similar cardboard refugia. When the two Loxosceles species were given choices between refugia previously occupied by their own and by the congeneric species, neither showed a species-specific preference; however, each chose refugia coated with conspecific silk rather than those previously inhabited by a distantly related cribellate spider, Metaltella simoni (Keyserling). When L. laeta spiders were offered refugia that were freshly removed from silk donors compared with heated, aged refugia from the same silk donor, older refugia were preferred. Solvent extracts of L. laeta silk were chosen approximately as often as control refugia when a range of solvents (methylene chloride:methanol, water, and hexane) were used. However, when acetone was used on similar silk, there was a statistical preference for the control, indicating that there might be a mildly repellent aspect to acetone-washed silk. Considering the inability to show attraction to chemical aspects of fresh silk, it seems that physical attributes may be more important for selection and that there might be repellency to silk of a recently vacated spider. These findings are discussed in regard to pest management strategies to control recluse spiders.

  6. How spiders practice aggressive and Batesian mimicry

    Directory of Open Access Journals (Sweden)

    Ximena J. NELSON, Robert R. JACKSON

    2012-08-01

    Full Text Available To understand communication, the interests of the sender and the receiver/s of signals should be considered separately. When our goal is to understand the adaptive significance of specific responses to specific signals by the receiver, questions about signal information are useful. However, when our goal is to understand the adaptive significance to the sender of generating a signal, it may be better to envisage the receiver’s response to signals as part of the sender’s extended phenotype. By making signals, a sender interfaces with the receiver’s model of the world and indirectly manipulates its behaviour. This is especially clear in cases of mimicry, where animals use deceptive signals that indirectly manipulate the behaviour of receivers. Many animals adopt Batesian mimicry to deceive their predators, or aggressive mimicry to deceive their prey. We review examples from the lite­rature on spiders to illustrate how these phenomena, traditionally thought of as distinct, can become entangled in a web of lies [Current Zoology 58 (4: 620–629, 2012].

  7. Multivariable control of a rolling spider drone

    Science.gov (United States)

    Lyu, Haifeng

    The research and application of Unmanned Aerial Vehicles (UAVs) has been a hot topic recently. A UAV is dened as an aircraft which is designed not to carry a human pilot or operated with remote electronic input by the flight controller. In this thesis, the design of a control system for a quadcopter named Rolling Spider Drone is conducted. The thesis work presents the design of two kinds of controllers that can control the Drone to keep it balanced and track different kinds of input trajectories. The nonlinear mathematical model for the Drone is derived by the Newton-Euler method. The rotational subsystem and translational system are derived to describe the attitude and position motion of Drone. Techniques from linear control theory are employed to linearize the highly coupled and nonlinear quadcopter plant around equilibrium points and apply the linear feedback controller to stabilize the system. The controller is a digital tracking system that deploys LQR for system stability design. Fixed gain and adaptive gain scheduled controllers are developed and compared with different LQR weights. Step references and reference trajectories involving signicant variation for the yaw angle in the xy-plane and three-dimensional spaces are tracked in the simulation. The physical implementation and an output feedback controller are considered for future work.

  8. Efficient Journaling for the Spider Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Oral, H Sarp [ORNL; Wang, Feiyi [ORNL; Shipman, Galen M [ORNL; Dillow, David A [ORNL; Miller, Ross G [ORNL; Drokin, Oleg [ORNL

    2003-01-01

    Journaling is a widely used technique to increase file system robustness against meta data and/or data corruptions. While the overhead of journaling can be negligible for small-scale file systems, we found that two aspects of local back-end file system journaling significantly lower the overall performance of a large-scale parallel file system such as Lustre: extra head seeks and serialization of incoming client requests. Journal transactions reside on a separate area of the disk that the file data, and each commit of the journal requires a head seek. Incoming client requests become serialized and take a latency hit by waiting for a commit to occur before the reply is sent. In this paper we present two different approaches to increase the local back-end file system journaling efficiency, thus increasing the overall aggregate parallel file system efficiency. First, we present a hardware-based solution where a solid-state device is used as an external journaling device to minimize the disk head seek. Second, we introduce a software-based optimization to allow asynchronously commit multiple journal transactions on the local back-end file system to minimize the penalty of serialization. Both our solutions are experimentally tested on Oak Ridge National Laboratory's large-scale Spider storage system and our tests show that both methods nearly double the overall parallel write performance.

  9. Development of locomotion in a subsocial spider.

    Science.gov (United States)

    Ahn, Soon Kil; Kim, Kil Won

    2015-04-01

    Following consumption of their mother, the subsocial spider Amaurobius ferox remain together, exhibiting distinctive behaviours in response to intruders into the natal nest. We examined the ontogeny and characteristics of locomotory behaviours in A. ferox during this post-maternal social period. Locomotion of the spiderlings, elicited by the introduction of a cricket larva into the natal web, fell into two categories: 'abrupt locomotion' (AL) and 'ordinary locomotion' (OL). AL involved rapid and linear movement, whereas OL involved slower motion, not necessarily in a straight line. Both types of locomotion varied with spiderling age. AL appeared for only a limited period of time whereas the frequency of OL increased linearly over time. AL occurred more collectively than OL: the percentage of participants in a bout of locomotion was 18.67±17.71% vs. 10.22±9.33%. The collective tendency of AL increased up until the seventh day and then decreased, whereas that of OL progressively decreased. The direction of AL responses to the intruder did not vary over time; however, for OL, movements towards increased in frequency over time. Locomotory responses also varied with the intensity of intruder movement. Including transient behaviours, the chronology of different behaviours suggests that behavioural development in A. ferox involves maternal influences and weakens group cohesion and collective tendency. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Final design of thermal diagnostic system in SPIDER ion source

    Energy Technology Data Exchange (ETDEWEB)

    Brombin, M., E-mail: matteo.brombin@igi.cnr.it; Dalla Palma, M.; Pasqualotto, R.; Pomaro, N. [Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova (Italy)

    2016-11-15

    The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H{sup −} production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements. This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.

  11. Tool use in wild spider monkeys (Ateles geoffroyi).

    Science.gov (United States)

    Lindshield, Stacy M; Rodrigues, Michelle A

    2009-07-01

    Tool use has been observed in a variety of primate species, including both New and Old World monkeys. However, such reports mainly address the most prodigious tool users and frequently limit discussions of tool-using behavior to a foraging framework. Here, we present observations of novel and spontaneous tool use in wild black-handed spider monkeys (Ateles geoffroyi), where female spider monkeys used detached sticks in a self-directed manner. We introduce factors to explain Ateles tool-using abilities and limitations, and encourage the synthesis of relevant research in order to gain insight into the cognitive abilities of spider monkeys and the evolution of tool-using behaviors in primates.

  12. Adhesion modulation using glue droplet spreading in spider capture silk.

    Science.gov (United States)

    Amarpuri, Gaurav; Zhang, Ci; Blackledge, Todd A; Dhinojwala, Ali

    2017-05-01

    Orb web spiders use sticky capture spiral silk to retain prey in webs. Capture spiral silk is composed of an axial fibre of flagelliform silk covered with glue droplets that are arranged in a beads-on-a-string morphology that allows multiple droplets to simultaneously extend and resist pull off. Previous studies showed that the adhesion of capture silk is responsive to environmental humidity, increasing up to an optimum humidity that varied among different spider species. The maximum adhesion was hypothesized to occur when the viscoelasticity of the glue optimized contributions from glue spreading and bulk cohesion. In this study, we show how glue droplet shape during peeling contributes significantly to capture silk adhesion. Both overspreading and underspreading of glue droplets reduces adhesion through changes in crack propagation and failure regime. Understanding the mechanism of stimuli-responsive adhesion of spider capture silk will lead to new designs for smarter adhesives. © 2017 The Author(s).

  13. Vision in the nocturnal wandering spider Leucorchestris arenicola (Araneae: Sparassidae)

    DEFF Research Database (Denmark)

    Nørgaard, Thomas; Nilsson, Dan-Eric; Henschel, Joh R

    2008-01-01

    At night the Namib Desert spider Leucorchestris arenicola performs long-distance homing across its sand dune habitat. By disabling all or pairs of the spiders' eight eyes we found that homing ability was severely reduced when vision was fully abolished. Vision, therefore, seems to play a key role...... in the nocturnal navigational performances of L. arenicola. After excluding two or three pairs of eyes, the spiders were found to be able to navigate successfully using only their lateral eyes or only their anterior median eyes. Measurement of the eyes' visual fields showed that the secondary eyes combined have...... a near full (panoramic) view of the surroundings. The visual fields of the principal eyes overlap almost completely with those of the anterior lateral eyes. Electroretinogram recordings indicate that each eye type contains a single photopigment with sensitivity peaking at approximately 525 nm...

  14. [The black widow spider--its appearance and control].

    Science.gov (United States)

    Landeka, Nediljko; Plenković, Jasminka

    2003-03-01

    Between 1995 and 2002, a massive appearance of black widow (Latrodectus mactans tredecimguttatus, Rossi 1790) was recorded along the Croatia coast. This paper gives a historical review of latrodectism and observations from Istria and Dalmatia, paying particular attention to the spider's habitat. There are several reasons for the black widow to appear in a new habitat such as the introduction of leguminous plants, watermelons and melons where crops were grown earlier. Black widow can also be found near buildings and gardens. Human contacts with the spider are usually without consequences for humans, thanks to education and a relatively good visibility of the spider. The authors describe their experience in fighting black widow and emphasise the importance of education in preventing lactrodectism.

  15. Stable isotope analyses of web-spinning spider assemblages along a headwater stream in Puerto Rico

    Directory of Open Access Journals (Sweden)

    Sean P. Kelly

    2015-10-01

    Full Text Available Web-spinning spiders that inhabit stream channels are considered specialists of aquatic ecosystems and are major consumers of emerging aquatic insects, while other spider taxa are more commonly found in riparian forests and as a result may consume more terrestrial insects. To determine if there was a difference in spider taxa abundance between riverine web-spinning spider assemblages within the stream channel and the assemblages 10 m into the riparian forest, we compared abundances for all web-spinning spiders along a headwater stream in El Yunque National Forest in northeast Puerto Rico. By using a nonmetric dimensional scaling (NMDS abundance analysis we were able to see a clear separation of the two spider assemblages. The second objective of the study was to determine if aquatic insects contributed more to the diet of the spider assemblages closest to the stream channel and therefore stable isotope analyses of δ15N and δ13C for web-spinning spiders along with their possible prey were utilized. The results of the Bayesian mixing model (SIAR however showed little difference in the diets of riverine (0 m, riparian (10 m and upland (25 m spiders. We found that aquatic insects made up ∼50% of the diet for web-spinning spiders collected at 0 m, 10 m, and 25 m from the stream. This study highlights the importance of aquatic insects as a food source for web-spinning spiders despite the taxonomic differences in assemblages at different distances from the stream.

  16. A preliminary checklist of spiders (Araneae: Arachnida in Chinnar Wildlife Sanctuary, Western Ghats, India

    Directory of Open Access Journals (Sweden)

    C. K. Adarsh

    2016-04-01

    Full Text Available A preliminary study was conducted to document spider diversity in Chinnar Wildlife Sanctuary, Idukki District, Kerala State in southern India.  The study was conducted from October to November 2012.  A total of 101 species of spiders belonging to 65 genera from 29 families were identified from the sanctuary.  This accounted for 6.98% of Indian spider species, 17.81% of Indian spider genera and 48.33% of the spider families of India.  The dominant families were Lycosidae (11 species and Araneidae (10.  Two endemic genera of Indian spiders such as Annandaliella and Neoheterophrictus were found at Chinnar, each representing one species each, and belonging to the family Theraphosidae.  A guild structure analysis of the spiders revealed seven feeding guilds such as orb weavers, stalkers, ground runners, foliage runners, sheet web builders, space web builders and ambushers. 

  17. Latrodectism—Effects of the Black Widow Spider Bite

    Science.gov (United States)

    Timms, Patrick K.; Gibbons, Robert B.

    1986-01-01

    Latrodectism—envenomation by the black widow spider, Latrodectus mactans—has been reported in virtually every state. The spider is particularly prevalent in the Southwest, Southeast and California, and symptoms from its bite are painful and may be confusing to clinicians. Prompt improvement can be expected in most cases with administration of calcium and muscle relaxant, but some patients may require treatment with antivenin. No deaths occurred in our series of 11 patients, although one case was complicated by serum sickness. PMID:3962294

  18. Learning from animal sensors: the clever "design" of spider mechanoreceptors

    Science.gov (United States)

    Barth, Friedrich G.

    2012-04-01

    Three types of spider sensors responding to different forms of mechanical energy are chosen to illustrate the power of evolutionary constraints to fine-tune the functional "design" of animal sensors to the particular roles they play in particular behavioral contexts. As demonstrated by the application of computational biomechanics and a fruitful cooperation between biologists and engineers there are remarkable "technical" tricks to be found by which spider tactile sensors, airflow sensors, and strain sensors are adjusted to their biologically relevant stimulus patterns. The application of such "tricks" to technical solutions of measuring problems similar to those animals have to cope with, seems both realistic and very promising.

  19. Australianness as fairness

    DEFF Research Database (Denmark)

    Plage, Stefanie; Willing, Indigo; Skrbis, Zlatko

    2017-01-01

    This article provides an account of interwoven and often competing repertoires of cosmopolitanism and nationalism on which Australians draw when encountering diversity. Using interview and focus group data the article first explores how the notion of Australianness grounded in civic virtues such ......-go’ principle at times conceptually overlaps with cosmopolitan ethics. However, it also bears the potential to hinder cosmopolitan practices. Ultimately national and cosmopolitan ethical frameworks have to be interrogated simultaneously when applied to micro-level interactions.......This article provides an account of interwoven and often competing repertoires of cosmopolitanism and nationalism on which Australians draw when encountering diversity. Using interview and focus group data the article first explores how the notion of Australianness grounded in civic virtues...

  20. Volatile compounds from leaves of the African spider plant (Gynandropsis gynandra) with bioactivity against spider mite (Tetranychus urticae)

    DEFF Research Database (Denmark)

    Nyalala, Samuel Odeyo; Petersen, Mikael Agerlin; Grout, Brian William Wilson

    2013-01-01

    Previous studies have demonstrated that Gynandropsis gynandra emits acetonitrile as a foliar volatile from intact plants and isolated leaves, and that this compound is an effective spider mite repellent. This study has used gas chromatography–mass spectrometry to investigate volatile compounds...... emitted from homogenised G. gynandra leaves to evaluate their tissue acetonitrile content and to look for other compounds that might be exploited for the management of spider mites. Acetonitrile was absent from the homogenised tissues of five lines of G. gynandra, studied over two seasons. Thirteen...... volatile compounds were emitted by G. gynandra at significantly higher levels than mite-susceptible pot roses, including isothiocyanates, aldehydes, esters, alcohols and terpenes. Six representative compounds were selected to assess bioactivity. Spider mite populations were completely inactive after a 2¿h...

  1. Mechanism of diffusive transport in molecular spider models

    Science.gov (United States)

    Semenov, Oleg; Olah, Mark J.; Stefanovic, Darko

    2011-02-01

    Recent advances in single-molecule chemistry have led to designs for artificial multipedal walkers that follow tracks of chemicals. We investigate the motion of a class of walkers, called molecular spiders, which consist of a rigid chemically inert body and several flexible enzymatic legs. The legs can reversibly bind to chemical substrates on a surface and through their enzymatic action convert them to products. The legs can also reversibly bind to products, but at a different rate. Antal and Krapivsky have proposed a model for molecular spider motion over regular one-dimensional lattices [T. Antal and P. L. Krapivsky, Phys. Rev. ENATUAS1539-375510.1103/PhysRevE.76.021121 76, 021121 (2007).]. In the model the legs hop from site to site under constraints imposed by connection to a common body. The first time a leg visits a site, the site is an uncleaved substrate, and the leg hops from this site only once it has cleaved it into a product. This cleavage happens at a rate rr=1. The effect of cleavage is to slow down the hopping rate for legs that visit a site for the first time. Along with the constraints imposed on the legs, this leads to an effective bias in the direction of unvisited sites that decreases the average time needed to visit n sites. The overall motion, however, remains diffusive in the long time limit. We have reformulated the Antal-Krapivsky model as a continuous-time Markov process and simulated many traces of this process using kinetic Monte Carlo techniques. Our simulations show a previously unpredicted transient behavior wherein spiders with small r values move superdiffusively over significant distances and times. We explain this transient period of superdiffusive behavior by describing the spider process as switching between two metastates: a diffusive state D wherein the spider moves in an unbiased manner over previously visited sites, and a boundary state B wherein the spider is on the boundary between regions of visited and unvisited sites

  2. Insecticidal toxins from black widow spider venom.

    Science.gov (United States)

    Rohou, A; Nield, J; Ushkaryov, Y A

    2007-03-15

    The biological effects of Latrodectus spider venom are similar in animals from different phyla, but these symptoms are caused by distinct phylum-specific neurotoxins (collectively called latrotoxins) with molecular masses ranging from 110 to 140 kDa. To date, the venom has been found to contain five insecticidal toxins, termed alpha, beta, gamma, delta and epsilon-latroinsectotoxins (LITs). There is also a vertebrate-specific neurotoxin, alpha-latrotoxin (alpha-LTX), and one toxin affecting crustaceans, alpha-latrocrustatoxin (alpha-LCT). These toxins stimulate massive release of neurotransmitters from nerve terminals and act (1) by binding to specific receptors, some of which mediate an exocytotic signal, and (2) by inserting themselves into the membrane and forming ion-permeable pores. Specific receptors for LITs have yet to be identified, but all three classes of vertebrate receptors known to bind alpha-LTX are also present in insects. All LTXs whose structures have been elucidated (alpha-LIT, delta-LIT, alpha-LTX and alpha-LCT) are highly homologous and have a similar domain architecture, which consists of a unique N-terminal sequence and a large domain composed of 13-22 ankyrin repeats. Three-dimensional (3D) structure analysis, so far done for alpha-LTX only, has revealed its dimeric nature and an ability to form symmetrical tetramers, a feature probably common to all LTXs. Only tetramers have been observed to insert into membranes and form pores. A preliminary 3D reconstruction of a delta-LIT monomer demonstrates the spatial similarity of this toxin to the monomer of alpha-LTX.

  3. Spider Silk Processing for Spidroin Recovery from Crossopriza Lyoni Web

    Science.gov (United States)

    Mohtar, J. A.; Ooi, W. L.; Yusuf, F.

    2018-03-01

    Spider silk is a potential biomaterial that can be used in various applications for its outstanding physicomechanical properties attributed by the spidroin composition. Efforts for commercializing spider silks have been mainly focused on the characterization of spidroins from the Entelegyne spiders for exceptional fibre construction. Hence, studies on silk proteins from the Haplogyne species remain neglected. The aim of this study is to isolate spidroin from Crossopriza lyoni web. Silk processing involved the pretreatment of fibres for the shell layer removal from the surface. A screening study was conducted to analyze the effect of temperature, incubation time and agitation speed on spidroin extraction using Ajisawa’s reagent by OFAT analysis followed by statistical optimization of the extraction process via RSM for maximal protein recovery. All parameters exerted significant effect on spidroin recovery (p<0.05) in which the maximum protein concentration (451.78 ± 0.110 µg/ml) was obtained at optimal condition of 70°C, 350 rpm and 1.25 hours. The discovery of spidroin from this study provides a basic platform for engineering spider silk to meet the demand for a variety of silk-based products in the near future.

  4. variability in condensed tannins and bitterness in spider plant ...

    African Journals Online (AJOL)

    ACSS

    Spider plant (Cleome gynandra L.) contributes considerably to the nutrition and medicines of communities in southern Africa. However, its utilisation is limited by its bitterness caused by condensed tannins. Unfortunately, processing options that reduce the bitterness also remove nutritionally and medicinally useful ...

  5. Spider bite in southern Africa: diagnosis and management

    African Journals Online (AJOL)

    older specimens the red stripes and spots may have disappeared completely. The legs are evenly black. .... Africa. (Map: Ansie Dippenaar.) Fig. 6. Brown widow spider depicting consistent orange to red hourglass .... Both cholinesterase inhibitors and α-latrotoxin give rise to an increase in acetylcholine concentration in the ...

  6. Biotechnological Trends in Spider and Scorpion Antivenom Development

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard; Solà, Mireia; Jappe, Emma Christine

    2016-01-01

    Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest...

  7. Preservice Teachers' Conceptions about Animals and Particularly about Spiders

    Science.gov (United States)

    Jambrina, Carmen Urones; Vacas, Jose Manuel; Sanchez-Barbudo, Miguel

    2010-01-01

    Introduction: This article explores the scientific ideas and alternative conceptions that pre-service teachers have regarding animal classification and spiders in particular. Method: The study involved 40 pre-service teachers of elementary education in Spain and the data was collected by means of questionnaires, descriptions and drawings. The…

  8. Ant-Mimicking Spiders: Strategies for Living with Social Insects

    Directory of Open Access Journals (Sweden)

    Fadia Sara Ceccarelli

    2013-01-01

    Full Text Available Mimicry is a fascinating topic, in particular when viewed in terms of selective forces and evolutionary strategies. Mimicry is a system involving a signaller, a signal receiver, and a model and has evolved independently many times in plants and animals. There are several ways of classifying mimicry based on the interactions and cost-benefit scenarios of the parties involved. In this review, I briefly outline the dynamics of the most common types of mimicry to then apply it to some of the spider-ant associative systems known to date. In addition, this review expands on the strategies that ant-associating (in particular ant-mimicking spiders have developed to minimise the costs of living close to colonies of potentially dangerous models. The main strategy that has been noted to date is either chemical mimicry or actively avoiding contact with ants. If these strategies warrant protection for the spider (living close to potentially dangerous models, then the benefits of ant associations would outweigh the costs, and the association will prevail.

  9. Determination of PCDDs in spider webs: preliminary studies

    Directory of Open Access Journals (Sweden)

    Rybak Justyna

    2018-01-01

    Full Text Available The application of spider webs for determination of polichlorinated dibenzo-para-dioxins (PCDDs has been studied for the first time. The aim of the studies was to find out if spider webs are suitable for such examinations as it was proved in the previous research they are excellent indicators of air pollutants. Spiders are ubiquitous, thus collection of samples is easy and non-invasive. Studies were conducted within the city of Wrocław and surroundings, one of the biggest and at the same time heaviest polluted city in Poland. Five research sites have been chosen, where spider webs were collected after 60 days of continuous exposure time. Webs belonging to two genera Tegenaria sylvestris and Tegenaria ferruginea (family Agelenidae have been chosen as they are large and very dense, thus they are very suitable for such examinations. Webs were found to retain dioxins probably mainly by external exposure. These promising results should be continued and expanded in the future research.

  10. Trial by fire: Social spider colony demographics in periodically ...

    African Journals Online (AJOL)

    Nests of social spiders of the genus Stegodyphus (Eresidae) are a prominent feature of African savannas and their size and visibility make them potentially good indicators of ecological consequences of fire. The colonies are sedentary and their nests may persist for several years, although individuals have an annual life ...

  11. Central European habitats inhabited by spiders with disjunctive distributions

    Czech Academy of Sciences Publication Activity Database

    Růžička, Vlastimil

    2011-01-01

    Roč. 59, č. 2 (2011), s. 367-380 ISSN 1505-2249 Institutional research plan: CEZ:AV0Z50070508 Keywords : spider s * glacial relicts * boreomontane species Subject RIV: EH - Ecology , Behaviour Impact factor: 0.506, year: 2011

  12. Ballooning behavior in the golden orbweb spider Nephilapilipes (Araneae: Nephilidae

    Directory of Open Access Journals (Sweden)

    Vanessa M.J. Lee

    2015-01-01

    Full Text Available Ballooning, a mode of aerial dispersal in spiders, is an innate behavior that requires appropriate physiological and meteorological conditions. Although only rarely reported in the golden orbweb spiders, family Nephilidae, the large geographic distributions of most nephilids—in particular of Nephila species—would imply that these spiders likely routinely disperse by ballooning in spite of giant female sizes. Here we study ballooning behavior in the golden orbweb spider Nephila pilipes (Fabricius, 1793. Specifically, we test for the propensity of spiderlings to deploy ballooning as a dispersal mechanism. We subjected a total of 59 first-instar spiderlings to a wind experiment at two wind speeds (2.17 ± 0.02 m s-1 and 3.17 ± 0.02 m s-1 under laboratory conditions. Under an average wind speed of 3.17 m s-1, none of the spiderlings exhibited pre-ballooning or ballooning behavior. However, at an average wind speed of 2.17 m s-1, 53 (89.8% spiderlings showed pre-ballooning behavior, and 17 (32.1% of the pre-ballooners ultimately ballooned. Our results concur with prior reports on spiderlings of other families that pre-ballooning behavior is a requirement for ballooning to occur. Furthermore, although we cannot rule out other dispersal mechanisms such as synanthropic spread, our findings suggest that the widespread N. pilipes uses ballooning to colonize remote oceanic islands.

  13. Spiders of the Vine Plants in Southern Moravia

    Directory of Open Access Journals (Sweden)

    Lucie Havlová

    2015-01-01

    Full Text Available Araneofauna of vineyards is relatively known in Central Europe but we have a lack of knowledge about araneofauna which occur directly on the vine plants. Our investigation was focused on spiders which live on vine plants, especially on the vine plants trunks. We investigated spiders in six vineyards in southern Moravia (Šatov, Mikulov, Popice, Morkůvky, Nosislav and Blučina. Vineyards were under different soil management, traps were placed on different parts of particular locality (terraced and plain and all localities were under integrated pest management. We employed two types of cardboard traps for spider collecting during whole vegetation season. Altogether, we collected 21 spider species which belong to seven families. The most important species was Marpissa nivoyi (Lucas, 1836, which is mentioned in the Red List as vulnerable (VU and Sibianor tantulus (Simon, 1868 which had unknown distribution in the Czech Republic. The other very interesting result is that the most common species is myrmecomorph Synageles venator (Lucas, 1836, which is scarcely recorded in such huge numbers as we documented in our study.

  14. Spiders (Araneae) as polyphagous natural enemies in orchards

    NARCIS (Netherlands)

    Bogya, S.

    1999-01-01

    Spiders (Araneae) occur in high abundance in all terrestrial ecosystems including agro-ecosystems. They are a very heterogeneous group of animals with different hunting tactics and therefore they play very different ecological roles. At family level these tactics are rather similar thus

  15. Effects of Packaging and Storage Conditions on Quality of Spider ...

    African Journals Online (AJOL)

    The purpose of this research was to increase insight into how the seed quality of spider plant is affected by different packaging containers, seed moisture content and storage temperatures, with a view to finding out the optimal method of packaging and storing of these seeds. This study was carried out using seeds dried ...

  16. Female mating strategy during precopulatory mate guarding in spider mites

    NARCIS (Netherlands)

    Oku, K.

    2009-01-01

    In some taxa, females choose their mates indirectly by using male combat. In the Kanzawa spider mite, Tetranychus kanzawai, adult males guard prereproductive quiescent females. In a dual choice experiment, more males first approached females already guarded by a conspecific male than approached

  17. The Spider's Web: Creativity and Survival in Dynamic Balance.

    Science.gov (United States)

    Cohen, Bill

    2001-01-01

    The spider's web is presented as a model for Indigenous education and community transformation, grounded in Okanagan philosophy. Children are at the center and benefit from the influence of extended family and community. The model's relevance for language revitalization, cultural maintenance, and educational planning and assessment is discussed.…

  18. The sejugal furrow in camel spiders and acariform mites

    Directory of Open Access Journals (Sweden)

    Dunlop, Jason A.

    2012-07-01

    Full Text Available Camel spiders (Arachnida: Solifugae are one of the arachnid groups characterised by a prosomal dorsal shield composed of three distinct elements: the pro-, meso- and metapeltidium. These are associated respectively with prosomal appendages one to four, five, and six. What is less well known, although noted in the historical literature, is that the coxae of the 4th and 5th prosomal segments (i.e. walking legs 2 and 3 of camel spiders are also separated ventrally by a distinct membranous region, which is absent between the coxae of the other legs. We suggest that this essentially ventral division of the prosoma specifically between coxae 2 and 3 is homologous with the so-called sejugal furrow (the sejugal interval sensu van der Hammen. This division constitutes a fundamental part of the body plan in acariform mites (Arachnida: Acariformes. If homologous, this sejugal furrow could represent a further potential synapomorphy for (Solifugae + Acariformes; a relationship with increasing morphological and molecular support. Alternatively, outgroup comparison with sea spiders (Pycnogonida and certain early Palaeozoic fossils could imply that the sejugal furrow defines an older tagma, derived from a more basal grade of organisation. In this scenario the (still divided prosoma of acariform mites and camel spiders would be plesiomorphic. This interpretation challenges the textbook arachnid character of a peltidium (or ‘carapace’ covering an undivided prosoma.

  19. Czech Republic – the type material of spiders (Araneae)

    Czech Academy of Sciences Publication Activity Database

    Růžička, Vlastimil; Kůrka, A.; Buchar, J.; Řezáč, M.

    2005-01-01

    Roč. 174, 1-4 (2005), s. 13-64 ISSN 0139-9543 R&D Projects: GA AV ČR(CZ) IAA6007401 Institutional research plan: CEZ:AV0Z50070508 Keywords : spiders * type material * Czech Republic Subject RIV: EG - Zoology

  20. Shedding light on the optical properties of spider silk fiber

    OpenAIRE

    Chow, Desmond M.; Tow, Kenny Hey; Vollrath, Fritz; Dicaire, Isabelle; Gheysens, Tom; Thevenaz, Luc

    2015-01-01

    Optical characterisation of a Nephila edulis spider dragline silk is performed. The silk fiber transmits light up to 1400 nm with a propagation loss of ∼9 dB/cm and birefringence of 8×10−3 measured at 1302 nm.

  1. 46 SPIDER WEBS AS INDICATORS OF COBALT AND LEAD ...

    African Journals Online (AJOL)

    Spider webs were collected from the indoor and outdoor of 120 sampling sites of 10 zones of Kano. Municipality. The samples were analysed for .... from 120 sampling sites in 10 sampling zones of. Kano municipality. Each sampling zone ... London (Fergusson and Ryan, 1984); New Zealand. (Fergusson et al., 1986); Kano ...

  2. Infrared and Raman Study of the Recluse Spider Silk

    Science.gov (United States)

    Wang, S. L.; Wang, Qijue; Xing, Zhen; Schniepp, H. C.; Qazilbash, M. M.

    Spider silk exhibits remarkable mechanical properties, such as high tensile strength and toughness. We want to gain insight into the composition and structure of spider silk to discover the origin of these properties. We are especially interested in the organization of the crystalline beta sheets that are expected to contribute to the high strength of the silk from the recluse spider, Loxosceles laeta. The recluse spider produces a silk that has a unique geometry amongst arachnids. We measure the silk's optical properties, particularly the infrared-active and Raman-active vibrations. Broadband infrared transmission spectra were collected in the spectral range between 600 cm-1 and 4000 cm-1, with light polarized parallel and perpendicular to the long axis of the silk. Raman micro-spectroscopy was performed in the spectral range 500 cm-1 and 4000 cm- 1 with a 514 nm laser. The infrared and Raman vibrational modes are fit with Lorentzian and pseudo-Voigt functions. The vibrational modes are assigned to specific structures and electronic bonds in the silk. This work was supported by NASA/ Virginia Space Grant Consortium.

  3. Characteristics of the first recorded spider (Arthropoda: Arachnida fauna from Sheringal, Khyber Pakhtunkhwa, Pakistan

    Directory of Open Access Journals (Sweden)

    Farzana Khan Perveen

    2015-12-01

    Full Text Available The spiders (order: Aranae are an important environmental indicator and play a significant role as predators in biological control of the most of the key insect pests. The present study was conducted to establish the characteristics of the first recorded spider fauna from Sheringal, Dir Upper (DU, Khyber Pakhtunkhwa (KP, Pakistan during June 2013-July 2014. Their 10 species belong to 7 families, and 10 genera (nt=123: total; ni=77: identified; nui=46: unidentified were recorded in the 6 quadrates, i.e., Daramdala, Doki, Guryaal, Samang, Shahoor and Sia-Sheringal of Sheringal. The largest family was Lycosidae (wolf spiders with respect to size and numbers of specimens collected (n=20, which contained Arctosa littorali Simon, 1897; Hippasa partita Takidar, 1970; Pardosa distincta Backwall, 1867, while the smallest family was Gnphosidae (ground spiders (n=3 with Gnaphosa eucalyptus Ghafoor and Beg, 2002; while other families Sparassidae (huntsman spiders (n=19 Halconia insignis Thorell, 1836, and Isopeda tuhogniga Barrion and Litsinger, 1995, Opilionidae (harvestmen spiders (n=12 Hadrobunus grandis Sundevall, 1833; Pholcidae (cellar spider (n=10 have Crossopriza lyoni Blackwall, 1867; Hersiliidae (two-tailed spiders (n=6 is having Harsilia savignyi Lucas, 1836; (n=5 with Araneus diadematus Clerck, 1757 were recorded. It was concluded that 50% of the spiders collected from the study area were venomous. A detail study is required for further exploration of spider fauna of Sheringal, KP, Pakistan with special reference to their taxonomical, physiological and ecological characteristics.

  4. Evaluating Stem Cell Response to a Spider Silk Scaffold

    Science.gov (United States)

    Hafner, Katherine Lee

    Micropatterning on a surface using fibers, channels, and troughs, can act as an effective means of inducing cell attachment and alignment. These morphological and pattern changes as a response to physical cues can impact the potential that a cell has to differentiate into a different cell line. This thesis evaluated the response of human dental pulp stem cells (DPSCs), and other cell types, to spider dragline silk fibers, a potential scaffold material for tissue regeneration, and further observed the effects of morphology, orientation, and composition of silk on the adherence of cells. Several cell lines were studied in this thesis, including adipose derived stem cells (ADSCs), osteoblasts (7F2s), and fibroblasts (3T3s), but DPSCs were the main cell type of interest. This is due to the fact that DPSCs are a proposed source of stem cells for nerve regeneration based on their close embryonic origin to neurons and the ease with which DPSCs can be obtained from a donor. The cells' morphologies and spread patterns were characterized after they were plated onto Nephila clavipes dragline fibers in media. The inclusion of 3T3s and 7F2s in this study allowed for both direct comparisons to prior published work and a qualitative comparison to the morphology of the DPSCs. After twelve days, the DPSCs exhibited greater relative alignment and adherence to the spider dragline fibers than the 3T3s and 7F2s when silk was wrapped in an aligned orientation rather than a random orientation. The impact of a common sterilization method (ultraviolet light) on the spider dragline fiber surface and subsequent cell response to this modified surface was also characterized. Exposure of the silk to ultraviolet light did not have a measureable effect on cell alignment, but it did eliminate bacterial growth and changed fiber surface roughness. Spiders' exposure to stressful environments did not have an effect on silk to impair cell alignment or adhesion, and synthetic recombinant protein silk

  5. Global patterns of guild composition and functional diversity of spiders.

    Directory of Open Access Journals (Sweden)

    Pedro Cardoso

    Full Text Available The objectives of this work are: (1 to define spider guilds for all extant families worldwide; (2 test if guilds defined at family level are good surrogates of species guilds; (3 compare the taxonomic and guild composition of spider assemblages from different parts of the world; (4 compare the taxonomic and functional diversity of spider assemblages and; (5 relate functional diversity with habitat structure. Data on foraging strategy, prey range, vertical stratification and circadian activity was collected for 108 families. Spider guilds were defined by hierarchical clustering. We searched for inconsistencies between family guild placement and the known guild of each species. Richness and abundance per guild before and after correcting guild placement were compared, as were the proportions of each guild and family between all possible pairs of sites. Functional diversity per site was calculated based on hierarchical clustering. Eight guilds were discriminated: (1 sensing, (2 sheet, (3 space, and (4 orb web weavers; (5 specialists; (6 ambush, (7 ground, and (8 other hunters. Sixteen percent of the species richness corresponding to 11% of all captured individuals was incorrectly attributed to a guild by family surrogacy; however, the correlation of uncorrected vs. corrected guilds was invariably high. The correlation of guild richness or abundances was generally higher than the correlation of family richness or abundances. Functional diversity was not always higher in the tropics than in temperate regions. Families may potentially serve as ecological surrogates for species. Different families may present similar roles in the ecosystems, with replacement of some taxa by other within the same guild. Spiders in tropical regions seem to have higher redundancy of functional roles and/or finer resource partitioning than in temperate regions. Although species and family diversity were higher in the tropics, functional diversity seems to be also

  6. SPIDERS (ARANEI OF THE REPUBLIC OF SOUTH OSSETIA

    Directory of Open Access Journals (Sweden)

    Alexander V. Ponomarev

    2015-01-01

    Full Text Available Aim. Until recently, spider fauna of the Republic of South Ossetia has been the least studied among the regional araneofaunas of the Caucasus. According to the literature data, as little as 30 spider species have been known from the republic’s territory (Mkheidze, 1997, Mikhailov, 1990; Ponomarev, Dvadnenko, 2013; Trilicauscas, Komarov, 2014. Therefore, the aim of the present article is to summarize available data on the spider fauna of South Ossetia.Location. Republic of South Ossetia.Methods. The material was collected in various districts of South Ossetia in 2011-2014 by Yu.E. Komarov. Mainly, the collecting was performed in the city of Tskhinvali and its environs, and in the South Ossetian State Reserve. Spiders were sampled with pitfall traps and sweep netting. The time of traps’ exposure is April–December.Results and main conclusions. To date, the spider fauna of the Republic of South Ossetia includes 230 species from 29 families. 222 species were registered by the authors, eight species (Clubiona pseudosimilis, Gnaphosa lugubris, Linyphia hortensis, Neriene peltata, Geolycosa vultuosa, Pardosa azerifalcata, Ero aphana, and Philodromus rufus are known from the literature only. Seven species are new to the Caucasus (Clubiona pseudosimilis, Gnaphosa lugubris, Linyphia hortensis, Neriene peltata, Geolycosa vultuosa, Pardosa azerifalcata, Ero aphana, and Philodromus rufus. Of these, two species were known earlier only from Turkey (Pardosa consimilis, Ozyptila spirembolus, and one species (Tegenaria pseudolyncea only from Azerbaijan. Against the background of the widespread species predominance, the Caucasian element is small and presented by twelve species (Tegenaria pseudolyncea, Dysdera tkibuliensis, Haplodrassus caucasius, Zelotes khostensis, Mansuphantes ovalis, Sintula oseticus, Tenuiphantes teberdaensis, Pardosa azerifalcata, P. caucasica, Piratula hurkai, Trochosa cachetiensis, and Xysticus ukrainicus.

  7. Global Patterns of Guild Composition and Functional Diversity of Spiders

    Science.gov (United States)

    Cardoso, Pedro; Pekár, Stano; Jocqué, Rudy; Coddington, Jonathan A.

    2011-01-01

    The objectives of this work are: (1) to define spider guilds for all extant families worldwide; (2) test if guilds defined at family level are good surrogates of species guilds; (3) compare the taxonomic and guild composition of spider assemblages from different parts of the world; (4) compare the taxonomic and functional diversity of spider assemblages and; (5) relate functional diversity with habitat structure. Data on foraging strategy, prey range, vertical stratification and circadian activity was collected for 108 families. Spider guilds were defined by hierarchical clustering. We searched for inconsistencies between family guild placement and the known guild of each species. Richness and abundance per guild before and after correcting guild placement were compared, as were the proportions of each guild and family between all possible pairs of sites. Functional diversity per site was calculated based on hierarchical clustering. Eight guilds were discriminated: (1) sensing, (2) sheet, (3) space, and (4) orb web weavers; (5) specialists; (6) ambush, (7) ground, and (8) other hunters. Sixteen percent of the species richness corresponding to 11% of all captured individuals was incorrectly attributed to a guild by family surrogacy; however, the correlation of uncorrected vs. corrected guilds was invariably high. The correlation of guild richness or abundances was generally higher than the correlation of family richness or abundances. Functional diversity was not always higher in the tropics than in temperate regions. Families may potentially serve as ecological surrogates for species. Different families may present similar roles in the ecosystems, with replacement of some taxa by other within the same guild. Spiders in tropical regions seem to have higher redundancy of functional roles and/or finer resource partitioning than in temperate regions. Although species and family diversity were higher in the tropics, functional diversity seems to be also influenced by

  8. Synthetic Spider Silk Production on a Laboratory Scale

    Science.gov (United States)

    Hsia, Yang; Gnesa, Eric; Pacheco, Ryan; Kohler, Kristin; Jeffery, Felicia; Vierra, Craig

    2012-01-01

    As society progresses and resources become scarcer, it is becoming increasingly important to cultivate new technologies that engineer next generation biomaterials with high performance properties. The development of these new structural materials must be rapid, cost-efficient and involve processing methodologies and products that are environmentally friendly and sustainable. Spiders spin a multitude of different fiber types with diverse mechanical properties, offering a rich source of next generation engineering materials for biomimicry that rival the best manmade and natural materials. Since the collection of large quantities of natural spider silk is impractical, synthetic silk production has the ability to provide scientists with access to an unlimited supply of threads. Therefore, if the spinning process can be streamlined and perfected, artificial spider fibers have the potential use for a broad range of applications ranging from body armor, surgical sutures, ropes and cables, tires, strings for musical instruments, and composites for aviation and aerospace technology. In order to advance the synthetic silk production process and to yield fibers that display low variance in their material properties from spin to spin, we developed a wet-spinning protocol that integrates expression of recombinant spider silk proteins in bacteria, purification and concentration of the proteins, followed by fiber extrusion and a mechanical post-spin treatment. This is the first visual representation that reveals a step-by-step process to spin and analyze artificial silk fibers on a laboratory scale. It also provides details to minimize the introduction of variability among fibers spun from the same spinning dope. Collectively, these methods will propel the process of artificial silk production, leading to higher quality fibers that surpass natural spider silks. PMID:22847722

  9. Brown Spider (Loxosceles genus Venom Toxins: Tools for Biological Purposes

    Directory of Open Access Journals (Sweden)

    Andrea Senff-Ribeiro

    2011-03-01

    Full Text Available Venomous animals use their venoms as tools for defense or predation. These venoms are complex mixtures, mainly enriched of proteic toxins or peptides with several, and different, biological activities. In general, spider venom is rich in biologically active molecules that are useful in experimental protocols for pharmacology, biochemistry, cell biology and immunology, as well as putative tools for biotechnology and industries. Spider venoms have recently garnered much attention from several research groups worldwide. Brown spider (Loxosceles genus venom is enriched in low molecular mass proteins (5–40 kDa. Although their venom is produced in minute volumes (a few microliters, and contain only tens of micrograms of protein, the use of techniques based on molecular biology and proteomic analysis has afforded rational projects in the area and permitted the discovery and identification of a great number of novel toxins. The brown spider phospholipase-D family is undoubtedly the most investigated and characterized, although other important toxins, such as low molecular mass insecticidal peptides, metalloproteases and hyaluronidases have also been identified and featured in literature. The molecular pathways of the action of these toxins have been reported and brought new insights in the field of biotechnology. Herein, we shall see how recent reports describing discoveries in the area of brown spider venom have expanded biotechnological uses of molecules identified in these venoms, with special emphasis on the construction of a cDNA library for venom glands, transcriptome analysis, proteomic projects, recombinant expression of different proteic toxins, and finally structural descriptions based on crystallography of toxins.

  10. Post-Eocene climate change across continental Australia and the diversification of Australasian spiny trapdoor spiders (Idiopidae: Arbanitinae).

    Science.gov (United States)

    Rix, Michael G; Cooper, Steven J B; Meusemann, Karen; Klopfstein, Seraina; Harrison, Sophie E; Harvey, Mark S; Austin, Andrew D

    2017-04-01

    The formation and spread of the Australian arid zone during the Neogene was a profoundly transformative event in the biogeographic history of Australia, resulting in extinction or range contraction in lineages adapted to mesic habitats, as well as diversification and range expansion in arid-adapted taxa (most of which evolved from mesic ancestors). However, the geographic origins of the arid zone biota are still relatively poorly understood, especially among highly diverse invertebrate lineages, many of which are themselves poorly documented at the species level. Spiny trapdoor spiders (Idiopidae: Arbanitinae) are one such lineage, having mesic 'on-the-continent' Gondwanan origins, while also having experienced major arid zone radiations in select clades. In this study, we present new orthologous nuclear markers for the phylogenetic inference of mygalomorph spiders, and use them to infer the phylogeny of Australasian Idiopidae with a 12-gene parallel tagged amplicon next-generation sequencing approach. We use these data to test the mode and timing of diversification of arid-adapted idiopid lineages across mainland Australia, and employ a continent-wide sampling of the fauna's phylogenetic and geographic diversity to facilitate ancestral area inference. We further explore the evolution of phenotypic and behavioural characters associated with both arid and mesic environments, and test an 'out of south-western Australia' hypothesis for the origin of arid zone clades. Three lineages of Idiopidae are shown to have diversified in the arid zone during the Miocene, one (genus Euoplos) exclusively in Western Australia. Arid zone Blakistonia likely had their origins in South Australia, whereas in the most widespread genus Aganippe, a more complex scenario is evident, with likely range expansion from southern Western Australia to southern South Australia, from where the bulk of the arid zone fauna then originated. In Aganippe, remarkable adaptations to phragmotic burrow

  11. Research on Artificial Spider Web Model for Farmland Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2018-01-01

    Full Text Available Through systematic analysis of the structural characteristics and invulnerability of spider web, this paper explores the possibility of combining the advantages of spider web such as network robustness and invulnerability with farmland wireless sensor network. A universally applicable definition and mathematical model of artificial spider web structure are established. The comparison between artificial spider web and traditional networks is discussed in detail. The simulation result shows that the networking structure of artificial spider web is better than that of traditional networks in terms of improving the overall reliability and invulnerability of communication system. A comprehensive study on the advantage characteristics of spider web has important theoretical and practical significance for promoting the invulnerability research of farmland wireless sensor network.

  12. Loss of legs: is it or not a handicap for an orb-weaving spider?

    Science.gov (United States)

    Pasquet, Alain; Anotaux, Mylène; Leborgne, Raymond

    2011-07-01

    Leg loss is a common phenomenon in spiders, and according to the species 5% to 40% of the adults can present at least one missing leg. There is no possibility of regeneration after adult moult and the animal must manage with its missing appendages until its death. With the loss of one or more legs, female orb-weaving spiders can be penalized twice: firstly, because the legs are necessary for web construction and secondly, the legs are essential for the control of the prey after its interception by the web. During development, spiders may be also penalized because regeneration has energetic costs that take away resources for survival, growth and reproduction. All these consequences should influence negatively the development of the spider and thus its fitness. We investigated the impact of leg loss in the orb-weaving spider, Zygiella x-notata by studying its frequency in a natural population and web building and prey capture behaviours in laboratory. In field populations, 9.5% to 13%, of the adult females presented the loss of one or more legs; the majority of individuals had lost only one leg (in 48% of cases, a first one). Leg loss seems to affect all the adult spiders, as there is no difference of mass between intact spiders and those with missing leg. Data obtained with laboratory-reared spiders, showed that the loss of legs due to the moult is rare (less than 1%). Considering changes in web design, spiders with missing legs decreased their silk investment, increased the distance between spiral turns but did not change the capture surface of the web. Under our laboratory experimental conditions, spiders with one or two lost legs did not present any difference in prey capture efficiency. In laboratory conditions, spiders with lost leg(s) did not show any difference in egg sac production or in longevity (adult lifespan) compared to intact spiders.

  13. Evaluation of fixative solutions for ultrastructural analysis of brown spider Loxosceles intermedia (araneae: sicariidae) tissues

    OpenAIRE

    Costa-Ayub,C. L. S.; Faraco,C. D.; Freire,C. A.

    2006-01-01

    In view of the widely varying compositions of fixative solutions used for studying spiders, five different fixative formulas were tested for fixing male brown-spider (Loxosceles intermedia) gonad tissues. The brown spider represents a public health problem in Curitiba (Paraná State, Brazil). Morphological study of its gonads may aid in understanding the reproductive strategies of this species, and possibly in developing a reproduction control program. The fixatives tested contained glutaralde...

  14. On the predation of fly, Chrysomya rufifacies (Macquart) by a spider, Oxyopes sp. Latreille (Oxyopidae).

    Science.gov (United States)

    Heo, C C; Mohamad, A M; John, J; Baharudin, O

    2008-04-01

    During a forensic entomological study conducted in a palm oil plantation in Tg.Sepat, Selangor in September 2007, a spider (Arachnida), Oxyopes sp. (Oxyopidae) was found to predate on a calliphorid fly (Chrysomya rufifacies). The female spider laid a silk thread, or "drag line", behind it as it moved. This spider bites its prey by using a pairs of chelicerae, and injecting venom into the fly. The fly was moving its wing trying to escape, however, it succumbed to the deadly bite.

  15. Exploring of the first recorded spider (Arachenida: Aranae) species of Sheringal, Khyber Pakhtunkhwa, Pakistan

    OpenAIRE

    Farzana Perveen; Numan Khan

    2015-01-01

    The spiders (Arthropoada: Arachenida) are one of the groups of grasping animals. Their carapaces are found on the dorsal side of the cephalothorax, which is an important characteristic of spiders. The present study was conducted to explore the first recorded spider species (nti=75) of Sheringal, Dir Upper (DU), Khyber Pakhtunkhwa (KP), Dir Upper, Khyber Pakhtunkhwa, Pakistan. The 10 genera with 10 species under 7 families were recorded from June 2013-July 2014. According to length of legs, th...

  16. Exploring of the first recorded spider (Arachenida: Aranae species of Sheringal, Khyber Pakhtunkhwa, Pakistan

    Directory of Open Access Journals (Sweden)

    Farzana Perveen

    2015-09-01

    Full Text Available The spiders (Arthropoada: Arachenida are one of the groups of grasping animals. Their carapaces are found on the dorsal side of the cephalothorax, which is an important characteristic of spiders. The present study was conducted to explore the first recorded spider species (nti=75 of Sheringal, Dir Upper (DU, Khyber Pakhtunkhwa (KP, Dir Upper, Khyber Pakhtunkhwa, Pakistan. The 10 genera with 10 species under 7 families were recorded from June 2013-July 2014. According to length of legs, the largest spider was the huntsman spider, Halconia insignis Thorell having length of the first leg was 1.9±0.20, however, the same of the last leg was 1.44±0.25 (n=9. In the same contest, the smallest spider was the ground spider, Gnaphosa eucalyptus Ghafoor and Beg having length of the first leg was 0.4±0.08, while the same of the last leg was 0.4±0.08 (n=3. According to length of cephalothorax and abdomen, the largest spider was the wolf spider, Hippasa partita Takidar having length of the cephalothorax was 1.1±0.01, however, the same of the abdomen was 0.7±0.1 (n=6. In the same contest, the smallest spider was the harvestmen, Hadrobunus grandis Sundevall having length of the cephalothorax was 0.1±0.04, while the same of the abdomen was 0.3±0.04 (n=12. During present research, 10 spider species of Sheringal with different sizes were explored. The present research will be useful to educate and create awareness about spiders in the people of Sheringal.

  17. Case report: compartment syndrome after a suspected black widow spider bite.

    Science.gov (United States)

    Cohen, Jennifer; Bush, Sean

    2005-04-01

    Widow spider envenomations generally produce systemic neurologic syndromes without significant local injury. We report a patient who sustained a black widow spider bite to the left forearm and presented to the emergency department with rhabdomyolysis and compartment syndrome. We documented a decrease in symptoms and compartment pressure after administration of antivenom. No surgical intervention was performed. We believe this report to be the first documenting compartment syndrome associated with black widow spider bite.

  18. Diet-dependent fecundity of the spiders Atypena formosana and Pardosa pseudoannulata, predators in irrigated rice

    DEFF Research Database (Denmark)

    Sigsgaard, Lene; Toft, Søren; Villareal, Sylvia

    2001-01-01

    of Collembola and D. melanogaster had the highest quality for both spiders, the BPH-GLH-Collembola and the full mixed diets were intermediate in quality, the quality of the BPH diet was intermediate to low and quality of the GLH and BPH-GLH diets was low. There need not be a contradiction between low dietary...... value of hoppers and successful natural biological control provided that the nutritional needs of the spiders are met by sufficient alternative prey. The hopper-spider relationship is comparable to that of aphids and spiders in temperate cereals, suggesting that low dietary quality of Homopterans...

  19. Methods of assembling and disassembling spider and burnable poison rod structures for nuclear reactors

    International Nuclear Information System (INIS)

    Edwards, G.T.; Schluderberg, D.C.

    1981-01-01

    A technique is provided for engaging and disengaging burnable poison rods from a spider in a nuclear reactor fuel assembly. A cap on the end of each of the burnable poison rods is provided with a shank or stem that is received in a respective bore formed in the spider. A frangible flange secures the shank and rod to the spider. Pressing the shank in the direction of the bore axis by means, e.g., of a plate ruptures the frangible flange to release the rod from the spider. (author)

  20. Functional Group of Spiders in Cultivated Landscape Dominated by Paddy Fields in West Java, Indonesia

    Directory of Open Access Journals (Sweden)

    I WAYAN SUANA

    2009-03-01

    Full Text Available Distribution of spiders in all colonized environments is limited by biotic and abiotic factors requiring adaptations with respect to, for example microhabitat choice and hunting behavior. These two factors were frequently used to group spiders into functional groups. In this study our objectives were to (i group of genera of spiders into functional group based on their microhabitat specificity, hunting behavior, and daily activity; and (ii compare the number and composition of functional group of spider at each habitat type and period of paddy growth. The study was conducted at a landscape dominated by paddy fields in Cianjur Watershed for a period of 9 months. Four different habitat types (paddy, vegetable, non-crop, and mixed garden, were sampled using five trapping techniques (pitfall traps, farmcop suction, sweep netting, yellow-pan traps, and sticky traps. The Unweighted Pair-Group Average and the Euclidean Distances were used to generate dendrogram of functional group of spider. We found 14 functional groups of spider at genus level. The number of functional group of spider at four habitat types was differing, but the composition was similar, because all habitats were closed to each other. Habitat structure diversity and disturbance level influenced the number of functional group of spider. Different architecture of vegetation and availability of differ prey during paddy growth, causing the composition of functional group of spider in each period of paddy growth was changed, although its number was unchanged.

  1. Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution.

    Science.gov (United States)

    Clarke, Thomas H; Garb, Jessica E; Hayashi, Cheryl Y; Arensburger, Peter; Ayoub, Nadia A

    2015-06-08

    The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  2. Spiders do not evoke greater early posterior negativity in the event-related potential as snakes.

    Science.gov (United States)

    He, Hongshen; Kubo, Kenta; Kawai, Nobuyuki

    2014-09-10

    It has been long believed that both snakes and spiders are archetypal fear stimuli for humans. Furthermore, snakes have been assumed as stronger threat cues for nonhuman primates. However, it is still unclear whether spiders hold a special status in human perception. The current study explored to what extent spider pictures draw early visual attention [as assessed with early posterior negativity (EPN)] when compared with insects similar to spiders. To measure the EPN, participants watched a random rapid serial presentation of pictures, which consisted of two conditions: spider condition (spider, wasp, bumblebee, beetle) and snake condition (snake, bird). EPN amplitudes revealed no significant difference between spider, wasp, bumblebee, and beetle pictures, whereas EPN amplitudes were significantly larger for snake pictures relative to bird pictures. In addition, EPN amplitudes were significantly larger for snake pictures relative to spider pictures. These results suggest that the early visual attentional capture of animate objects is stronger for snakes, whereas spiders do not appear to hold special early attentional value.

  3. Australian uranium today

    International Nuclear Information System (INIS)

    Fisk, B.

    1978-01-01

    The subject is covered in sections, entitled: Australia's resources; Northern Territory uranium in perspective; the government's decision [on August 25, 1977, that there should be further development of uranium under strictly controlled conditions]; Government legislation; outlook [for the Australian uranium mining industry]. (U.K.)

  4. Across the Indian Ocean: A remarkable example of trans-oceanic dispersal in an austral mygalomorph spider.

    Directory of Open Access Journals (Sweden)

    Sophie E Harrison

    Full Text Available The Migidae are a family of austral trapdoor spiders known to show a highly restricted and disjunct distribution pattern. Here, we aim to investigate the phylogeny and historical biogeography of the group, which was previously thought to be vicariant in origin, and examine the biogeographic origins of the genus Moggridgea using a dated multi-gene phylogeny. Moggridgea specimens were sampled from southern Australia and Africa, and Bertmainus was sampled from Western Australia. Sanger sequencing methods were used to generate a robust six marker molecular dataset consisting of the nuclear genes 18S rRNA, 28S rRNA, ITS rRNA, XPNPEP3 and H3 and the mitochondrial gene COI. Bayesian and Maximum Likelihood methods were used to analyse the dataset, and the key dispersal nodes were dated using BEAST. Based on our data, we demonstrate that Moggridgea rainbowi from Kangaroo Island, Australia is a valid member of the otherwise African genus Moggridgea. Molecular clock dating analyses show that the inter-specific divergence of M. rainbowi from African congeners is between 2.27-16.02 million years ago (Mya. This divergence date significantly post-dates the separation of Africa from Gondwana (95 Mya and therefore does not support a vicariant origin for Australian Moggridgea. It also pre-dates human colonisation of Kangaroo Island, a result which is further supported by the intra-specific divergence date of 1.10-6.39 Mya between separate populations on Kangaroo Island. These analyses provide strong support for the hypothesis that Moggridgea colonised Australia via long-distance trans-Indian Ocean dispersal, representing the first such documented case in a mygalomorph spider.

  5. A Spider That Lays Its Eggs in Rows

    Directory of Open Access Journals (Sweden)

    Robert L. Edwards

    2000-01-01

    Full Text Available The small (2.5-3.0 mm, colorful metine spider, Homalometa nigritarsis Simon 1897, Family Tetragnathidae, has previously been reported from northern Mexico, Panama and the southern islands of the Lesser Antilles (Levi 1986. In the rain forest of northeastern Puerto Rico it is most frequently found with webbing on the larger outer concave surfaces of pendulous leaves. H. nigritarsis typically makes a circular, relatively flat retreat within which the female deposits two parallel rows of naked eggs. The rows are produced at intervals; as one row hatches another replaces it shortly thereafter. Evidence of up to four generations of rows has been observed. Above the retreat, and closely aligned with it, the spider builds a nearly invisible, delicate orb web, typically from edge to edge of the leaf (Fig. 1a and b. While retaining the traditional orb-web, H. nigritarsis has adopted a unique habitat and set of life history features.

  6. Lethal intragroup aggression by adult male spider monkeys (Ateles geoffroyi).

    Science.gov (United States)

    Campbell, Christina J

    2006-12-01

    I report three cases of coalitionary aggression by adult male black-handed spider monkeys (Ateles geoffroyi) against subadult males within their community on Barro Colorado Island (BCI), Panama. Two of these cases were followed by the disappearance and presumed death of the victim. Similar behavior was recently reported by Valero et al. [in press], who suggested that this behavior may be the result of intense male reproductive competition. Like the single instance they reported, the cases I report all occurred when the operational sex ratio was approximately 1:1, which suggests that intense competition among males for access to reproductively viable females may be a contributing factor. Additionally the very low density of spider monkeys on BCI may play a significant role in the occurrence of this lethal aggression. Large numbers of adult males are not necessary to protect a territorial boundary against neighboring groups, and additional males may act merely as mating competition. (c) 2006 Wiley-Liss, Inc.

  7.  “Spiders and Webs in American Literature”

    Directory of Open Access Journals (Sweden)

    Vincent Dussol

    2012-05-01

    Full Text Available From Jonathan Edwards to Jorie Graham, spiders are strikingly present in American literature. The purpose of this article is first to show how that theme may have become something of a national tradition as very different writers, all of them careful observers of aranae, answered one another through the years. It is very likely that the attention paid to spiders by American authors was increased by those Native American myths in which spiders are a central figure. More than occasionally, on the female side of the American counter-culture, especially among its feminist and lesbian exponents, simple activists and creative writers have harnessed the symbolic power invested in the spider by Native Americans.There may be deeper reasons accounting for American authors’ fascination with spiders. The country’s phobia of disunion is one; a nation of settlers’ acute consciousness of the precariousness of its occupation of the territory is another. In demonstrating outstanding skills for adjustment to unknown places, spiders epitomize a form of identity permanence. The predominantly positive character of spider symbols in American literature will occasionally be inverted. Following the national logic of checks and balances, any web covering the whole of the United States will tend to come under suspicion.This study ends with an inventory of cultural productions linked with spiders and webs and whose Americanness is yet to be clearly determined.De Jonathan Edwards à Jorie Graham, l’araignée apparaît dans un nombre frappant de textes littéraires américains. On a d’abord voulu tenter de montrer comment a pu se construire cette tradition thématique et faire la preuve que différents écrivains, réunis par un souci de l’observation, se sont répondus à travers elle. L’attention prêtée à l’araignée s’est certainement trouvée renforcée par les récits mythologiques des peuples premiers américains qui font de l’araignée une

  8. Comparing the rheology of native spider and silkworm spinning dope

    Science.gov (United States)

    Holland, C.; Terry, A. E.; Porter, D.; Vollrath, F.

    2006-11-01

    Silk production has evolved to be energetically efficient and functionally optimized, yielding a material that can outperform most industrial fibres, particularly in toughness. Spider silk has hitherto defied all attempts at reproduction, despite advances in our understanding of the molecular mechanisms behind its superb mechanical properties. Spun fibres, natural and man-made, rely on the extrusion process to facilitate molecular orientation and bonding. Hence a full understanding of the flow characteristics of native spinning feedstock (dope) will be essential to translate natural spinning to artificial silk production. Here we show remarkable similarity between the rheologies for native spider-dragline and silkworm-cocoon silk, despite their independent evolution and substantial differences in protein structure. Surprisingly, both dopes behave like typical polymer melts. This observation opens the door to using polymer theory to clarify our general understanding of natural silks, despite the many specializations found in different animal species.

  9. Optics of the ultraviolet reflecting scales of a jumping spider

    Science.gov (United States)

    Land, Michael F; Horwood, Julia; Lim, Matthew L.M; Li, Daiqin

    2007-01-01

    The jumping spider Cosmophasis umbratica from Singapore is strongly sexually dimorphic. The males, but not the females, reflect ultraviolet as well as green–orange light. The scales responsible for this are composed of a chitin–air–chitin sandwich in which the chitin layers are three-quarters of a wavelength thick and the air gap a quarter wavelength (where λ=600 nm, the peak wavelength of the principal reflection maximum). It is shown that this configuration produces a second reflectance peak at approximately 385 nm, accounting for the observed reflection in the ultraviolet. Other scales have a similar thickness of chitin but lack the air gap and thus produce a dull purple reflection. This novel mechanism provides the spiders with two colour signals, both of which are important in mating displays. PMID:17456453

  10. Battre sa (super) coulpe : Spider-Man (1962)

    OpenAIRE

    Tomasovic, Dick

    2016-01-01

    L’édification est l'une des grandes fonctions traditionnelles de la littérature de jeunesse. Spider-Man, héros populaire s'il en est, s'est révélé bien sûr l'ambassadeur de nombreuses valeurs sociétales américaines (le do it yourself, l'esprit d'entreprise et d'indépendance, la tolérance, la fidélité , la célébration du système éducationnel, la transmission et la solidarité intergénérationnelle, le sens des responsabilités, évidemment, etc.). Spider-Man se bat moins qu'il ne se débat. Il est ...

  11. Black widow spider envenomation, a rare cause of Horner's syndrome.

    Science.gov (United States)

    Strowd, Roy E; Scott, Blake; Walker, Francis O

    2012-06-01

    Horner's syndrome involves a triad of eyelid ptosis, miosis, and facial anhidrosis that results from disruption of the oculosympathetic pathway. Acquired Horner's syndrome is associated with a variety of medical conditions including Pancoast tumor and carotid dissection. We report the unique case of a 47-year-old man presenting with Horner's syndrome 4 weeks after black widow spider envenomation. Workup did not reveal any alternative explanatory etiology. We hypothesize that late sequelae of black widow spider envenomation secondary to autonomic nerve injury or retrograde axonal transport after mechanical inoculation may have led to an acquired defect in the oculosympathetic pathway resulting in a Horner's syndrome. This case introduces a rare cause of Horner's syndrome and highlights the importance of environmental exposures in the evaluation of these patients. Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  12. Gravity Reception and Cardiac Function in the Spider

    Science.gov (United States)

    Finck, A.

    1985-01-01

    The following features of the arachnid gravity system were studied. (1) the absolute threshold to hyper-gz is quite low indicating fine proprioreceptive properties of the lyriform organ, the Gz/vibration detector; (2) the neurogenic heart of the spider is a good dependent variable for assessing its behavior to Gz and other stimuli which produce mechanical effects on the exoskeleton; (3) Not only is the cardiac response useful but it is now understood to be an integral part of the system which compensates for the consequences of gravity in the spider (an hydraulic leg extension); and (4) a theoretical model was proposed in which a mechanical amplifier, the leg lever, converts a weak force (at the tarsus) to a strong force (at the patella), capable of compressing the exoskeleton and consequently the lyriform receptor.

  13. Structure to function: Spider silk and human collagen

    Science.gov (United States)

    Rabotyagova, Olena S.

    Nature has the ability to assemble a variety of simple molecules into complex functional structures with diverse properties. Collagens, silks and muscles fibers are some examples of fibrous proteins with self-assembling properties. One of the great challenges facing Science is to mimic these designs in Nature to find a way to construct molecules that are capable of organizing into functional supra-structures by self-assembly. In order to do so, a construction kit consisting of molecular building blocks along with a complete understanding on how to form functional materials is required. In this current research, the focus is on spider silk and collagen as fibrous protein-based biopolymers that can shed light on how to generate nanostructures through the complex process of self-assembly. Spider silk in fiber form offers a unique combination of high elasticity, toughness, and mechanical strength, along with biological compatibility and biodegrability. Spider silk is an example of a natural block copolymer, in which hydrophobic and hydrophilic blocks are linked together generating polymers that organize into functional materials with extraordinary properties. Since silks resemble synthetic block copolymer systems, we adopted the principles of block copolymer design from the synthetic polymer literature to build block copolymers based on spider silk sequences. Moreover, we consider spider silk to be an important model with which to study the relationships between structure and properties in our system. Thus, the first part of this work was dedicated to a novel family of spider silk block copolymers, where we generated a new family of functional spider silk-like block copolymers through recombinant DNA technology. To provide fundamental insight into relationships between peptide primary sequence, block composition, and block length and observed morphological and structural features, we used these bioengineered spider silk block copolymers to study secondary structure

  14. Black widow spider (Latrodectus mactans) envenomation in a term pregnancy.

    Science.gov (United States)

    Sherman; Groll; Gonzalez; Aerts

    2000-07-01

    Description of a black widow spider (Latrodectus mactans) envenomation in a term pregnancy.Case report conducted at an Air Force tertiary care hospital of a 27-year-old primigravida at 38 1/7 weeks pregnancy.Latrodectus mactans antivenin can be given to treat symptoms of black widow envenomation.Black widow envenomations can cause symptoms associated with acute intra-abdominal processes. In pregnancy, envenomations can result in symptoms and signs similar to those seen in preeclampsia (abdominal pain, headache, hypertension, and proteinuria). Latrodectism should be considered in patients complaining of these symptoms in association with a spider bite. If latrodectism is considered to be the underlying origin for these symptoms, appropriate treatment should be administered. In cases of pregnancy, treatment should include L. mactans antivenin if believed to be clinically indicated. There is no current evidence that this antivenin is contraindicated in pregnancy. (Curr Surg 57:346-348)

  15. Environmental Engineering Approaches toward Sustainable Management of Spider Mites.

    Science.gov (United States)

    Suzuki, Takeshi

    2012-10-26

    Integrated pest management (IPM), which combines physical, biological, and chemical control measures to complementary effect, is one of the most important approaches to environmentally friendly sustainable agriculture. To expand IPM, we need to develop new pest control measures, reinforce existing measures, and investigate interactions between measures. Continued progress in the development of environmental control technologies and consequent price drops have facilitated their integration into plant production and pest control. Here I describe environmental control technologies for the IPM of spider mites through: (1) the disturbance of photoperiod-dependent diapause by artificial light, which may lead to death in seasonal environments; (2) the use of ultraviolet radiation to kill or repel mites; and (3) the use of water vapor control for the long-term cold storage of commercially available natural enemies. Such environmental control technologies have great potential for the efficient control of spider mites through direct physical effects and indirect effects via natural enemies.

  16. A troglomorphic spider from Java (Araneae, Ctenidae, Amauropelma)

    Science.gov (United States)

    Miller, Jeremy; Rahmadi, Cahyo

    2012-01-01

    Abstract A new troglomorphic spider from caves in Central Java, Indonesia, is described and placed in the ctenid genus Amauropelma Raven, Stumkat & Gray, until now containing only species from Queensland, Australia. Only juveniles and mature females of the new species are known. We give our reasons for placing the new species in Amauropelma, discuss conflicting characters, and make predictions about the morphology of the as yet undiscovered male that will test our taxonomic hypothesis. The description includes DNA barcode sequence data. PMID:22303127

  17. Traditions in Spider Monkeys Are Biased towards the Social Domain

    OpenAIRE

    Santorelli, Claire J.; Schaffner, Colleen M.; Campbell, Christina J.; Notman, Hugh; Pavelka, Mary S.; Weghorst, Jennifer A.; Aureli, Filippo

    2011-01-01

    Cross-site comparison studies of behavioral variation can provide evidence for traditions in wild species once ecological and genetic factors are excluded as causes for cross-site differences. These studies ensure behavior variants are considered within the context of a species' ecology and evolutionary adaptations. We examined wide-scale geographic variation in the behavior of spider monkeys (Ateles geoffroyi) across five long-term field sites in Central America using a well established ethn...

  18. Innate pattern recognition and categorization in a jumping spider.

    Directory of Open Access Journals (Sweden)

    Yinnon Dolev

    Full Text Available The East African jumping spider Evarcha culicivora feeds indirectly on vertebrate blood by preferentially preying upon blood-fed Anopheles mosquitoes, the vectors of human malaria1, using the distinct resting posture and engorged abdomen characteristic of these specific prey as key elements for their recognition. To understand perceptual categorization of objects by these spiders, we investigated their predatory behavior toward different digital stimuli--abstract 'stick figure' representations of Anopheles constructed solely by known key identification elements, disarranged versions of these, as well as non-prey items and detailed images of alternative prey. We hypothesized that the abstract images representing Anopheles would be perceived as potential prey, and would be preferred to those of non-preferred prey. Spiders perceived the abstract stick figures of Anopheles specifically as their preferred prey, attacking them significantly more often than non-preferred prey, even when the comprising elements of the Anopheles stick figures were disarranged and disconnected from each other. However, if the relative angles between the elements of the disconnected stick figures of Anopheles were altered, the otherwise identical set of elements was no longer perceived as prey. These data show that E. culicivora is capable of making discriminations based on abstract concepts, such as the hypothetical angle formed by discontinuous elements. It is this inter-element angle rather than resting posture that is important for correct identification of Anopheles. Our results provide a glimpse of the underlying processes of object recognition in animals with minute brains, and suggest that these spiders use a local processing approach for object recognition, rather than a holistic or global approach. This study provides an excellent basis for a comparative analysis on feature extraction and detection by animals as diverse as bees and mammals.

  19. Spiders in mountain habitats of the Giant Mountains

    Czech Academy of Sciences Publication Activity Database

    Růžička, Vlastimil; Vaněk, J.; Šmilauer, P.

    2012-01-01

    Roč. 43, č. 4 (2012), s. 341-347 ISSN 1067-4136 Institutional research plan: CEZ:AV0Z50070508 Keywords : Giant Mountains (Krkonoše, Karkonosze) * spider s * anemo-orographic systems Subject RIV: EH - Ecology , Behaviour Impact factor: 0.236, year: 2012 http://www.springerlink.com/content/0k5g721q1155r146/fulltext.pdf

  20. Colonization of subterranean habitats by spiders in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Růžička, Vlastimil; Šmilauer, P.; Mlejnek, R.

    2013-01-01

    Roč. 42, č. 2 (2013), s. 133-140 ISSN 0392-6672 Grant - others:GA JU(CZ) GAJU 04-142/2010/P Institutional support: RVO:60077344 Keywords : superficial and deep subterranean habitats * caves * spider s Subject RIV: EH - Ecology , Behaviour Impact factor: 1.275, year: 2013 http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=1288&context=ijs

  1. Early environmental conditions shape personality types in a jumping spider

    Directory of Open Access Journals (Sweden)

    Jannis eLiedtke

    2015-12-01

    Full Text Available Individuals of many species across the animal kingdom are found to be less plastic than expected, even in behavioral traits. The existence of consistent behavioral differences between individuals, termed personality differences, is puzzling, since plastic behavior is considered ideal to enable animals to adaptively respond to changes in environmental conditions. In order to elucidate which mechanisms are important for the evolution of personality differences, it is crucial to understand which aspects of the environment are important for the development of personality differences. Here, we tested whether physical or social aspects of the environment during development influence individual differentiation (mean level of behavior using the jumping spider Marpissa muscosa. Furthermore, we assessed whether those behaviors were repeatable, i.e. whether personalities existed. We applied a split-brood design and raised spider siblings in three different environments: a deprived environment with no enrichment, a socially and a physically enriched environment. We focused on exploratory behavior and repeatedly assessed individual behavior in a novel environment and a novel object test. Results show that the environment during development influenced spiders’ exploratory tendencies: spiders raised in enriched environments tended to be more exploratory. Most investigated behaviors were repeatable (i.e. personalities existed across all individuals tested, whereas only few behaviors were also repeatable across individuals that had experienced the same environmental condition. Taken together, our results indicate that external stimuli can influence the development of one aspect of personality, the inter-individual variation (mean level of behavior, in a jumping spider. We also found family by environment interactions on behavioral traits potentially suggesting genetic variation in developmental plasticity.

  2. Damage, Self-Healing, and Hysteresis in Spider Silks

    OpenAIRE

    De Tommasi, D.; Puglisi, G.; Saccomandi, G.

    2010-01-01

    In this article, we propose a microstructure-based continuum model to describe the material behavior of spider silks. We suppose that the material is composed of a soft fraction with entropic elasticity and a hard, damageable fraction. The hard fraction models the presence of stiffer, crystal-rich, oriented regions and accounts for the effect of softening induced by the breaking of hydrogen bonds. To describe the observed presence of crystals with different size, composition, and orientation,...

  3. A Parasitoid Wasp Induces Overwintering Behaviour in Its Spider Host

    OpenAIRE

    Korenko, Stanislav; Pekár, Stano

    2011-01-01

    Parasites and parasitoids control behaviors of their hosts. However, the origin of the behavior evoked by the parasitic organism has been rarely identified. It is also not known whether the manipulation is universal or host-specific. Polysphinctine wasps, koinobiont ectoparasitoids of several spider species that manipulate host web-spinning activity for their own protection during pupation, provide an ideal system to reveal the origin of the evoked behavior. Larva of Zatypota percontatoria pe...

  4. [Neurotoxic manifestations of black widow spider envenomation in paediatric patients].

    Science.gov (United States)

    Sotelo-Cruz, N; Gómez-Rivera, N

    2016-05-01

    Envenomation by black widow spiders manifests clinically with signs of neurotoxicity in paediatric patients. Identify typical neurological signs and symptoms in paediatric patients of different ages, and describe treatment and outcomes in a paediatric hospital in northwest Mexico. We reviewed 70 clinical records of patients hospitalised due to black widow spider bite between 1978 and 2014. We divided the total into 2 groups: Group 1, infants and preschool children; and Group 2, school-age children and adolescents. The demographic variables were age, sex, birthplace, place where envenomation occurred, body part(s) affected, degree of envenomation according to signs and symptoms, treatment, clinical outcome, and statistical differences. Boys accounted for 61.4% of all cases, and infants younger than one year old made up 14.2%. Most patients (70%) were bitten by the spider at home; the anatomical areas most frequently affected were the legs, neck, thorax, and abdomen. The neurological signs and symptoms displayed by Group 1 were irritability, constant crying, sialorrhoea, nausea, tachycardia, arrhythmias, fatigue when walking, agitation, muscle spasms paraesthesia, tetany, seizures, and nystagmus. Signs in Group 2 included localized pain, headache, sialorrhoea, paraesthesia, profuse sweating, anxiety, muscle weakness, muscle spasms, and fine tremor. The predominant autonomic sign in Group 1 was sialorrhoea (P<.0001) and in Group 2, paraesthesia (P<.0001). Patients who received Fab antivenom treatment displayed better outcomes and shorter hospital stays than those who did not. No deaths were reported. The neurological signs and symptoms caused by black widow spider bite are predominantly autonomic, and identifying them permits early diagnosis and more effective treatment. Copyright © 2015 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Visual Discrimination Learning in the Jumping Spider Phidippus regius

    OpenAIRE

    Massimo De Agrò; Lucia Regolin; Enzo Moretto

    2017-01-01

    Over the past decade, research in comparative psychology has increasingly focused on non-vertebrate models of cognition. Jumping spiders provide excellent models for the study of visually mediated behaviors, such as associative learning or the navigation of complex environments. Here, we tested visual and memory abilities of Phidippus regius to discriminate between artificial geometrical stimuli and to generalize the learned discrimination to illusory stimuli, using the amodal completion mech...

  6. Evidence for antimicrobial activity associated with common house spider silk

    Directory of Open Access Journals (Sweden)

    Wright Simon

    2012-06-01

    Full Text Available Abstract Background Spider silk is one of the most versatile materials in nature with great strength and flexibility. Native and synthetically produced silk has been used in a wide range of applications including the construction of artificial tendons and as substrates for human cell growth. In the literature there are anecdotal reports that suggest that native spider silk may also have antimicrobial properties. Findings In this study we compared the growth of a Gram positive and a Gram negative bacterium in the presence and absence of silk produced by the common house spider Tegenaria domestica. We demonstrate that native web silk of Tegenaria domestica can inhibit the growth of the Gram positive bacterium, Bacillus subtilis. No significant inhibition of growth was detected against the Gram negative bacterium, Escherichia coli. The antimicrobial effect against B. subtilis appears to be short lived thus the active agent potentially acts in a bacteriostatic rather than bactericidal manner. Treatment of the silk with Proteinase K appears to reduce the ability to inhibit bacterial growth. This is consistent with the active agent including a protein element that is denatured or cleaved by treatment. Tegenaria silk does not appear to inhibit the growth of mammalian cells in vitro thus there is the potential for therapeutic applications.

  7. Artificial insemination in black-handed spider monkey (Ateles geoffroyi).

    Science.gov (United States)

    Hernández-López, L; Cerda-Molina, A L; Páez-Ponce, D L; Rojas-Maya, S; Mondragón-Ceballos, R

    2007-01-15

    Artificial insemination (AI) was performed in spider monkeys; these primates are vulnerable to extinction and usually do not reproduce spontaneously in captivity. Uterine cycles were followed by daily assessment of vaginal cytology, and corroborated a posteriori by concentrations of 17-beta estradiol and progesterone, measured by radioimmunoassay (RIA), in fecal samples collected once daily. Five females between 13 to 27 years old were inseminated intravaginally (with fresh semen) twice each during the periovulatory phase (Days 9-12 of the menstrual cycle; Day 0, first day of menstrual bleeding), from September to the first 3 weeks of November (most fertile months). Transcervical AI was not useful in this primate because the liquid portion of the semen completely solidified instead of liquefying as in other primates. Pregnancies were apparently achieved in 5 of 14 attempts. One female became pregnant after the first round of inseminations, delivered a healthy infant, was inseminated and got pregnant again (subsequently aborted). One female aborted, apparently due to an intramural uterine leiomyoma. Another two females stopped menstruating for a few months, then restarted menstruating (these females may have been pregnant and aborted). In conclusion, in spider monkeys: (1) captivity-induced stress did not inhibit reproduction; (2) fecal steroid hormones were useful to assess cyclicity; (3) the semen coagulum, which apparently is a tightly packed and large reservoir of spermatozoa, must not be discarded but used in AI; (4) old female spider monkeys did not have cessation of reproductive function.

  8. Epigeic spiders of the pastures of northern Wielkopolska

    Directory of Open Access Journals (Sweden)

    Woźny, Marek

    2000-10-01

    Full Text Available The fauna of epigeic spiders (Araneae occurring on three different types of pastures in northern Wielkopolska was analysed. Studies were conducted from May 1992 to October 1993. The 18,995 specimens collected were classified as belonging to 137 species and 17 families. The family Linyphiidae proved the richest in species while Lycosidae was the most abundantly in terms of number of specimens. Zoocenological analysis of spider communities showed their differentiation testifying to differences in the sites studied. The dominants were: 1 Osowo Stare (Site 1: Pardosa palustris, 2 Sycyn Dolny (Site 2: Xerolycosa miniata, P. palustris, Xysticus kochi, 3 Braczewo (Site 3: Erigone dentipalpis, P. palustris. Seasonal changes of dominance of the species at each site were established. A comparison of changes of the species’ dominances in the years 1992 and 1993 disclosed similar values of the individual dominance coefficient at the sites in Osowo Stare and Braczewo. This result indicates the occurrence of the process of stabilization of these biocenoses and a tendency to equilibrium in the environment. The least stable proved to be the site at Sycyn Dolny. Analysis of the seasonal dynamics of epigeic spider communities was also made by determining the mean number of species at each site in the two years of study. The highest number of species was noted in spring. It is interesting to note the appearance of species which are rare or very rare in Poland such as: Lepthyphantes insignis, Ostearius melanopygius, Enoplognatha mordax and Enoplognatha oelandica.

  9. Seasonal variation of ground spiders in a Brazilian Savanna

    Directory of Open Access Journals (Sweden)

    Marina Farcic Mineo

    2010-06-01

    Full Text Available The Brazilian Savanna Ecoregion (Cerrado is one of the richest biomes in the world, with a characteristic highly seasonal climate a dry season between May and September and a rainy season from October through April. Ground-dwelling spiders from three Cerrado phytophysiognomies, "campo cerrado", "cerrado" and "cerrad��o", were sampled using pitfall traps during two years, totaling 111 species and 3,529 individuals. The abundance of individuals and species richness was higher during the wet season. Fifty-eight species were captured exclusively during that period, whereas only nineteen were restricted to the dry season. Only two species were found in all samples. The number of juveniles was higher than the number of adults in all phytophysiognomies and in all species during both seasons. The highest abundance was registered in October and the lowest in April. Overall sex ratio was male-biased in all vegetation types sampled. Distinct climate variables affected the abundance of spiders depending on sex, age and vegetal physiognomy where they were sampled. This study involved the longest sampling of spider abundance and diversity on the ground of a Brazilian Savanna.

  10. A New Limit on CMB Circular Polarization from SPIDER

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, A. J.; Eriksen, H. K.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, A. E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, L.; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, B.; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, T. M.; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; List, J. F. Van Der; Weber, A. C.; Wehus, I. K.; Wiebe, D. V.; Young, E. Y.

    2017-08-01

    We present a new upper limit on CMB circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for $B$-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the non-zero circular-to-linear polarization coupling of the HWP polarization modulators, data from SPIDER's 2015 Antarctic flight provides a constraint on Stokes $V$ at 95 and 150 GHz from $33<\\ell<307$. No other limits exist over this full range of angular scales, and SPIDER improves upon the previous limit by several orders of magnitude, providing 95% C.L. constraints on $\\ell (\\ell+1)C_{\\ell}^{VV}/(2\\pi)$ ranging from 141 $\\mu K ^2$ to 203 $\\mu K ^2$ at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain stronger constraints on circular polarization.

  11. Optimal foraging, not biogenetic law, predicts spider orb web allometry.

    Science.gov (United States)

    Gregorič, Matjaž; Kiesbüy, Heine C; Lebrón, Shakira G Quiñones; Rozman, Alenka; Agnarsson, Ingi; Kuntner, Matjaž

    2013-03-01

    The biogenetic law posits that the ontogeny of an organism recapitulates the pattern of evolutionary changes. Morphological evidence has offered some support for, but also considerable evidence against, the hypothesis. However, biogenetic law in behavior remains underexplored. As physical manifestation of behavior, spider webs offer an interesting model for the study of ontogenetic behavioral changes. In orb-weaving spiders, web symmetry often gets distorted through ontogeny, and these changes have been interpreted to reflect the biogenetic law. Here, we test the biogenetic law hypothesis against the alternative, the optimal foraging hypothesis, by studying the allometry in Leucauge venusta orb webs. These webs range in inclination from vertical through tilted to horizontal; biogenetic law predicts that allometry relates to ontogenetic stage, whereas optimal foraging predicts that allometry relates to gravity. Specifically, pronounced asymmetry should only be seen in vertical webs under optimal foraging theory. We show that, through ontogeny, vertical webs in L. venusta become more asymmetrical in contrast to tilted and horizontal webs. Biogenetic law thus cannot explain L. venusta web allometry, but our results instead support optimization of foraging area in response to spider size.

  12. Differential predictive power of self report and implicit measures on behavioural and physiological fear responses to spiders

    NARCIS (Netherlands)

    van Bockstaele, B.; Verschuere, B.; Koster, E.H.W.; Tibboel, H.; de Houwer, J.; Crombez, G.

    2011-01-01

    In this study, we investigated to what extent indirect measures predict behavioural and physiological fear responses towards spiders. Implicit attitudes towards spiders were assessed using an implicit association test and attentional bias towards spiders was assessed using a dot probe task and a

  13. Spider-mediated flux of PCBs from contaminated sediments to terrestrial ecosystems and potential risks to arachnivorous birds

    Science.gov (United States)

    Walters, D.M.; Mills, M.A.; Fritz, K.M.; Raikow, D.F.

    2010-01-01

    We investigated aquatic insect utilization and PCB exposure in riparian spiders at the Lake Hartwell Superfund site (Clemson, SC). We sampled sediments, adult chironomids, terrestrial insects, riparian spiders (Tetragnathidae, Araneidae, and Mecynogea lemniscata), and upland spiders (Araneidae) along a sediment contamination gradient. Stable isotopes (?13C, ? 15N) indicated that riparian spiders primarily consumed aquatic insects whereas upland spiders consumed terrestrial insects. PCBs in chironomids (mean 1240 ng/g among sites) were 2 orders of magnitude higher than terrestrial insects (15.2 ng/g), similar to differences between riparian (820?2012 ng/g) and upland spiders (30 ng/g). Riparian spider PCBs were positively correlated with sediment concentrations for all taxa (r2 = 0.44?0.87). We calculated spider-based wildlife values (WVs, the minimum spider PCB concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Spider concentrations exceeded WVs for most birds at heavily contaminated sites and were ?14-fold higher for the most sensitive species (chickadee nestlings, Poecile spp.). Spiders are abundant and ubiquitous in riparian habitats, where they depend on aquatic insect prey. These traits, along with the high degree of spatial correlation between spider and sediment concentrations we observed, suggest that they are model indicator species for monitoring contaminated sediment sites and assessing risks associated with contaminant flux into terrestrial ecosystems. ?? This article not subject to U.S. Copyright. Published 2009 by the American Chemical Society.

  14. An insect-feeding guild of carnivorous plants and spiders: does optimal foraging lead to competition or facilitation?

    Science.gov (United States)

    Crowley, Philip H; Hopper, Kevin R; Krupa, James J

    2013-12-01

    Carnivorous plants and spiders, along with their prey, are main players in an insect-feeding guild found on acidic, poorly drained soils in disturbed habitat. Darwin's notion that these plants must actively attract the insects they capture raises the possibility that spiders could benefit from proximity to prey hotspots created by the plants. Alternatively, carnivorous plants and spiders may deplete prey locally or (through insect redistribution) more widely, reducing each other's gain rates from predation. Here, we formulate and analyze a model of this guild, parameterized for carnivorous sundews and lycosid spiders, under assumptions of random movement by insects and optimal foraging by predators. Optimal foraging here involves gain maximization via trap investment (optimal web sizes and sundew trichome densities) and an ideal free distribution of spiders between areas with and without sundews. We find no facilitation: spiders and sundews engage in intense exploitation competition. Insect attraction by plants modestly increases sundew gain rates but slightly decreases spider gain rates. In the absence of population size structure, optimal spider redistribution between areas with and without sundews yields web sizes that are identical for all spiders, regardless of proximity to sundews. Web-building spiders have higher gain rates than wandering spiders in this system at high insect densities, but wandering spiders have the advantage at low insect densities. Results are complex, indicating that predictions to be tested empirically must be based on careful quantitative assessment.

  15. Untangling spider silk evolution with spidroin terminal domains

    Directory of Open Access Journals (Sweden)

    Garb Jessica E

    2010-08-01

    Full Text Available Abstract Background Spidroins are a unique family of large, structural proteins that make up the bulk of spider silk fibers. Due to the highly variable nature of their repetitive sequences, spidroin evolutionary relationships have principally been determined from their non-repetitive carboxy (C-terminal domains, though they offer limited character data. The few known spidroin amino (N-terminal domains have been difficult to obtain, but potentially contain critical phylogenetic information for reconstructing the diversification of spider silks. Here we used silk gland expression data (ESTs from highly divergent species to evaluate the functional significance and phylogenetic utility of spidroin N-terminal domains. Results We report 11 additional spidroin N-termini found by sequencing ~1,900 silk gland cDNAs from nine spider species that shared a common ancestor > 240 million years ago. In contrast to their hyper-variable repetitive regions, spidroin N-terminal domains have retained striking similarities in sequence identity, predicted secondary structure, and hydrophobicity. Through separate and combined phylogenetic analyses of N-terminal domains and their corresponding C-termini, we find that combined analysis produces the most resolved trees and that N-termini contribute more support and less conflict than the C-termini. These analyses show that paralogs largely group by silk gland type, except for the major ampullate spidroins. Moreover, spidroin structural motifs associated with superior tensile strength arose early in the history of this gene family, whereas a motif conferring greater extensibility convergently evolved in two distantly related paralogs. Conclusions A non-repetitive N-terminal domain appears to be a universal attribute of spidroin proteins, likely retained from the origin of spider silk production. Since this time, spidroin N-termini have maintained several features, consistent with this domain playing a key role in silk

  16. The spider Harpactea sadistica: co-evolution of traumatic insemination and complex female genital morphology in spiders

    Science.gov (United States)

    Řezáč, Milan

    2009-01-01

    The males of invertebrates from a few phyla, including arthropods, have been reported to practise traumatic insemination (TI; i.e. injecting sperm by using the copulatory organ to penetrate the female's body wall). As all previously reported arthropod examples have been insects, there is considerable interest in whether TI might have evolved independently in other arthropods. The research reported here demonstrates the first case of TI in the arthropod subphylum Chelicerata, in particular how the genital morphology and mating behaviour of Harpactea sadistica (Řezáč 2008), a spider from Israel, has become adapted specifically for reproduction based on TI. Males have needle-like intromittent organs and females have atrophied spermathecae. In other spiders, eggs are fertilized simultaneously with oviposition, but the eggs of H. sadistica are fertilized in the ovaries (internal fertilization) and develop as embryos before being laid. Sperm-storage organs of phylogenetically basal groups to H. sadistica provide males with last male sperm priority and allow removal of sperm by males that mate later, suggesting that TI might have evolved as an adaptive strategy to circumvent an unfavourable structure of the sperm-storage organs, allowing the first male to mate with paternity advantage. Understanding the functional significance of TI gives us insight into factors underlying the evolution of the genital and sperm-storage morphology in spiders. PMID:19403531

  17. Vibration transmission through sheet webs of hobo spiders (Eratigena agrestis) and tangle webs of western black widow spiders (Latrodectus hesperus).

    Science.gov (United States)

    Vibert, Samantha; Scott, Catherine; Gries, Gerhard

    2016-11-01

    Web-building spiders construct their own vibratory signaling environments. Web architecture should affect signal design, and vice versa, such that vibratory signals are transmitted with a minimum of attenuation and degradation. However, the web is the medium through which a spider senses both vibratory signals from courting males and cues produced by captured prey. Moreover, webs function not only in vibration transmission, but also in defense from predators and the elements. These multiple functions may impose conflicting selection pressures on web design. We investigated vibration transmission efficiency and accuracy through two web types with contrasting architectures: sheet webs of Eratigena agrestis (Agelenidae) and tangle webs of Latrodectus hesperus (Theridiidae). We measured vibration transmission efficiencies by playing frequency sweeps through webs with a piezoelectric vibrator and a loudspeaker, recording the resulting web vibrations at several locations on each web using a laser Doppler vibrometer. Transmission efficiencies through both web types were highly variable, with within-web variation greater than among-web variation. There was little difference in transmission efficiencies of longitudinal and transverse vibrations. The inconsistent transmission of specific frequencies through webs suggests that parameters other than frequency are most important in allowing these spiders to distinguish between vibrations of prey and courting males.

  18. Australian Hackers and Ethics

    Directory of Open Access Journals (Sweden)

    M.J. Warren

    2003-05-01

    Full Text Available The aim of the paper is to look at the way hackers act and ways in which society can protect itself. The paper will show the current views and attitudes of hackers in an Australian context. The paper will also include a case study to show how a hacking incident can develop and how technology can be used to protect against hacking.

  19. High-toughness silk produced by a transgenic silkworm expressing spider (Araneus ventricosus dragline silk protein.

    Directory of Open Access Journals (Sweden)

    Yoshihiko Kuwana

    Full Text Available Spider dragline silk is a natural fiber that has excellent tensile properties; however, it is difficult to produce artificially as a long, strong fiber. Here, the spider (Araneus ventricosus dragline protein gene was cloned and a transgenic silkworm was generated, that expressed the fusion protein of the fibroin heavy chain and spider dragline protein in cocoon silk. The spider silk protein content ranged from 0.37 to 0.61% w/w (1.4-2.4 mol% native silkworm fibroin. Using a good silk-producing strain, C515, as the transgenic silkworm can make the raw silk from its cocoons for the first time. The tensile characteristics (toughness of the raw silk improved by 53% after the introduction of spider dragline silk protein; the improvement depended on the quantity of the expressed spider dragline protein. To demonstrate the commercial feasibility for machine reeling, weaving, and sewing, we used the transgenic spider silk to weave a vest and scarf; this was the first application of spider silk fibers from transgenic silkworms.

  20. Biased interpretation and memory in children with varying levels of spider fear

    NARCIS (Netherlands)

    Klein, A.M.; Titulaer, G.; Simons, C.; Allart, E.; de Gier, E.; Bögels, S.M.; Becker, E.S.; Rinck, M.

    2014-01-01

    This study investigated multiple cognitive biases in children simultaneously, to investigate whether spider-fearful children display an interpretation bias, a recall bias, and source monitoring errors, and whether these biases are specific for spider-related materials. Furthermore, the independent

  1. In Vitro Evaluation of Spider Silk Meshes as a Potential Biomaterial for Bladder Reconstruction

    NARCIS (Netherlands)

    Steins, A.; Dik, P.; Müller, W.H.; Vervoort, S.J.; Reimers, K.; Kubhier, J.W.; Vogt, P.M.; van Apeldoorn, Aart A.; Coffer, P.J.; Schepers, K.

    2015-01-01

    Reconstruction of the bladder by means of both natural and synthetic materials remains a challenge due to severe adverse effects such as mechanical failure. Here we investigate the application of spider major ampullate gland-derived dragline silk from the Nephila edulis spider, a natural biomaterial

  2. Photoluminescent properties of spider silk coated with Eu-doped nanoceria

    Energy Technology Data Exchange (ETDEWEB)

    Dmitrović, Svetlana, E-mail: svetlana8@vin.bg.ac.rs [University of Belgrade, Vinča Institute of Nuclear Sciences (Serbia); Nikolić, Marko G.; Jelenković, Branislav [University of Belgrade, Institute of Physics (Serbia); Prekajski, Marija [University of Belgrade, Vinča Institute of Nuclear Sciences (Serbia); Rabasović, Mihailo [University of Belgrade, Institute of Physics (Serbia); Zarubica, Aleksandra [University of Niš, Department of Chemistry, Faculty of Science and Mathematics (Serbia); Branković, Goran [University of Belgrade, Institute for Multidisciplinary Research, Department of Material Science (Serbia); Matović, Branko [University of Belgrade, Vinča Institute of Nuclear Sciences (Serbia)

    2017-02-15

    Spider dragline silk was coated with pure as well as Eu-doped ceria nanopowders at the room temperature. The treatment was done by immersion of the spider silk mesh into aqueous solutions of cerium nitrate (Ce(NO{sub 3}){sub 3}) and ammonium hydroxide (NH{sub 4}OH). Depending on the relationship between Ce{sup 3+} ion and ammonium hydroxide concentration, coated fibers exhibited a different thickness. Obtained materials were studied by means of FESEM. It was found that ceria nanoparticles of average size of 3 nm were coated along spider thread. X-ray diffraction (XRD) and selected-area electron diffraction (SAED) confirmed crystal nature of nanoparticle coating of spider silk. By using Williamson-Hall plots, crystallite size and strain were estimated. EDS measurement confirmed the presence of Eu in spider-Eu-doped ceria composite, and according to FTIR analysis, the interaction between CeO2 and spider silk was proposed. The morphology of obtained composite was observed by TEM. The photoluminescence emission spectra of spider silk coated with Eu-doped ceria were measured with two different excitations of 385 and 466 nm. The two-photon excited auto-fluorescence of spider silk coated with Eu-doped ceria was detected using a nonlinear laser scanning microscope. Obtained composite has a potential as a fluorescent labeling material in diverse applications.

  3. Heritability of defence and life-history traits in the two-spotted spider mite

    NARCIS (Netherlands)

    Tien, N.S.H.; Sabelis, M.W.; Egas, M.

    2009-01-01

    Background: Two-spotted spider mites hide against predatory mites in a web of self-produced sticky silk. The proteins invested in this shelter may reduce investment in reproduction. Questions: Do spider mite populations harbor genetic variation for web production, thereby enabling a response to

  4. High School Students' Attitudes Towards Spiders: A cross-cultural comparison

    Science.gov (United States)

    Prokop, Pavol; Tolarovičová, Andrea; Camerik, Anne M.; Peterková, Viera

    2010-08-01

    Spiders are traditionally considered to be among the least popular of animals. Current evidence suggests that a negative attitude towards spiders could be influenced by both cultural and evolutionary pressures. Some researchers suggest that science education activities could positively influence students' perceptions of spiders. Their evidence is, however, ambivalent. Using a five-point score Likert-type questionnaire in which the items were developed in a similar way to four of Kellert's categories of attitude (scientistic, negativistic, naturalistic, and ecologistic) towards invertebrates, we compared the level of knowledge of and attitudes towards spiders of high school students from two countries, Slovakia (n = 354) and South Africa (n = 382). The students represented different cultures and followed dissimilar science education curricula. Only among the Slovakian students there was a statistically significant but low correlation between knowledge and attitude (r = 0.30). The South African students scored higher in the categories of scientistic, naturalistic, and ecologistic attitudes. Comparison of attitude towards spiders of indigenous Africans from coeducational Catholic schools revealed that South African students have greater fear of spiders than Slovakian students, supporting the biological preparedness hypothesis. This hypothesis predicts a greater fear of spiders in South Africa than in Europe since several South African spiders possess venoms that are dangerous to humans. The results of this study are discussed from science education, cultural, and evolutionary perspectives.

  5. Methods of assembling and disassembling spider and burnable poison rod structures for nuclear reactors

    International Nuclear Information System (INIS)

    Walton, L.A.

    1981-01-01

    A method is described of joining burnable poison rods to the spider arms of a pressurised water power reactor fuel assembly which is proof against the reactor core environment but permits these rods to be removed from the spider simply, swiftly and delicately. (U.K.)

  6. Parasitization of a huntsman spider (Arachnida: Araneae: Sparassidae: Heteropoda venatoria by a mermithid nematode (Nematoda: Mermithidae

    Directory of Open Access Journals (Sweden)

    Sachin P. Ranade

    2016-11-01

    Full Text Available The emergence of a mermithid worm from a huntsman spider Heteropoda venatoria was witnessed at Buxa Tiger Reserve, West Bengal.  It appears to be a first record of the spider family Sparassidae serving as a host for a member of the family Mermithidae. 

  7. Contamination vs. harm-relevant outcome expectancies and covariation bias in spider phobia

    NARCIS (Netherlands)

    de Jong, Peter J.; Peters, Madelon L.

    There is increasing evidence that spiders are not feared because of harmful outcome expectancies but because of disgust and contamination-relevant outcome expectancies. This study investigated the relative strength of contamination- and harm-relevant UCS expectancies and covariation bias in spider

  8. Differences among plant species in acceptance by the spider mite Tetranychus urticae Koch

    NARCIS (Netherlands)

    Boom, van den C.E.M.; Beek, van T.A.; Dicke, M.

    2003-01-01

    The spider mite Tetranychus urticae Koch has a broad range of host plants. However, the spider mite does not accept all plants to the same degree because of differences in nutritive and toxic constituents. Other factors, such as the induction of secondary metabolites, the morphology of a leaf

  9. fMRI neurofeedback facilitates anxiety regulation in females with spider phobia

    NARCIS (Netherlands)

    Zilverstand, Anna; Sorger, Bettina; Sarkheil, Pegah; Goebel, R.

    2015-01-01

    BACKGROUND: Spider phobics show an exaggerated fear response when encountering spiders. This fear response is aggravated by negative and irrational beliefs about the feared object. Cognitive reappraisal can target these beliefs, and therefore has a fear regulating effect. The presented study

  10. The spider anxiety and disgust screening for children: Reliability and validity of a screening for children

    NARCIS (Netherlands)

    Klein, A.M.; Niekerk, R.E. van; Baartmans, J.M.D.; Rinck, M.; Becker, E.S.

    2017-01-01

    Objectives: Specific fears, such as fear of spiders, are often used as a model for studying the development of other fears because several studies suggest that the underlying processes of fear are similar. For the screening of spider fear in children, a good, fast, and reliable screening instrument

  11. Utility Assessment Report for SPIDERS Phase 2: Ft. Carson (Rev 1.0)

    Energy Technology Data Exchange (ETDEWEB)

    Barr, Jonathan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tuffner, Francis K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hadley, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schneider, Kevin P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-01-01

    This document contains the Utility Assessment Report (UAR) for the Phase 2 operational Demonstration (OD) of the Smart Power Infrastructure Demonstration for Energy Reliability and Security (SPIDERS) Joint Capability Technology Demonstration (JCTD). The UAR for Phase 2 shows that the SPIDERS system was able to meet the requirements of the Implementation Directive at Ft. Carson.

  12. Postharvest fumigation of California table grapes with ozone to control Western black widow spider (Araneae: Theridiidae)

    Science.gov (United States)

    Ozone fumigations were evaluated for postharvest control of Western black widow spider (BWS), Latrodectus hesperus (Chamberlin and Ivie), in fresh table grapes destined for export from California USA. Mature adult female black widow spiders were contained in separate gas-permeable cages within a flo...

  13. Species status and conservation issues of New Zealand's endemic Latrodectus spider species (Araneae: Theridiidae)

    DEFF Research Database (Denmark)

    Vink, Cor J; Sirvid, Phillip J; Malumbres-Olarte, Jagoba

    2008-01-01

    New Zealand has two endemic widow spiders, Latrodectus katipo Powell, 1871 and L. atritus Urquhart, 1890. Both species face many conservation threats and are actively managed. The species status of the Latrodectus spiders of New Zealand was assessed using molecular (COI, ITS1, ITS2) and morpholog...

  14. Neural correlation of successful cognitive behaviour therapy for spider phobia: a magnetoencephalography study.

    Science.gov (United States)

    Wright, Barry; Alderson-Day, Ben; Prendergast, Garreth; Kennedy, Juliette; Bennett, Sophie; Docherty, Mary; Whitton, Clare; Manea, Laura; Gouws, Andre; Tomlinson, Heather; Green, Gary

    2013-12-30

    Cognitive behavioural therapy (CBT) can be an effective treatment for spider phobia, but the underlying neural correlates of therapeutic change are yet to be specified. The present study used magnetoencephalography (MEG) to study responses within the first half second, to phobogenic stimuli in a group of individuals with spider phobia prior to treatment (n=12) and then in nine of them following successful CBT (where they could touch and manage live large common house spiders) at least 9 months later. We also compared responses to a group of age-matched healthy control participants (n=11). Participants viewed static photographs of real spiders, other fear-inducing images (e.g. snakes, sharks) and neutral stimuli (e.g. kittens). Beamforming methods were used to localise sources of significant power changes in response to stimuli. Prior to treatment, participants with spider phobia showed a significant maximum response in the right frontal pole when viewing images of real spiders specifically. No significant frontal response was observed for either control participants or participants with spider phobia post-treatment. In addition, participants' subjective ratings of spider stimuli significantly predicted peak responses in right frontal regions. The implications for understanding brain-based effects of cognitive therapies are discussed. © 2013 Published by Elsevier Ireland Ltd.

  15. Species richness and composition assessment of spiders in a Mediterranean scrubland

    DEFF Research Database (Denmark)

    Bondoso Cardoso, Pedro Miguel; Henriques, Sérgio S.; Gaspar, Clara

    2009-01-01

    Intensive fieldwork has been undertaken in Portugal in order to develop a standardized and optimized sampling protocol for Mediterranean spiders. The present study had the objectives of testing the use of semi-quantitative sampling for obtaining an exhaustive species richness assessment of spider...

  16. Web orientation and prey resources for web-building spiders in eastern hemlock.

    Science.gov (United States)

    Mallis, Rachael E; Rieske, Lynne K

    2010-10-01

    We examined the arthropod community on eastern hemlock, Tsuga canadensis (L.) Carr, in the context of its role in providing potential prey items for hemlock-associated web-weaving spiders. Using sticky traps simulating spider webs, we evaluated what prey items are available to web-weaving spiders in eastern hemlock based on web orientation (horizontal versus vertical) and cardinal direction. We found that the overwhelming majority (>70%) of prey items available to spiders in hemlock canopies were Diptera. Psocoptera, Hymenoptera, and Hemiptera comprised most of the remaining potential prey. A significant direction × orientation interaction, and greater trap capture in some direction-orientation combinations, suggests that spiders might locate their webs in eastern hemlock canopies for thermoregulatory purposes, ultimately optimizing prey capture. We also evaluated these findings in the context of hemlock infestation by the invasive hemlock woolly adelgid, Adelges tsugae Annand. The adelgid is a sedentary insect with a mobile crawler stage that provides a readily available, easily obtained food source for predators in hemlock canopies. However, an abundance of alternative prey will affect within canopy spider distribution and the potential intensity with which spiders consume these prey. Understanding the response of spiders to potential prey availability is essential to understanding the trophic interactions involving these predators and their potential for influencing herbivore populations.

  17. Red-back spider (Latrodectus mactans hasselti) envenomation in a neonate.

    Science.gov (United States)

    Byrne, G C; Pemberton, P J

    A case of red-back spider (Latrodectus mactans hasselti) envenomation in a neonate is presented. The signs of envenomation in a neonate are discussed, together with the dose of antivenom necessary for the successful treatment of envenomation. In episodes of untractable crying in neonates, the possibility that the baby has been bitten by a red-back spider should be considered.

  18. Salivary proteins of spider mites suppress defenses in Nicotiana benthamiana and promote mite reproduction

    NARCIS (Netherlands)

    Villarroel, C.A.; Jonckheere, W.; Alba Cano, J.M.; Glas, J.J.; Dermauw, W.; Haring, M.A.; Van Leeuwen, T.; Schuurink, R.C.; Kant, M.R.

    2016-01-01

    Spider mites (Tetranychidae sp.) are widely occurring arthropod pests on cultivated plants. Feeding by the two-spotted spider mite T. urticae, a generalist herbivore, induces a defense response in plants that mainly depends on the phytohormones jasmonic acid and salicylic acid (SA). On tomato

  19. The path to the nest of spiders The path to the nest of spiders

    Directory of Open Access Journals (Sweden)

    Eliane Luz Bayer

    2008-04-01

    Full Text Available Italo Calvino writes in his preface to The Path to the Nest of Spiders that the novel answers to the "ripeness of the time" since ht wrote it after wartime, a period when everyone had a tale to tell. He tells us that this is a story in which iobody is a hero and nobody has the class consciousness necessary to unify them in the struggle. Calvino acknowledges that it was difficult to conciliate his experiences with the postwar literary movement which he calls Neo-expresSionism, a term which, he thinks, describes better Italian Neo-realism. This is a book with a full realistic depictior of the incongruousness of the whole situation, showing rumen beings driven by loneliness, aggressiveness, unfulfilment and failure to meet, their nerves frayed by the War. It reveals human beings in their weaknesses, subjected to deterministic fates changing roles according to circumstance. Partisans shift to the Nazi side and inform on their f rmer allies and vice-versa, being later chased in revenge. The novel has as its setting Italy under Fascism and unde German occupation, the Italian people being divided betw en the fascists of the "Black Brigade" and the "Partisa4s" who belonged to the Resistance. Although this is a pOlitical book, it has universal appeal. At the same time that it livens up historical facts about the period, it moves our feelings. Calvino's book is about World War II as it is viewed and felt by a small outcast, Pin, who makes considerable efforts to be accepted and understood by adults. In his daily life Pinsuffers the consequences Of the war. His aggressive disposition reflects the environment which he has been brought up in: since he was born, his country has been at war. Besides that, his only sister is a whore, whom he hates and despises. Italo Calvino writes in his preface to The Path to the Nest of Spiders that the novel answers to the "ripeness of the time" since ht wrote it after wartime, a period when everyone had a tale to tell

  20. Australian synchrotron radiation science

    International Nuclear Information System (INIS)

    White, J.W.

    1996-01-01

    Full text: The Australian Synchrotron Radiation Program, ASRP, has been set up as a major national research facility to provide facilities for scientists and technologists in physics, chemistry, biology and materials science who need access to synchrotron radiation. Australia has a strong tradition in crystallography and structure determination covering small molecule crystallography, biological and protein crystallography, diffraction science and materials science and several strong groups are working in x-ray optics, soft x-ray and vacuum ultra-violet physics. A number of groups whose primary interest is in the structure and dynamics of surfaces, catalysts, polymer and surfactant science and colloid science are hoping to use scattering methods and, if experience in Europe, Japan and USA can be taken as a guide, many of these groups will need third generation synchrotron access. To provide for this growing community, the Australian National Beamline at the Photon Factory, Tsukuba, Japan, has been established since 1990 through a generous collaboration with Japanese colleagues, the beamline equipment being largely produced in Australia. This will be supplemented in 1997 with access to the world's most powerful synchrotron x-ray source at the Advanced Photon Source, Argonne National Laboratory, USA. Some recent experiments in surface science using neutrons as well as x-rays from the Australian National Beamline will be used to illustrate one of the challenges that synchrotron x-rays may meet

  1. The time course of location-avoidance learning in fear of spiders.

    Science.gov (United States)

    Rinck, Mike; Koene, Marieke; Telli, Sibel; Moerman-van den Brink, Wiltine; Verhoeven, Barbara; Becker, Eni S

    2016-01-01

    Two experiments were designed to study the time course of avoidance learning in spider fearfuls (SFs) under controlled experimental conditions. To achieve this, we employed an immersive virtual environment (IVE): While walking freely through a virtual art museum to search for specific paintings, the participants were exposed to virtual spiders. Unbeknown to the participants, only two of four museum rooms contained spiders, allowing for avoidance learning. Indeed, the more SF the participants were, the faster they learned to avoid the rooms that contained spiders (Experiment. 1), and within the first six trials, high fearfuls already developed a preference for starting their search task in rooms without spiders (Experiment 2). These results illustrate the time course of avoidance learning in SFs, and they speak to the usefulness of IVEs in fundamental anxiety research.

  2. Proximate mechanism of behavioral manipulation of an orb-weaver spider host by a parasitoid wasp.

    Directory of Open Access Journals (Sweden)

    Thiago Gechel Kloss

    Full Text Available Some ichneumonid wasps induce modifications in the web building behavior of their spider hosts to produce resistant "cocoon" webs. These structures hold and protect the wasp's cocoon during pupa development. The mechanism responsible for host manipulation probably involves the inoculation of psychotropic chemicals by the parasitoid larva during a specific developmental period. Recent studies indicate that some spiders build cocoon webs similar to those normally built immediately before ecdysis, suggesting that this substance might be a molting hormone or a precursor chemical of this hormone. Here, we report that Cyclosa spider species exhibiting modified behavior presented higher 20-OH-ecdysone levels than parasitized spiders acting normally or unparasitized individuals. We suggest that the lack of control that spiders have when constructing modified webs can be triggered by anachronic activation of ecdysis.

  3. Community structure of spiders in coastal habitats of a Mediterranean delta region (Nestos Delta, NE Greece

    Directory of Open Access Journals (Sweden)

    S. Buchholz

    2009-01-01

    Full Text Available (pp 101-115Habitat zonation and ecology of spider assemblages have been poorly studied in Mediterranean ecosystems. A first analysis of spider assemblages in coastal habitats in the east Mediterranean area is presented. The study area is the 250 km² Nestos Delta, located in East Macedonia in the North-East of Greece. Spiders were caught in pitfall traps at 17 sites from the beginning of April to the end of June 2004. Nonparametric estimators were used to determine species richness and alpha diversity. Ordination analysis (redundancy analysis indicated four clearly separable spider species groups (salt meadows, dunes, mea-dows and floodplain forests, along a soil salinity and moisture gradient. Based on these results we discuss the habitat preferences of these spiders and include the first ecological data on several species.

  4. Association of spiders and lichen on Robben Island, South Africa: a case report

    Directory of Open Access Journals (Sweden)

    A. Mukherjee

    2010-04-01

    Full Text Available The present study is a firstrecord of spider occurrence on Robben Island, South Africa. Some habitats were rich in lichens. As we know, lichens enhance wildlife habitat in less direct ways. The objective of the study was to examine the potential importance of lichens in enriching spider diversity and abundance. A total of 260 spiders (170 from lichens and 90 from bush were collected following the visual search method over one year. Seasonal trends in overall species richness and abundance indicated that the relative density of spiders was greater in lichens than in bushes. The result suggests that habitat structure, such as branch size and epiphytic lichen abundance, can be an explanation for the greater number of spiders in lichen-rich patches of the island.

  5. Conditions for Australian consent to reprocessing

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    This article contains the text of the statement by the Australian Minister for Foreign Affairs to the House of Representatives, Noember 1980, on conditions for Australian consent to the reprocessing of nuclear material of Australian origin

  6. Adaptation of the spiders to the environment: the case of some Chilean species

    Directory of Open Access Journals (Sweden)

    Mauricio eCanals

    2015-08-01

    Full Text Available Spiders are small arthropods that have colonized terrestrial environments. These impose three main problems: i terrestrial habitats have large fluctuations in temperature and humidity; ii the internal concentration of water is higher than the external environment in spiders, which exposes them continually to water loss; and iii their small body size determines a large surface / volume ratio, affecting energy exchange and influencing the life strategy. In this review we focus on body design, energetic, thermal selection, and water balance characteristics of some spider species present in Chile and correlate our results with ecological and behavioral information. Preferred temperatures and critical temperatures of Chilean spiders vary among species and individuals and may be adjusted by phenotypic plasticity. For example in the mygalomorph high-altitude spider Paraphysa parvula the preferred temperature is similar to that of the lowland spider Grammostola rosea; but while P. parvula shows phenotypic plasticity, G. rosea does not. The araneomorph spiders Loxosceles laeta and Scytodes globula have greater daily variations in preferred temperatures at twilight and during the night, which are set to the nocturnal activity rhythms of these species. They also present acclimation of the minimum critical temperatures. Dysdera crocata has a low preferred temperature adjusted to its favorite prey, the woodlouse. Spider metabolic rate is low compared to other arthropods, which may be associated with its sit and wait predatory strategy particularly in primitive hunter and weavers. In mygalomorph spiders the respiratory system is highly optimized with high oxygen conductance, for example G. rosea needs only a difference of 0.12 to 0.16 kPa in the oxygen partial pressure across the air-hemolymph barrier to satisfy its resting oxygen consumption demands. Water loss is a significant stress for spiders. Paraphysa parvula shows an evaporative water loss ten times

  7. Review of Australian Higher Education: An Australian Policy Perspective

    Science.gov (United States)

    Montague, Alan

    2013-01-01

    Higher education is one of the key foundations that economic prosperity is founded upon. Government policies, funding and strategic planning require a fine balance to stimulate growth, prosperity health and well-being. The key Australian government policies influenced by a Review of Australian Higher Education report include attracting many more…

  8. SPIDERS (ARANEI IN HEPRETOBIONT MESOFAUNA OF THE NORTHWEST CAUCASUS

    Directory of Open Access Journals (Sweden)

    A. V. Ponomarev

    2014-01-01

    Full Text Available Abstract. Aim. We discussed in previous work a herpetobiont fauna of arachnids (Arachnida from the isolated yewboxwood wood, located in the Caucasian State Biosphere Reserve, 20 km near Sochi (Ponomarev, Chumachenko, 2007. The aim of the paper is to summarize available data about herpetobiont araneofauna of the Northwest Caucasus. Location. Republic of Adygea, Russia.Methods. Material was collected in 2009 on north macroslope of Main Caucasian Ridge within the territory of the Caucasian State Biosphere Reserve between 1000–1820 m. The following plant communities are studied: beech-silver fir (assotiation Abieti-Fagetion orientalis Korotkov et Belonovskaya 1987, maple forest (assotiation Petasito albae-Abietetum nordmannianae subassotiation Aceretosum trautvetteri Francuzov 2006, subalpine meadow (assotiation Poa longifolii – Calamagrostietum arundinaceae Semagina, 1992. Soil traps were used for collection of spiders.Results and main conclusions. During the period of study 100 species of spiders from 19 families are registered. Most diverse araneofauna of subalpine meadows includs 54 species belonging to 14 families. The least diverse araneofauna is in maple forest (24 species of 7 families. In beech-silver fir includes 45 species of 16 families of spiders. Only 3 species (Pireneitega ovtchinnikovi, Cybaeus abchasicus, Tenuiphantes mengei were found in all surveyed habitats. These 3 species clearly tend to forest habitats. Herpetobiont araneofauna of the Northwest Caucasus characterized by high taxonomic diversity with clear predominance of representatives of the family Linyphiidae. Specificity of araneofauna in different types of plant communities is high.

  9. Variation in protein intake induces variation in spider silk expression.

    Directory of Open Access Journals (Sweden)

    Sean J Blamires

    Full Text Available BACKGROUND: It is energetically expensive to synthesize certain amino acids. The proteins (spidroins of spider major ampullate (MA silk, MaSp1 and MaSp2, differ in amino acid composition. Glutamine and proline are prevalent in MaSp2 and are expensive to synthesize. Since most orb web spiders express high proline silk they might preferentially attain the amino acids needed for silk from food and shift toward expressing more MaSp1 in their MA silk when starved. METHODOLOGY/PRINCIPAL FINDINGS: We fed three spiders; Argiope aetherea, Cyrtophora moluccensis and Leucauge blanda, high protein, low protein or no protein solutions. A. aetherea and L. blanda MA silks are high in proline, while C. moluccesnsis MA silks are low in proline. After 10 days of feeding we determined the amino acid compositions and mechanical properties of each species' MA silk and compared them between species and treatments with pre-treatment samples, accounting for ancestry. We found that the proline and glutamine of A. aetherea and L. blanda silks were affected by protein intake; significantly decreasing under the low and no protein intake treatments. Glutmaine composition in C. moluccensis silk was likewise affected by protein intake. However, the composition of proline in their MA silk was not significantly affected by protein intake. CONCLUSIONS: Our results suggest that protein limitation induces a shift toward different silk proteins with lower glutamine and/or proline content. Contradictions to the MaSp model lie in the findings that C. moluccensis MA silks did not experience a significant reduction in proline and A. aetherea did not experience a significant reduction in serine on low/no protein. The mechanical properties of the silks could not be explained by a MaSp1 expressional shift. Factors other than MaSp expression, such as the expression of spidroin-like orthologues, may impact on silk amino acid composition and spinning and glandular processes may impact

  10. Spider monkey, Muriqui and Woolly monkey relationships revisited.

    Science.gov (United States)

    de Lima, Margarida Maria Celeira; Sampaio, Iracilda; Vieira, Ricardo dos Santos; Schneider, Horacio

    2007-01-01

    The taxonomic relationships among the four genera of the Atelidae family, Alouatta (Howler), Ateles (Spider), Lagothrix (Woolly) and Brachyteles (Muriqui), have been the subject of great debate. In general, almost all authors agree with the assignment of Howler monkeys as the basal genus, either in its own tribe Alouattini or in the subfamily Alouattinae, but they disagree on the associations among the other members of the family. Muriquis have been grouped with Spider monkeys based on the fact that they share various behavioral and morphological characteristics. Cladistic analyses using morphological, biochemical, karyotype and behavioral characteristics depicted a phylogenetic tree that places Howler as the basal genus and the remaining genera in an unresolved politomy. More recent studies using molecular data have suggested that Muriqui and Woolly monkeys are sister groups. However, a recent study based on nuclear and mtDNA argued that politomy is what best represents the relationships among Spider, Woolly and Muriqui. To contribute to this debate we have added new data from two nuclear genes, Transferrin and von Willebrand Factor, and using an alignment of 17,997 bp we demonstrate that a total analysis strongly supports the Muriqui-Woolly clade. A gene-to-gene approach showed that four of the eight nuclear genes provide support for the Muriqui-Woolly clade, two strongly and two moderately, while none of the eight genes provide support for any alternative arrangement. The mitochondrial genes were not able to resolve the politomy. A possible reason for the difficulty in resolving atelid relationships may be the short period of time separating each cladogenetic event in the evolutionary process that shaped this family.

  11. Male mating tactics in spider monkeys: sneaking to compete.

    Science.gov (United States)

    Gibson, K Nicole

    2010-09-01

    I investigated the mating system and male mating tactics for a population of wild spider monkeys (Ateles belzebuth chamek), to identify the behaviors males used to achieve and maintain access to sexually receptive females, and to examine if some males used more tactics than other males and/or had differential access to females. Results show that the mating system mostly involved scramble competition polygyny and that males used a range of mating tactics and behaviors, previously unreported for spider monkeys. The most unusual feature of spider monkey mating behavior was the secretive nature of copulations-nearly all copulations were clandestine, but a few were in the presence of other group members. Fifteen sexually mature males were observed to copulate 43 times. These data provide the first opportunity to evaluate how female availability influences male-male competition. First, the operational sex ratio was highly skewed toward males because usually only one female was receptive in each community per month. Second, females only mated with a few males in their community in any one mating period, but some females mated over the course of multiple consecutive mating periods, eventually mating with most or all of the males in their community. Across all communities, 9 (21%) of the 43 copulations involved a single male-female partner, 20 (47%) involved four males mating with the same female, and males mated with from one to four different females. Fourteen of the 16 total adult males and 1 subadult male (10 total) copulated. One or two males in each community were successful in monopolizing access to receptive females, and these males did not usually have the highest rates of copulation. In this system, clandestine copulations are one behavioral solution to the complex problem of gaining mating exclusivity and, probably, exercising mate choice. (c) 2010 Wiley-Liss, Inc.

  12. Peptidomic and transcriptomic profiling of four distinct spider venoms.

    Science.gov (United States)

    Oldrati, Vera; Koua, Dominique; Allard, Pierre-Marie; Hulo, Nicolas; Arrell, Miriam; Nentwig, Wolfgang; Lisacek, Frédérique; Wolfender, Jean-Luc; Kuhn-Nentwig, Lucia; Stöcklin, Reto

    2017-01-01

    Venom based research is exploited to find novel candidates for the development of innovative pharmacological tools, drug candidates and new ingredients for cosmetic and agrochemical industries. Moreover, venomics, as a well-established approach in systems biology, helps to elucidate the genetic mechanisms of the production of such a great molecular biodiversity. Today the advances made in the proteomics, transcriptomics and bioinformatics fields, favor venomics, allowing the in depth study of complex matrices and the elucidation even of minor compounds present in minute biological samples. The present study illustrates a rapid and efficient method developed for the elucidation of venom composition based on NextGen mRNA sequencing of venom glands and LC-MS/MS venom proteome profiling. The analysis of the comprehensive data obtained was focused on cysteine rich peptide toxins from four spider species originating from phylogenetically distant families for comparison purposes. The studied species were Heteropoda davidbowie (Sparassidae), Poecilotheria formosa (Theraphosidae), Viridasius fasciatus (Viridasiidae) and Latrodectus mactans (Theridiidae). This led to a high resolution profiling of 284 characterized cysteine rich peptides, 111 of which belong to the Inhibitor Cysteine Knot (ICK) structural motif. The analysis of H. davidbowie venom revealed a high richness in term of venom diversity: 95 peptide sequences were identified; out of these, 32 peptides presented the ICK structural motif and could be classified in six distinct families. The profiling of P. formosa venom highlighted the presence of 126 peptide sequences, with 52 ICK toxins belonging to three structural distinct families. V. fasciatus venom was shown to contain 49 peptide sequences, out of which 22 presented the ICK structural motif and were attributed to five families. The venom of L. mactans, until now studied for its large neurotoxins (Latrotoxins), revealed the presence of 14 cysteine rich

  13. Australian methane fluxes

    International Nuclear Information System (INIS)

    Williams, D.J.

    1990-01-01

    Estimates are provided for the amount of methane emitted annually into the atmosphere in Australia for a variety of sources. The sources considered are coal mining, landfill, motor vehicles, natural gas suply system, rice paddies, bushfires, termites, wetland and animals. This assessment indicates that the major sources of methane are natural or agricultural in nature and therefore offer little scope for reduction. Nevertheless the remainder are not trival and reduction of these fluxes could play a significant part in any Australian action on the greenhouse problem. 19 refs., 7 tabs., 1 fig

  14. SPIDERS Bi-Directional Charging Station Interconnection Testing

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, M.

    2013-09-01

    The Smart Power Infrastructure Demonstration for Energy Reliability and Security (SPIDERS) program is a multi-year Department of Defense-Department of Energy (DOE) collaborative effort that will demonstrate integration of renewables into island-able microgrids using on-site generation control, demand response, and energy storage with robust security features at multiple installations. Fort Carson, Colorado, will be the initial development and demonstration site for use of plug-in electric vehicles as energy storage (also known as vehicle-to-grid or V2G).

  15. Native spider silk as a biological optical fiber

    Science.gov (United States)

    Huby, N.; Vié, V.; Renault, A.; Beaufils, S.; Lefèvre, T.; Paquet-Mercier, F.; Pézolet, M.; Bêche, B.

    2013-03-01

    In this study, we demonstrate the use of eco-friendly native spider silk as an efficient optical fiber in air, highly bent fibers, and physiological liquid. We also integrated the silk filament in a photonic chip made of polymer microstructures fabricated by UV lithography. The molding process is non-destructive for silk and leads to an efficient micro-optical coupling between silk and synthetic optical structures. These optical performances combined with the unique biocompatibility, bioresorbability, flexibility, and tensile strength of silk filaments pave the way for new applications in biological media and for original biophotonic purposes.

  16. Climatic Variables Do Not Directly Predict Spider Richness and Abundance in Semiarid Caatinga Vegetation, Brazil.

    Science.gov (United States)

    Carvalho, Leonardo S; Sebastian, Nicholas; Araújo, Helder F P; Dias, Sidclay C; Venticinque, Eduardo; Brescovit, Antonio D; Vasconcellos, Alexandre

    2015-02-01

    Spiders are abundant in tropical ecosystems and exert predatory pressure on a wide variety of invertebrate populations and also serve as prey for many others organisms, being part of complex interrelationships influenced directly and indirectly by a myriad of factors. We examined the influence of biotic (i.e., prey availability) and abiotic (i.e., temperature, precipitation, relative humidity, real evapotranspiration) factors on species richness and abundance during a two-year period in the semiarid Caatinga vegetation in northeastern Brazil. Data were analyzed through partial autocorrelation functions, cross correlations, and a path analysis. A total of 2522 spiders were collected with beating tray, pit-fall traps, and malaise traps, comprising 91 species and 34 families. Spider abundance peaked in the rainy season. Our results suggest that total invertebrate abundance has a direct influence on spider richness and abundance, whereas the effects of precipitation were mainly indirectly related to most spider assemblage parameters. The increase in vegetation cover with the rainy season in the Caatinga provides more breeding and foraging sites for spiders and stimulates their activities. Additionally, rainfall in arid and semiarid ecosystems stimulated the activity and reproduction of many herbivore and detritivore invertebrates dependent on plant biomass and necromass consumption, leading to an increase in spider prey availability. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Psychophysiology of spider phobia in 8- to 12-year-old girls.

    Science.gov (United States)

    Leutgeb, Verena; Schäfer, Axel; Köchel, Angelika; Scharmüller, Wilfried; Schienle, Anne

    2010-12-01

    The present investigation focused on late event-related potentials (ERPs) and facial electromyographic (EMG) activity in response to symptom provocation in 8- to 12-year-old spider phobic girls and compared results to those in non-fearful controls. Fourteen patients and 14 controls were presented with phobia-relevant, generally fear-inducing, disgust-inducing and affectively neutral pictures in an EEG/EMG session. ERPs were extracted in the time-windows 340-500ms (P300) and 550-770ms (late positive potential, LPP). Relative to controls, phobics showed enhanced amplitudes of P300 and LPP in response to spider pictures. This result is interpreted to reflect motivated attention to emotionally salient stimuli. Moreover, phobics showed enhanced average facial EMG activity of the levator labii and the corrugator supercilii in response to spider pictures, reflecting the negative valence and disgust relevance of spiders. Additionally, spider phobic girls relative to controls showed higher overall disgust proneness and heightened average facial EMG activity in both muscle regions in response to disgust stimuli, possibly revealing a disgust-based origin of spider phobia in children. These aspects should be considered in psychotherapeutic treatment of childhood spider phobia. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Heat Tolerance of the Brown Recluse Spider (Araneae: Sicariidae): Potential for Pest Control.

    Science.gov (United States)

    Cramer, Kenneth L; Zagar, Lindsey M

    2016-02-01

    The brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, is a well-known venomous spider common in the south-central United States where infestations can reach thousands of individuals in a single structure. Bites from this spider pose a risk of dermonecrotic lesions (loxoscelism) or, rarely, more serious systemic effects. The heat tolerance of this spider is understudied but may offer an alternative pest control solution to pesticides or fumigation, both of which have their disadvantages. We subjected brown recluse spiders to increasing temperatures to establish the upper lethal temperature (LT). Using probit analysis to generate probability of mortality at increasing temperatures, we then exposed adult spiders to the observed LT50 to simulate whole-room heat treatment. Laboratory results predict exposure to 48°C for 130 min will achieve 100% mortality of adult spiders. Field tests need to be conducted to determine the efficacy of heat treatment in a variety of real-world situations. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Brain dynamics in spider-phobic individuals exposed to phobia-relevant and other emotional stimuli.

    Science.gov (United States)

    Michalowski, Jaroslaw M; Melzig, Christiane A; Weike, Almut I; Stockburger, Jessica; Schupp, Harald T; Hamm, Alfons O

    2009-06-01

    Dense sensor event-related brain potentials were measured in participants with spider phobia and nonfearful controls during viewing of phobia-relevant spider and standard emotional (pleasant, unpleasant, neutral) pictures. Irrespective of the picture content, spider phobia participants responded with larger P1 amplitudes than controls, suggesting increased vigilance in this group. Furthermore, spider phobia participants showed a significantly enlarged early posterior negativity (EPN) and late positive potential (LPP) during the encoding of phobia-relevant pictures compared to nonfearful controls. No group differences were observed for standard emotional materials indicating that these effects were specific to phobia-relevant material. Within group comparisons of the spider phobia group, though, revealed comparable EPN and LPP evoked by spider pictures and emotional (unpleasant and pleasant) picture contents. These results demonstrate a temporal unfolding in perceptual processing from unspecific vigilance (P1) to preferential responding (EPN and LPP) to phobia-relevant materials in the spider phobia group. However, at the level of early stimulus processing, these effects of increased attention seem to be related to emotional relevance of the stimulus cues rather than reflecting a fear-specific response.

  20. Mechanical behavior of silk during the evolution of orb-web spinning spiders.

    Science.gov (United States)

    Elices, Manuel; Plaza, Gustavo R; Arnedo, Miquel A; Pérez-Rigueiro, José; Torres, Fernando G; Guinea, Gustavo V

    2009-07-13

    The development of an accurate and reproducible approach to measuring the tensile behavior of spider silk has allowed characterizing and comparing the range of mechanical properties exhibited by different spider species with unprecedented detail. The comparison of silks spun by spiders belonging to different phylogenetic groups has revealed that evolution locked in many of the important properties of spider silks very early in the history of orb-web weaving spiders, despite the fact that the silk gland system is relatively isolated in physiological terms from the rest of the organism and should thus mutate quickly. The variations observed between species may be grouped in at least two patterns that are shown not to be related to phylogeny. Beyond the relevance of these results for the evolutionary biology of spiders and silks, the conservation of the basic traits observed in the mechanical behavior of spider silks is likely to set a limit to the range of properties that can be expected from artificial fibers bioinspired in natural silks.

  1. Phantom spiders 2: More notes on dubious spider species from Europe

    Directory of Open Access Journals (Sweden)

    Breitling, Rainer

    2016-09-01

    Full Text Available A surprisingly large number of European spider species have never been reliably rediscovered since their first description many decades ago. Most of these are probably synonymous with other species or unidentifiable, due to insufficient descriptions or missing type material. In this second part of a series on this topic, we discuss about 100 of these cases, focusing mainly on species described in the early 20th century by Pelegrín Franganillo Balboa and Gabor von Kolosváry, as well as a number of jumping spiders and various miscellaneous species. In most cases, the species turned out to be unidentifiable nomina dubia, but for some of them new synonymies could be established as follows: Alopecosa accentuata auct., nec (Latreille, 1817 = Alopecosa farinosa (Herman, 1879 syn. nov., comb. nov.; Alopecosa barbipes oreophila Simon, 1937 = Alopecosa farinosa (Herman, 1879 syn. nov., comb. nov.; Alopecosa mariae orientalis (Kolosváry, 1934 = Alopecosa mariae (Dahl, 1908 syn. nov.; Araneus angulatus afolius (Franganillo, 1909 and Araneus angulatus atricolor Simon, 1929 = Araneus angulatus Clerck, 1757 syn. nov.; Araneus angulatus castaneus (Franganillo, 1909 = Araneus pallidus (Olivier, 1789 syn. nov.; Araneus angulatus levifolius (Franganillo, 1909, Araneus angulatus niger (Franganillo, 1918 and Araneus angulatus nitidifolius (Franganillo, 1909 = Araneus angulatus Clerck 1757 syn. nov.; Araneus angulatus pallidus (Franganillo, 1909, Araneus angulatus crucinceptus (Franganillo, 1909, Araneus angulatus fuscus (Franganillo, 1909 and Araneus angulatus iberoi (Franganillo, 1909 = Araneus pallidus (Olivier, 1789 syn. nov.; Araneus circe strandi (Kolosváry, 1935 = Araneus circe (Audouin, 1826 syn. nov.; Araneus diadematus nemorosus Simon, 1929 and Araneus diadematus soror (Simon, 1874 = Araneus diadematus Clerck, 1757 syn. nov.; Araneus pyrenaeus (Simon, 1874 = Araneus pallidus (Olivier, 1789 syn. nov.; Araneus sericinus (Roewer, 1942 = Aculepeira armida

  2. Functional relations between locomotor performance traits in spiders and implications for evolutionary hypotheses

    Directory of Open Access Journals (Sweden)

    Taylor Phillip W

    2010-11-01

    Full Text Available Abstract Background Locomotor performance in ecologically relevant activities is often linked to individual fitness. Recent controversy over evolution of extreme sexual size dimorphism (SSD in spiders centres on the relationship between size and locomotor capacity in males. Advantages for large males running over horizontal surfaces and small males climbing vertically have been proposed. Models have implicitly treated running and climbing as functionally distinct activities and failed to consider the possibility that they reflect common underlying capacities. Findings We examine the relationship between maximum climbing and running performance in males of three spider species. Maximum running and climbing speeds were positively related in two orb-web spiders with high SSD (Argiope keyserlingi and Nephila plumipes, indicating that for these species assays of running and climbing largely reveal the same underlying capacities. Running and climbing speeds were not related in a jumping spider with low SSD (Jacksonoides queenslandica. We found no evidence of a performance trade-off between these activities. Conclusions In the web-spiders A. keyserlingi and N. plumipes good runners were also good climbers. This indicates that climbing and running largely represent a single locomotor performance characteristic in these spiders, but this was not the case for the jumping spider J. queenslandica. There was no evidence of a trade-off between maximum running and climbing speeds in these spiders. We highlight the need to establish the relationship between apparently disparate locomotor activities when testing alternative hypotheses that yield predictions about different locomotor activities. Analysis of slopes suggests greater potential for an evolutionary response on performance in the horizontal compared to vertical context in these spiders.

  3. Compositional changes in spider (Araneae) assemblages along an urbanisation gradient near a Danish town

    DEFF Research Database (Denmark)

    Horváth, R.; Elek, Zoltán; Lövei, Gabor L

    2014-01-01

    Spider (Araneae) assemblages were studied over two years by pitfall trapping along an urbanisation gradient of forested habitats (rural forest - suburban forest fragment - urban forest fragment) in a Danish town, using the Globenet protocol. During the two years, we collected 4340 individuals of 90...... species, with money spiders (Linyphiidae) and wolf spiders (Lycosidae) being most numerous. One species, Ero aphana, was new to the Danish fauna. In 2004, 45-47 species were captured in the habitats in various stages of urbanisation, while in 2005 (with a smaller collection effort), 28 (urban) - 37 (rural...

  4. Spider Gland Fluids: From Protein-Rich Isotropic Liquid to Insoluble Super Fiber

    Science.gov (United States)

    2013-09-17

    depend on the ratio of the two proteins. Finally, we have succeeded in imaging the major ampullate gland with MRI on a live black widow spider and...MRI images of the silk producing glands and ducts within the abdomen of a live Black Widow spider . The (a) top down view and (b) profile view of the...monitored by exposing the major Fig. 10 The 1H liquid-state NMR spectrum of major ampullate glands excised from Black widow spiders . The spectrum

  5. Subsocial behaviour and brood adoption in mixed-species colonies of two theridiid spiders

    DEFF Research Database (Denmark)

    Grinsted, Lena; Agnarsson, Ingi; Bilde, Trine

    2012-01-01

    , aggression and cooperation through behavioural experiments and examine the potential for adoption of foreign brood. Morphological and genetic analyses confirmed that colonies consisted of two related species Chikunia nigra (O.P. Cambridge, 1880) new combination (previously Chrysso nigra) and a yet...... as in territorial, colonial spiders. Mixed species spider colonies, involving closely related species, have rarely been documented. We examined social interactions in newly discovered mixed-species colonies of theridiid spiders on Bali, Indonesia. Our aim was to test the degree of intra- and interspecific tolerance...

  6. Adaptation of the spiders to the environment: the case of some Chilean species.

    Science.gov (United States)

    Canals, Mauricio; Veloso, Claudio; Solís, Rigoberto

    2015-01-01

    Spiders are small arthropods that have colonized terrestrial environments. These impose three main problems: (i) terrestrial habitats have large fluctuations in temperature and humidity; (ii) the internal concentration of water is higher than the external environment in spiders, which exposes them continually to water loss; and (iii) their small body size determines a large surface/volume ratio, affecting energy exchange and influencing the life strategy. In this review we focus on body design, energetic, thermal selection, and water balance characteristics of some spider species present in Chile and correlate our results with ecological and behavioral information. Preferred temperatures and critical temperatures of Chilean spiders vary among species and individuals and may be adjusted by phenotypic plasticity. For example in the mygalomorph high-altitude spider Paraphysa parvula the preferred temperature is similar to that of the lowland spider Grammostola rosea; but while P. parvula shows phenotypic plasticity, G. rosea does not. The araneomorph spiders Loxosceles laeta and Scytodes globula have greater daily variations in preferred temperatures at twilight and during the night, which are set to the nocturnal activity rhythms of these species. They also present acclimation of the minimum critical temperatures. Dysdera crocata has a low preferred temperature adjusted to its favorite prey, the woodlouse. Spider metabolic rate is low compared to other arthropods, which may be associated with its sit and wait predatory strategy particularly in primitive hunter and weavers. In mygalomorph spiders the respiratory system is highly optimized with high oxygen conductance, for example G. rosea needs only a difference of 0.12-0.16 kPa in the oxygen partial pressure across the air-hemolymph barrier to satisfy its resting oxygen consumption demands. Water loss is a significant stress for spiders. Paraphysa parvula shows an evaporative water loss 10 times more than usual when

  7. A parasitoid wasp induces overwintering behaviour in its spider host.

    Directory of Open Access Journals (Sweden)

    Stanislav Korenko

    Full Text Available Parasites and parasitoids control behaviors of their hosts. However, the origin of the behavior evoked by the parasitic organism has been rarely identified. It is also not known whether the manipulation is universal or host-specific. Polysphinctine wasps, koinobiont ectoparasitoids of several spider species that manipulate host web-spinning activity for their own protection during pupation, provide an ideal system to reveal the origin of the evoked behavior. Larva of Zatypota percontatoria performed species-specific manipulation of theridiid spiders, Neottiura bimaculata and Theridion varians, shortly before pupation. Parasitized N. bimaculata produced a dense web, whereas parasitized T. varians built a cupola-like structure. The larva pupated inside of either the dense web or the cupola-like structure. We discovered that unparasitized N. bimaculata produce an analogous dense web around their eggsacs and for themselves during winter, while T. varians construct an analogous 'cupola' only for overwintering. We induced analogous manipulation in unparasitized hosts by altering ambient conditions. We discovered that the behavior evoked by larvae in two hosts was functionally similar. The larva evoked protective behaviors that occur in unparasitized hosts only during specific life-history periods.

  8. Nectar Meals of a Mosquito-Specialist Spider

    Directory of Open Access Journals (Sweden)

    Josiah O. Kuja

    2012-01-01

    Full Text Available Evarcha culicivora, an East African jumping spider, is known for feeding indirectly on vertebrate blood by actively choosing blood-carrying mosquitoes as prey. Using cold-anthrone tests to detect fructose, we demonstrate that E. culicivora also feeds on nectar. Field-collected individuals, found on the plant Lantana camara, tested positive for plant sugar (fructose. In the laboratory, E. culicivora tested positive for fructose after being kept with L. camara or one of another ten plant species (Aloe vera, Clerodendron magnifica, Hamelia patens, Lantana montevideo, Leonotis nepetaefolia, Parthenium hysterophorus, Ricinus communis, Senna didymobotrya, Striga asiatica, and Verbena trivernia. Our findings demonstrate that E. culicivora acquires fructose from its natural diet and can ingest fructose directly from plant nectaries. However, experiments in the laboratory also show that E. culicivora can obtain fructose indirectly by feeding on prey that have fed on fructose, implying a need to consider this possibility when field-collected spiders test positive for fructose. In laboratory tests, 53.5% of 1,215 small juveniles, but only 3.4% of 622 adult E. culicivora, left with plants for 24 hours, were positive for fructose. These findings, along with the field data, suggest that fructose is especially important for early-instar juveniles of E. culicivora.

  9. Functional anatomy of the pretarsus in whip spiders (Arachnida, Amblypygi).

    Science.gov (United States)

    Wolff, Jonas O; Seiter, Michael; Gorb, Stanislav N

    2015-11-01

    Whip spiders (Amblypygi) are a small, cryptic order of arachnids mainly distributed in the tropics. Some basal lineages (families Charinidae and Charontidae) have adhesive pads on the tips of their six walking legs. The present study describes the macro- and ultrastructure of these pads and investigates their contact mechanics and adhesive strength on smooth and rough substrates. Furthermore, the structure of the pretarsus and its kinematics are compared in Charon cf. grayi (with an adhesive pad) and Phrynus longipes (without an adhesive pad). The adhesive pads exhibit an elaborate structure with a unique combination of structural features of smooth and hairy foot pads including a long transversal contact zone performing lateral detachment, a thick internally-branched cuticle with longitudinal ribs and hexagonal surface microstructures with spatulate keels. The contact area of the pads on smooth glass is discontinuous due to the spatulate microstructures with a discontinuous detachment, which could be observed in vivo by high speed videography at a rate of up to 10,000 fps. Adhesive strength was measured with vertical whole animal pull-off tests, obtaining mean values between 55 and 200 kPa. The occurrence of viscous lipid secretions between microstructures was occasionally observed, which, however, seems not to be a necessity for good foothold. The results are discussed in relation to the whip spider's ecology and evolution. Structure-function relationships of the adhesive pads are compared to those of insects and vertebrates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Compliant threads maximize spider silk connection strength and toughness

    Science.gov (United States)

    Meyer, Avery; Pugno, Nicola M.; Cranford, Steven W.

    2014-01-01

    Millions of years of evolution have adapted spider webs to achieve a range of functionalities, including the well-known capture of prey, with efficient use of material. One feature that has escaped extensive investigation is the silk-on-silk connection joints within spider webs, particularly from a structural mechanics perspective. We report a joint theoretical and computational analysis of an idealized silk-on-silk fibre junction. By modifying the theory of multiple peeling, we quantitatively compare the performance of the system while systematically increasing the rigidity of the anchor thread, by both scaling the stress–strain response and the introduction of an applied pre-strain. The results of our study indicate that compliance is a virtue—the more extensible the anchorage, the tougher and stronger the connection becomes. In consideration of the theoretical model, in comparison with rigid substrates, a compliant anchorage enormously increases the effective adhesion strength (work required to detach), independent of the adhered thread itself, attributed to a nonlinear alignment between thread and anchor (contact peeling angle). The results can direct novel engineering design principles to achieve possible load transfer from compliant fibre-to-fibre anchorages, be they silk-on-silk or another, as-yet undeveloped, system. PMID:25008083

  11. Damage, Self-Healing, and Hysteresis in Spider Silks

    Science.gov (United States)

    De Tommasi, D.; Puglisi, G.; Saccomandi, G.

    2010-01-01

    Abstract In this article, we propose a microstructure-based continuum model to describe the material behavior of spider silks. We suppose that the material is composed of a soft fraction with entropic elasticity and a hard, damageable fraction. The hard fraction models the presence of stiffer, crystal-rich, oriented regions and accounts for the effect of softening induced by the breaking of hydrogen bonds. To describe the observed presence of crystals with different size, composition, and orientation, this hard fraction is modeled as a distribution of materials with variable properties. The soft fraction describes the remaining regions of amorphous material and is here modeled as a wormlike chain. During stretching, we consider the effect of bond-breaking as a transition from the hard- to the soft-material phase. As we demonstrate, a crucial effect of bond-breaking that accompanies the softening of the material is an increase in contour length associated with chains unraveling. The model describes also the self-healing properties of the material by assuming partial bond reconnection upon unloading. Despite its simplicity, the proposed mechanical system reproduces the main experimental effects observed in cyclic loading of spider silks. Moreover, our approach is amenable to two- or three-dimensional extensions and may prove to be a useful tool in the field of microstructure optimization for bioinspired materials. PMID:20441758

  12. A parasitoid wasp induces overwintering behaviour in its spider host.

    Science.gov (United States)

    Korenko, Stanislav; Pekár, Stano

    2011-01-01

    Parasites and parasitoids control behaviors of their hosts. However, the origin of the behavior evoked by the parasitic organism has been rarely identified. It is also not known whether the manipulation is universal or host-specific. Polysphinctine wasps, koinobiont ectoparasitoids of several spider species that manipulate host web-spinning activity for their own protection during pupation, provide an ideal system to reveal the origin of the evoked behavior. Larva of Zatypota percontatoria performed species-specific manipulation of theridiid spiders, Neottiura bimaculata and Theridion varians, shortly before pupation. Parasitized N. bimaculata produced a dense web, whereas parasitized T. varians built a cupola-like structure. The larva pupated inside of either the dense web or the cupola-like structure. We discovered that unparasitized N. bimaculata produce an analogous dense web around their eggsacs and for themselves during winter, while T. varians construct an analogous 'cupola' only for overwintering. We induced analogous manipulation in unparasitized hosts by altering ambient conditions. We discovered that the behavior evoked by larvae in two hosts was functionally similar. The larva evoked protective behaviors that occur in unparasitized hosts only during specific life-history periods.

  13. Tetracycline Reduces Kidney Damage Induced by Loxosceles Spider Venom

    Directory of Open Access Journals (Sweden)

    Cinthya Kimori Okamoto

    2017-03-01

    Full Text Available Envenomation by Loxosceles spider can result in two clinical manifestations: cutaneous and systemic loxoscelism, the latter of which includes renal failure. Although incidence of renal failure is low, it is the main cause of death, occurring mainly in children. The sphingomyelinase D (SMase D is the main component in Loxosceles spider venom responsible for local and systemic manifestations. This study aimed to investigate the toxicity of L. intermedia venom and SMase D on kidney cells, using both In vitro and in vivo models, and the possible involvement of endogenous metalloproteinases (MMP. Results demonstrated that venom and SMase D are able to cause death of human kidney cells by apoptosis, concomitant with activation and secretion of extracellular matrix metalloproteases, MMP-2 and MMP-9. Furthermore, cell death and MMP synthesis and secretion can be prevented by tetracycline. In a mouse model of systemic loxoscelism, Loxosceles venom-induced kidney failure was observed, which was abrogated by administration of tetracycline. These results indicate that MMPs may play an important role in Loxosceles venom-induced kidney injury and that tetracycline administration may be useful in the treatment of human systemic loxoscelism.

  14. Endogenous cortisol levels influence exposure therapy in spider phobia.

    Science.gov (United States)

    Lass-Hennemann, Johanna; Michael, Tanja

    2014-09-01

    Previous research in patients with phobia showed that the administration of glucocorticoids reduces fear in phobic situations and enhances exposure therapy. Glucocorticoids underlie a daily cycle with a peak in the morning and low levels during the evening and night. The aim of the present study was to investigate whether exposure is more effective when conducted in the morning when endogenous cortisol levels are high. Sixty patients meeting DSM IV criteria for specific phobia (animal type) were randomly assigned to one-session exposure treatment either at 08.00 a.m. (high cortisol group) or at 06.00 p.m. (low cortisol group). Participants returned for a posttreatment assessment one week after therapy and a follow-up assessment three months after therapy. Both groups showed good outcome, but patients treated in the morning exhibited significantly less fear of spiders in the behavioral approach test (BAT) and a trend for lower scores on the Fear of Spiders Questionnaire (FSQ) than patients treated in the evening. This effect was present at posttreatment and follow-up. Our findings indicate that exposure therapy is more effective in the morning than in the evening. We suggest that this may be due to higher endogenous cortisol levels in the morning group that enhance extinction memory. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Attention bias modification in specific fears: Spiders versus snakes.

    Science.gov (United States)

    Luo, Xijia; Ikani, Nessa; Barth, Anja; Rengers, Lea; Becker, Eni; Rinck, Mike

    2015-12-01

    Attention Bias Modification (ABM) is used to manipulate attention biases in anxiety disorders. It has been successful in reducing attention biases and anxious symptoms in social anxiety and generalized anxiety, but not yet in specific fears and phobias. We designed a new version of the dot-probe training task, aiming to train fearful participants' attention away from or towards pictures of threatening stimuli. Moreover, we studied whether the training also affected participants' avoidance behavior and their physical arousal upon being confronted with a real threat object. In Experiment 1, students with fear of spiders were trained. We found that the attention manipulation was successful, but the training failed to affect behavior or arousal. In Experiment 2, the same procedure was used on snake-fearful students. Again, attention was trained in the expected directions. Moreover, participants whose attention had been trained away from snakes showed lower physiological arousal upon being confronted with a real snake. The study involved healthy students with normal distribution of the fear of spider/snake. Future research with clinical sample could help with determining the generalizability of the current findings. The effect of ABM on specific phobia is still in question. The finding in the present study suggested the possibility to alter attentional bias with a dot-probe task with general positive stimuli and this training could even affect the behavior while encountering a real threat. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The Australian synchrotron research program

    International Nuclear Information System (INIS)

    Garrett, R.F.

    1998-01-01

    Full text: The Australian Synchrotron Research Program (ASRP) was established in 1996 under a 5 year grant from the Australian Government, and is managed by ANSTO on behalf of a consortium of Australian universities and research organisations. It has taken over the operation of the Australian National Beamline Facility (ANBF) at the Photon Factory, and has joined two CATS at the Advanced Photon Source: the Synchrotron Radiation Instrumentation CAT (SRI-CAT) and the Consortium for Advanced Radiation Sources (CARS). The ASRP thus manages a comprehensive range of synchrotron radiation research facilities for Australian science. The ANBF is a general purpose hard X-ray beamline which has been in operation at the Photon Factory since 1993. It currently caters for about 35 Australian research teams per year. The facilities available at the ANBF will be presented and the research program will be summarised. The ASRP facilities at the APS comprise the 5 sectors operated by SRI-CAT, BioCARS and ChemMatCARS. A brief description will be given of the ASRP research programs at the APS, which will considerably broaden the scope of Australian synchrotron science

  17. Australian coal industry continues expansion

    International Nuclear Information System (INIS)

    Edwards, G.E.

    1991-01-01

    Recent saleable Australian black coal production figures are given along with trends in development of new operations and new technology aiming to provide a sound basis for the continuing expansion of the Australian coal industry. Export prices from 1982 to 1991 to Japan (Australia's major export market) are provided, together with Australian dollar return to exporters at the exchange rate prevailing at the start of each contract year. An increased demand for steaming coal is expected, thus maintaining Australia's position as the world's larger exporter. 4 tabs

  18. Predator perception of detritus and eggsac decorations spun by orb-web spiders Cyclosa octotuberculata: Do they function to camouflage the spiders?

    Directory of Open Access Journals (Sweden)

    Wenjin GAN, Fengxiang LIU, Zengtao ZHANG, Daiqin LI

    2010-06-01

    Full Text Available Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or eggsacs to their webs called web decorations. Web decorations resembling spider body colour pattern have been considered to camouflage the spider from predators. While this camouflage is obvious from a human’s perspective, it has rarely been investigated from a predator’s perspective. In this study, we tested the visibility of web decorations by calculating chromatic and achromatic contrasts of detritus and eggsac decorations built by Cyclosa octotuberculata, against four different backgrounds viewed by both bird (e.g., blue tits and hymenopteran (e.g. wasps predators. We showed that both juvenile and adult spiders on webs with detritus or egg-sac decorations were undetectable by both hymenopteran and bird predators over short and long distances. Our results thus suggest that decorating webs with detritus or eggsacs by C. octotuberculata may camouflage the spider from both hymenopteran and bird predators in their common habitats [Current Zoology 56 (3: 379–387, 2010].

  19. Active optical sensor assessment of spider mite damage on greenhouse beans and cotton.

    Science.gov (United States)

    Martin, Daniel E; Latheef, Mohamed A

    2018-02-01

    The two-spotted spider mite, Tetranychus urticae Koch, is an important pest of cotton in mid-southern USA and causes yield reduction and deprivation in fiber fitness. Cotton and pinto beans grown in the greenhouse were infested with spider mites at the three-leaf and trifoliate stages, respectively. Spider mite damage on cotton and bean canopies expressed as normalized difference vegetation index indicative of changes in plant health was measured for 27 consecutive days. Plant health decreased incrementally for cotton until day 21 when complete destruction occurred. Thereafter, regrowth reversed decline in plant health. On spider mite treated beans, plant vigor plateaued until day 11 when plant health declined incrementally. Results indicate that pinto beans were better suited as a host plant than cotton for rearing T. urticae in the laboratory.

  20. The distribution of spiders and Harvestmen (Chelicerata) in the Dutch National Park "De Hoge Veluwe"

    NARCIS (Netherlands)

    Hammen, van der L.

    1983-01-01

    A preliminary study is made of the distribution of Araneida and Opilionida (Chelicerata) in a National Park in The Netherlands. Special attention is paid to the influence of vegetation structure on the distribution of the spiders.

  1. Composition and Humidity Response of the Black Widow Spider's Gumfoot Silk and its Implications on Adhesion

    Science.gov (United States)

    Jain, Dharamdeep; Zhang, Ci; Cool, Lydia Rose; Blackledge, Todd. A.; Wesdemiotis, Chrys; Miyoshi, Toshikazu; Dhinojwala, Ali

    Humidity plays an important part in the performance of biomaterials such as pollen, gecko toe, wheat awns, bird feathers and dragline silk. Capture silk produced by web building spiders form an interesting class of humidity responsive biological glues. The adhesive properties of the widely studied `viscid silk' produced by orbweb-weaving spiders is highly humidity sensitive. On the other hand, relatively less is known about the dependence of composition and humidity response towards adhesion for `gumfoot' silk produced by cobweb-weaving spiders. In the present study, we investigate the gumfoot silk produced by Black Widow using adhesion mechanics, microscopy and spectroscopic methods. The results show the presence of hygroscopic salts, glycoproteins and previously known spider coating peptides in silk and their importance in the humidity response and adhesion. The current study elucidates the role of constituents of capture silk in its adhesion mechanism and offers insights to novel ways for fabricating bio-inspired adhesives.

  2. Epigeic Spiders from Lowland Oak Woodlands in the South Moravia Region (Czech Republic

    Directory of Open Access Journals (Sweden)

    Kamila Surovcová

    2017-01-01

    Full Text Available This paper presents spider faunistics from abandoned coppice oak forest stands located along the South Moravia region. Spiders were collected from May to July 2012 by pitfall trapping at eight different localities. We collected 1945 adult spiders representing 20 families, 53 genera, and 90 species. More than one-third of all the species are known to be xerothermophilous with ecological restrictions to open and partly shaded habitats such as forest-steppe and sparse forests which belong to endangered habitats along central Europe. The most abundant species were Pardosa alacris, P. lugubris and Arctosa lutetiana from the family Lycosidae. In the surveyed area, 24 species were found listed in the Red List of Threatened Species in the Czech Republic (CR – 1 species, EN – 2 species, VU – 15 species, LC – 6 species. In general, we discovered a substantially diversified spider community with a large presence of rare and endangered species characteristic for open and xeric habitats.

  3. Intersexual Trophic Niche Partitioning in an Ant-Eating spider (Araneae: Zodariidae)

    DEFF Research Database (Denmark)

    Pekár, Stanislav; Martisová, Martina; Bilde, T.

    2011-01-01

    lead to higher energy demands in females driven by fecundity selection, while males invest in mate searching. We tested predictions of the two hypotheses underlying intersexual trophic niche partitioning in a natural population of spiders. Zodarion jozefienae spiders specialize on Messor barbarus ants...... that are polymorphic in body size and hence comprise potential trophic niches for the spider, making this system well-suited to study intersexual trophic niche partitioning. Methodology/Principal Findings Comparative analysis of trophic morphology (the chelicerae) and body size of males, females and juveniles...... demonstrated highly female biased SSD (Sexual Size Dimorphism) in body size, body weight, and in the size of chelicerae, the latter arising from sex-specific growth patterns in trophic morphology. In the field, female spiders actively selected ant sub-castes that were larger than the average prey size...

  4. Prediction of abundance of forest spiders according to climate warming in South Korea

    Directory of Open Access Journals (Sweden)

    Tae-Sung Kwon

    2014-06-01

    Full Text Available Distribution of spiders will be changed as climate warms. Abundance of spider species was predicted nationwide in South Korea. Abundance of spiders was projected using temperature species distribution model based on a nationwide data (366 forest sites according to climate change scenario RCP 4.5 and 8.5. The model predicts that 9 out of 17 species will increase in abundance while 8 species will decrease. Based on this finding, a qualitative prediction (increase or decrease was conducted on the species with more than 1% occurrence: 68 species are expected to decrease, 9 to increase, and 8 to change a little. In pooled estimation, 76 species (75% are expected to decrease, 18 species (18% to increase, and by 8 species (8% to have little change. The projection indicates that majority of spider species will decrease, but minority of species will increase as climate warms, suggesting great increase of remained species in lowlands.

  5. Contamination and Harm Relevant UCS-Expectancy Bias in Spider Phobic Individuals : Influence of Treatment

    NARCIS (Netherlands)

    van Overveld, Mark; de Jong, Peter J.; Huijding, Jorg; Peters, Madelon L.

    2010-01-01

    Phobic individuals expect aversive UCS's following encounters with phobic stimuli. Previous research using a thought-experiment procedure showed that contamination rather than harm-related outcome expectancies differentiated best between high and low spider fearful undergraduates. This study

  6. Mediterranean Recluse Spider, Loxosceles rufescens (Araneae: Sicariidae from Charkhab Cave, Southern Iran

    Directory of Open Access Journals (Sweden)

    Saber Sadeghi

    2017-04-01

    Full Text Available Background: The best-known dangerous spiders belong to the six genera. The genus Loxosceles or violin spiders are well known for their ability to cause skin necrosis or loxoscelism. All Loxosceles species have medical im­portance due to their necrotizing venom. The present article reports the occurrence of L. rufescens in Charkhab Cave, south of Iran (Larestan.Methods: The specimens were collected from the Charkhab Cave using handling forceps, paintbrush and aspirator and preserved in 96% ethanol.Results: Loxosceles rufescens, a medically important spider, is recorded from Charkhab Cave in Fars Province (southwest of Iran. Identification of L. rufescens was performed based on external morphology and the features of male genitalia.Conclusion: Presence of L. rufescens in south of Iran especially in a cave confirmed that this species is a widely distributed species in Iran. Therefore, cavers or cave visitors should be aware of this poisonous spider in caves.

  7. Envia garciai, a new genus and species of mygalomorph spiders (Araneae, Microstigmatidae from Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Ott Ricardo

    2003-01-01

    Full Text Available The genus Envia, comprising only the new species Envia garciai, is proposed. These small mygalomorph spiders were abundantly collected in soil cores and litter samples in primary rain forests near Manaus, Amazonas, Brazil.

  8. Novel Spider 3D Woven Seamless ADEPT Aero-Shell, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Bally Ribbon Mills will demonstrate the proposed novel weaving technique and produce a one-piece spider weave for the ADEPT aero-shell. NASA AMES has been working...

  9. SpiderFab: Process for On-Orbit Construction of Kilometer-Scale Apertures

    Data.gov (United States)

    National Aeronautics and Space Administration — SpiderFab is a novel additive manufacturing technique which combines the techniques of fused deposition modeling (FDM) with methods derived from automated composite...

  10. Recognition and successful treatment of priapism and suspected black widow spider bite with antivenin.

    Science.gov (United States)

    Goel, Sheila Choudhury; Yabrodi, Mouhammad; Fortenberry, James

    2014-10-01

    Priapism, although uncommon in preadolescent children, is considered a true emergency. Envenomation by a black widow spider bite has been reported to induce priapism as a manifestation of its toxicity. Early recognition and timely administration of antivenin have been reported to be effective in relieving priapism. Clinicians who care for children need to be aware of this unusual presentation. The diagnosis is traditionally from either direct observation of a spider bite or capture of a spider. We report a case of a previously healthy 2-year-old boy who presented with severe irritability, leg cramps, and stomach ache. The diagnosis of a likely black widow spider envenomation was made on the basis of clinical suspicion and suggestive physical findings in absence of demonstrated exposure. This case highlights the importance of early recognition and successful resolution of symptoms with administration of antivenin and supportive care.

  11. Biomimetic Spider Leg Joints: A Review from Biomechanical Research to Compliant Robotic Actuators

    Directory of Open Access Journals (Sweden)

    Stefan Landkammer

    2016-07-01

    Full Text Available Due to their inherent compliance, soft actuated joints are becoming increasingly important for robotic applications, especially when human-robot-interactions are expected. Several of these flexible actuators are inspired by biological models. One perfect showpiece for biomimetic robots is the spider leg, because it combines lightweight design and graceful movements with powerful and dynamic actuation. Building on this motivation, the review article focuses on compliant robotic joints inspired by the function principle of the spider leg. The mechanism is introduced by an overview of existing biological and biomechanical research. Thereupon a classification of robots that are bio-inspired by spider joints is presented. Based on this, the biomimetic robot applications referring to the spider principle are identified and discussed.

  12. SpiderFab: Architecture for On-Orbit Construction of Kilometer-Scale Apertures

    Data.gov (United States)

    National Aeronautics and Space Administration — The SpiderFab effort has investigated the value proposition and technical feasibility of radically changing the way we build and deploy spacecraft in order to escape...

  13. Captive spider monkeys (Ateles geoffroyi) arm-raise to solicit allo-grooming.

    Science.gov (United States)

    Scheel, Matthew H; Edwards, Dori

    2012-03-01

    Old World monkeys solicit allo-grooming from conspecifics. However, there are relatively few studies of allo-grooming among spider monkeys, and descriptions of allo-grooming solicitation among spider monkeys are anecdotal. In this study, eighty-one hours of video, shot over eight weeks, captured 271 allo-grooming bouts among small groups of captive spider monkeys. Six of eight monkeys made heretofore unreported arm-raises that solicited higher than normal rates of allo-grooming. Allo-grooming bout durations following arm-raises also tended to be longer than bouts not preceded by arm-raises. The efficacy of the arm-raise at soliciting allo-grooming suggests spider monkeys are capable of intentional communication. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. The brown spider Loxosceles laeta: source of the remedy Tarentula cubensis?

    Science.gov (United States)

    Richardson-Boedler, C

    2002-07-01

    The homeopathic remedy Tarentula cubensis (Cuban tarantula), used in homeopathy to treat abscesses with burning pains, gangrene, septicaemia, toxaemia, has been grouped by homeopathic authorities with either the mygalomorph or wolf spiders. The original specimen used for preparation of the mother tincture was decomposed, leaving the spider's exact identity in doubt. Investigation of the toxicological and clinical literature, compared with homeopathic materia medica, reveals the brown spider, Loxosceles laeta, indigenous to South America but present also in Mid- and North America, as a more likely source. Venoms of spiders of the genus Loxosceles cause severe necrotic arachnidism, as well as, in some cases, a life-threatening systemic reaction marked by renal failure, disseminated intravascular coagulation, thrombocytopeania, coma and convulsions.

  15. Detritus decorations of an orb-weaving spider, Cyclosa mulmeinensis (Thorell): for food or camouflage?

    Science.gov (United States)

    Tan, Eunice J; Li, Daiqin

    2009-06-01

    Many species of the orb-web spider genus Cyclosa often adorn their webs with decorations of prey remains, egg sacs and/or plant detritus, termed ;detritus decorations'. These detritus decorations have been hypothesised to camouflage the spider from predators or prey and thus reduce predation risk or increase foraging success. In the present study, we tested these two alternative hypotheses simultaneously using two types of detritus decorations (prey remain and egg sac) built by Cyclosa mulmeinensis (Thorell). By monitoring the possible responses of predators to spiders on their webs with and without decorations in the field, we tested whether web decorations would reduce the mortality of spiders. Wasp predators were observed to fly in the vicinity of webs with decorations slightly more often than in the vicinity of webs without decorations but there were very few attacks on spiders by wasps. By comparing the insect interception rates of webs with and without decorations in the field, we tested whether web decorations would increase the foraging success. Webs decorated with prey remains or egg sacs intercepted more insects than those without in the field. By calculating colour contrasts of both prey-remain and egg-sac decorations against spiders viewed by bird (blue tits) and hymenopteran (e.g. wasps) predators as well as hymenopteran (bees) prey, we showed that C. mulmeinensis spiders on webs with egg-sac decorations were invisible to both hymenopteran prey and predators and bird predators over short and long distances. While spiders on webs with prey-remain decorations were invisible to both hymenopterans and birds over short distances, spiders on webs with prey-remain decorations were visible to both predators and prey over long distances. Our results thus suggest that decorating webs with prey remains and egg sacs in C. mulmeinensis may primarily function as camouflage to conceal the spider from insects rather than as prey attractants, possibly contributing to

  16. Spider fauna of semi-dry grasslands on a military training base in Northwest Germany (Münster

    Directory of Open Access Journals (Sweden)

    Buchholz, Sascha

    2008-07-01

    Full Text Available The spider fauna of semi-dry grasslands on the military training area of Dorbaum near Münster (North Rhine-Westphalia was investigated. From 2002 to 2003 a total of 11,194 mature spiders from 141 species and 20 families was caught by pitfall trapping and hand sampling. Among them are 18 species listed in the Red Data Book of North Rhine-Westphalia, four species are rare or previously rarely recorded. Most of the spiders are habitat generalists that extend their occurrence into all types of habitats, while the number of species which are stenotopic to sand habitats is noticeably low (n = 13. The spider data were analysed with Principal Component Analysis (PCA. It is possible to distinguish spider communities of neighbouring forested habitats from species groups of open habitats, but there is no uniform spider community which is characteristic for semi-dry grassland.

  17. Web building and silk properties functionally covary among species of wolf spider.

    Science.gov (United States)

    Lacava, M; Camargo, A; Garcia, L F; Benamu, M; Santana, M; Fang, J; Wang, X; Blamires, S J

    2018-04-15

    While phylogenetic studies have shown covariation between the properties of spider major ampullate (MA) silk and web building, both spider webs and silks are highly plastic so we cannot be sure whether these traits functionally co-vary or just vary across environments that the spiders occupy. Since MaSp2-like proteins provide MA silk with greater extensibility, their presence is considered necessary for spider webs to effectively capture prey. Wolf spiders (Lycosidae) are predominantly non-web building, but a select few species build webs. We accordingly collected MA silk from two web building and six non-web building species found in semi-rural ecosystems in Uruguay to test whether the presence of MaSp2-like proteins (indicated by amino acid composition), silk mechanical properties, and silk nanostructures, were associated with web building across the group. The web building and non-web building species were from disparate subfamilies so we estimated a genetic phylogeny to perform appropriate comparisons. For all of the properties measured we found differences between web building and non-web building species. A phylogenetic regression model confirmed that web building and not phylogenetic inertia influences silk properties. Our study definitively showed an ecological influence over spider silk properties. We expect that the presence of the MaSp2-like proteins and the subsequent nanostructures improves the mechanical performance of silks within the webs. Our study furthers our understanding of spider web and silk co-evolution and the ecological implications of spider silk properties. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. A checklist of the spiders (Araneae) of the Chornohora Mountain massif (the Ukrainian Carpathians)

    OpenAIRE

    Hirna, Anna; Gnelitsa, Valery; Zhukovets, Evgeni

    2016-01-01

    The present checklist of spiders native to the Chornohora Mts of the Ukrainian Carpathians is based both on literature-derived data and on material collected by the authors in 1999, 2006 and 2011-2014. The majority of these studies (approximately 80 %) were conducted in the upper montane forests, subalpine and alpine levels on the slopes of the main ridge and adjacent spurs and mountains. The study also covers glacial cirques and river valleys. A few spiders were collected from local villages...

  19. On Graceful Spider Graphs with at Most Four Legs of Lengths Greater than One

    Directory of Open Access Journals (Sweden)

    A. Panpa

    2016-01-01

    Full Text Available A graceful labeling of a tree T with n edges is a bijection f:V(T→{0,1,2,…,n} such that {|f(u-f(v|:uv∈E(T} equal to {1,2,…,n}. A spider graph is a tree with at most one vertex of degree greater than 2. We show that all spider graphs with at most four legs of lengths greater than one admit graceful labeling.

  20. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems.

    Science.gov (United States)

    Kraus, Johanna M; Gibson, Polly P; Walters, David M; Mills, Marc A

    2017-05-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI, USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r 2  > 0.78) and had similar mean ΣPCB concentrations when averaged across all years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa less effective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2017;36:1278-1286. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in

  1. Linking Native and Invader Traits Explains Native Spider Population Responses to Plant Invasion.

    Directory of Open Access Journals (Sweden)

    Jennifer N Smith

    Full Text Available Theoretically, the functional traits of native species should determine how natives respond to invader-driven changes. To explore this idea, we simulated a large-scale plant invasion using dead spotted knapweed (Centaurea stoebe stems to determine if native spiders' web-building behaviors could explain differences in spider population responses to structural changes arising from C. stoebe invasion. After two years, irregular web-spiders were >30 times more abundant and orb weavers were >23 times more abundant on simulated invasion plots compared to controls. Additionally, irregular web-spiders on simulated invasion plots built webs that were 4.4 times larger and 5.0 times more likely to capture prey, leading to >2-fold increases in recruitment. Orb-weavers showed no differences in web size or prey captures between treatments. Web-spider responses to simulated invasion mimicked patterns following natural invasions, confirming that C. stoebe's architecture is likely the primary attribute driving native spider responses to these invasions. Differences in spider responses were attributable to differences in web construction behaviors relative to historic web substrate constraints. Orb-weavers in this system constructed webs between multiple plants, so they were limited by the overall quantity of native substrates but not by the architecture of individual native plant species. Irregular web-spiders built their webs within individual plants and were greatly constrained by the diminutive architecture of native plant substrates, so they were limited both by quantity and quality of native substrates. Evaluating native species traits in the context of invader-driven change can explain invasion outcomes and help to identify factors limiting native populations.

  2. Biological control of two-spotted spider mites using phytoseiid predators

    OpenAIRE

    Sabelis, M.W.

    1982-01-01

    The searching behaviour of individual predators of four phytoseiid species ( Phytoseiulus persimilis , Amblyseius p o tentillae , Amblyseius bibens , Metaseiulus occidentalis ) is investigated in relation to the two-spotted spider mite ( Tetranychus urticae ), which infests greenhouse roses. Especially the role of spider- mite webbing in the predator-prey relation is s...

  3. Coagulopathy after spider bites in a six-year-old boy

    Directory of Open Access Journals (Sweden)

    Ansari SH.

    2008-06-01

    Full Text Available Background: Spider bites are common in most parts of the world. In some areas, where snake or scorpion bites are common, spider bites may not be considered a significant problem by the general public and those who have been bitten by spiders may not go to a hospital. However, significant problems are observed in the victims of certain species of spiders including: widow spider (of the genus Latrodectus, including the black widow and brown spiders (of the genus Loxosceles, such as the brown recluse. Case: We report a six-year-old boy, admitted to the hospital two weeks after suffering a spider bite. The patient presented with a severe nose bleed, ecchymosis and purpura, as well as anemia, indicating a clotting disorder. Laboratory results revealed abnormal values for prothrombin time (PT >50 sec, partial thromboplastin time (PTT >120 min and fibrinogen = 0 mg/dl, whereas factor VIII was normal according to a mixing study, with a normal platelet count of 350,000/µl. The patient was managed with fresh frozen plasma every 12 h, and was discharged one week after hospital admission. At present, the patient is well with more normal laboratory results one month after treatment: PT=13.4 sec, PTT= 34 sec, fibrinogen=105 mg/dl.         Conclusions: Although spider bites are uncommon in Iran, severe systemic reactions may occur in the pediatric population requiring admission to the pediatric intensive care unit. These systemic reactions may include hemolytic anemia coagulopathy and renal failure.

  4. Reversible Myocarditis and Pericarditis after Black Widow Spider Bite or Kounis Syndrome?

    OpenAIRE

    Yaman, Mehmet; Mete, Turkan; Ozer, Ismail; Yaman, Elif; Beton, Osman

    2015-01-01

    Clinical manifestation of black widow spider bite is variable and occasionally leads to death in rural areas. Cases of myocarditis and pericarditis after black widow spider bite are rare and the associated prognostic significance is unknown. Kounis syndrome has been defined as an acute coronary syndrome in the setting of allergic or hypersensitivity and anaphylactic or anaphylactoid insults that manifests as vasospastic angina or acute myocardial infarction or stent thrombosis. Allergic myoca...

  5. Recruitment and diversification of an ecdysozoan family of neuropeptide hormones for black widow spider venom expression

    OpenAIRE

    McCowan, Caryn; Garb, Jessica E.

    2013-01-01

    Venoms have attracted enormous attention because of their potent physiological effects and dynamic evolution, including the convergent recruitment of homologous genes for venom expression. Here we provide novel evidence for the recruitment of genes from the Crustacean Hyperglycemic Hormone (CHH) and arthropod Ion Transport Peptide (ITP) superfamily for venom expression in black widow spiders. We characterized latrodectin peptides from venom gland cDNAs from the Western black widow spider (Lat...

  6. The Treatment of Black Widow Spider Envenomation with Antivenin Latrodectus Mactans: A Case Series

    OpenAIRE

    Offerman, Steven R; Daubert, G Patrick; Clark, Richard F

    2011-01-01

    Black widow spiders (Latrodectus mactans) are found throughout the US. Though bites are relatively uncommon, they pose a significant health problem with over 2500 reported to American poison control centers annually. Black widow spider bites cause a characteristic envenomation syndrome consisting of severe pain, muscle cramping, abdominal pain, and back pain. The significant pain associated with envenomation is often refractory to traditional analgesics. Antivenom (Antivenin Latrodectus macta...

  7. Peptidomic and transcriptomic profiling of four distinct spider venoms.

    Directory of Open Access Journals (Sweden)

    Vera Oldrati

    Full Text Available Venom based research is exploited to find novel candidates for the development of innovative pharmacological tools, drug candidates and new ingredients for cosmetic and agrochemical industries. Moreover, venomics, as a well-established approach in systems biology, helps to elucidate the genetic mechanisms of the production of such a great molecular biodiversity. Today the advances made in the proteomics, transcriptomics and bioinformatics fields, favor venomics, allowing the in depth study of complex matrices and the elucidation even of minor compounds present in minute biological samples. The present study illustrates a rapid and efficient method developed for the elucidation of venom composition based on NextGen mRNA sequencing of venom glands and LC-MS/MS venom proteome profiling. The analysis of the comprehensive data obtained was focused on cysteine rich peptide toxins from four spider species originating from phylogenetically distant families for comparison purposes. The studied species were Heteropoda davidbowie (Sparassidae, Poecilotheria formosa (Theraphosidae, Viridasius fasciatus (Viridasiidae and Latrodectus mactans (Theridiidae. This led to a high resolution profiling of 284 characterized cysteine rich peptides, 111 of which belong to the Inhibitor Cysteine Knot (ICK structural motif. The analysis of H. davidbowie venom revealed a high richness in term of venom diversity: 95 peptide sequences were identified; out of these, 32 peptides presented the ICK structural motif and could be classified in six distinct families. The profiling of P. formosa venom highlighted the presence of 126 peptide sequences, with 52 ICK toxins belonging to three structural distinct families. V. fasciatus venom was shown to contain 49 peptide sequences, out of which 22 presented the ICK structural motif and were attributed to five families. The venom of L. mactans, until now studied for its large neurotoxins (Latrotoxins, revealed the presence of 14

  8. Physical characterization of functionalized spider silk: electronic and sensing properties

    Directory of Open Access Journals (Sweden)

    Eden Steven, Jin Gyu Park, Anant Paravastu, Elsa Branco Lopes, James S Brooks, Ongi Englander, Theo Siegrist, Papatya Kaner and Rufina G Alamo

    2011-01-01

    Full Text Available This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of β-sheet (crystalline and amorphous (helical structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 °C, has a strong effect on the morphology of silk bundles (increasing their size, on the process of pyrolization (suppressing mass loss rates and on the resulting carbonized fiber structure (that becomes more robust against bending and strain. The effects of iodine doping and other functional parameters (vacuum and thin film coating motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and β-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR spectroscopy, revealing a partial transformation of β-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof

  9. Evaluation of the efficacy of vacuum cleaners for the integrated control of brown spider Loxosceles intermedia

    Directory of Open Access Journals (Sweden)

    E. N. Ramires

    2007-01-01

    Full Text Available Some venomous spiders of the genus Loxosceles can reach high population densities inside and around houses. In Brazil, most spider accidents are related to Loxosceles intermedia. Control of loxoscelism should utilize integrated pest management tools, such as vacuum cleaners, to eliminate egg sacs, webs and spiders. The present study tested the efficacy of one type of vacuum cleaner (for professional and domestic use in the control of L. intermedia populations. Cockroaches (Pycnoscelus surinamensis were used in some tests for comparison. Vacuuming using standard accessories or a paper tube resulted in the death of all female (n=60, male (n=60, young (n=60 and just-hatched (n=60 L. intermedia, and all egg sacs (n=5 were destroyed. The removal of the plastic plate present at the bottom of the vacuuming tube inside the machine allowed some spiders to survive the vacuuming process. When kept inside a vacuum bag full of dust and debris, adult females (n=10 survived for 10 days; however, significant mortality was observed among male (n=10 and young individuals (n=10. Addition of cornstarch to the vacuum bag did not affect the spiders (n=20. Vacuum cleaners, such as the one used in the present investigation, are promising tools for integrated management of L. intermedia and other spiders in domestic environments.

  10. Plasticity in major ampullate silk production in relation to spider phylogeny and ecology.

    Directory of Open Access Journals (Sweden)

    Cecilia Boutry

    Full Text Available Spider major ampullate silk is a high-performance biomaterial that has received much attention. However, most studies ignore plasticity in silk properties. A better understanding of silk plasticity could clarify the relative importance of chemical composition versus processing of silk dope for silk properties. It could also provide insight into how control of silk properties relates to spider ecology and silk uses. We compared silk plasticity (defined as variation in the properties of silk spun by a spider under different conditions between three spider clades in relation to their anatomy and silk biochemistry. We found that silk plasticity exists in RTA clade and orbicularian spiders, two clades that differ in their silk biochemistry. Orbiculariae seem less dependent on external spinning conditions. They probably use a valve in their spinning duct to control friction forces and speed during spinning. Our results suggest that plasticity results from different processing of the silk dope in the spinning duct. Orbicularian spiders seem to display better control of silk properties, perhaps in relation to their more complex spinning duct valve.

  11. Tactile learning by a whip spider, Phrynus marginemaculatus C.L. Koch (Arachnida, Amblypygi).

    Science.gov (United States)

    Santer, Roger D; Hebets, Eileen A

    2009-04-01

    The ability of animals to learn and remember underpins many behavioural actions and can be crucial for survival in certain contexts, for example in finding and recognising a habitual refuge. The sensory cues that an animal learns in such situations are to an extent determined by its own sensory specialisations. Whip spiders (Arachnida, Amblypygi) are nocturnal and possess uniquely specialised sensory systems that include elongated 'antenniform' forelegs specialised for use as chemo- and mechanosensory feelers. We tested the tactile learning abilities of the whip spider Phrynus marginemaculatus in a maze learning task with two tactile cues of different texture--one associated with an accessible refuge, and the other with an inaccessible refuge. Over ten training trials, whip spiders got faster and more accurate at finding the accessible refuge. During a subsequent test trial where both refuges were inaccessible, whip spiders searched for significantly longer at the tactile cue previously associated with the accessible refuge. Using high-speed cinematography, we describe three distinct antenniform leg movements used by whip spiders during tactile examination. We discuss the potential importance of tactile learning in whip spider behaviour and a possible role for their unique giant sensory neurons in accessing tactile information.

  12. Temperature-dependent fumigant activity of essential oils against twospotted spider mite (Acari: Tetranychidae).

    Science.gov (United States)

    Lim, Eu Gene; Roh, Hyun Sik; Coudron, Thomas A; Park, Chung Gyoo

    2011-04-01

    Fumigant activity of 34 commercial essential oils was assessed on female adults and eggs of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) at three temperatures (5, 15, and 25 degrees C). Common thyme, cinnamon, and lemongrass oils were equally effective on twospotted spider mite adults showing 85.8-100% mortality at 5 and 10 microl/liter air at 25 degrees C. At a lower temperature of 15 degrees C, lemongrass and peppermint resulted in > or =90% mortality of adults at 10 microl/liter air. Only lemongrass was relatively active at 5 microl/liter air, at 15 degrees C. At 5 degrees C, lemongrass and peppermint caused significantly higher adult mortality than controls but only at 10 microl/liter air. Common thyme oil showed the highest ovicidal activity at 5 microl/liter air at 25 degrees C. Among the main components of common thyme and lemongrass oils, citral was lethal to twospotted spider mite adults at all tested temperatures. Carvacrol, thymol, and citral caused the same inhibitory effects on the hatch of twospotted spider mite eggs at 25 degrees C. However, citral was more active than other compounds to twospotted spider mite eggs at 15 degrees C. Therefore, we conclude that citral has the best potential for development as a fumigant against twospotted spider mite on agricultural products harvested late in the growing season.

  13. Nutritional compound analysis and morphological characterization of spider plant (Cleome gynandra) - an African indigenous leafy vegetable.

    Science.gov (United States)

    Omondi, Emmanuel O; Engels, Christof; Nambafu, Godfrey; Schreiner, Monika; Neugart, Susanne; Abukutsa-Onyango, Mary; Winkelmann, Traud

    2017-10-01

    Spider plant is among the important indigenous African leafy vegetables having the potential to contribute to food and nutritional security in sub-Saharan Africa. The main objective of this study was to quantify the mineral concentration, to identify and quantify glucosinolates and flavonoids in spider plant and further to characterize spider plant entries using important morphological traits. Thirty spider plant entries from different African countries, comprising of farmers' cultivars, gene bank accessions and advanced lines were grown in a field experiment and harvested for leaves, stems, flowers and siliques at different developmental stages. Five plant types based on the stem and petiole colorations were identified. Significant genotypic differences were shown for all the morphological traits except for 100 seed weight and silique weight. High mineral concentrations in the leaf tissue were observed especially for potassium, calcium, magnesium, phosphorus, iron, manganese and zinc. The aliphatic 3-hydroxypropyl glucosinolate was the main glucosinolate detected in all tissues with the highest concentrations in the reproductive organs. Glycosides of quercetin, kaempferol and isorhamnetin were the main flavonoids. Isorhamnetin glycosides were detected in trace amounts in both, leaves and inflorescences, while quercetin and kaempferol glycosides were the dominant flavonoids in the leaves and inflorescences, respectively. This knowledge of beneficial nutrient contents is an incentive for promoting spider plant consumption for improved human health while the morphological diversity analysis will be important for the further development of the spider plant germplasm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Local and Landscape Correlates of Spider Activity Density and Species Richness in Urban Gardens.

    Science.gov (United States)

    Otoshi, Michelle D; Bichier, Peter; Philpott, Stacy M

    2015-08-01

    Urbanization is a major threat to arthropod biodiversity and abundance due to reduction and loss of suitable natural habitat. Green spaces and small-scale agricultural areas may provide habitat and resources for arthropods within densely developed cities. We studied spider activity density (a measure of both abundance and degree of movement) and diversity in urban gardens in Santa Cruz, Santa Clara, and Monterey counties in central California, USA. We sampled for spiders with pitfall traps and sampled 38 local site characteristics for 5 mo in 19 garden sites to determine the relative importance of individual local factors. We also analyzed 16 landscape variables at 500-m and 1-km buffers surrounding each garden to determine the significance of landscape factors. We identified individuals from the most common families to species and identified individuals from other families to morphospecies. Species from the families Lycosidae and Gnaphosidae composed 81% of total adult spider individuals. Most of the significant factors that correlated with spider activity density and richness were local rather than landscape factors. Spider activity density and richness increased with mulch cover and flowering plant species, and decreased with bare soil. Thus, changes in local garden management have the potential to promote diversity of functionally important spiders in urban environments. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Composition and Function of Spider Glues Maintained During the Evolution of Cobwebs.

    Science.gov (United States)

    Jain, Dharamdeep; Zhang, Ci; Cool, Lydia Rose; Blackledge, Todd A; Wesdemiotis, Chrys; Miyoshi, Toshikazu; Dhinojwala, Ali

    2015-10-12

    Capture silks are an interesting class of biological glues that help spiders subdue their prey. Viscid capture silk produced by the orb web spiders is a combination of hygroscopic salts that aid in water uptake and interact with adhesive glycoproteins to make them soft and sticky. The orb was a stepping stone to the evolution of new web types, but little is known about the adhesives in these webs. For instance, cobweb spiders evolved from orb-weaving ancestors and utilize glue in specialized sticky gumfoot threads rather than an elastic spiral. Early investigation suggests that gumfoot adhesives are quite different viscid glues because they lack a visible glycoprotein core, act as viscoelastic fluids rather than solids, and are largely invariant to humidity. Here, we use spectroscopic and staining methods to show that the gumfoot silk produced by Latrodectus hesperus (western black widow) is composed of hygroscopic organic salts and water insoluble glycoproteins, similar to viscid silk, in addition to a low concentration of spider coating peptides reported before. Our adhesion studies reveal that the organic salts play an important role in adhesion, similar to that seen in orb web spiders, but modulating function at much lower humidity. Our work shows more similarities in the viscid silk produced by orb web and cobweb spiders than previously anticipated and provide guidelines for developing synthetic adhesives that can work in dry to humid environments.

  16. Fecal and Salivary Cortisol Concentrations in Woolly (Lagothrix ssp. and Spider Monkeys (Ateles spp.

    Directory of Open Access Journals (Sweden)

    Kimberly D. Ange-van Heugten

    2009-01-01

    Full Text Available Detrimental physiological effects due to stressors can contribute to the low captive success of primates. The objective of this research was to investigate the potential impact of diet composition on cortisol concentrations in feces and saliva in woolly (n=27 and spider monkeys (n=61. The research was conducted in three studies: the first investigated spider monkeys in the United States, the second investigated spider monkeys within Europe, and the third investigated woolly monkeys within Europe. Fecal cortisol in spider monkeys in US zoos varied (P=.07 from 30 to 66 ng/g. The zoo with the highest fecal cortisol also had the highest salivary cortisol (P≤.05. For European zoos, fecal cortisol differed between zoos for both spider and woolly monkeys (P≤.05. Spider monkeys had higher fecal cortisol than woolly monkeys (P≤.05. Zoos with the highest dietary carbohydrates, sugars, glucose, and fruit had the highest cortisol. Cortisol was highest for zoos that did not meet crude protein requirements and fed the lowest percentage of complete feeds and crude fiber. Differences among zoos in housing and diets may increase animal stress. The lifespan and reproductive success of captive primates could improve if stressors are reduced and dietary nutrients optimized.

  17. Glucocorticoids enhance in vivo exposure-based therapy of spider phobia.

    Science.gov (United States)

    Soravia, Leila M; Heinrichs, Markus; Winzeler, Livia; Fisler, Melanie; Schmitt, Wolfgang; Horn, Helge; Dierks, Thomas; Strik, Werner; Hofmann, Stefan G; de Quervain, Dominique J-F

    2014-05-01

    Preclinical and clinical studies indicate that the administration of glucocorticoids may promote fear extinction processes. In particular, it has been shown that glucocorticoids enhance virtual reality based exposure therapy of fear of heights. Here, we investigate whether glucocorticoids enhance the outcome of in vivo exposure-based group therapy of spider phobia. In a double blind, block-randomized, placebo-controlled, between-subject study design, 22 patients with specific phobia of spiders were treated with two sessions of in vivo exposure-based group therapy. Cortisol (20 mg) or placebo was orally administered 1 hr before each therapy session. Patients returned for a follow-up assessment one month after therapy. Exposure-based group therapy led to a significant decrease in phobic symptoms as assessed with the Fear of Spiders Questionnaire (FSQ) from pretreatment to immediate posttreatment and to follow-up. The administration of cortisol to exposure therapy resulted in increased salivary cortisol concentrations and a significantly greater reduction in fear of spiders (FSQ) as compared to placebo at follow-up, but not immediately posttreatment. Furthermore, cortisol-treated patients reported significantly less anxiety during standardized exposure to living spiders at follow-up than placebo-treated subjects. Notably, groups did not differ in phobia-unrelated state-anxiety before and after the exposure sessions and at follow-up. These findings indicate that adding cortisol to in vivo exposure-based group therapy of spider phobia enhances treatment outcome. © 2013 Wiley Periodicals, Inc.

  18. First report of brown widow spider sightings in Peninsular Malaysia and notes on its global distribution.

    Science.gov (United States)

    Muslimin, Mustakiza; Wilson, John-James; Ghazali, Amir-Ridhwan M; Braima, Kamil A; Jeffery, John; Wan-Nor, Fitri; Alaa-Eldin, Mohamed E; Mohd-Zin, Siti-Waheeda; Wan-Yusoff, Wan S; Norma-Rashid, Yusoff; Lau, Yee L; Rohela, Mahmud; Abdul-Aziz, Noraishah M

    2015-01-01

    The brown widow spider (Latrodectus geometricus Koch, 1841) has colonised many parts of the world from its continent of origin, Africa. By at least 1841, the species had successfully established populations in South America and has more recently expanded its range to the southern states of North America. This highly adaptable spider has been far more successful in finding its niche around the world than its famous cousins, the black widow, Latrodectus mactans, found in the south-eastern states of North America, and the red-back, Latrodectus hasselti, found mostly in Australia, New Zealand and Japan. We performed an extensive web search of brown widow sightings and mapped the location of each sighting using ArcGIS. Specimens reputedly of the species L. geometricus were collected at three localities in Peninsular Malaysia. The spiders were identified and documented based on an examination of morphological characteristics and DNA barcoding. The spiders found in Peninsular Malaysia were confirmed to be Latrodectus geometricus based on their morphological characteristics and DNA barcodes. We recorded 354 sightings of the brown widow in 58 countries, including Peninsular Malaysia. Reports from the Americas and the Far East suggest a global-wide invasion of the brown widow spider. Herein we report the arrival of the brown widow spider in Peninsular Malaysia and provide notes on the identification of the species and its recently expanded range.

  19. Wolf spider feeding strategies: optimality of prey consumption in Pardosa hortensis.

    Science.gov (United States)

    Samu, F

    1993-05-01

    Feeding behaviour of the wolf spider Pardosa hortensis Thorell (Araneae, Lycosidae) was studied in the laboratory. Characteristics of feeding were measured while prey availability was increased and the results were compared with the predictions of three models: the marginal value theorem (MVT), gut limitation theory (GLT) and the digestion rate limitation model (DRL). As a result of more frequent encounters with prey, the wolf spiders were able to modify their feeding behaviour so that their net energy intake rate increased substantially. Handling time decreased by 30%, and consumption rate increased by 40%. Partial consumption of prey did not occur until the spiders became nearly satiated. This indicated that spiders did not reach the optimum predicted by MVT. The most plausible mechanism for the increased efficiency was prey-stimulated digestive enzyme production as suggested in DRL. The predictions of GLT were not applicable for most of the feeding session, though gut satiation had an influence on the final stages of feeding. P. hortensis seemed to apply a "responsive but cautious" strategy: (i) spiders improved feeding efficiency on entering the higher quality habitat, but (ii) feeding times appeared to be sub-optimal and (iii) spiders were also willing to continue feeding when, as they approached satiation, the previously high efficiency could not be maintained. Such feeding behaviour optimizes long-term energy intake when food is scarce and unpredictable, which corresponds well with the known degree of natural food limitation of these animals.

  20. Itsy bitsy spider?: Valence and self-relevance predict size estimation.

    Science.gov (United States)

    Leibovich, Tali; Cohen, Noga; Henik, Avishai

    2016-12-01

    The current study explored the role of valence and self-relevance in size estimation of neutral and aversive animals. In Experiment 1, participants who were highly fearful of spiders and participants with low fear of spiders rated the size and unpleasantness of spiders and other neutral animals (birds and butterflies). We found that although individuals with both high and low fear of spiders rated spiders as highly unpleasant, only the highly fearful participants rated spiders as larger than butterflies. Experiment 2 included additional pictures of wasps (not self-relevant, but unpleasant) and beetles. The results of this experiment replicated those of Experiment 1 and showed a similar bias in size estimation for beetles, but not for wasps. Mediation analysis revealed that in the high-fear group both relevance and valence influenced perceived size, whereas in the low-fear group only valence affected perceived size. These findings suggest that the effect of highly relevant stimuli on size perception is both direct and mediated by valence. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Spiders (Araneae of stony debris in North Bohemia

    Directory of Open Access Journals (Sweden)

    Růžička, Vlastimil

    1996-12-01

    Full Text Available The arachnofauna was studied at five stony debris sites in northern Bohemia. In Central Europe, the northern and montane species inhabiting cold places live not only on mountain tops and peat bogs but also on the lower edges of boulder debris, where air streaming through the system of inner compartments gives rise to an exceedingly cold microclimate. At such cold sites, spiders can live either on bare stones (Bathyphantes simillimus, Wubanoides uralensis, or in the rich layers of moss and lichen (Diplocentria bidentata. Kratochviliella bicapitata exhibits a diplostenoecious occurence in stony debris and on the tree bark. Latithorax faustus and Theonoe minutissima display diplostenoecious occurence in stony debris and on peat bogs. The occurence of the species Scotina celans in the Czech Republic was documented for the first time.

  2. Spiders in Fauna Europaea: dual use of the database

    Directory of Open Access Journals (Sweden)

    Helsdingen, Peter J. van

    2012-07-01

    Full Text Available The history and current work of the project Fauna Europaea is outlined. The different sources used for building up the database and the efforts to keep it updated are described. Available models of national checklists are discussed and the ideal checklist is described. The double use of the database as a matrix behind the official site of Fauna Europaea – as well as a directly visible document on the website of the European Society of Arachnology – are indicated and the differences in transparency, links to literature sources, and facilities such as distribution maps and calculations of numbers of scores per species or of species per country are discussed. The future of the project is briefly outlined. The need for a European identification tool for spiders is stressed.

  3. Scorpion and spider venom peptides: gene cloning and peptide expression.

    Science.gov (United States)

    Quintero-Hernández, V; Ortiz, E; Rendón-Anaya, M; Schwartz, E F; Becerril, B; Corzo, G; Possani, L D

    2011-12-01

    This communication reviews most of the important findings related to venom components isolated from scorpions and spiders, mainly by means of gene cloning and expression. Rather than revising results obtained by classical biochemical studies that report structure and function of venom components, here the emphasis is placed on cloning and identification of genes present in the venomous glands of these arachnids. Aspects related to cDNA library construction, specific or random ESTs cloning, transcriptome analysis, high-throughput screening, heterologous expression and folding are briefly discussed, showing some numbers of species and components already identified, but also shortly mentioning limitations and perspectives of research for the future in this field. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Mating duration and sperm precedence in the spider Linyphia triangularis

    DEFF Research Database (Denmark)

    Weldingh, Ditte L.; Toft, Søren; Larsen, Ole Næsbye

    2011-01-01

    , especially the males, are able to influence the outcome of mating for their own benefit. We studied the linyphiid spider Linyphia triangularis in which mating follows a strict sequence during which the male inducts two droplets of sperm and transfers them to the female. We performed sperm competition...... experiments (sterile-male technique) including four treatments, in which the copulation of the first male was interrupted at prescribed phases of the mating sequence, while the second male was allowed a complete mating. Second males spent a shorter time than first males on the behaviours prior to sperm...... transfer, but the amount of sperm (2 droplets) and the time spent in sperm transfer were independent of the females’ mating status. The proportion of females accepting the second male depended on the mating duration of the first male, i.e. whether the first male had transferred one or two sperm droplets...

  5. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  6. Systemic lupus erythematosus flare triggered by a spider bite.

    Science.gov (United States)

    Martín Nares, Eduardo; López Iñiguez, Alvaro; Ontiveros Mercado, Heriberto

    2016-01-01

    Systemic lupus erythematosus is a chronic autoimmune disease with a relapsing and remitting course characterized by disease flares. Flares are a major cause of hospitalization, morbidity and mortality in patients with systemic lupus erythematosus. Some triggers for these exacerbations have been identified, including infections, vaccines, pregnancy, environmental factors such as weather, stress and drugs. We report a patient who presented with a lupus flare with predominantly mucocutaneous, serosal and cardiac involvement after being bitten by a spider and we present the possible mechanisms by which the venom elicited such a reaction. To the best of our knowledge, this is the first such case reported in the literature. Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  7. Remote sensing of spider mite damage in California peach orchards

    Science.gov (United States)

    Luedeling, Eike; Hale, Adam; Zhang, Minghua; Bentley, Walter J.; Dharmasri, L. Cecil

    2009-08-01

    Remote sensing techniques can decrease pest monitoring costs in orchards. To evaluate the feasibility of detecting spider mite damage in orchards, we measured visible and near infrared reflectance of 1153 leaves and 392 canopies in 11 peach orchards in California. Pairs of significant wavelengths, identified by Partial Least Squares regression, were combined into normalized difference indices. These and 9 previously published indices were evaluated for correlation with mite damage. Eight spectral regions for leaves and two regions for canopies (at blue and red wavelengths) were significantly correlated with mite damage. These findings were tested by calculating normalized difference indices from the Red and Blue bands of six multispectral aerial images. Index values were linearly correlated with mite damage ( R2 = 0.47), allowing identification of mite hotspots in orchards. However, better standardization of aerial imagery and accounting for perturbing environmental factors will be necessary for making this technique applicable for early mite detection.

  8. Priapism after western black widow spider (Latrodectus hesperus) envenomation.

    Science.gov (United States)

    Bush, Sean; McCune, Rohn; Phan, Tammy

    2014-03-01

    Priapism in children after a black widow spider bite is a rare phenomenon with only a few case reports noted in the literature. Black widow bites are commonly associated with pain, muscle cramping, hypertension, and tachycardia. Initial treatment includes pain control with opiate or opioid medications and benzodiazepines, with antivenom reserved for severe cases of envenomation manifested by uncontrolled pain or hypertension. Treatment with antivenom for priapism is not well described; however, it has been noted to resolve priapism in the few cases that have been reported. We present a case of a 3-year-old boy who was bitten by a black widow and presented with abdominal cramping and priapism. © 2014 Wilderness Medical Society Published by Wilderness Medical Society All rights reserved.

  9. Novel Compact Spider Microstrip Antenna with New Defected Ground Structure

    Science.gov (United States)

    Ghoname, R. S.; Mohamed, M. A.; Hennawy, A. El.

    2012-08-01

    Two novel Defected Ground Structures (DGS) were first proposed, which have better results than that of the dumbbell (published shape). Using the general model of DGS, its equivalent parameters were extracted. The two new proposed shapes of DGS were then used to design a novel compact spider microstrip antenna to minimize its area. The size of the developed antenna was reduced to about 90.5% of that of the conventional one. This antenna with two different novel shapes of DGS was designed and simulated by using the ready-made software package Zeland-IE3D. Finally, it was fabricated by using thin film and photolithographic technique and measured by using vector network analyzer. Good agreements were found between the simulated and measured results.

  10. David and Goliath: potent venom of an ant-eating spider (Araneae) enables capture of a giant prey

    Science.gov (United States)

    Pekár, Stano; Šedo, Onřej; Líznarová, Eva; Korenko, Stanislav; Zdráhal, Zdeněk

    2014-07-01

    It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey.

  11. Traditions in spider monkeys are biased towards the social domain.

    Directory of Open Access Journals (Sweden)

    Claire J Santorelli

    Full Text Available Cross-site comparison studies of behavioral variation can provide evidence for traditions in wild species once ecological and genetic factors are excluded as causes for cross-site differences. These studies ensure behavior variants are considered within the context of a species' ecology and evolutionary adaptations. We examined wide-scale geographic variation in the behavior of spider monkeys (Ateles geoffroyi across five long-term field sites in Central America using a well established ethnographic cross-site survey method. Spider monkeys possess a relatively rare social system with a high degree of fission-fusion dynamics, also typical of chimpanzees (Pan troglodytes and humans (Homo sapiens. From the initial 62 behaviors surveyed 65% failed to meet the necessary criteria for traditions. The remaining 22 behaviors showed cross-site variation in occurrence ranging from absent through to customary, representing to our knowledge, the first documented cases of traditions in this taxon and only the second case of multiple traditions in a New World monkey species. Of the 22 behavioral variants recorded across all sites, on average 57% occurred in the social domain, 19% in food-related domains and 24% in other domains. This social bias contrasts with the food-related bias reported in great ape cross-site comparison studies and has implications for the evolution of human culture. No pattern of geographical radiation was found in relation to distance across sites. Our findings promote A. geoffroyi as a model species to investigate traditions with field and captive based experiments and emphasize the importance of the social domain for the study of animal traditions.

  12. Habitat quality of the woolly spider monkey (Brachyteles hypoxanthus).

    Science.gov (United States)

    da Silva Júnior, Wilson Marcelo; Alves Meira-Neto, João Augusto; da Silva Carmo, Flávia Maria; Rodrigues de Melo, Fabiano; Santana Moreira, Leandro; Ferreira Barbosa, Elaine; Dias, Luiz Gustavo; da Silva Peres, Carlos Augusto

    2009-01-01

    This study examines how habitat structure affects the home range use of a group of Brachyteles hypoxanthus in the Brigadeiro State Park, Brazil. It has been reported that most of the annual feeding time of woolly spider monkeys is spent eating leaves, but they prefer fruits when available. We hypothesise that the protein-to-fibre ratio (PF; best descriptor of habitat quality for folivorous primates) is a better descriptor of habitat quality and abundance for these primates than the structural attributes of forests (basal area is the best descriptor of habitat quality for frugivorous primates of Africa and Asia). We evaluated plant community structure, successional status, and PF of leaf samples from the dominant tree populations, both within the core and from a non-core area of the home range of our study group. Forest structure was a combination of stem density and basal area of dominant tree populations. The core area had larger trees, a higher forest basal area, and higher stem density than the non-core area. Mean PF did not differ significantly between these sites, although PF was influenced by differences in tree regeneration guilds. Large-bodied monkeys could be favoured by later successional stages of forests because larger trees and denser stems prevent the need for a higher expenditure of energy for locomotion as a consequence of vertical travel when the crowns of trees are disconnected in early successional forests. Forest structure variables (such as basal area of trees) driven by succession influence woolly spider monkey abundance in a fashion similar to frugivorous monkeys of Asia and Africa, and could explain marked differences in ranging behaviour and home range use by B. hypoxanthus. Copyright 2009 S. Karger AG, Basel.

  13. Repeated Diversification of Ecomorphs in Hawaiian Stick Spiders.

    Science.gov (United States)

    Gillespie, Rosemary G; Benjamin, Suresh P; Brewer, Michael S; Rivera, Malia Ana J; Roderick, George K

    2018-03-19

    Insular adaptive radiations in which repeated bouts of diversification lead to phenotypically similar sets of taxa serve to highlight predictability in the evolutionary process [1]. However, examples of such replicated events are rare. Cross-clade comparisons of adaptive radiations are much needed to determine whether similar ecological opportunities can lead to the same outcomes. Here, we report a heretofore uncovered adaptive radiation of Hawaiian stick spiders (Theridiidae, Ariamnes) in which different species exhibit a set of discrete ecomorphs associated with different microhabitats. The three primary ecomorphs (gold, dark, and matte white) generally co-occur in native forest habitats. Phylogenetic reconstruction mapped onto the well-known chronosequence of the Hawaiian Islands shows both that this lineage colonized the islands only once and relatively recently (2-3 mya, when Kauai and Oahu were the only high islands in the archipelago) and that the distinct ecomorphs evolved independently multiple times following colonization of new islands. This parallel evolution of ecomorphs matches that of "spiny-leg" long-jawed spiders (Tetragnathidae, Tetragnatha), also in Hawaii [2]. Both lineages are free living, and both have related lineages in the Hawaiian Islands that show quite different patterns of diversification with no evidence of deterministic evolution. We argue that repeated evolution of ecomorphs results from a rugged adaptive landscape, with the few peaks associated with camouflage for these free-living taxa against the markedly low diversity of predators on isolated islands. These features, coupled with a limited genetic toolbox and reduced dispersal between islands, appear to be common to situations of repeated evolution of ecomorphs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Peripheral synapses and giant neurons in whip spiders.

    Science.gov (United States)

    Foelix, Rainer; Troyer, David; Igelmund, Peter

    2002-08-15

    Among invertebrates the synapses between neurons are generally restricted to ganglia, i.e., to the central nervous system (CNS). As an exception, synapses occur in the sensory nerves of arachnid legs, indicating that some nervous integration is already taking place far out in the periphery. In the antenniform legs of whip spiders (Amblypygi), a very special synaptic circuit is present. These highly modified legs contain several large interneurons (giant neurons) that receive mechanosensory input from 700-1,500 tarsal bristles. Some of the sensory cell axons contact a giant neuron at its short, branched dendrite, a few at the soma, but most synapse onto the long giant axon. The fine structure of these synapses resembles that of typical chemical synapses in other arthropods. Although thousands of sensory fibers converge on a single giant neuron, there is no reduction in the actual number of sensory fibers, because these afferent fibers continue their course to the CNS after having made several en passant synapses onto the giant neuron. Touching a single tarsal bristle is sufficient to elicit action potentials in a giant neuron. Owing to the large diameter of the giant axon (10-20 microm), the action potentials reach the CNS within 55 ms, at conduction velocities of up to 7 m/s. However, mechanical stimulation of the tarsal bristles does not elicit a fast escape response, in contrast to giant fiber systems in earthworms, certain insects, and crayfishes. A quick escape is observed in whip spiders, but only after stimulation of the filiform hairs (trichobothria) on the regular walking legs. Although the giant fiber system in the antenniform legs undoubtedly provides a fast sensory pathway, its biological significance is not clearly understood at the moment. Copyright 2002 Wiley-Liss, Inc.

  15. Untangling taxonomy: a DNA barcode reference library for Canadian spiders.

    Science.gov (United States)

    Blagoev, Gergin A; deWaard, Jeremy R; Ratnasingham, Sujeevan; deWaard, Stephanie L; Lu, Liuqiong; Robertson, James; Telfer, Angela C; Hebert, Paul D N

    2016-01-01

    Approximately 1460 species of spiders have been reported from Canada, 3% of the global fauna. This study provides a DNA barcode reference library for 1018 of these species based upon the analysis of more than 30,000 specimens. The sequence results show a clear barcode gap in most cases with a mean intraspecific divergence of 0.78% vs. a minimum nearest-neighbour (NN) distance averaging 7.85%. The sequences were assigned to 1359 Barcode index numbers (BINs) with 1344 of these BINs composed of specimens belonging to a single currently recognized species. There was a perfect correspondence between BIN membership and a known species in 795 cases, while another 197 species were assigned to two or more BINs (556 in total). A few other species (26) were involved in BIN merges or in a combination of merges and splits. There was only a weak relationship between the number of specimens analysed for a species and its BIN count. However, three species were clear outliers with their specimens being placed in 11-22 BINs. Although all BIN splits need further study to clarify the taxonomic status of the entities involved, DNA barcodes discriminated 98% of the 1018 species. The present survey conservatively revealed 16 species new to science, 52 species new to Canada and major range extensions for 426 species. However, if most BIN splits detected in this study reflect cryptic taxa, the true species count for Canadian spiders could be 30-50% higher than currently recognized. © 2015 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

  16. An account of money Spiders from down under (Araneida, Linyphiidae)

    NARCIS (Netherlands)

    Helsdingen, van P.J.

    1972-01-01

    The Australian and New Zealand regions so far were left out of consideration when studying the Linyphiidae (Linyphiinae) on a world-wide basis. When revising the genus Linyphia it appeared that a fair number of species had been described from these regions; but it also became very clear, by a

  17. Observation of predation of the giant fishing spider Ancylometes rufus (Walckenaer, 1837) (Araneae, Ctenidae) on Dendropsophus melanargyreus Cope, 1877 (Anura, Hylidae)

    OpenAIRE

    Moura,Mário Ribeiro; Azevedo,Leonardo Pimenta

    2011-01-01

    We report here an observation of predation of the giant spider Ancylometes rufus on the tree frog Dendropsophus melanargyreus in a southern region of Amazonia Forest. We also reviewed the available literature on predation of this spider species on vertebrates.

  18. Gamma irradiation as a quarantine treatment for spider mites (Acarina: tetranychidae) in horticultural products

    International Nuclear Information System (INIS)

    Ignatowicz, S.; Banasik-Solgala, K.

    1999-01-01

    The carmine spider mite, Tetranychus cinnabarinus (Boisd.), and the two-spotted spider mite, Tetranychus urticae Koch, are closely related species of tetranychid mites (Acarina, Tetranychidae) that respond to gamma irradiation in a similar way. Eggs of both species exposed to gamma radiation early in embryonic development were considerably more susceptible to irradiation than older eggs. The tolerance of eggs to gamma radiation increased in 3-4-day-old eggs, when eye-spots were formed. Nymphs were more resistant to gamma radiation than eggs and larvae. Deteriorative effects of irradiation treatment were reflected in the immatures by their mortality in subsequent developmental stages. A positive relationship between dosage and the percent egg mortality or the mortality of subsequent stages was usually found when the immature stages were irradiated. The sex ratio of adults developed from irradiated eggs, larvae, and nymphs was affected by the irradiation treatment; the ratio was usually skewed towards males. Irradiation of females resulted in increased mortality, lowered fecundity, reduced egg viability, and sex ratio distortion in their progeny. Two-day-old females of the carmine spider mite and the two-spotted spider mite irradiated with 200 or 300 Gy lived as long as the controls. Mortality occurred after 3 weeks. The number of eggs laid by irradiated females of spider mites was considerably lower than in the control, and it decreased as the absorbed dose increased. The higher the dose of gamma radiation applied to adults of the spider mites (the parental generation, P), the higher the mortality of the F1 mites during their embryonic development. Viability of eggs laid by irradiated females of spider mites mated with irradiated males was significantly reduced. Young females treated with a dose of 0.2 kGy produced 40-50% nonviable eggs, while control mites produced only 6.0-6.6% nonviable eggs. A dose of 0.3 kGy caused high mortality of eggs; 88% and 97% nonviable

  19. Zero-order manipulation task to obtain a food reward in Colombian black spider monkeys (Ateles fusciceps rufiventris) kept in a zoo

    OpenAIRE

    Högberg, Sofia

    2010-01-01

    Spider monkeys (Ateles sp.) are common in zoological parks, but rare in scientific publications. Studies on tool use in primates have mostly focused on impressive tool users such as chimpanzees. Spider monkeys fulfill several criteria that are known to be associated with tool use. To be able to give an appropriate environment and enrichment for spider monkeys in captivity more knowledge is needed about their cognitive abilities. In this study we wanted to see if five male spider m...

  20. A comparative analysis of the morphology and evolution of permanent sperm depletion in spiders.

    Directory of Open Access Journals (Sweden)

    Peter Michalik

    2011-01-01

    Full Text Available Once thought to be energetically cheap and easy to produce, empirical work has shown that sperm is a costly and limited resource for males. In some spider species, there is behavioral evidence that sperm are permanently depleted after a single mating. This extreme degree of mating investment appears to co-occur with other reproductive strategies common to spiders, e.g. genital mutilation and sexual cannibalism. Here we corroborate that sperm depletion in the golden orb-web spider Nephila clavipes is permanent by uncovering its mechanistic basis using light and electron microscopy. In addition, we use a phylogeny-based statistical analysis to test the evolutionary relationships between permanent sperm depletion (PSD and other reproductive strategies in spiders. Male testes do not produce sperm during adulthood, which is unusual in spiders. Instead, spermatogenesis is nearly synchronous and ends before the maturation molt. Testis size decreases as males approach their maturation molt and reaches its lowest point after sperm is transferred into the male copulatory organs (pedipalps. As a consequence, the amount of sperm available to males for mating is limited to the sperm contained in the pedipalps, and once it is used, males lose their ability to fertilize eggs. Our data suggest that PSD has evolved independently at least three times within web-building spiders and is significantly correlated with the evolution of other mating strategies that limit males to monogamy, including genital mutilation and sexual cannibalism. We conclude that PSD may be an energy-saving adaptation in species where males are limited to monogamy. This could be particularly important in web-building spiders where extreme sexual size dimorphism results in large, sedentary females and small, searching males who rarely feed as adults and are vulnerable to starvation. Future work will explore possible energetic benefits and the evolutionary lability of PSD relative to other

  1. 'Natural experiment' demonstrates top-down control of spiders by birds on a landscape level.

    Directory of Open Access Journals (Sweden)

    Haldre Rogers

    Full Text Available The combination of small-scale manipulative experiments and large-scale natural experiments provides a powerful approach for demonstrating the importance of top-down trophic control on the ecosystem scale. The most compelling natural experiments have come from studies examining the landscape-scale loss of apex predators like sea otters, wolves, fish and land crabs. Birds are dominant apex predators in terrestrial systems around the world, yet all studies on their role as predators have come from small-scale experiments; the top-down impact of bird loss on their arthropod prey has yet to be examined at a landscape scale. Here, we use a unique natural experiment, the extirpation of insectivorous birds from nearly all forests on the island of Guam by the invasive brown tree snake, to produce the first assessment of the impacts of bird loss on their prey. We focused on spiders because experimental studies showed a consistent top-down effect of birds on spiders. We conducted spider web surveys in native forest on Guam and three nearby islands with healthy bird populations. Spider web densities on the island of Guam were 40 times greater than densities on islands with birds during the wet season, and 2.3 times greater during the dry season. These results confirm the general trend from manipulative experiments conducted in other systems however, the effect size was much greater in this natural experiment than in most manipulative experiments. In addition, bird loss appears to have removed the seasonality of spider webs and led to larger webs in at least one spider species in the forests of Guam than on nearby islands with birds. We discuss several possible mechanisms for the observed changes. Overall, our results suggest that effect sizes from smaller-scale experimental studies may significantly underestimate the impact of bird loss on spider density as demonstrated by this large-scale natural experiment.

  2. Induction of direct and indirect plant responses by jasmonic acid, low spider mite densities, or a combination of jasmonic acid treatment and spider mite infestation

    NARCIS (Netherlands)

    Gols, G.J.Z.; Roosjen, M.; Dijkman, H.; Dicke, M.

    2003-01-01

    Jasmonic acid (JA) and the octadecanoid pathway are involved in both induced direct and induced indirect plant responses. In this study, the herbivorous mite, Tetranychus urticae, and its predator, Phytoseiulus persimilis, were given a choice between Lima bean plants induced by JA or spider mites

  3. An Australian view of the uranium market

    International Nuclear Information System (INIS)

    Lloyd, B.

    1978-01-01

    The subject is covered in sections, entitled as shown. Numerical data are indicated in parenthesis. Introduction (principal Australian uranium deposits, possible Australian production, estimates of world-wide uranium resources and production, estimates of world-wide uranium requirements); Australian marketing policy; commercial considerations; uncertainties affecting the industry, including unnecessary and undesirable government involvement, and supply and demand. (U.K.)

  4. Australian Journalists' Professional and Ethical Values.

    Science.gov (United States)

    Henningham, John

    1996-01-01

    Reports on the first comprehensive national study of Australian journalists. Finds that Australian journalists are similar to their United States colleagues in distributions of age, sex, and socioeconomic background, but have less formal education. Shows that Australians have mixed professional and ethical values and are committed both to…

  5. Effects of hunger level and nutrient balance on survival and acetylcholinesterase activity of dimethoate exposed wolf spiders

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Dall, Lars G.; Sorensen, Bo C.

    2002-01-01

    The influence of two nutritional factors (food quantity and quality) on the responses of a wolf spider, Pardosa prativaga (L.K.), to a high dose of the insecticide dimethoate, was investigated in a fully factorial experimental design. Spider groups with different (good and bad) nutrient balance w...

  6. Effect of pest management systems on foliage- and grass-dwelling spider communities in an apple orchard in Hungary

    NARCIS (Netherlands)

    Bogya, S.; Marko, V.; Szinetár, C.

    2000-01-01

    Spider communities (Araneae) inhabiting the canopy, the herbaceous layer and the borders, as well as the populations overwintering on the tree trunks of different aged IPM and conventional apple orchards were investigated in Hungary. Abundance and species richness of entire spider communities in IPM

  7. Tomato whole genome transcriptional response to Tetranychus urticae identifies divergence of spider mite-induced responses between tomato and Arabidopsis

    NARCIS (Netherlands)

    Martel, C.; Zhurov, V.; Navarro, M.; Martinez, M.; Cazaux, M.; Auger, P.; Migeon, A.; Santamaria, M.E.; Wybouw, N.; Diaz, I.; Van Leeuwen, T.; Navajas, M.; Grbic, M.; Grbic, V.

    2015-01-01

    The two-spotted spider mite Tetranychus urticae is one of the most significant mite pests in agriculture, feeding on more than 1,100 plant hosts, including model plants Arabidopsis thaliana and tomato, Solanum lycopersicum. Here, we describe timecourse tomato transcriptional responses to spider mite

  8. Habitat preferences, diet, feeding strategy and social organization of the black spider monkey (Ateles paniscus paniscus Linnaeus 1758) in Surinam

    NARCIS (Netherlands)

    Roosmalen, van M.G.M.

    1980-01-01

    This study describes habitat choice of the Surinam black spider monkey ( Atelespaniscuspaniscus ) and clarifies complex temporal and spatial effects of food sources on the behaviour of a group of spider monkeys in a 350 ha study area in

  9. The response of Phytoseiulus persimilis to spider mite-induced volatiles from gerbera: influence of starvation and experience

    NARCIS (Netherlands)

    Krips, O.E.; Willems, P.E.I.; Gols, R.; Posthumus, M.A.; Dicke, M.

    1999-01-01

    When leaves of the ornamental crop Gerbera jamesonii are damaged by the spider mite Tetranychus urticae, they produce many volatile compounds in large quantities. Undamaged gerbera leaves produce only a few volatiles in very small quantities. In the headspace of spider mite-damaged gerbera leaves

  10. Kettle Holes in the Agrarian Landscape: Isolated and Ecological Unique Habitats for Carabid Beetles (Col.: Carabidae and Spiders (Arach.: Araneae

    Directory of Open Access Journals (Sweden)

    Platen Ralph

    2016-11-01

    Full Text Available Kettle holes are small depressional wetlands and because of the high variability of site factors they are potential hotspots of biodiversity in the monotone arable land. We investigated eight kettle holes and two agrarian reference biotopes for carabid beetles and spiders. The animals were captured with pitfall traps from May to August 2005, along with surveys of the soil and vegetation. We asked whether each kettle hole has specific ecological properties which match with characteristic carabid beetle and spider coenoses and whether they represent isolated biotopes. Differences in the composition of ecological and functional groups of carabid beetles and spiders between the plots were tested with an ANOVA. The impact of the soil variables and vegetation structure on the distribution of species was analyzed with a Redundancy Analysis. The assemblage similarities between the kettle hole plots were calculated by the Wainstein-Index. Ecological groups and habitat preferences of carabid beetles had maximal expressions in seven different kettle holes whereas most of the ecological characteristics of the spiders had maximal expression in only two kettle holes. High assemblage similarity values of carabid beetle coenoses were observed only in a few cases whereas very similar spider coenoses were found between nearly all of the kettle holes. For carabid beetles, kettle holes represent much more isolated habitats than that for spiders. We concluded that kettle holes have specific ecological qualities which match with different ecological properties of carabid beetles and spiders and that isolation effects affect carabid beetles more than spiders.

  11. Is web oscillation in the orb-web spider Argiope lobata (Pallas, 1772)(Araneidae) an anti-predatory behaviour?

    DEFF Research Database (Denmark)

    Cedhagen, Tomas; Björklund, S.

    2007-01-01

    of the spider allow it to move the centre of gravity quickly, and thereby to oscillate. (2) The great elasticity and strength of its web allow the spider to control the oscillations so that slow movements are reduced to a minimum. (3) When it is oscillating. the eyes of a predator cannot accommodate to keep...

  12. Spider World: A Robot Language for Learning to Program. Assessing the Cognitive Consequences of Computer Environments for Learning (ACCCEL).

    Science.gov (United States)

    Dalbey, John; Linn, Marcia

    Spider World is an interactive program designed to help individuals with no previous computer experience to learn the fundamentals of programming. The program emphasizes cognitive tasks which are central to programming and provides significant problem-solving opportunities. In Spider World, the user commands a hypothetical robot (called the…

  13. Host specificity and temporal and seasonal shifts in host preference of a web-spider parasitoid Zatypota percontatoria.

    Science.gov (United States)

    Korenko, Stanislav; Michalková, Veronika; Zwakhals, Kees; Pekár, Stano

    2011-01-01

    Current knowledge about polysphinctine parasite wasps' interactions with their spider hosts is very fragmented and incomplete. This study presents the host specificity of Zatypota percontatoria (Müller) (Hymenoptera: Ichneumonidae) and its adaptation to varying host availability. Two years of field observations show that Z. percontatoria is a stenophagous parasitoid that parasitizes only five closely related web-building spiders of the family Theridiidae (Araneae). Within the Theridiidae it attacks only species belonging to a small group of species, here called the "Theridion" group. These hosts have a similar biology, but are available at different levels of abundance and at different sizes over the season. Laboratory experiments showed that this wasp species ignores linyphiid, araneid or dictynid spiders and accepts only theridiid spiders of the "Theridion" group. In the field study, wasp females preferred older juvenile and sub-adult female spider instars with intermediate body size. Only 5% of the parasitized spiders were males. Parasitism in the natural population of theridiid spiders was on average 1.3%. Parasitism was most frequent on two species, Theridion varians Hahn in 2007 and Neottiura bimaculata Linnaeus in 2008. The parasitization rate was positively correlated with spider abundance. The wasp responded adaptively to seasonal changes in host abundance and host body size and shifted host preference according to the availability of suitable hosts during, as well as between, seasons. In spring and summer the highest percentage of parasitism was on T. varians and in autumn it was on N. bimaculata.

  14. The relative contributions of fear and disgust reductions to improvements in spider phobia following exposure-based treatment

    NARCIS (Netherlands)

    Olatunji, Bunmi O.; Huijding, Jorg; de Jong, Peter J.; Smits, Jasper A. J.

    The present study examines the relative contributions of changes in state fear and disgust emotions to improvements in spider phobia observed with exposure-based treatment. Sixty-one treatment-seeking spider fearful individuals underwent a one-session exposure in vivo treatment. Growth curve

  15. Recruitment and diversification of an ecdysozoan family of neuropeptide hormones for black widow spider venom expression.

    Science.gov (United States)

    McCowan, Caryn; Garb, Jessica E

    2014-02-25

    Venoms have attracted enormous attention because of their potent physiological effects and dynamic evolution, including the convergent recruitment of homologous genes for venom expression. Here we provide novel evidence for the recruitment of genes from the Crustacean Hyperglycemic Hormone (CHH) and arthropod Ion Transport Peptide (ITP) superfamily for venom expression in black widow spiders. We characterized latrodectin peptides from venom gland cDNAs from the Western black widow spider (Latrodectus hesperus), the brown widow (Latrodectus geometricus) and cupboard spider (Steatoda grossa). Phylogenetic analyses of these sequences with homologs from other spider, scorpion and wasp venom cDNAs, as well as CHH/ITP neuropeptides, show latrodectins as derived members of the CHH/ITP superfamily. These analyses suggest that CHH/ITP homologs are more widespread in spider venoms, and were recruited for venom expression in two additional arthropod lineages. We also found that the latrodectin 2 gene and nearly all CHH/ITP genes include a phase 2 intron in the same position, supporting latrodectin's placement within the CHH/ITP superfamily. Evolutionary analyses of latrodectins suggest episodes of positive selection along some sequence lineages, and positive and purifying selection on specific codons, supporting its functional importance in widow venom. We consider how this improved understanding of latrodectin evolution informs functional hypotheses regarding its role in black widow venom as well as its potential convergent recruitment for venom expression across arthropods. Copyright © 2014. Published by Elsevier B.V.

  16. Reversible Myocarditis and Pericarditis after Black Widow Spider Bite or Kounis Syndrome?

    Directory of Open Access Journals (Sweden)

    Mehmet Yaman

    2015-01-01

    Full Text Available Clinical manifestation of black widow spider bite is variable and occasionally leads to death in rural areas. Cases of myocarditis and pericarditis after black widow spider bite are rare and the associated prognostic significance is unknown. Kounis syndrome has been defined as an acute coronary syndrome in the setting of allergic or hypersensitivity and anaphylactic or anaphylactoid insults that manifests as vasospastic angina or acute myocardial infarction or stent thrombosis. Allergic myocarditis is caused by myocardial inflammation triggered by infectious pathogens, toxic, ischemic, or mechanical injuries, such as drug-related inflammation and other immune reactions. A 15-year-old child was admitted to the emergency department with pulmonary edema after spider bite. ST segment depression on ECG, elevated cardiac enzymes and global left ventricular hypokinesia (with ejection fraction of 22%, and local pericardial effusion findings confirmed the diagnosis of myopericarditis. After heart failure and pulmonary edema oriented medical therapy, clinical status improved. Patient showed a progressive improvement and LV functions returned to normal on the sixth day. Myopericarditis complicating spider bite is rare and sometimes fatal. The mechanism is not clearly known. Alpha-latrotoxin of the black widow spider is mostly convicted in these cases. But allergy or hypersensitivity may play a role in myocardial damage.

  17. Stable isotopes of Hawaiian spiders reflect substrate properties along a chronosequence

    Directory of Open Access Journals (Sweden)

    Susan R. Kennedy

    2018-03-01

    Full Text Available The Hawaiian Islands offer a unique opportunity to test how changes in the properties of an isolated ecosystem are propagated through the organisms that occur within that ecosystem. The age-structured arrangement of volcanic-derived substrates follows a regular progression over space and, by inference, time. We test how well documented successional changes in soil chemistry and associated vegetation are reflected in organisms at higher trophic levels—specifically, predatory arthropods (spiders—across a range of functional groups. We focus on three separate spider lineages: one that builds capture webs, one that hunts actively, and one that specializes on eating other spiders. We analyze spiders from three sites across the Hawaiian chronosequence with substrate ages ranging from 200 to 20,000 years. To measure the extent to which chemical signatures of terrestrial substrates are propagated through higher trophic levels, we use standard stable isotope analyses of nitrogen and carbon, with plant leaves included as a baseline. The target taxa show the expected shift in isotope ratios of δ15N with trophic level, from plants to cursorial spiders to web-builders to spider eaters. Remarkably, organisms at all trophic levels also precisely reflect the successional changes in the soil stoichiometry of the island chronosequence, demonstrating how the biogeochemistry of the entire food web is determined by ecosystem succession of the substrates on which the organisms have evolved.

  18. Inhibition of Return in Fear of Spiders: Discrepant Eye Movement and Reaction Time Data

    Directory of Open Access Journals (Sweden)

    Elisa Berdica

    2014-01-01

    Full Text Available Inhibition of return (IOR refers to a bias against returning the attention to a previously attended location. As a foraging facilitator it is thought to facilitate systematic visual search. With respect to neutral stimuli, this is generally thought to be adaptive, but when threatening stimuli appear in our environment, such a bias may be maladaptive. This experiment investigated the influence of phobia-related stimuli on the IOR effect using a discrimination task. A sample of 50 students (25 high, 25 low in spider fear completed an IOR task including schematic representations of spiders or butterflies as targets. Eye movements were recorded and to assess discrimination among targets, participants indicated with button presses if targets were spiders or butterflies. Reaction time data did not reveal a significant IOR effect but a significant interaction of group and target; spider fearful participants were faster to respond to spider targets than to butterflies. Furthermore, eye-tracking data showed a robust IOR effect independent of stimulus category. These results offer a more comprehensive assessment of the motor and oculomotor factors involved in the IOR effect.

  19. [Diversity of insects captured by weaver spiders (Arachnida: Araneae) in the cocoa agroecosystem in Tabasco, Mexico].

    Science.gov (United States)

    Pérez-de La Cruz, Manuel; Sánchez-Soto, Saúl; Ortíz-García, Carlos F; Zapata-Mata, Raúl; Cruz-Pérez, Aracely de la

    2007-01-01

    The aim of this work was to know the diversity of insects captured by weaver spiders in a plantation of cocoa (Theobroma cacao L.) of 6 ha in the State of Tabasco, Mexico. The study was carried out from July 2004 to June 2005 by means biweekly samples of the insects captured on the spiders webs. The total of 3,041 webs of 54 species of spiders belonging to seven families (Araneidae, Theridiidae, Tetragnathidae, Uloboridae, Pholcidae, Dyctinidae and Linyphiidae) were revised. We found 1,749 specimens belonging to 10 orders of insects, represented by 93 families, the majority of Coleoptera, Diptera and Hemiptera that constituted 74% of the identified families. The biggest number of specimens of all orders was captured by Araneidae, except of Isoptera, whose specimens were captured mainly by the family Theridiidae. The index of diversity (H'), evenness (J') and similarity (Is), applied to know the diversity of families of insects captured among families of spiders, varied from 0.00 to 3.24, 0.00 to 0.81, and 0.04 to 0.522, respectively. We conclude that there is a wide diversity of insects predated by the weaver spiders in the cocoa agroecosystem, and that there are species that can be promising for the biological control of pests.

  20. fMRI neurofeedback facilitates anxiety regulation in females with spider phobia

    Directory of Open Access Journals (Sweden)

    Anna eZilverstand

    2015-06-01

    Full Text Available Background: Spider phobics show an exaggerated fear response when encountering spiders. This fear response is aggravated by negative and irrational beliefs about the feared object. Cognitive reappraisal can target these beliefs, and therefore has a fear regulating effect. The presented study investigated if neurofeedback derived from functional magnetic resonance imaging (fMRI would facilitate anxiety regulation by cognitive reappraisal, using spider phobia as a model of anxiety disorders. Feedback was provided based on activation in left dorsolateral prefrontal cortex and right insula, as indicators of engagement and regulation success, respectively.Methods: Eighteen female spider phobics participated in a randomized, controlled, single-blinded study. All participants completed a training session in the MRI scanner. Participants assigned to the neurofeedback condition were instructed to shape their regulatory strategy based on the provided feedback. Participants assigned to the control condition were asked to adapt their strategy intuitively.Results: Neurofeedback participants exhibited lower anxiety levels than the control group at the end of the training. In addition, only neurofeedback participants achieved down-regulation of insula activation levels by cognitive reappraisal. Group differences became more pronounced over time, supporting learning as a mechanism behind this effect. Importantly, within the neurofeedback group, achieved changes in insula activation levels during training predicted long-term anxiety reduction.Conclusions: The conducted study provides first evidence that fMRI neurofeedback has a facilitating effect on anxiety regulation in spider phobia.

  1. The prevalence of brown widow and black widow spiders (Araneae: Theridiidae) in urban southern California.

    Science.gov (United States)

    Vetter, Richard S; Vincent, Leonard S; Danielsen, Douglas W R; Reinker, Kathryn I; Clarke, Daniel E; Itnyre, Amelia A; Kabashima, John N; Rust, Michael K

    2012-07-01

    The brown widow spider, Latrodectus geometricus C. L. Koch, has become newly established in southern California during the first decade of the 21st century. Brown widows and egg sacs were collected within the urban Los Angeles Basin using timed searches. We also collected and compared the abundance and distribution of the native western black widow spider, Latrodectus hesperus Chamberlin & Ivie, to brown widows. Brown widows were very common around urban structures especially outside homes, in parks, under playground equipment, in plant nurseries and landscaping areas, greatly outnumbering native western black widows, and were very rare or nonexistent in garages, agricultural crops, and natural areas. Western black widows predominated in xeric habitats and were less prevalent around homes. Neither species was found in the living space of homes. In southern California, envenomation risk exists because brown widows are now common in urban areas and the spiders hide where people place their fingers and exert pressure to move objects (e.g., under the curled lip of potted plants, in the recessed handle of plastic trash bins). Nonetheless, brown widow spider bites are less toxic than those of native western black widow spiders and, hence, if they are displacing black widows, overall widow envenomation risk may actually be lower than before brown widow establishment.

  2. Black widow spider bites experience from tertiary care center in Saudi Arabia.

    Science.gov (United States)

    Al Bshabshe, Ali; Alfaifi, Musa; Alsayed, Ahmed Fouad

    2017-01-01

    Black widow spiders are one of the most poisonous species to humans; there are more than 30 species of widow spiders in the globe but good thing that not all of them are dangerous. Some of these spiders produce toxic venoms, which cause broad spectrum of clinical manifestations including skin lesions, neurotoxicity, cardiac toxicity and death in some occasions. In Saudi Arabia there were no much reports of black widow spider bites apart from the case series by BUCUR and his group in ALBAHA region. In 2 years period a total of 8 patients were presented to the emergency departments diagnosed to have black widow spider bites based on description by the patients. 100 % of the cohort were males, aged between 25-58 years. The time between bite and presentation to emergency room was one hour in average (30 min to 4 hours). 75% occured during summer season. All of them 100% had one bite only and reported the bite to be at nighttime in 75% of the times. The average pain score at presentation was 4 /10.100% of the bites were in the lower extremities and almost all progressed to have lower back pain. Three patients had gastrointestinal tract manifestation in form of abdominal cramps and nausea. One had bilateral ptosis, none of them had cardiac or pulmonary complications. The outcome was excellent in all patients and the average of hospital stay was 2.5 days (1-5).

  3. Blueprint for a high-performance biomaterial: full-length spider dragline silk genes.

    Directory of Open Access Journals (Sweden)

    Nadia A Ayoub

    Full Text Available Spider dragline (major ampullate silk outperforms virtually all other natural and manmade materials in terms of tensile strength and toughness. For this reason, the mass-production of artificial spider silks through transgenic technologies has been a major goal of biomimetics research. Although all known arthropod silk proteins are extremely large (>200 kiloDaltons, recombinant spider silks have been designed from short and incomplete cDNAs, the only available sequences. Here we describe the first full-length spider silk gene sequences and their flanking regions. These genes encode the MaSp1 and MaSp2 proteins that compose the black widow's high-performance dragline silk. Each gene includes a single enormous exon (>9000 base pairs that translates into a highly repetitive polypeptide. Patterns of variation among sequence repeats at the amino acid and nucleotide levels indicate that the interaction of selection, intergenic recombination, and intragenic recombination governs the evolution of these highly unusual, modular proteins. Phylogenetic footprinting revealed putative regulatory elements in non-coding flanking sequences. Conservation of both upstream and downstream flanking sequences was especially striking between the two paralogous black widow major ampullate silk genes. Because these genes are co-expressed within the same silk gland, there may have been selection for similarity in regulatory regions. Our new data provide complete templates for synthesis of recombinant silk proteins that significantly improve the degree to which artificial silks mimic natural spider dragline fibers.

  4. Reversible Myocarditis and Pericarditis after Black Widow Spider Bite or Kounis Syndrome?

    Science.gov (United States)

    Yaman, Mehmet; Mete, Turkan; Ozer, Ismail; Yaman, Elif; Beton, Osman

    2015-01-01

    Clinical manifestation of black widow spider bite is variable and occasionally leads to death in rural areas. Cases of myocarditis and pericarditis after black widow spider bite are rare and the associated prognostic significance is unknown. Kounis syndrome has been defined as an acute coronary syndrome in the setting of allergic or hypersensitivity and anaphylactic or anaphylactoid insults that manifests as vasospastic angina or acute myocardial infarction or stent thrombosis. Allergic myocarditis is caused by myocardial inflammation triggered by infectious pathogens, toxic, ischemic, or mechanical injuries, such as drug-related inflammation and other immune reactions. A 15-year-old child was admitted to the emergency department with pulmonary edema after spider bite. ST segment depression on ECG, elevated cardiac enzymes and global left ventricular hypokinesia (with ejection fraction of 22%), and local pericardial effusion findings confirmed the diagnosis of myopericarditis. After heart failure and pulmonary edema oriented medical therapy, clinical status improved. Patient showed a progressive improvement and LV functions returned to normal on the sixth day. Myopericarditis complicating spider bite is rare and sometimes fatal. The mechanism is not clearly known. Alpha-latrotoxin of the black widow spider is mostly convicted in these cases. But allergy or hypersensitivity may play a role in myocardial damage.

  5. Investigating the transverse optical structure of spider silk micro-fibers using quantitative optical microscopy

    Science.gov (United States)

    Little, Douglas J.; Kane, Deb M.

    2017-01-01

    The transverse optical structure of two orb-weaver (family Araneidae) spider dragline silks was investigated using a variant of the inverse-scattering technique. Immersing the silks in a closely refractive index-matched liquid, the minimum achievable image contrast was greater than expected for an optically homogeneous silk, given what is currently known about the optical absorption of these silks. This "excess contrast" indicated the presence of transverse optical structure within the spider silk. Applying electromagnetic scattering theory to a transparent double cylinder, the minimum achievable irradiance contrast for the Plebs eburnus and Argiope keyserlingi dragline silks was determined to be consistent with step index refractive index contrasts of 1-4×10-4 and 6-7×10-4, respectively, supposing outer-layer thicknesses consistent with previous TEM studies (50 nm and 100 nm, respectively). The possibility of graded index refractive index contrasts within the spider silks is also discussed. This is the strongest evidence, to date, that there is a refractive index contrast associated with the layered morphology of spider silks and/or variation of proportion of nanocrystalline components within the spider silk structure. The method is more generally applicable to optical micro-fibers, including those with refractive index variations on a sub-wavelength scale.

  6. Investigating the transverse optical structure of spider silk micro-fibers using quantitative optical microscopy

    Directory of Open Access Journals (Sweden)

    Little Douglas J.

    2016-10-01

    Full Text Available The transverse optical structure of two orb-weaver (family Araneidae spider dragline silks was investigated using a variant of the inverse-scattering technique. Immersing the silks in a closely refractive index-matched liquid, the minimum achievable image contrast was greater than expected for an optically homogeneous silk, given what is currently known about the optical absorption of these silks. This “excess contrast” indicated the presence of transverse optical structure within the spider silk. Applying electromagnetic scattering theory to a transparent double cylinder, the minimum achievable irradiance contrast for the Plebs eburnus and Argiope keyserlingi dragline silks was determined to be consistent with step index refractive index contrasts of 1−4×10−4 and 6–7×10−4, respectively, supposing outer-layer thicknesses consistent with previous TEM studies (50 nm and 100 nm, respectively. The possibility of graded index refractive index contrasts within the spider silks is also discussed. This is the strongest evidence, to date, that there is a refractive index contrast associated with the layered morphology of spider silks and/or variation of proportion of nanocrystalline components within the spider silk structure. The method is more generally applicable to optical micro-fibers, including those with refractive index variations on a sub-wavelength scale.

  7. The house spider genome reveals an ancient whole-genome duplication during arachnid evolution.

    Science.gov (United States)

    Schwager, Evelyn E; Sharma, Prashant P; Clarke, Thomas; Leite, Daniel J; Wierschin, Torsten; Pechmann, Matthias; Akiyama-Oda, Yasuko; Esposito, Lauren; Bechsgaard, Jesper; Bilde, Trine; Buffry, Alexandra D; Chao, Hsu; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dugan, Shannon; Eibner, Cornelius; Extavour, Cassandra G; Funch, Peter; Garb, Jessica; Gonzalez, Luis B; Gonzalez, Vanessa L; Griffiths-Jones, Sam; Han, Yi; Hayashi, Cheryl; Hilbrant, Maarten; Hughes, Daniel S T; Janssen, Ralf; Lee, Sandra L; Maeso, Ignacio; Murali, Shwetha C; Muzny, Donna M; Nunes da Fonseca, Rodrigo; Paese, Christian L B; Qu, Jiaxin; Ronshaugen, Matthew; Schomburg, Christoph; Schönauer, Anna; Stollewerk, Angelika; Torres-Oliva, Montserrat; Turetzek, Natascha; Vanthournout, Bram; Werren, John H; Wolff, Carsten; Worley, Kim C; Bucher, Gregor; Gibbs, Richard A; Coddington, Jonathan; Oda, Hiroki; Stanke, Mario; Ayoub, Nadia A; Prpic, Nikola-Michael; Flot, Jean-François; Posnien, Nico; Richards, Stephen; McGregor, Alistair P

    2017-07-31

    The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.

  8. Magnetic susceptibility of spider webs as a proxy of airborne metal pollution.

    Science.gov (United States)

    Rachwał, Marzena; Rybak, Justyna; Rogula-Kozłowska, Wioletta

    2018-03-01

    The purpose of this pilot study was to test spider webs as a fast tool for magnetic biomonitoring of air pollution. The study involved the investigation of webs made by four types of spiders: Pholcus phalangioides (Pholcidae), Eratigena atrica and Agelena labirynthica (Agelenidae) and Linyphia triangularis (Linyphiidae). These webs were obtained from outdoor and indoor study sites. Compared to the clean reference webs, an increase was observed in the values of magnetic susceptibility in the webs sampled from both indoor and outdoor sites, which indicates contamination by anthropogenically produced pollution particles that contain ferrimagnetic iron minerals. This pilot study has demonstrated that spider webs are able to capture particulate matter in a manner that is equivalent to flora-based bioindicators applied to date (such as mosses, lichens, leaves). They also have additional advantages; for example, they can be generated in isolated clean habitats, and exposure can be monitored in indoor and outdoor locations, at any height and for any period of time. Moreover, webs are ubiquitous in an anthropogenic, heavily polluted environment, and they can be exposed throughout the year. As spider webs accumulate pollutants to which humans are exposed, they become a reliable source of information about the quality of the environment. Therefore, spider webs are recommended for magnetic biomonitoring of airborne pollution and for the assessment of the environment because they are non-destructive, low-cost, sensitive and efficient. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Convergent evolution of behavior in an adaptive radiation of Hawaiian web-building spiders.

    Science.gov (United States)

    Blackledge, Todd A; Gillespie, Rosemary G

    2004-11-16

    Species in ecologically similar habitats often display patterns of divergence that are strikingly comparable, suggesting that natural selection can lead to predictable evolutionary change in communities. However, the relative importance of selection as an agent mediating in situ diversification, versus dispersal between habitats, cannot be addressed without knowledge of phylogenetic history. We used an adaptive radiation of spiders within the Hawaiian Islands to test the prediction that species of spiders on different islands would independently evolve webs with similar architectures. Tetragnatha spiders are the only nocturnal orb-weaving spiders endemic to the Hawaiian archipelago, and multiple species of orb-weaving Tetragnatha co-occur within mesic and wet forest habitats on each of the main islands. Therefore, comparison of web architectures spun by spiders on different islands allowed study of replicated evolutionary events of past behavioral diversification. We found that species within each island construct webs with architectures that differ from one another. However, pairs of species on different islands, "ethotypes," share remarkable similarities in web architectures. Phylogenetic analysis demonstrated that the species comprising these ethotypes evolved independent of one another. Our study illustrates the high degree of predictability that can be exhibited by the evolutionary diversification of complex behaviors. However, not all web architectures were shared between islands, demonstrating that unique effects also have played an important role in the historical diversification of behavior.

  10. Variations in Loxosceles spider venom composition and toxicity contribute to the severity of envenomation.

    Science.gov (United States)

    de Oliveira, Kátia C; Gonçalves de Andrade, Rute M; Piazza, Roxane M F; Ferreira, Jorge M C; van den Berg, C W; Tambourgi, Denise V

    2005-03-15

    Envenomation by Loxosceles spiders causes two main clinical manifestations: cutaneous and systemic loxoscelism. The factors contributing to the severity of loxoscelism are not fully understood. We have analysed biochemical and toxicity variations in venom of L. laeta and L. intermedia, with the aim to find a correlation with the seriousness of loxoscelism. Differences in expression of proteins, glycoproteins and sphingomyelinase activity were observed between venom from male and female spiders and between venom from the two species. These differences were reflected in the toxicity of the venoms including the capacity to induce complement-dependent haemolysis, dermonecrosis and lethality. Comparative analysis of gender and species, showed that these biological activities were more prominent in venom from female spiders, especially from L. laeta. Antiserum raised against venom from females L. laeta spiders had the highest efficacy in neutralizing venoms of males and females of both species. These results indicate that the severity of loxoscelism depends, at least partially, on the species and sex of the spider and suggest that for accidents involving L. laeta an specific serum therapy is necessary. Furthermore, it emphasizes the efficacy of the antiserum produced against L. laeta female venom in neutralizing Loxosceles venoms from different species and gender.

  11. The Australian solar scene

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, Paul [IT Power Australia (Australia)

    2007-06-15

    This presentation mainly talks about the actions taken by the Australian country concerning the use of renewable energy and the reduction of the peak load in some areas. In the first part, there are found both the geographical aspects as well as the major political, e.g. Asia-Pacific Partnership on Clean development and Climate. There are also explained the issues related to peak load growth and it is shown a comparison graphic having information about the most used photovoltaic systems. Then, there are mentioned the communities that are testing one of the model photovoltaic systems in order to: reduce the peak load, use the energy in a properly way, reduce the energy cost, among others. Finally, it is succinctly explained the photovoltaic rebate program as well as the use of the off-grid systems, besides, it is given relevant information about those remote communities of Australia and the benefits of the implementation of Bushlight. [Spanish] Esta presentacion trata primordialmente de las acciones, referentes al uso de energia renovable, tomadas por Australia y creadas con el fin de reducir la maxima demanda en algunas regiones de este pais. En la primera parte, se encuentran tanto los aspectos geograficos como los principales aspectos politicos; por ejemplo, la Sociedad Asia-Pacifico para el Desarrollo no Contaminante y el Clima. Asimismo, se da una explicacion acerca de las cuestiones relacionadas al crecimiento de la maxima demanda; ademas, se muestra un cuadro comparativo, que contiene informacion relacionada con los sistemas fotovoltaicos mas utilizados. Despues, se mencionan aquellas comunidades que tienen en periodo de prueba alguno de los modelos fotovoltaicos con el fin de: reducir la maxima demanda, utilizar eficientemente la energia, reducir el costo de la misma, entre otros aspectos mas. Finalmente, se explica escuetamente el programa de reembolso centrado en el uso de sistemas fotovoltaicos, asi como el uso de sistemas asilados de la red; ademas, se

  12. DNA barcode data accurately assign higher spider taxa

    Directory of Open Access Journals (Sweden)

    Jonathan A. Coddington

    2016-07-01

    Full Text Available The use of unique DNA sequences as a method for taxonomic identification is no longer fundamentally controversial, even though debate continues on the best markers, methods, and technology to use. Although both existing databanks such as GenBank and BOLD, as well as reference taxonomies, are imperfect, in best case scenarios “barcodes” (whether single or multiple, organelle or nuclear, loci clearly are an increasingly fast and inexpensive method of identification, especially as compared to manual identification of unknowns by increasingly rare expert taxonomists. Because most species on Earth are undescribed, a complete reference database at the species level is impractical in the near term. The question therefore arises whether unidentified species can, using DNA barcodes, be accurately assigned to more inclusive groups such as genera and families—taxonomic ranks of putatively monophyletic groups for which the global inventory is more complete and stable. We used a carefully chosen test library of CO1 sequences from 49 families, 313 genera, and 816 species of spiders to assess the accuracy of genus and family-level assignment. We used BLAST queries of each sequence against the entire library and got the top ten hits. The percent sequence identity was reported from these hits (PIdent, range 75–100%. Accurate assignment of higher taxa (PIdent above which errors totaled less than 5% occurred for genera at PIdent values >95 and families at PIdent values ≥ 91, suggesting these as heuristic thresholds for accurate generic and familial identifications in spiders. Accuracy of identification increases with numbers of species/genus and genera/family in the library; above five genera per family and fifteen species per genus all higher taxon assignments were correct. We propose that using percent sequence identity between conventional barcode sequences may be a feasible and reasonably accurate method to identify animals to family/genus. However

  13. Event-related potentials when identifying or color-naming threatening schematic stimuli in spider phobic and non-phobic individuals

    Directory of Open Access Journals (Sweden)

    Musial Frauke

    2006-09-01

    Full Text Available Abstract Background Previous studies revealed increased parietal late positive potentials (LPPs in response to spider pictures in spider phobic individuals. This study searched for basic features of fear-relevant stimuli by investigating whether schematic spider images are sufficient to evoke differential behavioral as well as differential early and late ERP responses in spider phobic, social phobic (as a clinical control group, and non-phobic control participants. Methods Behavioral and electrophysiological correlates of the processing of schematic spider and flower images were investigated while participants performed a color (emotional Stroop and an object identification task. Stimuli were schematic pictures of spiders and flowers matched with respect to constituting visual elements. Results Consistent with previous studies using photographic spider pictures, spider phobic persons showed enhanced LPPs when identifying schematic spiders compared to schematic flowers. In addition, spider phobic individuals showed generally faster responses than the control groups. This effect was interpreted as evidence for an increased general behavioral hypervigilance in this anxiety disorder group. Furthermore, both phobic groups showed enhanced P100 amplitudes compared to controls, which was interpreted as evidence for an increased (cortical hypervigilance for incoming stimuli in phobic patients in general. Finally, all groups showed faster identification of and larger N170 amplitudes in response to schematic spider than flower pictures. This may reflect either a general advantage for fear-relevant compared to neutral stimuli, or might be due to a higher level of expertise in processing schematic spiders as compared to the more artificially looking flower stimuli. Conclusion Results suggest that schematic spiders are sufficient to prompt differential responses in spider-fearful and spider-non-fearful persons in late ERP components. Early ERP components, on

  14. A GIS model predicting potential distributions of a lineage: a test case on hermit spiders (Nephilidae: Nephilengys.

    Directory of Open Access Journals (Sweden)

    Magdalena Năpăruş

    Full Text Available BACKGROUND: Although numerous studies model species distributions, these models are almost exclusively on single species, while studies of evolutionary lineages are preferred as they by definition study closely related species with shared history and ecology. Hermit spiders, genus Nephilengys, represent an ecologically important but relatively species-poor lineage with a globally allopatric distribution. Here, we model Nephilengys global habitat suitability based on known localities and four ecological parameters. METHODOLOGY/PRINCIPAL FINDINGS: We geo-referenced 751 localities for the four most studied Nephilengys species: N. cruentata (Africa, New World, N. livida (Madagascar, N. malabarensis (S-SE Asia, and N. papuana (Australasia. For each locality we overlaid four ecological parameters: elevation, annual mean temperature, annual mean precipitation, and land cover. We used linear backward regression within ArcGIS to select two best fit parameters per species model, and ModelBuilder to map areas of high, moderate and low habitat suitability for each species within its directional distribution. For Nephilengys cruentata suitable habitats are mid elevation tropics within Africa (natural range, a large part of Brazil and the Guianas (area of synanthropic spread, and even North Africa, Mediterranean, and Arabia. Nephilengys livida is confined to its known range with suitable habitats being mid-elevation natural and cultivated lands. Nephilengys malabarensis, however, ranges across the Equator throughout Asia where the model predicts many areas of high ecological suitability in the wet tropics. Its directional distribution suggests the species may potentially spread eastwards to New Guinea where the suitable areas of N. malabarensis largely surpass those of the native N. papuana, a species that prefers dry forests of Australian (subtropics. CONCLUSIONS: Our model is a customizable GIS tool intended to predict current and future potential

  15. Vertical distribution of spiders associated to Quercus humboldtii and clusia spp. at sanctuary of fauna and flora Iguaque, Colombia

    International Nuclear Information System (INIS)

    Vanegas, Silvia; Fagua, Giovanny; Florez, Eduardo

    2012-01-01

    the vertical distribution of spiders associated to trees of quercus humboldtii and clusia spp. with different architectural model, was studied at sanctuary of fauna and flora of Iguaque; for this, we selected trees of each architectural model, stratified them each three m in high starting at the base to the canopy of the tree. We took samples in each stratus for 20 min during the day and at night. Also, we took samples in the nearest ground plot (4 m 2) . We collected 1,261 specimens of 104 morphospecies and 20 families. The most frequent families were theridiidae, salticidae, araneidae, linyphiidae, anyphaenidae, and theridiosomatidae. We observed differences in the spiders' vertical distribution in abundance, richness, composition, time period, and sex ratio, all of them attributable to plant architectures and its stratification. Clusia spider community was the most diverse, quercus spider community was the richest rain, period of time at day, and support availability affected the spiders' composition.

  16. Notes on spider (Theridiidae, Salticidae) predation of the harvester ant, Pogonomyrmex salinus Olsen (Hymenoptera: Formicidae: Myrmicinae), and a possible parasitoid fly (Chloropidae)

    Energy Technology Data Exchange (ETDEWEB)

    Clark, W.H. (Albertson College of Idaho, Caldwell (United States) Univ. of Idaho, Moscow (United States)); Blom, P.E. (Univ. of Idaho, Moscow (United States))

    1992-12-01

    Spiders are known predators of ants. Pressure exerted by consistent spider predation can alter the behavior of ant colonies (MacKay 1982) and may be a selective pressure contributing to the seed-harvesting behavior of Pogonomyrmex (MacKay and MacKay 1984). The authors observed the spider Euryopis formosa Banks (Araneae: Theridiidae) capture and transport workers of the harvester ant (Pogonomyrmex salinus Olsen [Hymenoptera: Formicidae, Myrmicinae]) in southeastern Idaho. Additional observations revealed a crab spider of the genus Xysticus preying on P. salinus and the presence of a chloropid fly (Incertella) that may have been parasitizing the moribund prey subdued by the spider.

  17. Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks

    Directory of Open Access Journals (Sweden)

    Robert B. Suter

    2003-07-01

    Full Text Available Fishing spiders (Pisauridae frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs, attacks by bullfrogs (Rana catesbiana and green frogs (R. clamitans on Dolomedes triton were studied. Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at 250 frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. Qualitatively, the spiders responded to these mock-attacks just as they had to attacks by live frogs: jumping (N=29 jumps, 56.9% of instances, rearing the legs nearest the attacking frog (N=15, 29.4%, or showing no visible response (N=7, 13.7%. Spiders that jumped always did so away (in the vertical plane from the attack (mean =137° vs. vertical at 90° or horizontally toward the frog at 0°. The involvement of the trichobothria (leg hairs sensitive to air movements, and the eyes as sensory mediators of the evasion response was assessed. Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response. Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack.

  18. House spider genome uncovers evolutionary shifts in the diversity and expression of black widow venom proteins associated with extreme toxicity.

    Science.gov (United States)

    Gendreau, Kerry L; Haney, Robert A; Schwager, Evelyn E; Wierschin, Torsten; Stanke, Mario; Richards, Stephen; Garb, Jessica E

    2017-02-16

    Black widow spiders are infamous for their neurotoxic venom, which can cause extreme and long-lasting pain. This unusual venom is dominated by latrotoxins and latrodectins, two protein families virtually unknown outside of the black widow genus Latrodectus, that are difficult to study given the paucity of spider genomes. Using tissue-, sex- and stage-specific expression data, we analyzed the recently sequenced genome of the house spider (Parasteatoda tepidariorum), a close relative of black widows, to investigate latrotoxin and latrodectin diversity, expression and evolution. We discovered at least 47 latrotoxin genes in the house spider genome, many of which are tandem-arrayed. Latrotoxins vary extensively in predicted structural domains and expression, implying their significant functional diversification. Phylogenetic analyses show latrotoxins have substantially duplicated after the Latrodectus/Parasteatoda split and that they are also related to proteins found in endosymbiotic bacteria. Latrodectin genes are less numerous than latrotoxins, but analyses show their recruitment for venom function from neuropeptide hormone genes following duplication, inversion and domain truncation. While latrodectins and other peptides are highly expressed in house spider and black widow venom glands, latrotoxins account for a far smaller percentage of house spider venom gland expression. The house spider genome sequence provides novel insights into the evolution of venom toxins once considered unique to black widows. Our results greatly expand the size of the latrotoxin gene family, reinforce its narrow phylogenetic distribution, and provide additional evidence for the lateral transfer of latrotoxins between spiders and bacterial endosymbionts. Moreover, we strengthen the evidence for the evolution of latrodectin venom genes from the ecdysozoan Ion Transport Peptide (ITP)/Crustacean Hyperglycemic Hormone (CHH) neuropeptide superfamily. The lower expression of latrotoxins in

  19. Australian Queer Science Fiction Fans.

    Science.gov (United States)

    Kerry, Stephen Craig

    2017-10-23

    Science fiction (sf) does more than provide a fleeting moment of entertainment; it has many personal and social functions. In addition to offering audiences "romantic escapism" (Gerrold, 1996, pp. 5-6), sf also enables the "postulation of an alternative reality from which to contemplate this one" (Gerrold, 1996, pp. 5-6); as such, it is especially important "for groups which have had limited stakes in the status quo" (Jenkins, 1995, p. 242). To date, no research has been undertaken on the relationship between Australian queers and sf fandom. This article reports the findings of an online survey and explores the psycho-social features of Australian queer sf fans and why they like the genre. While the characteristics of this sample mirror those of Australian queers generally, they also have slightly higher rates of mental illness and are far more likely to state they have "no religion." Furthermore, while enjoying the "sciency" (P10, bisexual woman) aspects of sf, Australian queers also like the "poignant metaphors for our own civilization" (P45, asexual man).

  20. The 2005 Australian Informatics Competition

    Science.gov (United States)

    Clark, David

    2006-01-01

    This article describes the Australian Informatics Competition (AIC), a non-programming competition aimed at identifying students with potential in programming and algorithmic design. It is the first step in identifying students to represent Australia at the International Olympiad in Informatics. The main aim of the AIC is to increase awareness of…

  1. Energy and the Australian economy

    International Nuclear Information System (INIS)

    Brain, P.; Schuyers, G.

    1981-01-01

    The economic consequences of developing, and of failing to develop, potential sources of energy in Australia are examined. The analysis is preceded by a review of the past and present structure and performance of the Australian energy sector and a survey of the prospective world demand for energy in its various forms

  2. Australian Naturalism and Its Critics.

    Science.gov (United States)

    Hyung, Park Sun

    1997-01-01

    Details the ongoing debate between Australian naturalists and their critics since the publication of C.W. Evers and G. Lakomski's seminal book "Knowing Educational Administration." Examines critics' views in several categories: the coherence concept, coherentism criteria, the naturalistic fallacy, and questions concerning foundations and…

  3. Analysis of cases caused by acute spider bite

    Directory of Open Access Journals (Sweden)

    Zihni Sulaj

    2015-08-01

    Full Text Available We performed a retrospective study of 176 patients in the University Hospital Center of Tirana (Albania, during the period 2001–2011, admitted with the diagnosis of a suspected spider bite. Three fatalities were registered during this decade covered from our study, with a clinical picture of marked hypertension, tachycardia and acute cardiac failure leading to death within a minimum of 25 h and a maximum of 42 h from the occurrence. Out of the total of 176 patients, we had 59% (104 cases females, and 41% males. The overwhelming majority of the patients lived in rural areas (155 of the cases; extremities were mostly affected from the bites. A summary of clinical signs and a brief review of the available literature are made in the results and discussion section of this paper. Authors advocate that special precautions should be taken especially in severe forms of interesting autonomous nerve system, with aggressive fluid resuscitation, supportive therapy and close monitoring of vital signs.

  4. Sensory system plasticity in a visually specialized, nocturnal spider.

    Science.gov (United States)

    Stafstrom, Jay A; Michalik, Peter; Hebets, Eileen A

    2017-04-21

    The interplay between an animal's environmental niche and its behavior can influence the evolutionary form and function of its sensory systems. While intraspecific variation in sensory systems has been documented across distant taxa, fewer studies have investigated how changes in behavior might relate to plasticity in sensory systems across developmental time. To investigate the relationships among behavior, peripheral sensory structures, and central processing regions in the brain, we take advantage of a dramatic within-species shift of behavior in a nocturnal, net-casting spider (Deinopis spinosa), where males cease visually-mediated foraging upon maturation. We compared eye diameters and brain region volumes across sex and life stage, the latter through micro-computed X-ray tomography. We show that mature males possess altered peripheral visual morphology when compared to their juvenile counterparts, as well as juvenile and mature females. Matching peripheral sensory structure modifications, we uncovered differences in relative investment in both lower-order and higher-order processing regions in the brain responsible for visual processing. Our study provides evidence for sensory system plasticity when individuals dramatically change behavior across life stages, uncovering new avenues of inquiry focusing on altered reliance of specific sensory information when entering a new behavioral niche.

  5. The jumping spiders from Xishuangbanna, Yunnan, China (Araneae, Salticidae

    Directory of Open Access Journals (Sweden)

    Qi Cao

    2016-11-01

    Full Text Available Twenty one jumping spider species from South Yunnan are reported, diagnosed, described and illustrated; 19 of them are described as new: Afraflacilla ballarini Cao & Li, sp. n. (♂, Agorius tortilis Cao & Li, sp. n. (♂♀, Bavia exilis Cao & Li, sp. n. (♂, Carrhotus kevinlii Cao & Li, sp. n. (♂♀, Carrhotus sarahcrewsae Cao & Li, sp. n. (♂, Chinattus wengnanensis Cao & Li, sp. n. (♂♀, Chinophrys mengyangensis Cao & Li, sp. n. (♂♀, Cocalus menglaensis Cao & Li, sp. n. (♂♀, Cosmophasis xiaolonghaensis Cao & Li, sp. n. (♂♀, Cytaea yunnanensis Cao & Li, sp. n. (♂, Gedea pinguis Cao & Li, sp. n. (♂, Gelotia zhengi Cao & Li, sp. n. (♂, Icius bamboo Cao & Li, sp. n. (♂, Nannenus menghaiensis Cao & Li, sp. n. (♂♀, Pancorius latus Cao & Li, sp. n. (♂, Phintella lepidus Cao & Li, sp. n. (♂♀, Phintella sancha Cao & Li, sp. n. (♂, Ptocasius paraweyersi Cao & Li, sp. n. (♂♀, and Stenaelurillus fuscus Cao & Li, sp. n. (♂. Females of Bavia capistrata (C.L. Koch, 1846 and Phintella suavisoides Lei & Peng, 2013 are described for the first time. DNA barcodes of 12 species were obtained for future use.

  6. Black widow spider (Latrodectus mactans) antivenom in clinical practice.

    Science.gov (United States)

    Monte, Andrew A

    2012-08-01

    Black widow spider (Latrodectus mactans) envenomation has been recognized since antiquity. The syndrome, latrodectism, is characterized by painful muscle rigidity and autonomic disturbances such as tachycardia, hypertension, and diaphoresis. Symptoms typically last for 1-3 days. Treatment has ranged from local folk remedies to administration of specific antivenom. Opioid analgesics combined with muscle relaxants, such as benzodiazepines, are only effective at symptomatic and temporary control. Antivenom is by far the most efficacious therapy available based on symptom resolution, need for subsequent therapy, and hospital admission rates. Fear of allergic type reactions from antivenom administration has limited its use in the United States. A new purified F(ab)2 fragment Latrodectus mactans antivenom, Analatro®, is currently undergoing clinical trials. The product is expected to have similar efficacy and be associated with fewer adverse reactions when compared to the currently available partially purified whole IgG Merck product. This shift in the risk-benefit analysis may ultimately lead to more antivenom administration in significantly envenomated patients.

  7. A checklist of the spiders (Araneae of the Chornohora Mountain massif (the Ukrainian Carpathians

    Directory of Open Access Journals (Sweden)

    Hirna, Anna

    2016-04-01

    Full Text Available The present checklist of spiders native to the Chornohora Mts of the Ukrainian Carpathians is based both on literature-derived data and on material collected by the authors in 1999, 2006 and 2011-2014. The majority of these studies (approximately 80 % were conducted in the upper montane forests, subalpine and alpine levels on the slopes of the main ridge and adjacent spurs and mountains. The study also covers glacial cirques and river valleys. A few spiders were collected from local villages. The list of spiders includes records from the collections of the Museum of Natural History of the Wroclaw University and Museum (Poland and the Institute of Zoology, Polish Academy of Sciences, Warsaw. A total of 252 valid species from 22 families is known from the Chornohora Mt. massif.

  8. Cuticular hydrocarbons as potential kin recognition cues in a subsocial spider

    DEFF Research Database (Denmark)

    Grinsted, Lena; Bilde, Trine; D'Ettorre, Patrizia

    2011-01-01

    of recognition cues in subsocial species can provide insights into evolutionary pathways leading to permanent sociality and kin-selected benefits of cooperation. In subsocial spiders, empirical evidence suggests the existence of both kin recognition and benefits of cooperating with kin, whereas the cues for kin...... recognition have yet to be identified. However, cuticular hydrocarbons have been proposed to be involved in regulation of tolerance and interattraction in spider sociality. Here, we show that subsocial Stegodyphus lineatus spiderlings have cuticular hydrocarbon profiles that are sibling-group specific, making...... be branched alkanes that are influenced very little by rearing conditions and may be genetically determined. This indicates that a specific group of cuticular chemicals, namely branched alkanes, could have evolved to act as social recognition cues in both insects and spiders....

  9. Quantitative analysis of spider locomotion employing computer-automated video tracking

    DEFF Research Database (Denmark)

    Baatrup, E; Bayley, M

    1993-01-01

    The locomotor activity of adult specimens of the wolf spider Pardosa amentata was measured in an open-field setup, using computer-automated colour object video tracking. The x,y coordinates of the animal in the digitized image of the test arena were recorded three times per second during four...... consecutive 12-h periods, alternating between white and red (lambda > 600 nm) illumination. Male spiders were significantly more locomotor active than female spiders under both lighting conditions. They walked, on average, twice the distance of females, employed higher velocities, and spent less time...... in quiescence. Both male and female P. amentata were significantly less active in red light (simulated dark environment) than in white light. The results also revealed that P. amentata administers its walking velocity and periods of quiescence according to consistent distributions, which can be approximated...

  10. Investigation of spiders (Araneae of the Nature Monument Jesličky (South Moravia, Czech Republic

    Directory of Open Access Journals (Sweden)

    Ondřej Košulič

    2012-01-01

    Full Text Available Faunistic records of spiders (Araneae in the Nature Monument Jesličky (South Moravia, Czech Republic are presented. Spiders were collected by pitfall trapping in 2009 and by sweeping of the herb vegetation in 2011. During the both periods a total of 847 specimens were collected, from which 617 adult spiders were determined. We found 88 species belonging to 20 families. Seven species listed on the Red List of Invertebrates of the Czech Republic were recorded: Titanoeca schineri L. Koch, 1872, Scotina celans (Blackwall, 1841, Haplodrassus dalmatensis (L. Koch, 1866, Ozyptila pullata (Thorell, 1875, Ozyptila simplex (O.P-Cambridge, 1862 and Marpissa nivoyi (Lucas, 1846. To the most significant finding belongs a very rare and endangered (EN Micaria guttulata (C. L. Koch, 1839. A significant and rich finding of bioindicators of the well preserved steppe habitats Atypus piceus (Sulzer, 1776, Eresus kollari Rossi, 1846 and Alopecosa sulzeri (Pavesi, 1873 are to be mentioned.

  11. The treatment of black widow spider envenomation with antivenin latrodectus mactans: a case series.

    Science.gov (United States)

    Offerman, Steven R; Daubert, G Patrick; Clark, Richard F

    2011-01-01

    Black widow spiders (Latrodectus mactans) are found throughout the US. Though bites are relatively uncommon, they pose a significant health problem with over 2500 reported to American poison control centers annually. Black widow spider bites cause a characteristic envenomation syndrome consisting of severe pain, muscle cramping, abdominal pain, and back pain. The significant pain associated with envenomation is often refractory to traditional analgesics. Antivenom (Antivenin Latrodectus mactans) is available and effective, but is often withheld because of a fear of acute hypersensitivity reactions. We report four cases of symptomatic black widow spider envenomation. One of the reported cases was managed without antivenom, and, in contrast, three were treated successfully with Antivenin Latrodectus mactans. We believe that these cases demonstrate safe and effective use of black widow antivenom. This article presents the rationale for use of antivenom in these cases, and a nonsystematic review of the pertinent literature.

  12. Biomaterial evolution parallels behavioral innovation in the origin of orb-like spider webs.

    Science.gov (United States)

    Blackledge, Todd A; Kuntner, Matjaž; Marhabaie, Mohammad; Leeper, Thomas C; Agnarsson, Ingi

    2012-01-01

    Correlated evolution of traits can act synergistically to facilitate organism function. But, what happens when constraints exist on the evolvability of some traits, but not others? The orb web was a key innovation in the origin of >12,000 species of spiders. Orb evolution hinged upon the origin of novel spinning behaviors and innovations in silk material properties. In particular, a new major ampullate spidroin protein (MaSp2) increased silk extensibility and toughness, playing a critical role in how orb webs stop flying insects. Here, we show convergence between pseudo-orb-weaving Fecenia and true orb spiders. As in the origin of true orbs, Fecenia dragline silk improved significantly compared to relatives. But, Fecenia silk lacks the high compliance and extensibility found in true orb spiders, likely due in part to the absence of MaSp2. Our results suggest how constraints limit convergent evolution and provide insight into the evolution of nature's toughest fibers.

  13. Integrated Assessment Plan Template and Operational Demonstration for SPIDERS Phase 2: Fort Carson

    Energy Technology Data Exchange (ETDEWEB)

    Barr, Jonathan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tuffner, Francis K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hadley, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kreyling, Sean J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schneider, Kevin P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-09-01

    This document contains the Integrated Assessment Plan (IAP) for the Phase 2 Operational Demonstration (OD) of the Smart Power Infrastructure Demonstration for Energy Reliability (SPIDERS) Joint Capability Technology Demonstration (JCTD) project. SPIDERS will be conducted over a three year period with Phase 2 being conducted at Fort Carson, Colorado. This document includes the Operational Demonstration Execution Plan (ODEP) and the Operational Assessment Execution Plan (OAEP), as approved by the Operational Manager (OM) and the Integrated Management Team (IMT). The ODEP describes the process by which the OD is conducted and the OAEP describes the process by which the data collected from the OD is processed. The execution of the OD, in accordance with the ODEP and the subsequent execution of the OAEP, will generate the necessary data for the Quick Look Report (QLR) and the Utility Assessment Report (UAR). These reports will assess the ability of the SPIDERS JCTD to meet the four critical requirements listed in the Implementation Directive (ID).

  14. Structural optimization of 3D-printed synthetic spider webs for high strength.

    Science.gov (United States)

    Qin, Zhao; Compton, Brett G; Lewis, Jennifer A; Buehler, Markus J

    2015-05-15

    Spiders spin intricate webs that serve as sophisticated prey-trapping architectures that simultaneously exhibit high strength, elasticity and graceful failure. To determine how web mechanics are controlled by their topological design and material distribution, here we create spider-web mimics composed of elastomeric filaments. Specifically, computational modelling and microscale 3D printing are combined to investigate the mechanical response of elastomeric webs under multiple loading conditions. We find the existence of an asymptotic prey size that leads to a saturated web strength. We identify pathways to design elastomeric material structures with maximum strength, low density and adaptability. We show that the loading type dictates the optimal material distribution, that is, a homogeneous distribution is better for localized loading, while stronger radial threads with weaker spiral threads is better for distributed loading. Our observations reveal that the material distribution within spider webs is dictated by the loading condition, shedding light on their observed architectural variations.

  15. Boomerang - the Australian light source

    International Nuclear Information System (INIS)

    Boldeman, J.W.; Garrett, R.F.

    2000-01-01

    Full text: The Australian Synchrotron Research Program (ASRP) was one of seven major national research facilities funded by the Federal Government in December 1995. The program provides guaranteed access and travel funds for Australian scientists to conduct synchrotron radiation-based research at two overseas facilities - the Photon Factory at Tsukuba in Japan and the Advanced Photon Source at the Argonne National Laboratory in the US. The Federal Government also provided funding of $100K to carry out a Feasibility Study for an Australian-based facility. This has been completed and included a mission to a number of laboratories overseas that were or had recently constructed a facility that could be considered for Australia. Following the mission, consensus was achieved within the community for the specifications of a proposed Australian facility. The proposed facility, Boomerang, has an energy of 3 GeV, an emittance of 16 nm rad and will be equipped in the first phase with 9 instrument stations. Boomerang will be competitive in performance with other facilities currently under construction overseas. A detailed proposal has been submitted to the Federal Government for funding. No site has been specified in the proposal. The proposal was prepared within the Australian Synchrotron Research Program (ASRP) following extensive consultation with industrial and scientific groups in all Australian states. Valuable contributions have been made by members of all the committees of the ASRP, the Australian synchrotron research community that works through the ASRP and the National Synchrotron Steering Committee. Important contributions have also been made by many industrial groups including consortia in Victoria, Queensland and New South Wales. The input from the ANKA staff at Forschungszentrum Karlsruhe and, in particular. Professor Einfeld has been a critical component. The estimated capital cost of a no frills laboratory has been estimated to be $100M in 1999 dollars. The

  16. Conferring biological activity to native spider silk: A biofunctionalized protein-based microfiber.

    Science.gov (United States)

    Wu, Hsuan-Chen; Quan, David N; Tsao, Chen-Yu; Liu, Yi; Terrell, Jessica L; Luo, Xiaolong; Yang, Jen-Chang; Payne, Gregory F; Bentley, William E

    2017-01-01

    Spider silk is an extraordinary material with physical properties comparable to the best scaffolding/structural materials, and as a fiber it can be manipulated with ease into a variety of configurations. Our work here demonstrates that natural spider silk fibers can also be used to organize biological components on and in devices through rapid and simple means. Micron scale spider silk fibers (5-10 μm in diameter) were surface modified with a variety of biological entities engineered with pentaglutamine tags via microbial transglutaminase (mTG). Enzymes, enzyme pathways, antibodies, and fluorescent proteins were all assembled onto spider silk fibers using this biomolecular engineering/biofabrication process. Additionally, arrangement of biofunctionalized fiber should in of itself generate a secondary level of biomolecular organization. Toward this end, as proofs of principle, spatially defined arrangement of biofunctionalized spider silk fiber was shown to generate effects specific to silk position in two cases. In one instance, arrangement perpendicular to a flow produced selective head and neck carcinoma cell capture on silk with antibodies complexed to conjugated protein G. In a second scenario, asymmetric bacterial chemotaxis arose from asymmetric conjugation of enzymes to arranged silk. Overall, the biofabrication processes used here were rapid, required no complex chemistries, were biologically benign, and also the resulting engineered silk microfibers were flexible, readily manipulated and functionally active. Deployed here in microfluidic environments, biofunctional spider silk fiber provides a means to convey complex biological functions over a range of scales, further extending its potential as a biomaterial in biotechnological settings. Biotechnol. Bioeng. 2017;114: 83-95. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. An RNA Virome Associated to the Golden Orb-Weaver Spider Nephila clavipes

    Directory of Open Access Journals (Sweden)

    Humberto J. Debat

    2017-10-01

    Full Text Available The golden orb-weaver spider Nephila clavipes, known for its sexual size dimorphism, is abundant and widespread in the New World. The first annotated genome of orb-weaver spiders, exploring N. clavipes, has recently been reported. The study, focused primarily on the diversity of silk specific genes, shed light into the complex evolutionary history of spiders. Furthermore, a robust transcriptome analysis provided a massive resource for N. clavipes RNA survey. Here, I present evidence of viral sequences corresponding to the first 10 extant virus species associated to N. clavipes and indeed, nephilids. The putatively new species are linked to ssRNA positive-strand viruses, such as Picornavirales, and to ssRNA negative-strand and dsRNA viruses. In addition, I detected sequence data of new strains of two recently reported arthropod viruses, which complemented and extended the corresponding sequence references. The identified viruses appear to be complete, potentially functional, and presenting the typical architecture and consistent viral domains. The intrinsic nature of the detected sequences and their absence in the recently generated genome assembly, suggest that they correspond to bona fide RNA virus sequences. The available RNA data allowed for the first time to address a tissue/organ specific analysis of virus loads/presence in spiders, suggesting a complex spatial and differential distribution of the tentative viruses, encompassing the spider brain and also silk and venom glands. Until recently, the virus landscape associated to spiders remained elusive. The discovered viruses described here provide only a fragmented glimpse of the potential magnitude of the Aranea virosphere. Future studies should focus not only on complementing and expanding these findings, but also on addressing the potential ecological role of these viruses, which might influence the biology of these outstanding arthropod species.

  18. Enhanced discriminative fear learning of phobia-irrelevant stimuli in spider-fearful individuals

    Directory of Open Access Journals (Sweden)

    Carina eMosig

    2014-10-01

    Full Text Available Avoidance is considered as a central hallmark of all anxiety disorders. The acquisition and expression of avoidance which leads to the maintenance and exacerbation of pathological fear is closely linked to Pavlovian and operant conditioning processes. Changes in conditionability might represent a key feature of all anxiety disorders but the exact nature of these alterations might vary across different disorders. To date, no information is available on specific changes in conditionability for disorder-irrelevant stimuli in specific phobia (SP. The first aim of this study was to investigate changes in fear acquisition and extinction in spider-fearful individuals as compared to non-fearful participants by using the de novo fear conditioning paradigm. Secondly, we aimed to determine whether differences in the magnitude of context-dependent fear retrieval exist between spider-fearful and non-fearful individuals. Our findings point to an enhanced fear discrimination in spider-fearful individuals as compared to non-fearful individuals at both the physiological and subjective level. The enhanced fear discrimination in spider-fearful individuals was neither mediated by increased state anxiety, depression, nor stress tension. Spider-fearful individuals displayed no changes in extinction learning and/or fear retrieval. Surprisingly, we found no evidence for context-dependent modulation of fear retrieval in either group. Here we provide first evidence that spider-fearful individuals show an enhanced discriminative fear learning of phobia-irrelevant (de novo stimuli. Our findings provide novel insights into the role of fear acquisition and expression for the development and maintenance of maladaptive responses in the course of SP.

  19. Evaluation of the design effects of different agropastoral systems on the diversity and density of spiders

    Directory of Open Access Journals (Sweden)

    Melina S. Almada

    2017-04-01

    Full Text Available Sustainable agro-ecological design is challenging when the goal is self-regulation of the system. The objective of this study was to evaluate if the agropastoral design system affects the spider community, as spiders are the main predators in these production systems, and to determine those designs which maximize the diversity and density of spiders. The study was conducted during 2009/2010, at the Experimental Research Station of Agriculture (EEA-INTA Reconquista (Santa Fe, Argentina where we considered four different designs: C1 (five agricultural fields, C2 (three agricultural fields and four livestock fields, C3 (six agricultural fields and one livestock field and C4 (five agricultural fields and one forest area. In each design, the spiders were collected by pitfall traps and suction samples with a G-Vac (garden-vacuum. The designs proposed were considered on the basis of environmental heterogeneity. The C4 treatment had the greatest number of species, followed by C2, C3 and C1 (183, 178, 144 and 142 species, respectively, and C2 presented the greatest abundance of spiders followed by C4, C3 and C1 (n=5708, 4785, 4271 and 3448, respectively. Eight guilds were present in C3 and C4. This study is the first to evaluate the diversity of spiders in agropastoral systems in Argentina. Our results show that designs that include more fields with livestock or equal to those for agriculture, as well as forest areas, increase environmental heterogeneity. Therefore, the presence of a biological controller and dominant predatory group will be possible with sustainable designs that have environmental heterogeneity, contributing to improved pest control in agricultural systems.

  20. Influence of direct or indirect contact for the cytotoxicity and blood compatibility of spider silk.

    Science.gov (United States)

    Kuhbier, J W; Coger, V; Mueller, J; Liebsch, C; Schlottmann, F; Bucan, V; Vogt, P M; Strauss, S

    2017-08-01

    Spider silk became one of the most-researched biomaterials in the last years due to its unique mechanical strength and most favourable chemical composition for tissue engineering purposes. However, standardized analysis of cytocompatibility is missing. Therefore, the aim of this study was to investigate hemolysis, cytotoxicity of native spider silk as well as influences on the cell culture medium. Changes of cell culture medium composition, osmolarity as well as glucose and lactate content were determined via ELISA measurement. Possible hemolysis and cytotoxicity in vitro of spider silk were performed via measurement of hemoglobin release of human red blood cells or relative metabolic activity of L929 fibroblasts, respectively, according to international standard procedures. In ELISA measurement, no significant changes in medium composition could be found in this study. Spider silk was not hemolytic in direct and indirect testing. However, a borderline cytotoxicity according to definitions was found in indirect cytotoxicity testing. Nevertheless, in direct cytotoxicity testing, relative metabolic activity measurement revealed that spider silk is not cytotoxic under these conditions. This is the first study to conduct standardized tests regarding cytotoxicity and hemolysis of native spider silk, which might be considered inert in cell culture. As neither hemolysis nor cytotoxicity was found in direct contact in standardized procedures, safety in biomedical applications may be assumed. The indirect cytotoxicity seems to play a minor role in vivo. However, a borderline toxicity was revealed, suggesting potential leachables not yet identified. Displays one of the weaving frames used in this study after seeding with the single drop technique described herein.

  1. Male palp organ morphology of three species of ground spiders (Araneae, Gnaphosidae

    Directory of Open Access Journals (Sweden)

    Zakharov, Boris

    2013-06-01

    Full Text Available A detailed morphological account of the male copulatory organs of three species of ground spiders, Sergiolus capulatus, Herpyllus propinquus and Callilepis pluto (Araneae, Gnaphosidae, is presented. The large sclerites (subtegulum, tegulum and embolus appear to be homologous in all spiders. Sergiolus and Zelanda have a plesiomorphic palp organization. The increased complexity in the male bulb organization creates a locking mechanism that fixes the male palp position during intercourse in Callilepis, as well as in Encoptarthria, Trachyzelotes and Zelotes. The palp of Herpyllus, together with Anzacia, Drassodes and Intruda, demonstrates progressive modification of the male bulb.

  2. Spider Silk: From Protein-Rich Gland Fluids to Diverse Biopolymer Fibers

    Science.gov (United States)

    2016-01-06

    process of dragline silk and move into studying the dopes spiders use to spin egg cases (tubuliform and aciniform) and wrap prey (aciniform). We... drops dramatically at a pH = 4 leading to rapid fiber formation. When the dope is close to the spinneret, decreasing the pH below 4 can accelerate the...Weber, W.S., Mou, Q., Yarger, J.L., Lewis, R.V., “Mechanical and Physical Properties of Recombinant Spider Silk Films Using Organic and Aqueous

  3. A check list of the spider fauna of the Karoo National Park, South Africa (Arachnida: Araneae

    Directory of Open Access Journals (Sweden)

    Anna S. Dippenaar-Schoeman

    1999-07-01

    Full Text Available A check list of the spider species of the Karoo National Park collected over a period of 10 years is presented. Thirty-eight families, represented by 102 genera and 116 species have been collected. Of these species, 76 (66.4 were wanderers and 39 (33.6 web builders. The Araneidae have the highest number of species (14 followed by the Thomisidae (10 and the Gnaphosidae (8, while 14 families are represented by a single species. Information on spider guilds, their habitat preference and web types is provided. This study forms part of the South African National Survey of Arachnida (SANSA.

  4. Spider Silk Violin Strings with a Unique Packing Structure Generate a Soft and Profound Timbre

    Science.gov (United States)

    Osaki, Shigeyoshi

    2012-04-01

    We overcome the difficulties in pulling long draglines from spiders, twist bundles of dragline filaments, and succeed in preparing violin strings. The twisting is found to change the cross section shapes of filaments from circular to polygonal and to optimize the packing structure with no openings among filaments providing mechanically strong and elastic strings. The spider string signal peaks of overtones for the violin are relatively large at high frequencies, generating a soft and profound timbre. Such a preferable timbre is considered to be due to the unique polygonal packing structure which provides valuable knowledge for developing new types of materials.

  5. A rare finding of mites (Arachnida: Acari: Leeuwenhoekiidae) parasitising a whip spider (Arachnida: Amblypygi: Charinidae).

    Science.gov (United States)

    Gonçalves-Souza, Thiago; Giupponi, Alessandro P L; Hernandes, Fabio A

    2014-04-01

    Twelve larvae of unidentified species of Odontacarus Ewing, 1929 (Acari: Leeuwenhoekiidae) were found parasitising an adult male whip spider Charinus brasilianus Weygoldt (Charinidae) in Santa Teresa, mountainous region of Espirito Santo state, southeastern Brazil. These larvae occurred in the intersegmental membrane of prosoma and legs. This is the first report of ectoparasitic mites infecting a charinid whip spider and the first record of leeuwenhoekiid mites parasitising an invertebrate host. We suggest that future studies are essential to understand the reasons why these events of parasitism are so rare in the order Amblypygi.

  6. A case: Acute myocardial infarction in a child due to spider bite

    OpenAIRE

    Laho, Edmond; Puca, Edmond

    2015-01-01

    This report presents a case of a ten-years-old girl, who suffered myocardial ischemia following by "black widow" spider bite. A few minutes after the bite, her parents saw a small, black and shiny lesion in insect bite. The clinical signs began about 3-4 hours after the bite. The venom of the Latrodectus mactans "black widow" is toxic, resulting about 5-6 % fatality rate. The case of a black widow spider bite resulting in myocardial ischemia is very rare and has not been d...

  7. Use of antivenin to treat priapism after a black widow spider bite.

    Science.gov (United States)

    Hoover, Nancy G; Fortenberry, James D

    2004-07-01

    Black widow spider envenomation (BWSE) is commonly associated with severe abdominal pain, muscle cramping, and hypertension. Treatment is primarily symptomatic with the use of opiates and benzodiazepines. Priapism is a complication of BWSE that has only rarely been reported. We describe a 17-month-old male who developed priapism after known BWSE. His priapism did not respond to opiates or benzodiazepines, and he was treated with black widow spider antivenin. Complete detumescence followed within several hours. The patient required no additional opiates for pain and was discharged from the hospital the following day. The patient's rapid improvement after antivenin suggests its efficacy in treating BWSE-associated priapism.

  8. Molecular studies of a novel dragline silk from a nursery web spider, Euprosthenops sp. (Pisauridae).

    Science.gov (United States)

    Pouchkina-Stantcheva, Natalia N; McQueen-Mason, Simon J

    2004-08-01

    Various spider species produce dragline silks with different mechanical properties. The primary structure of silk proteins is thought to contribute to the elasticity and strength of the fibres. Previously published work has demonstrated that the dragline silk of Euprosthenops sp. is stiffer then comparable silk of Nephila edulis, Araneus diadematus and Latrodectus mactans. Our studies of Euprosthenops dragline silk at the molecular level have revealed that nursery web spider fibroin has the highest polyalanine content among previously characterised silks and this is likely to contribute to the superior qualities of pisaurid dragline.

  9. Latrodectus mactans (black widow spider) envenomation: an unusual cause for abdominal pain in pregnancy.

    Science.gov (United States)

    Scalzone, J M; Wells, S L

    1994-05-01

    The differential diagnosis of abdominal pain in pregnancy is extensive. An important consideration in endemic areas is a bite by a black widow spider. A 30-year-old woman at 30 weeks' gestation presented with acute abdominal pain following an insect bite. We based the diagnosis on classic symptomatology in an area endemic for Latrodectus mactans. Treatment consisted of supportive therapy and observation. Symptoms resolved over 48 hours and did not recur. The patient delivered a healthy child at 40 weeks' gestation. In endemic areas, black widow spider envenomation should be part of the differential diagnosis of abdominal pain in pregnancy.

  10. A faunistic study on ground-dwelling spiders (Araneae in the Tirana district, Albania

    Directory of Open Access Journals (Sweden)

    Vrenozi, Blerina

    2012-12-01

    Full Text Available Spiders from the Tirana district of Albania were investigated. Currently, 78 species from 24 families and a collection of 400 specimens from January to August 2010 were recorded for Tirana. A total of 32 new records for the Albanian fauna are included in the present paper. Agraecina lineata (Simon, 1878 is the first record for the Balkan Peninsula. Saitis graecus Kulczyński, 1905 was known before only from Greece and Bulgaria. Presently, 373 spider species are known for Albania.

  11. The unique ribbon morphology of the major ampullate silk of spiders from the genus Loxosceles (recluse spiders).

    Science.gov (United States)

    Coddington, Jonathan A; Chanzy, Henri D; Jackson, Catheryn L; Raty, Gail; Gardner, KennCorwin H

    2002-01-01

    The morphology of silk produced by recluse spiders (Loxosceles arizonica) was investigated by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. This silk consisted entirely of very long, thin ribbons of width 2-4 microm and thicknesses of no more than 40 nm. The correspondence in shape and dimension between the silk ribbons and the elongated aperture of the major ampullate spigot indicated that these ribbons were major ampullate silk. Selected area electron diffraction patterns from single ribbons were indexed with an orthorhombic unit cell (a = 9.43(2) A, b = 8.96(3) A, c = 6.96(1) A). This unit cell is in good agreement with that previously reported for synthetic poly(L-alanylglycine). Thus it is likely that the crystalline regions of the major ampullate silk of L. arizonica consist of an alternating glycine-L-alanine motif that has adopted a beta-sheet structure. The amino acid composition achieved with the silk of L. arizonica as well as that of L. laeta confirmed that the major amino acid constituents of this silk were glycine and L-alanine in nearly equal amounts. As it was noticed that the dry ribbons were highly electrostatic, it is suggested that the electrostatic interaction plays an important role in prey capture for Loxoseles.

  12. Plant invasion phenomenon enhances reproduction performance in an endangered spider

    Science.gov (United States)

    Pétillon, Julien; Puzin, Charlène; Acou, Anthony; Outreman, Yannick

    2009-10-01

    Current models in evolutionary ecology predict life history alterations in response to habitat suitability to optimize fitness. Only few empirical studies have demonstrated how life history traits that are expected to trade off against each other differ among environments. In Europe, many salt marshes have been recently invaded by the grass Elymus athericus. Previous studies however showed higher densities of the endangered spider Arctosa fulvolineata (Araneae: Lycosidae) in invaded salt marshes compared to natural habitats, which suggests a lower habitat suitability in the latter. The aim of this study was to determine if this emerging habitat (1) affects the amount of resource acquisition and (2) alters the balance between life history traits that are expected to trade off against each other in this stenotopic salt marsh species. As suggested by theoretical studies, an optimization of fitness by increasing egg size at the cost of decreasing fecundity in unsuitable (i.e., natural) habitats was expected. Females presenting cocoon were then collected in close invaded and natural salt marsh areas within the Mont Saint-Michel Bay (France). By considering female mass as covariate, cocoon mass, number of eggs, and egg volume were compared between both habitats. Clutch mass was strongly determined by female mass in both habitats. Clutch mass was however significantly smaller in the natural habitat compared to the invaded habitat, indicating a higher resource acquisition in the latter. When correcting for female size, fecundity was additionally increased in the invaded habitat through a significant decrease in egg size. This phenotypic response can be explained by differences in habitat structure between invaded and natural habitats: the former offers a more complex litter favoring nocturnal wanderers like A. fulvolineata. The existence of such an adaptive reproduction strategy depending on habitat suitability constitutes an original case of an invasion that favors an

  13. ARE THE SPIDER ANGIOMAS SKIN MARKERS OF HEPATOPULMONARY SYNDROME?

    Directory of Open Access Journals (Sweden)

    Americo de Oliveira SILVERIO

    2013-09-01

    Full Text Available Context Hepatopathies can significantly influence both veins and arteries, these changes may cause some cutaneous stigmas, such as spider angioma (SA and some systemic vascular changes, such as those observed in hepatopulmonary syndrome (HPS. Based on this common pathophysiological root we can assume that the SA can be skin markers of HPS. Objective The objective of this study is to assess whether there is a relationship between the presence of SA and HPS. Methods Records of 40 patients with liver cirrhosis who underwent contrast echocardiography were evaluated, in which we researched the description of SA, physical examination, and other clinical and laboratory data. For diagnosis of HPS we use these signs of the disease: presence of liver disease (cirrhosis in the case, abnormalities in gas exchange by arterial blood gases, and evidence of pulmonary vasodilations by the contrast echocardiography. Results The SA were found in 21/40 (52.5% patients and hepatopulmonary syndrome in 9/40 (22.5%. The HPS was observed in 8/21 (38.1% of patients with SA and 1/19 (5.3% patients were without this sign (P<0.01. We found no statistically significant difference between the SA and the presence of HPS with sex or age. Patients with SA had a higher hypoxemia [PaO2 84.8 ± 11.5 mmHg and 19.8 ± 14.7 mmHg alveolar-arterial gradient of oxygen (AAG] than those without SA (PaO2 90.8 ± 10.7 mmHg and 10.9 ± 11.7 AAG mmHg (P<0.05. Conclusion Our findings show a correlation between the presence of SA and HPS, suggesting that the SA may be cutaneous markers of HPS.

  14. Black widow spider toxins: the present and the future.

    Science.gov (United States)

    Grishin, E V

    1998-11-01

    The venom of the black widow spider Latrodectus mactans tredisimguttatus was found to contain a family of high molecular weight toxic proteins inducing a sharp increase in transmitter secretion from the affected nerve endings, which are highly specific for vertebrates, or for insects, or for crustaceans. Along with the known alpha-latrotoxin, five latroinsectotoxins affecting the neurotransmitter release from presynaptic endings of insects and one latrocrustatoxin active only for crustaceans were isolated and studied in detail. Alpha-latrotoxin provokes a massive transmitter release from different nerve endings of vertebrates, whereas other toxins increase the secretion process either in insects or crustaceans. The cDNAs encoding the putative alpha-latrotoxin and two latroinsectotoxins (alpha-latroinsectotoxin and delta-latroinsectotoxin) precursors were cloned and sequenced. These toxins are polypeptides of about 1000 amino acids and share a high level of amino acid identity. Analysis of amino acid sequences of the three toxins reveals the central regions being almost entirely composed of series of ankyrin-like repeats. Taking into account the size and multifunctional properties of latrotoxin its molecule can be divided into several functional domains. Immunochemical experiments indicated the presence in the alpha-latrotoxin molecule of distinguishable functional domains responsible for ionophoric and secretogenic actions. The highly purified preparation of alpha-latrotoxin was shown to contain an additional component, a low molecular weight protein structurally related to crustacean hyperglycemic hormones. Several attempts were made to characterize and isolate alpha-latrotoxin receptor components. The existence of Ca-dependent and Ca-independent binding proteins was found in the presynaptic membrane preparations.

  15. How did the spider cross the river? Behavioral adaptations for river-bridging webs in Caerostris darwini (Araneae: Araneidae.

    Directory of Open Access Journals (Sweden)

    Matjaž Gregorič

    Full Text Available Interspecific coevolution is well described, but we know significantly less about how multiple traits coevolve within a species, particularly between behavioral traits and biomechanical properties of animals' "extended phenotypes". In orb weaving spiders, coevolution of spider behavior with ecological and physical traits of their webs is expected. Darwin's bark spider (Caerostris darwini bridges large water bodies, building the largest known orb webs utilizing the toughest known silk. Here, we examine C. darwini web building behaviors to establish how bridge lines are formed over water. We also test the prediction that this spider's unique web ecology and architecture coevolved with new web building behaviors.We observed C. darwini in its natural habitat and filmed web building. We observed 90 web building events, and compared web building behaviors to other species of orb web spiders.Caerostris darwini uses a unique set of behaviors, some unknown in other spiders, to construct its enormous webs. First, the spiders release unusually large amounts of bridging silk into the air, which is then carried downwind, across the water body, establishing bridge lines. Second, the spiders perform almost no web site exploration. Third, they construct the orb capture area below the initial bridge line. In contrast to all known orb-weavers, the web hub is therefore not part of the initial bridge line but is instead built de novo. Fourth, the orb contains two types of radial threads, with those in the upper half of the web doubled. These unique behaviors result in a giant, yet rather simplified web. Our results continue to build evidence for the coevolution of behavioral (web building, ecological (web microhabitat and biomaterial (silk biomechanics traits that combined allow C. darwini to occupy a unique niche among spiders.

  16. Suppressor of Hairless and Presenilin phenotypes imply involvement of canonical Notch-signalling in segmentation of the spider Cupiennius salei.

    Science.gov (United States)

    Schoppmeier, Michael; Damen, Wim G M

    2005-04-01

    Arthropods, vertebrates, and annelids all have a segmented body. Our recent discovery of involvement of Notch-signalling in spider segmentation revived the discussion on the origin of segmented body plans and suggests the sharing of a common genetic program in a common ancestor. Here, we analysed the spider homologues of the Suppressor of Hairless and Presenilin genes, which encode components of the canonical Notch-pathway, to further explore the role of Notch-signalling in spider segmentation. RNAi silencing of two spider Suppressor of Hairless homologues and the spider Presenilin homologue causes severe segmentation phenotypes. The most prominent defect is the consistent breakdown of segmentation after the formation of three (Suppressor of Hairless) or five (Presenilin) opisthosomal segments. These phenotypes indicate that Notch-signalling during spider segmentation likely involves the canonical pathway via Presenilin and Suppressor of Hairless. Furthermore, it implies that Notch-signalling influences both the formation and patterning of the spider segments: it is required for the specification of the posterior segments and for proper specification of the segment boundaries. We argue that alternative, partly redundant, pathways might act in the formation of the anterior segments that are not active in the posterior segments. This suggests that at least some differences exist in the specification of anterior and posterior segments of the spider, a finding that may be valid for most short germ arthropods. Our data provide additional evidence for the similarities of Notch-signalling in spider segmentation and vertebrate somitogenesis and strengthen our previous notion that the formation of the segments in arthropods and vertebrates might have shared a genetic program in a common ancestor.

  17. Australian synchrotron light source - (boomerang)

    International Nuclear Information System (INIS)

    Boldeman, J.

    2001-01-01

    The Australian National Synchrotron Light Source - (Boomerang) is to be installed at the Monash University in Victoria. This report provides some background to the proposed facility and discusses aspects of a prospective design. Recently, significant effort was devoted to refining the in principle design and a lattice providing an emittance od 18 nm rad was obtained with a distributed dispersion in the straight section of 0.29m. Exhaustive studies have been made of the economic benefits that would accrue to Australia to Australia following the installation of this facility. This design is a refinement of the design concept presented to the SRI -2000, Berlin (Boldeman, Einfeld et al), to the meeting of the 4th Asian Forum and the Preliminary Design Study presented to the Australian Synchrotron Research Program

  18. Curators and Australian art history

    OpenAIRE

    Andrew Sayers

    2011-01-01

    Most Australians do not read art history, but they do look at art in museums. There, visitors experience displays that embody art histories. The enthusiasms and research interests of curators combine with collection strengths to create these art histories. In this process, particular artists, ideas and mediums are privileged. Drawing on personal experience this talk looked at some examples of influential curators, displays, exhibitions and collecting programs over the last thirty years. In th...

  19. Meteors in Australian Aboriginal Dreamings

    Science.gov (United States)

    Hamacher, Duane W.; Norris, Ray P.

    2010-06-01

    We present a comprehensive analysis of Australian Aboriginal accounts of meteors. The data used were taken from anthropological and ethnographic literature describing oral traditions, ceremonies, and Dreamings of 97 Aboriginal groups representing all states of modern Australia. This revealed common themes in the way meteors were viewed between Aboriginal groups, focusing on supernatural events, death, omens, and war. The presence of such themes around Australia was probably due to the unpredictable nature of meteors in an otherwise well-ordered cosmos.

  20. Home advantage in Australian soccer.

    Science.gov (United States)

    Goumas, Chris

    2014-01-01

    The aims of this study were to quantify the magnitude of home advantage (HA) in Australian soccer and to investigate how home-team crowd support and away-team travel may contribute to it. A paired design was used wherein each match contributed two observations, one for the home team and one for the away team. The data used in this study were all matches from the first seven seasons (2005/06-2011/12) of the Australian A-League - the major soccer league in Australia. Repeated measures Poisson regression analysis was used to investigate the effect that crowd size and density, distance and direction travelled by away teams, and crossing time zones may have on HA. HA in terms of the percentage of competition points gained by home teams in the A-League averaged 58% over the study period. HA increased significantly with increasing number of time zones crossed by away teams (pteam crowd support. Travel management programs aimed at reducing the effects of jet lag could significantly improve away team performance in Australian soccer. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. From Specialization in Spider Egg Predation to an Original Nesting Mode in a "Primitive" Ant: A New Kind of Lestobiosis

    Science.gov (United States)

    Dejean, A.; Grimal, A.; Malherbe, M.-C.; Suzzoni, J.-P.

    Mature colonies of Discothyrea oculata were observed nesting in cribellatid spider oothecas where they found both shelter and food although these oothecas, installed in preexisting cavities, were protected with crimped silk. Workers of colonies bred in test tubes during laboratory experiments recuperated the silk from spider oothecas introduced into their foraging area, using their mandibles and forelegs, to operculate and line the test tubes. Also, colonies left the test tubes to shelter in the cribellatid spider oothecas. The term "arachnolesty" is proposed for this new kind of lestobiosis.

  2. The male of the orb-weaving spider Plebs mitratus (Simon, 1895) and a redescription of the female (Araneae, Araneidae).

    Science.gov (United States)

    Paul, Jimmy; Sankaran, Pradeep M; Joseph, Mathew M; Sebastian, Pothalil A

    2016-10-28

    The orb-weaving spider genus Plebs Joseph & Framenau, 2012 currently has only two representatives in India: Plebs himalayaensis (Tikader, 1975) from the Himalayas and Plebs mitratus (Simon, 1895) from the Nilgiris and Anamudi Shola National Park (World Spider Catalog 2016), both are found in high altitude mountainous habitats (Joseph & Framenau 2012). Both species were known only from females (World Spider Catalog 2016), although Sherriffs (1918, 1919) provided a description of an immature male of P. mitratus. In the present paper, we provide the first description of the adult male of P. mitratus, together with the detailed redescription of its female demonstrating considerable intraspecific variation.

  3. Nazi medical experiments on Australian prisoners of war: Commentary on the testimony of an Australian soldier.

    Science.gov (United States)

    Weisz, George M

    2015-12-01

    Archival research reveals that Australian prisoners of war were exposed to non-consensual medical experiments during World War II. This article discusses the first known case of an Australian soldier exposed to German medical experiments.

  4. Molecular cloning and expression of the C-terminus of spider ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 32; Issue 4. Molecular cloning and expression of the C-terminus of spider flagelliform silk protein from Araneus ventricosus. Kwang Sik Lee Bo Yeon Kim Yeon Ho Je Soo Dong Woo Hung Dae Sohn Byung Rae Jin. Articles Volume 32 Issue 4 June 2007 pp 705-712 ...

  5. Lyriform slit sense organs on the pedipalps and spinnerets of spiders

    Indian Academy of Sciences (India)

    One LSSO is found only on anterior spinnerets and it is a common feature observed among spiders, irrespective of the variations in web building behaviour. The orb-weaving araneid Argiope pulchella, however, has two LSSOs on the anterior spinneret. As non-web builders and orb weavers do not differ markedly in terms ...

  6. Alternative phenotypes of male mating behaviour in the two-spotted spider mite

    NARCIS (Netherlands)

    Sato, Y.; Sabelis, M.W.; Egas, M.; Faraji, F.

    2013-01-01

    Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male-male

  7. The use of social Stegodyphus spider retreats as nest-lining by pale ...

    African Journals Online (AJOL)

    The pale chanting-goshawk (Melierax canorus) incorporates silk nests (hereafter 'retreats') of the social spider Stegodyphus dumicola (Araneae: Eresidae) in the construction of the nest-lining of their own nests. This study investigates whether pale chanting-goshawks in the Little Karoo, South Africa, show a preference for ...

  8. Amplified fragment length polymorphism fingerprints support limited gene flow among social spider populations

    NARCIS (Netherlands)

    Smith, Deborah; van Rijn, Sander; Henschel, Joh; Bilde, Trine; Lubin, Yael

    We used DNA fingerprints to determine whether the population structure and colony composition of the cooperative social spider Stegodyphus dumicola are compatible with requirements of interdemic ('group') selection: differential proliferation of demes or groups and limited gene flow among groups. To

  9. Spider webs as indicators of cobalt and lead pollution in Kano ...

    African Journals Online (AJOL)

    Spider webs were collected from the indoor and outdoor of 120 sampling sites of 10 zones of Kano Municipality. The samples were analysed for cobalt and lead by the use of ALPHA-4 model of Atomic Absorption Spectrophotometer (AAS). The analysis of the webs showed different levels of the metals in the indoor and ...

  10. A 4-year study of invasive and native spider populations in Maine

    Science.gov (United States)

    Jakob, Elizabeth M.; Porter, Adam H.; Ginsberg, Howard; Bednarski, Julie V.; Houser, Jeremy

    2011-01-01

    Invasive spiders pose potential threats to native spiders. In 2002, the European spider Linyphia triangularis (Clerck, 1757) (Araneae: Linyphiidae) was discovered in all but one county in Maine. At Acadia National Park, we conducted a 4-year study of L. triangularis and three native linyphiid species of a similar size (Frontinella communis (Hentz, 1850), Pityohyphantes subarcticus Chamberlin and Ivie, 1943, and Neriene radiata (Walckenaer, 1842)). Using line-transect surveys, we measured population densities in coastal and forest habitat. The density of L. triangularis varied across years but was always significantly higher on the coast than in the forest. In contrast, only one native species was present on the coast and at very low numbers. Coastal L. triangularis were larger and in better condition than those in the forest, and numbers and biomass of insect prey were also higher on the coast. In 2 years, we also conducted transects at a second coastal location in Maine where the invader was at low density. At that site, native densities were substantially higher than at either Acadia site. Our data are consistent with the hypothesis that L. triangularis is reducing populations of native spiders. Companion studies suggest that L. triangularis negatively impacts natives by usurping both web sites and webs.

  11. The spiders of the Swartberg Nature Reserve in South Africa (Arachnida: Araneae

    Directory of Open Access Journals (Sweden)

    A.S. Dippenaar-Schoeman

    2005-06-01

    Full Text Available The Swartberg Nature Reserve is situated in the Large Swartberg mountain range, in the Oudtshoorn district of the Western Cape Province. Spiders were collected from the reserve over a 10-year period. This is one of the inventory projects of the South African National Survey (SANSA for spiders of the Succulent Karoo Biome. A total of 45 families comprising 136 genera and 186 species were collected, all which are new records for the area. This represents about 9.4 of the total known South African spider fauna. Of the spiders collected 142 species (76.5 were wanderers and 44 (23.5 web dwellers. The plant dwellers comprised 43.3 of the total number of species and the ground dwellers 56.7 . The Gnaphosidae was the most diverse family represented by 33 species, followed by the Salticidae with 23 and Thomisidae with 15. Ten species are possibly new to science and the Filistatidae is a first record for South Africa. An annotated checklist with information on the guilds, habitat preference and web types are provided.

  12. Lyriform slit sense organs on the pedipalps and spinnerets of spiders

    Indian Academy of Sciences (India)

    Lyriform slits sense organs (LSSO) are a precise assembly of stress detecting cuticular slit sensilla found on the appendages of arachnids. While these structures on the legs of the wandering spider Cupennius salei are well studied in terms of morphology, function and contribution to behaviour, their distribution on ...

  13. Palpimanid spiders from Guyana: new species of the genera Fernandezina and Otiothops (Araneae, Palpimanidae, Otiothopinae

    Directory of Open Access Journals (Sweden)

    Grismado Cristian J.

    2002-01-01

    Full Text Available Two new species of the spider family Palpimanidae from Guyana are described: Fernandezina takutu, the first species of this genus known from this country andOtiothops giralunas, that seems to be the sister species of O. goloboffi Grismado, 1996 from northwestern Argentina.

  14. Spider silk as a template for obtaining magnesium oxide and magnesium hydroxide fibers

    Directory of Open Access Journals (Sweden)

    Dmitrović Svetlana

    2018-01-01

    Full Text Available Spider silk fibers, collected from Pholcus Phalangioides spider were used as a template for obtaining magnesium oxide (MgO, periclase as well as magnesium hydroxide (Mg(OH2, brucite fibers. Magnesium oxide fibers were obtained in a simple manner by heat induced decomposition of magnesium salt (MgCl2 in the presence of the spider silk fibers, while magnesium hydroxide fibers were synthesized by hydration of MgO fibers at 50, 70 and 90 C, for 48 and 96 h. According to Scanning electron microscopy (SEM, dimensions of spider silk fibers determined the dimension of synthesized MgO fibers, while for Mg(OH2 fibers, the average diameter was increased with prolonging the hydration period. The surface of Mg(OH2 fibers was noticed to be covered with brucite in a form of plates. X-Ray diffraction (XRD analysis showed that MgO fibers were single-phased (the pure magnesium oxide fibers were obtained, while Mg(OH2 fibers were two- or single-phased brucite depending on incubation period, and/or incubation temperature. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 45012

  15. Web-sharing Sociality and Cooperative Prey Capture in a Malagasy Spitting Spider (Araneae: Scytodidae)

    NARCIS (Netherlands)

    Miller, J.A.

    2006-01-01

    Web-sharing sociality and cooperative prey capture are reported for Scytodes socialis, sp. nov., a spitting spider discovered in a dry deciduous forest in Eastern Madagascar. Transect-based sampling was used to investigate colony demographics, estimate web volume and stratigraphic position, and

  16. Male behavioural plasticity depends on maternal mating status in the two-spotted spider mite

    NARCIS (Netherlands)

    Oku, Keiko; Den Beuken, van Tom P.G.

    2017-01-01

    In haplodiploid organisms including the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), both unmated and mated females can produce male offspring. A previous study reported that males produced by unmated females (UM males) find pre-reproductive females more quickly than males

  17. Thanatosis as an adaptive male mating strategy in the nuptial gift-giving spider Pisaura mirabilis

    DEFF Research Database (Denmark)

    Hansen, Line S.; Gonzalez, Sofía F.; Toft, Søren

    2008-01-01

    Males and females often experience different optima in mating rate, which may cause evolution of female resistance to matings and male counter adaptations to increase mating rate. Males of the spider Pisaura mirabilis display a spectacular mating behavior involving a nuptial gift and thanatosis...

  18. Distribution and habitats of the water spider Argyroneta aquatica (Clerck, 1757 (Araneae, Cybaeidae in Turkey

    Directory of Open Access Journals (Sweden)

    Seyyar O.

    2009-01-01

    Full Text Available The water spider Argyroneta aquatica has been found in different parts of Turkey, and its distribution is presented with a list of new localities. Observations on the ecology of the species are provided, and its habitats are photographed from the collection sites. The data indicate that A. aquatica was usually found in eutrophic ponds, marshes, and small lakes in Turkey.

  19. Role of cucurbitacin C in resistance to spider mite (Tetranychus urticae) in cucumber (Cucumber sativus L.)

    NARCIS (Netherlands)

    Balkema-Boomstra, A.G.; Zijlstra, S.; Verstappen, F.W.A.; Inggamer, H.; Mercke, P.

    2003-01-01

    Cucurbitacins are bitter triterpenoid compounds that are toxic to most organisms and occur widely in wild and cultivated Cucurbitaceae. The only cucurbitacin identified in Cucumis sativus is cucurbitacin C. The bitter taste of cucumber has been correlated with resistance to the spider mite

  20. Effect of pruning and trellising of tomatoes on red spider mite ...

    African Journals Online (AJOL)

    The International Centre of Insect Physiology and Ecology (ICIPE), together with National Research Institutions of eastern and southern Africa, are developing integrated control methods for this new pest. The effects of pruning and trellising on red spider mite incidence and control, as well as damage and yield of tomatoes ...

  1. Characterization of microsatellite loci in the subsocial spider Stegodyphus lineatus (Araneae: Eresidae)

    DEFF Research Database (Denmark)

    Bilde, T.; Tuni, Cristina; Cariani, A.

    2009-01-01

    Stegodyphus lineatus spiders live in groups consisting of closely related individuals. There appears to be no discrimination against related individuals as mates but females mate multiply, despite the fact that matings are shown to carry a cost. We have developed eight polymorphic dinucleotide...

  2. Short-term spider community monitoring after cattle removal in grazed grassland

    Directory of Open Access Journals (Sweden)

    Guilherme O. da Silva

    2017-10-01

    Full Text Available ABSTRACT. At the Pampa Biome, grazing, like others disturbances, affects fauna and flora, creating heterogeneity in the environment. Little is known about how the diversity and richness of arthropods change during this impact. To improve the knowledge of how spider diversity is affected by grazing, experiments were realized at Pampa. The hypothesis is that abundance of spider will be different when comparing grazed and ungrazed areas. A paired block, with two areas of one hectare each, was established in three areas in the Environmental Protection Area of Ibirapuitã (APA Ibirapuitã, state of Rio Grande do Sul, Brazil. One of these hectares was closed with fences, excluding the catle grazing, in August of 2012. Samplings were realized in November of 2011, 2012 and 2013 using Pitfall traps filled with formol 4% and disposed in an “X” format in each area. For statistical analyses, T test, ANOSIM, ANOVA and Rarefaction were performed. A total of 1,315 spiders were captured, comprising 77 species or morphospecies belonging to 20 families. The family most abundant was Lycosidae followed by Hahniidae, Linyphiidae and Theridiidae. Linyphiidae was the richest family with 14 species or morphospecies identified. All spiders, adults and juveniles, only adults in species and morphospecies, and most abundant species were used as models for statistics. These models revealed no significant difference between grazed and ungrazed areas after three and 15 months of cattle exclusion.

  3. Relatedness facilitates cooperation in the subsocial spider, Stegodyphus tentoriicola

    DEFF Research Database (Denmark)

    Ruch, Jasmin; Heinrich, Lisa; Bilde, T.

    2009-01-01

    Background Cooperative hunting and foraging in spiders is rare and prone to cheating such that the actions of selfish individuals negatively affect the whole group. The resulting social dilemma may be mitigated by kin selection since related individuals lose indirect fitness benefits by acting...

  4. Lyriform slit sense organs on the pedipalps and spinnerets of spiders

    Indian Academy of Sciences (India)

    Madhu

    The trochanter bears a LSSO of type D (Tr 1) with 10 slits on the dorsal side adjacent to the femur- trochanter joint. Bhavani Patil, Suphala Prabhu and K P Rajashekhar. 78. J. Biosci. 31(1), March 2006. Table 2. Slit sense organs found on different segments of pedipalps of the spiders studied. Number. Segment. LSSO. Type.

  5. Geometric morphometrics reveals sex-differential shape allometry in a spider

    Directory of Open Access Journals (Sweden)

    Carmen Fernández-Montraveta

    2017-07-01

    Full Text Available Common scientific wisdom assumes that spider sexual dimorphism (SD mostly results from sexual selection operating on males. However, testing predictions from this hypothesis, particularly male size hyperallometry, has been restricted by methodological constraints. Here, using geometric morphometrics (GMM we studied for the first time sex-differential shape allometry in a spider (Donacosa merlini, Araneae: Lycosidae known to exhibit the reverse pattern (i.e., male-biased of spider sexual size dimorphism. GMM reveals previously undetected sex-differential shape allometry and sex-related shape differences that are size independent (i.e., associated to the y-intercept, and not to size scaling. Sexual shape dimorphism affects both the relative carapace-to-opisthosoma size and the carapace geometry, arguably resulting from sex differences in both reproductive roles (female egg load and male competition and life styles (wandering males and burrowing females. Our results demonstrate that body portions may vary modularly in response to different selection pressures, giving rise to sex differences in shape, which reconciles previously considered mutually exclusive interpretations about the origins of spider SD.

  6. Substrate-dependent bioavailability of Deltamethrin for the epigeal spider Oedothorax apicatus (Blackwall) (Aranaea, Erigonidae).

    NARCIS (Netherlands)

    Jagers op Akkerhuis, G.A.J.M.; Hamers, T.H.M.

    1992-01-01

    Terrestrial arthropods are mainly exposed to pesticides by uptake from the substrate e.g. “residual” uptake, which depends on the bioavailability of the pesticide. The residual uptake of deltamethrin by female Oedothorax apicatus (Blackwall), a linyphiid spider, was studied in relation to dependence

  7. Emotion regulation in spider phobia: role of the medial prefrontal cortex

    Science.gov (United States)

    Schäfer, Axel; Walter, Bertram; Stark, Rudolf; Vaitl, Dieter; Schienle, Anne

    2009-01-01

    Phobic responses are strong emotional reactions towards phobic objects, which can be described as a deficit in the automatic regulation of emotions. Difficulties in the voluntary cognitive control of these emotions suggest a further phobia-specific deficit in effortful emotion regulation mechanisms. The actual study is based on this emotion regulation conceptualization of specific phobias. The aim is to investigate the neural correlates of these two emotion regulation deficits in spider phobics. Sixteen spider phobic females participated in a functional magnetic resonance imaging (fMRI) study in which they were asked to voluntarily up- and down-regulate their emotions elicited by spider and generally aversive pictures with a reappraisal strategy. In line with the hypothesis concerning an automatic emotion regulation deficit, increased activity in the insula and reduced activity in the ventromedial prefrontal cortex was observed. Furthermore, phobia-specific effortful regulation within phobics was associated with altered activity in medial prefrontal cortex areas. Altogether, these results suggest that spider phobic subjects are indeed characterized by a deficit in the automatic as well as the effortful regulation of emotions elicited by phobic compared with aversive stimuli. These two forms of phobic emotion regulation deficits are associated with altered activity in different medial prefrontal cortex subregions. PMID:19398537

  8. Fecal and Salivary Cortisol Concentrations in Woolly (Lagothrix ssp.) and Spider Monkeys (Ateles spp.)

    NARCIS (Netherlands)

    Ange-van Heugten, K.D.; Heugten, van E.; Timmer, S.; Bosch, G.; Elias, A.; Whisnant, S.; Swarts, H.J.M.; Ferket, P.; Verstegen, M.W.A.

    2009-01-01

    Detrimental physiological effects due to stressors can contribute to the low captive success of primates. The objective of this research was to investigate the potential impact of diet composition on cortisol concentrations in feces and saliva in woolly (n=27) and spider monkeys (n=61). The research

  9. Exposure Therapy for Fear of Spiders in an Adult with Learning Disabilities: A Case Report

    Science.gov (United States)

    Cowdrey, Felicity A.; Walz, Linda

    2015-01-01

    The evidence-base for exposure therapy in people with learning disabilities experiencing specific phobias is sparse. This case study describes the assessment, formulation and treatment of spider phobia in a woman with learning disabilities using an exposure-based intervention augmented with mindfulness practice and bereavement work. To evaluate…

  10. Black and brown widow spider bites in South Africa: A series of 45 ...

    African Journals Online (AJOL)

    Cases of black widow (Latrodectus indistinctus) and brown widow (L. geometricus) spider bites referred to the Tygerberg Pharmacology and' Toxicology Consultation Centre from the summer of 1987/88 to the summer of 1991/92 were entered into this series. Of a total of 45 patients, 30 had been bitten by black and 15 by ...

  11. Evidence from Multiple Species that Spider Silk Glue Component ASG2 is a Spidroin.

    Science.gov (United States)

    Collin, Matthew A; Clarke, Thomas H; Ayoub, Nadia A; Hayashi, Cheryl Y

    2016-02-15

    Spiders in the superfamily Araneoidea produce viscous glue from aggregate silk glands. Aggregate glue coats prey-capture threads and hampers the escape of prey from webs, thereby increasing the foraging success of spiders. cDNAs for Aggregate Spider Glue 1 (ASG1) and 2 (ASG2) have been previously described from the golden orb-weaver, Nephila clavipes, and Western black widow, Latrodectus hesperus. To further investigate aggregate glues, we assembled ASG1 and ASG2 from genomic target capture libraries constructed from three species of cob-web weavers and three species of orb-web weavers, all araneoids. We show that ASG1 is unlikely to be a glue, but rather is part of a widespread arthropod gene family, the peritrophic matrix proteins. For ASG2, we demonstrate its remarkable architectural and sequence similarities to spider silk fibroins, indicating that ASG2 is a member of the spidroin gene family. Thus, spidroins have diversified into glues in addition to task-specific, high performance fibers.

  12. Targeting Fear of Spiders with Control-, Acceptance-, and Information-Based Approaches

    Science.gov (United States)

    Wagener, Alexandra L.; Zettle, Robert D.

    2011-01-01

    The relative impact of control-, acceptance-, and information-based approaches in targeting a midlevel fear of spiders among college students was evaluated. Participants listened to a brief protocol presenting one of the three approaches before completing the Perceived-Threat Behavioral Approach Test (PT-BAT; Cochrane, Barnes-Holmes, &…

  13. Why is the Red Spider Mite (Tetranychus evansi) a threat to Dry ...

    African Journals Online (AJOL)

    Dry season tomato (Lycopersicon esculentum L.) growing is an important economic activity in semi-arid Tabora region of western Tanzania. However, red spider mite (Tetranychus evansi Baker & Prichard) has emerged as a threat to dry season tomato growing in smallholders' fields. A study was carried out in Tabora,

  14. Effect of aqueous plant extracts on tea red spider mite, Oligonychus ...

    African Journals Online (AJOL)

    Four aqueous plant extracts (APEs) of Acorus calamus (L), Xanthium strumarium (L), Polygonum hydropiper (L) and Clerodendron infortunatum (Gaertn) were evaluated under both laboratory and field conditions at 2.5, 5.0 and 10.0% (w/v) concentrations against tea red spider mite, Oligonychus coffeae (Nietner). Also, the ...

  15. Spiders in Motion: Demonstrating Adaptation, Structure-Function Relationships, and Trade-Offs in Invertebrates

    Science.gov (United States)

    Bowlin, Melissa S.; McLeer, Dorothy F.; Danielson-Francois, Anne M.

    2014-01-01

    Evolutionary history and structural considerations constrain all aspects of animal physiology. Constraints on invertebrate locomotion are especially straightforward for students to observe and understand. In this exercise, students use spiders to investigate the concepts of adaptation, structure-function relationships, and trade-offs. Students…

  16. Protocols for the delivery of small molecules to the two-spotted spider mite, Tetranychus urticae.

    Directory of Open Access Journals (Sweden)

    Takeshi Suzuki

    Full Text Available The two-spotted spider mite, Tetranychus urticae, is a chelicerate herbivore with an extremely wide host range and an extraordinary ability to develop pesticide resistance. Due to its responsiveness to natural and synthetic xenobiotics, the spider mite is becoming a prime pest herbivore model for studies of the evolution of host range, plant-herbivore interactions and mechanisms of xenobiotic resistance. The spider mite genome has been sequenced and its transcriptional responses to developmental and various biotic and abiotic cues have been documented. However, to identify biological and evolutionary roles of T. urticae genes and proteins, it is necessary to develop methods for the efficient manipulation of mite gene function or protein activity. Here, we describe protocols developed for the delivery of small molecules into spider mites. Starting with mite maintenance and the preparation of the experimental mite populations of developmentally synchronized larvae and adults, we describe 3 methods for delivery of small molecules including artificial diet, leaf coating, and soaking. The presented results define critical steps in these methods and demonstrate that they can successfully deliver tracer dyes into mites. Described protocols provide guidelines for high-throughput setups for delivery of experimental compounds that could be used in reverse genetics platforms to modulate gene expression or protein activity, or for screens focused on discovery of new molecules for mite control. In addition, described protocols could be adapted for other Tetranychidae and related species of economic importance such as Varroa, dust and poultry mites.

  17. Nuptial gifts of male spiders: sensory exploitation of the female's maternal care instinct or foraging motivation?

    DEFF Research Database (Denmark)

    Bilde, T.; Tuni, Cristina; Elsayed, Rehab

    2007-01-01

    Nuptial feeding can evolve as sensory traps where the male exploits the female's foraging motivation in a sexual context. The nuptial prey gift of the nursery-web spider Pisaura mirabilis is wrapped in white silk, and it has been suggested that males initially exploit the maternal care instinct...

  18. Beyond fear and disgust : The role of (automatic) contamination-related associations in spider phobia

    NARCIS (Netherlands)

    Huijding, Jorg; de Jong, Peter J.

    This study explored the role of threat and contamination-related associations in spider phobia. Treatment-seeking (n = 60) and non-phobic (n = 30) individuals completed threat and disgust-related Implicit Association Tests (IATs). Phobic individuals were assessed before and after one session of 2.5

  19. Beyond fear and disgust: the role of (automatic) contamination-related associations in spider phobia

    NARCIS (Netherlands)

    J. Huijding (Jorg); P.J. de Jong (Peter)

    2007-01-01

    textabstractThis study explored the role of threat and contamination-related associations in spider phobia. Treatment-seeking (n = 60) and non-phobic (n = 30) individuals completed threat and disgust-related Implicit Association Tests (IATs). Phobic individuals were assessed before and after one

  20. Side effects of kaolin particle films on apple orchard bug, beetle and spider communities

    NARCIS (Netherlands)

    Marko, V.; Bogya, S.; Kondorosy, E.; Blommers, L.H.M.

    2010-01-01

    The effects of multiple applications of hydrophobic kaolin particle film on apple orchard bug (Heteroptera), beetle (Coleoptera) and spider (Araneae) assemblages were studied in the Netherlands. Insecticide-free orchard plots served as a control. The kaolin applications significantly reduced the