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Sample records for jumping spider araneae

  1. The deep phylogeny of jumping spiders (Araneae, Salticidae

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    Wayne Maddison

    2014-09-01

    Full Text Available In order to resolve better the deep relationships among salticid spiders, we compiled and analyzed a molecular dataset of 169 salticid taxa (and 7 outgroups and 8 gene regions. This dataset adds many new taxa to previous analyses, especially among the non-salticoid salticids, as well as two new genes – wingless and myosin heavy chain. Both of these genes, and especially the better sampled wingless, confirm many of the relationships indicated by other genes. The cocalodines are placed as sister to lapsiines, in a broader clade with the spartaeines. Cocalodines, lapsiines, and spartaeines are each supported as monophyletic, though the first two have no known morphological synapomorphies. The lyssomanines appear to be non-monophyletic, of three separate groups: (1 Lyssomanes plus Chinoscopus, (2 Onomastus, and (3 the remainder of Old World species. Several previously-inferred relationships continue to be supported: hisponines as sister to the Salticoida, Amycoida as sister to the remaining Salticoida, and Saltafresia as monophyletic. The relationship of Salticus with Philaeus and relatives is now considered well enough corroborated to move the latter into the subfamily Salticinae. A new clade consisting of the Plexippoida + Aelurilloida + Leptorchesteae + Salticinae is recognized. Nungia is found to be an astioid, and Echeclus, Gedea and Diplocanthopoda to be hasariines. The euophryines are corroborated as monophyletic. The agoriines Agorius and Synagelides are salticoids, within the sister group to amycoids, but their further placement is problematical, perhaps because of their nuclear ribosomal genes’ high GC bias, as also seen in the similarly problematic Eupoa.

  2. Papuaneon, a new genus of jumping spiders from Papua New Guinea (Araneae: Salticidae: Neonini).

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    Maddison, Wayne P

    2016-11-29

    The genus Neon Simon stands alone as a phylogenetically isolated astioid jumping spider, the only member of the Neonini. The new genus Papuaneon is established for the jumping spider Papuaneon tualapa sp. nov. from Papua New Guinea. Resembling a large, hirsute Neon, it is here shown to be the sister group to Neon, based on data from the nuclear 28S and Actin 5C, and the mitochondrial 16SND1 region. Photographs of living specimens are provided.

  3. Contribution to the knowledge of jumping spiders (Araneae: Salticidae from vicinity of Jagodina, Central Serbia

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    Stanković, B.

    2012-09-01

    Full Text Available During last 10 years, based on personal collectings, 21 species from 14 genera of Salticidae (Araneae are recorded from vicinity of Jagodina: Ballus chalybeius, Carrhotus xanthogramma, Evarcha arcuata, Evarcha falcata, Heliophanus auratus, Heliophanus cupreus, Heliophanus flavipes, Heliophanus kochii, Icius hamatus, Icius subinermis, Leptorchestes berolinensis, Macaroeris nidicolens, Marpissa muscosa, Marpissa nivoyi, Mendoza canestrinii, Pellenes tripunctatus, Phintella castriesiana, Phlegra fasciata, Pseudeuophrys erratica, Pseudeuophrys lanigera, Salticus scenicus. All those species are provided with habitat notes and global distribution. New records for the spider fauna of Serbia are Heliophanus kochii (Simon 1868, Icius subinermis (Simon, 1937, Marpissa nivoyi (Lucas, 1846 and Mendoza canestrinii (Ninni, 1868.

  4. The complete mitogenome of a jumping spider Carrhotus xanthogramma (Araneae: Salticidae) and comparative analysis in four salticid mitogenomes.

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    Fang, Wen-Yuan; Wang, Zheng-Liang; Li, Chao; Yang, Xiao-Qing; Yu, Xiao-Ping

    2016-12-01

    The complete mitogenome of the jumping spider Carrhotus xanthogramma was determined and comparative analysis among four salticid mitogenomes was conducted. The circular genome is 14,563 bp in size and contains a complete set of genes that usually present in the metazoa. All of the 13 protein-coding genes begin with a typical ATN codon and stop with the canonical stop codons, except for ND4 and ND4L genes with an incomplete stop codon T. All of the tRNAs cannot be formed the fully paired acceptor stems and seven out of them cannot be folded into the typical cloverleaf-shaped secondary structures. The tRNA (Glu) gene translocates its position as compared to the mitogenomes of other three determined jumping spiders. The A+T content of the majority strand and the A+T-rich region are 75.1 and 80%, respectively. The phylogenetic relationships based on concatenated nucleotide and amino acid sequences of 13 protein-coding genes using Maximum Likelihood and Bayesian Inference methods indicated that mitogenome sequences were useful in resolving higher-level relationship of Araneae.

  5. Tisaniba, a new genus of marpissoid jumping spiders from Borneo (Araneae: Salticidae).

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    Zhang, Jun-Xia; Maddison, Wayne P

    2014-08-14

    Six new species of marpissoid jumping spiders from Sarawak, Borneo, are described in the new genus Tisaniba Zhang & Maddison. They are the type species, T. mulu Zhang & Maddison sp. nov., as well as the species T. bijibijan Zhang & Maddison sp. nov., T. dik Zhang & Maddison sp. nov., T. kubah Zhang & Maddison sp. nov., T. selan Zhang & Maddison sp. nov., and T. selasi Zhang & Maddison sp. nov. The spiders are small and brown to black, living in leaf litter in the tropical forest. Phylogenetic analyses based on 28s and 16sND1 genes indicate that they are a distinctive group within the marpissoids. Diagnostic illustrations and photographs of living spiders are provided for all species.

  6. Respiration in spiders (Araneae).

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    Schmitz, Anke

    2016-05-01

    Spiders (Araneae) are unique regarding their respiratory system: they are the only animal group that breathe simultaneously with lungs and tracheae. Looking at the physiology of respiration the existence of tracheae plays an important role in spiders with a well-developed tracheal system. Other factors as sex, life time, type of prey capture and the high ability to gain energy anaerobically influence the resting and the active metabolic rate intensely. Most spiders have metabolic rates that are much lower than expected from body mass; but especially those with two pairs of lungs. Males normally have higher resting rates than females; spiders that are less evolved and possess a cribellum have lower metabolic rates than higher evolved species. Freely hunting spiders show a higher energy turnover than spiders hunting with a web. Spiders that live longer than 1 year will have lower metabolic rates than those species that die after 1 year in which development and reproduction must be completed. Lower temperatures and starvation, which most spiders can cope with, will decrease the metabolic rate as well.

  7. Genera of euophryine jumping spiders (Araneae: Salticidae), with a combined molecular-morphological phylogeny.

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    Zhang, Junxia; Maddison, Wayne P

    2015-03-27

    Morphological traits of euophryine jumping spiders were studied to clarify generic limits in the Euophryinae and to permit phylogenetic classification of genera lacking molecular data. One hundred and eight genera are recognized within the subfamily. Euophryine generic groups and the delimitation of some genera are reviewed in detail. In order to explore the effect of adding formal morphological data to previous molecular phylogenetic studies, and to find morphological synapomorphies, eighty-two morphological characters were scored for 203 euophryine species and seven outgroup species. The morphological dataset does not perform as well as the molecular dataset (genes 28S, Actin 5C; 16S-ND1, COI) in resolving the phylogeny of Euophryinae, probably because of frequent convergence and reversal. The formal morphological data were mapped on the phylogeny in order to seek synapomorphies, in hopes of extending the phylogeny to include taxa for which molecular data are not available. Because of homoplasy, few globally-applicable morphological synapomorphies for euophryine clades were found. However, synapomorphies that are unique locally in subclades still help to delimit euophryine generic groups and genera. The following synonyms of euophryine genera are proposed: Maeotella with Anasaitis; Dinattus with Corythalia; Paradecta with Compsodecta; Cobanus, Chloridusa and Wallaba with Sidusa; Tariona with Mopiopia; Nebridia with Amphidraus; Asaphobelis and Siloca with Coryphasia; Ocnotelus with Semnolius; Palpelius with Pristobaeus; Junxattus with Laufeia; Donoessus with Colyttus; Nicylla, Pselcis and Thianitara with Thiania. The new genus Saphrys is erected for misplaced species from southern South America.

  8. Observations on web-invasion by the jumping spider Thyene imperialis in Israel (Araneae: Salticidae

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    Jäger, Peter

    2012-07-01

    Full Text Available Observations on Thyene imperialis (Rossi, 1846 in Israel, Negev desert, invading a web of Cyclosa deserticola Levy, 1998 are reported. The female leapt into the orb-web to catch Cyclosa spiders. Photographs are provided, and a link to additional film material is given.

  9. A new species of jumping spider Neonella Gertsch, with notes on the genus and male identification key (Araneae, Salticidae).

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    Rubio, Gonzalo D; Argañaraz, Carina I; Gleiser, Raquel M

    2015-01-01

    The American genus Neonella Gertsch, 1936 consists of very small jumping spiders whose biology is not well known. The genus currently includes eleven valid species, of which eight are known from both sexes and two are only known from one sex. This paper describes and illustrates a new species Neonella acostae sp. n., demonstrates male palpal variation in Neonella montana Galiano, 1988, and provides some information on the ecology of three sympatric species. New records of Neonella montana and Neonella minuta Galiano, 1965 are reported. Because the previously described species of Neonella were well illustrated and diagnosed, a dichotomous key to males is given along with genital illustrations of both sexes for all known species.

  10. A new species of jumping spider Neonella Gertsch, with notes on the genus and male identification key (Araneae, Salticidae)

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    Rubio, Gonzalo D.; Argañaraz, Carina I.; Gleiser, Raquel M.

    2015-01-01

    Abstract The American genus Neonella Gertsch, 1936 consists of very small jumping spiders whose biology is not well known. The genus currently includes eleven valid species, of which eight are known from both sexes and two are only known from one sex. This paper describes and illustrates a new species Neonella acostae sp. n., demonstrates male palpal variation in Neonella montana Galiano, 1988, and provides some information on the ecology of three sympatric species. New records of Neonella montana and Neonella minuta Galiano, 1965 are reported. Because the previously described species of Neonella were well illustrated and diagnosed, a dichotomous key to males is given along with genital illustrations of both sexes for all known species. PMID:26692804

  11. Araneae Sloveniae: a national spider species checklist

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    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.

  12. A new jumping spider species of the genus Maeota (Araneae: Salticidae: Euophryini, with new faunistic data of the tribe from Colombia

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    William Galvis

    2016-07-01

    Full Text Available A new species of jumping spider of the genus Maeota (Salticidae, M. galeanoae sp. nov., is described and illustrated from the Caribbean state of Magdalena, Colombia. Additionally, the genus Anasaitis is recorded for the first time from Colombia, with the species A. canalis, from the department of Chocó. Moreover, new records are presented for Maeota serrapophysis from the departments of Magdalena, Quindío and Valle del Cauca, Colombia, with individuals from the southern region presenting a slightly different pattern of coloration in which the prosoma, abdomen and legs have a reticulated brown and gray pattern. New faunistic data from Colombia are also presented for the species M. betancuri and Ilargus galianoae. Finally, a distribution map is presented, including new and previously published records for the taxa treated here.

  13. 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 properties a

  14. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders

    OpenAIRE

    Carver, Linnea M.; Perlaky, Patricia; Cressler, Alan; Kirk S Zigler

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave co...

  15. Detection and phylogenetic analysis of bacteriophage WO in spiders (Araneae).

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    Yan, Qian; Qiao, Huping; Gao, Jin; Yun, Yueli; Liu, Fengxiang; Peng, Yu

    2015-11-01

    Phage WO is a bacteriophage found in Wolbachia. Herein, we represent the first phylogenetic study of WOs that infect spiders (Araneae). Seven species of spiders (Araneus alternidens, Nephila clavata, Hylyphantes graminicola, Prosoponoides sinensis, Pholcus crypticolens, Coleosoma octomaculatum, and Nurscia albofasciata) from six families were infected by Wolbachia and WO, followed by comprehensive sequence analysis. Interestingly, WO could be only detected Wolbachia-infected spiders. The relative infection rates of those seven species of spiders were 75, 100, 88.9, 100, 62.5, 72.7, and 100 %, respectively. Our results indicated that both Wolbachia and WO were found in three different body parts of N. clavata, and WO could be passed to the next generation of H. graminicola by vertical transmission. There were three different sequences for WO infected in A. alternidens and two different WO sequences from C. octomaculatum. Only one sequence of WO was found for the other five species of spiders. The discovered sequence of WO ranged from 239 to 311 bp. Phylogenetic tree was generated using maximum likelihood (ML) based on the orf7 gene sequences. According to the phylogenetic tree, WOs in N. clavata and H. graminicola were clustered in the same group. WOs from A. alternidens (WAlt1) and C. octomaculatum (WOct2) were closely related to another clade, whereas WO in P. sinensis was classified as a sole cluster.

  16. Menemerus fagei new to Malta and Europe (Araneae: Salticidae

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    Freudenschuss, Mario

    2013-11-01

    Full Text Available The first record of Menemerus fagei Berland & Millot 1941 (Araneae, Salticidae from the Maltese Islands is reported and discussed. It is the 20th jumping spider species for Malta and a new record for Europe.

  17. Competition between introduced and native spiders (Araneae: Linyphiidae)

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    Houser, J.D.; Ginsberg, Howard S.; Jakob, Elizabeth M.

    2014-01-01

    The European sheet-web spider Linyphia triangularis (Araneae: Linyphiidae) has become established in Maine, where it often reaches very high densities. Two lines of evidence from previous work suggest that L. triangularis affects populations of the native linyphiid spider Frontinella communis. First, F. communis individuals are relatively scarce in both forest and coastal habitat where L. triangularis is common, but more common where L. triangularis is at low density. Second, in field experiments, F. communis species are less likely to settle in experimental plots when L. triangularis is present, and F. communis disappears from study plots when L. triangularis is introduced. Here we test two mechanisms that may underlie these patterns. First, we tested whether L. triangularis invades and usurps the webs of F. communis. When spiders were released onto webs of heterospecifics, L. triangularis was more likely to take over or share webs of F. communis than the reverse. We also observed natural takeovers of F. communis webs. Second, we explored the hypothesis that L. triangularis reduces prey availability for native species. We sampled flying prey in areas with L. triangularis and those where it had been removed, and found no effect of spider presence on measured prey density. We also found no effect of prey supplementation on web tenacity in F. communis, suggesting that F. communis movements are not highly dependent on prey availability. We conclude that web takeover is likely more important than prey reduction in driving negative effects of L. triangularis on F. communis.

  18. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders.

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    Carver, Linnea M; Perlaky, Patricia; Cressler, Alan; Zigler, Kirk S

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave communities, we know little about reproduction and feeding in this group. We addressed this knowledge gap by examining populations of two species on a monthly basis for one year. We made further observations on several other species and populations, totaling 671 individual spider observations. This more than doubled the reported observations of reproduction and feeding in troglobiotic Nesticus. Female Nesticus carry egg sacs, facilitating the determination of the timing and frequency of reproduction. We found that Nesticus exhibit reproductive seasonality. Females carried egg sacs from May through October, with a peak in frequency in June. These spiders were rarely observed with prey; only 3.3% (22/671) of individuals were observed with prey items. The frequency at which prey items were observed did not vary by season. Common prey items were flies, beetles and millipedes. Troglobiotic species constituted approximately half of all prey items observed. This result represents a greater proportion of troglobiotic prey than has been reported for various troglophilic spiders. Although our findings shed light on the life history of troglobiotic Nesticus and on their role in cave ecosystems, further work is necessary to support effective conservation planning for many of these rare species.

  19. A revision of the spider genus Zaitunia (Araneae, Filistatidae

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    Sergei Zonstein

    2016-07-01

    Full Text Available The spider genus Zaitunia Lehtinen, 1967 (Araneae, Filistatidae is revised. It was found to include 24 species distributed in the Eastern Mediterranean, Middle East and Central Asia: ♀ Z. afghana (Roewer, 1962 (Afghanistan, ♀ Z. alexandri Brignoli, 1982 (Iran, ♀ Z. akhanii Marusik & Zamani, 2015 (Iran, ♂♀ Z. annulipes (Kulczyński, 1908 (Cyprus, ♂♀ Z. beshkentica (Andreeva & Tyshchenko, 1969 (Tajikistan, Uzbekistan, ♀ Z. brignoliana sp. nov. (Iran, ♂♀ Z. ferghanensis sp. nov. (Kyrgyzstan, Uzbekistan, ♀ Z. feti sp. nov. (Turkmenistan, ♀ Z. halepensis sp. nov. (Syria, ♀ Z. huberi sp. nov. (Afghanistan, ♀ Z. inderensis Ponomarev, 2005 (Kazakhstan, ♂♀ Z. kunti sp. nov. (Cyprus, Turkey, ♂♀ Z. logunovi sp. nov. (Kazakhstan, Kyrgyzstan, ♂♀ Z. maracandica (Charitonov, 1946 (Uzbekistan, Kazakhstan, ♂♀ Z. martynovae (Andreeva & Tyshchenko, 1969 (Tajikistan, Turkmenistan, ♀ Z. medica Brignoli, 1982 (Iran, ♂♀ Z. minoica sp. nov. (Greece, ♀ Z. minuta sp. nov. (Uzbekistan, ♀ Z. persica Brignoli, 1982 (Iran, ♂ Z. psammodroma sp. nov. (Turkmenistan, ♂♀ Z. schmitzi (Kulczyński, 1911, the type species (Egypt, Israel, ♂♀ Z. spinimana sp. nov. (Kazakhstan, Turkmenistan, ♂♀ Z. wunderlichi sp. nov. (Kyrgyzstan and ♀ Z. zonsteini Fomichev & Marusik, 1969 (Kazakhstan. Twelve above-listed species are newly described, and males of Z. annulipes, Z. beshkentica, Z. maracandica and Z. martynovae are described for the first time. Two new combinations are established: Z. annulipes (Kulczyński, 1908 comb. nov., ex Filistata, and Pholcoides monticola (Spassky, 1941 comb. nov., ex Zaitunia. New data on distribution of the considered taxa are provided.

  20. Male palp organ morphology of three species of ground spiders (Araneae, Gnaphosidae

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    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.

  1. Web placement in sympatric linyphiid spiders ( Arachnida, Araneae): Individual foraging decisions reveal inter-specific competition

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    Herberstein, Marie Elisabeth

    1998-02-01

    The distribution of two sympatric web spiders, Frontinellina frutetorum (C. L. Koch) and Neriene radiata (Walckenaer) (Araneae: Linyphiidae) was studied on an area of forest regrowth in eastern Austria. Both species utilised significantly different heights on young conifer trees to construct their webs. F. frutetorum selected higher vegetation layers, whereas N. radiata constructed its webs, closer to the ground. This distribution may either be evidence of competition for web space or it may reflect specific distribution patterns unrelated to spider density. An experiment showed that when spiders of either species were released onto vacant trees they selected similar vegetation heights for web construction. On trees already occupied by a heterospecific individual however, F. frutetorum placed its webs significantly higher and N. radiata significantly lower compared to web placement on vacant trees suggesting that F. frutetorum and N. radiata compete for web space.

  2. 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......) species were captured. Twenty-five percent of the collected species occurred in all habitats, but about half of them were only collected in one of the urbanisation stages. The number of shared species was the highest between the suburban and urban habitats. The highest similarities between assemblages...

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

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    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.

  4. Influence of prescribed fire on carabid beetle (Carabidae) and spider (Araneae) assemblages in forest litter in southwestern Oregon.

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    Christine G. Niwa; Robert W. Peck

    2002-01-01

    The objective of this study was to determine if prescribed fire affects spider (Araneae) and carabid beetle (Carabidae) abundance, and whether the magnitude of this effect varies with time since fire. Within mixed conifer stands; nine understory fuels-reduction burns, ranging from

  5. Salticid predation as one potential driving force of ant mimicry in jumping spiders.

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    Huang, Jin-Nan; Cheng, Ren-Chung; Li, Daiqin; Tso, I-Min

    2011-05-07

    Many spiders possess myrmecomorphy, and species of the jumping spider genus Myrmarachne exhibit nearly perfect ant mimicry. Most salticids are diurnal predators with unusually high visual acuity that prey on various arthropods, including conspecifics. In this study, we tested whether predation pressure from large jumping spiders is one possible driving force of perfect ant mimicry in jumping spiders. The results showed that small non-ant-mimicking jumping spiders were readily treated as prey by large ones (no matter whether heterospecific or conspecific) and suffered high attack and mortality rates. The size difference between small and large jumping spiders significantly affected the outcomes of predatory interactions between them: the smaller the juvenile jumping spiders, the higher the predation risk from large ones. The attack and mortality rates of ant-mimicking jumping spiders were significantly lower than those of non-ant-mimicking jumping spiders, indicating that a resemblance to ants could provide protection against salticid predation. However, results of multivariate behavioural analyses showed that the responses of large jumping spiders to ants and ant-mimicking salticids differed significantly. Results of this study indicate that predation pressure from large jumping spiders might be one selection force driving the evolution of nearly perfect myrmecomorphy in spiders and other arthropods.

  6. Envenomation by spiders of the genus Hololena (Araneae: Agelenidae).

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    Vetter, Richard S

    2012-09-01

    Three verified bites from Hololena spiders (Family Agelenidae) are presented here. Two male victims, each over 100 kg weight (bitten by female spiders), experienced headaches and 4-h episodes of vomiting. A female bite victim (bitten by a male spider) experienced minor reaction. None sought medical attention; symptoms resolved in a few days. Although these incidents were not serious, reactions in the male victims were more dynamic than usual generic spider bites (minor edema, minor erythema). Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Spiders (Araneae) in the pesticide world: an ecotoxicological review.

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    Pekár, Stano

    2012-11-01

    Being one of the most abundant and species-rich groups of natural enemies occurring in all agroecosystems, spiders are variably affected by pesticide applications. Here, a review is given of research on spider ecotoxicology. More than 40 species of spiders and almost 130 pesticides (acaricides, insecticides, fungicides and herbicides) have been tested so far in the field or under laboratory conditions. Field studies show that the degree of population reduction following pesticide application is a function of a number of factors inherent to pesticides, crops and spider species (guilds). These studies also revealed indirect effects via habitat and prey disruption. Among laboratory studies, a number of papers have investigated only the direct lethal effect. A meta-analysis of these data reveals that spiders are mainly affected by acaricides and insecticides, particularly neurotoxic substances. Currently, ecotoxicological research on spiders is focused more on direct sublethal effects on a variety of behavioural traits (locomotion, predation, web-building, reproduction, development) and physiology. Yet a standardised approach to the evaluation of sublethal effects is lacking. A few studies have provided some evidence for hormesis in spiders. Future research should be more concentrated on sublethal effects and the estimation of long-term changes in spider populations as a result of pesticide treatment. Copyright © 2012 Society of Chemical Industry.

  8. The first account of a bite by the New Zealand native spider Trite planiceps (Araneae: Salticidae).

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    Derraik, José G B; Sirvid, Phil J; Rademaker, Marius

    2010-05-14

    New Zealand has very few arthropods that pose a threat to human health. While most New Zealand spiders are considered harmless, the bite effects of most species are unknown. Here, we describe a case of a bite by a native spider, in which a young man was bitten after rolling over in his bed. The spider was collected and identified as Trite planiceps (Salticidae, black headed jumping spider), a native species commonly encountered around homes. The initial reaction was a relatively painful, sting-like, sensation, followed by the appearance of two red puncture marks and an urticarial wheal. Symptoms eventually disappeared after 72 hours, and he has had no further dermatological problems. Trite planiceps is considered to be a rather docile spider with regard to humans, but even a docile species may still bite defensively as a last resort. Notes on this species and on treatment of spider bites are provided.

  9. Place avoidance learning and memory in a jumping spider.

    Science.gov (United States)

    Peckmezian, Tina; Taylor, Phillip W

    2017-03-01

    Using a conditioned passive place avoidance paradigm, we investigated the relative importance of three experimental parameters on learning and memory in a salticid, Servaea incana. Spiders encountered an aversive electric shock stimulus paired with one side of a two-sided arena. Our three parameters were the ecological relevance of the visual stimulus, the time interval between trials and the time interval before test. We paired electric shock with either a black or white visual stimulus, as prior studies in our laboratory have demonstrated that S. incana prefer dark 'safe' regions to light ones. We additionally evaluated the influence of two temporal features (time interval between trials and time interval before test) on learning and memory. Spiders exposed to the shock stimulus learned to associate shock with the visual background cue, but the extent to which they did so was dependent on which visual stimulus was present and the time interval between trials. Spiders trained with a long interval between trials (24 h) maintained performance throughout training, whereas spiders trained with a short interval (10 min) maintained performance only when the safe side was black. When the safe side was white, performance worsened steadily over time. There was no difference between spiders tested after a short (10 min) or long (24 h) interval before test. These results suggest that the ecological relevance of the stimuli used and the duration of the interval between trials can influence learning and memory in jumping spiders.

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

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    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.

  11. Taxonomic revision of the spider family Penestomidae (Araneae, Entelegynae)

    NARCIS (Netherlands)

    Miller, J.A.; Griswold, C.E.; Haddad, C.R.

    2010-01-01

    Conflicting character evidence and a scarcity of male specimens has historically made placement of the spider subfamily Penestominae Simon problematic. The Penestominae was recently removed from the family Eresidae and promoted to family rank based on the results of a molecular phylogenetic study; a

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

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    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. Food caching in orb-web spiders (Araneae: Araneoidea)

    Science.gov (United States)

    Champion de Crespigny, Fleur E.; Herberstein, Marie E.; Elgar, Mark A.

    2001-01-01

    Caching or storing surplus prey may reduce the risk of starvation during periods of food deprivation. While this behaviour occurs in a variety of birds and mammals, it is infrequent among invertebrates. However, golden orb-web spiders, Nephila edulis, incorporate a prey cache in their relatively permanent web, which they feed on during periods of food shortage. Heavier spiders significantly reduced weight loss if they were able to access a cache, but lost weight if the cache was removed. The presence or absence of stored prey had no effect on the weight loss of lighter spiders. Furthermore, N. edulis always attacked new prey, irrespective of the number of unprocessed prey in the web. In contrast, females of Argiope keyserlingi, who build a new web every day and do not cache prey, attacked fewer new prey items if some had already been caught. Thus, a necessary pre-adaptation to the evolution of prey caching in orb-web spiders may be a durable or permanent web, such as that constructed by Nephila.

  14. Spiders (Arachnida: Araneae) Of Milbridge, Washington County, Maine

    Science.gov (United States)

    Daniel T. Jennings; Frank Jr. Graham

    2007-01-01

    An inventory or spiders associated with diverse habitats of Milbridge, a 6,290-ha area of the East Coastal BioPhysical Region, yielded 6,979 individuals of 19 families, 145 genera, and 302 species (4 unknown). Species richness per genus ranged from 1 to 13, with 88 genera represented by a single species. Total species composition favored web spinners over hunters;...

  15. Spatial distribution of Madeira Island Laurisilva endemic spiders (Arachnida: Araneae)

    Science.gov (United States)

    2014-01-01

    Abstract Madeira island presents a unique spider diversity with a high number of endemic species, many of which are still poorly known. A recent biodiversity survey on the terrestrial arthropods of the native forest, Laurisilva, provided a large set of standardized samples from various patches throughout the island. Out of the fifty two species recorded, approximately 33.3% are Madeiran endemics, many of which had not been collected since their original description. Two new species to science are reported – Ceratinopsis n. sp. and Theridion n. sp. – and the first records of Poeciloneta variegata (Blackwall, 1841) and Tetragnatha intermedia Kulczynski, 1891 are reported for the first time for Madeira island. Considerations on species richness and abundance from different Laurisilva locations are presented, together with distribution maps for endemic species. These results contribute to a better understanding of spider diversity patterns and endemic species distribution in the native forest of Madeira island. PMID:24855443

  16. Spatial distribution of Madeira Island Laurisilva endemic spiders (Arachnida: Araneae

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    Luís Crespo

    2014-02-01

    Full Text Available Madeira island presents a unique spider diversity with a high number of endemic species, many of which are still poorly known. A recent biodiversity survey on the terrestrial arthropods of the native forest, Laurisilva, provided a large set of standardized samples from various patches throughout the island. Out of the fifty two species recorded, approximately 33.3% are Madeiran endemics, many of which had not been collected since their original description. Two new species to science are reported – Ceratinopsis n. sp. and Theridion n. sp. – and the first records of Poeciloneta variegata (Blackwall, 1841 and Tetragnatha intermedia Kulczynski, 1891 are reported for the first time for Madeira island. Considerations on species richness and abundance from different Laurisilva locations are presented, together with distribution maps for endemic species. These results contribute to a better understanding of spider diversity patterns and endemic species distribution in the native forest of Madeira island.

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

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    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

  18. First Record of the Mediterranean Recluse Spider Loxosceles rufescens (Araneae: Sicariidae from Iran.

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    Alireza Zamani

    2014-12-01

    Full Text Available Loxosceles rufescens, commonly known as the Mediterranean Recluse or Mediterranean Fiddle-Back Spider is recorded from Iran for the first time. The genus Loxosceles contains 103 accepted species, two of them (including L. rufescens are cosmopolitan. All Loxosceles species tested so far possess necrotic venoms, which is a unique characteristic among the Order Araneae. Considering this characteristic, it is of medical importance to determine a specific geographical distribution of these spiders. Collecting methods include visual inspection and direct hand collecting. All of the specimens were collected in Tehran. Six specimens of both sexes were collected from parks, houses and apartments. The characteristics of the genus, which are the unique arrangement of six eyes in three diads, the violin shaped mark on the cephalothorax, and the short tibia of adult male palpi with narrow base and it's embolus which is about as long as the width of the globular bulb were observed and recorded. Having the cytotoxicity of the venom and its urban distribution in mind, L. rufescens is probably among the more important spider species of Iran. Since there are no reports of loxoscelism from Iran, we assume that the bites are either infrequent or misdiagnosed. Therefore further studies are needed to clarify the medical importance degree of this species.

  19. The oldest haplogyne spider (Araneae: Plectreuridae), from the Middle Jurassic of China

    Science.gov (United States)

    Selden, Paul A.; Huang, Diying

    2010-05-01

    New fossil spiders (Arachnida: Araneae) from Middle Jurassic (ca. 165 Ma) strata of Daohugou, Inner Mongolia, China are described as Eoplectreurys gertschi gen. et sp. nov. and referred to the modern haplogyne family Plectreuridae. This small family is restricted to southwestern USA, Mexico, and the adjacent Caribbean area today and hitherto has only a sparse Cenozoic fossil record. The morphology of Eoplectreurys is remarkably similar to modern forms and thus demonstrates great evolutionary conservatism. This new discovery not only extends the fossil record of the family by at least 120 Ma to the Middle Jurassic but also supports the hypothesis of a different distribution of the family in the past than today and subsequent extinction over much of its former range.

  20. Visual perception in the brain of a jumping spider.

    Science.gov (United States)

    Menda, Gil; Shamble, Paul S; Nitzany, Eyal I; Golden, James R; Hoy, Ronald R

    2014-11-03

    Jumping spiders (Salticidae) are renowned for a behavioral repertoire that can seem more vertebrate, or even mammalian, than spider-like in character. This is made possible by a unique visual system that supports their stalking hunting style and elaborate mating rituals in which the bizarrely marked and colored appendages of males highlight their song-and-dance displays. Salticids perform these tasks with information from four pairs of functionally specialized eyes, providing a near 360° field of view and forward-looking spatial resolution surpassing that of all insects and even some mammals, processed by a brain roughly the size of a poppy seed. Salticid behavior, evolution, and ecology are well documented, but attempts to study the neurophysiological basis of their behavior had been thwarted by the pressurized nature of their internal body fluids, making typical physiological techniques infeasible and restricting all previous neural work in salticids to a few recordings from the eyes. We report the first survey of neurophysiological recordings from the brain of a jumping spider, Phidippus audax (Salticidae). The data include single-unit recordings in response to artificial and naturalistic visual stimuli. The salticid visual system is unique in that high-acuity and motion vision are processed by different pairs of eyes. We found nonlinear interactions between the principal and secondary eyes, which can be inferred from the emergence of spatiotemporal receptive fields. Ecologically relevant images, including prey-like objects such as flies, elicited bursts of excitation from single units.

  1. Bites by Australian mygalomorph spiders (Araneae, Mygalomorphae), including funnel-web spiders (Atracinae) and mouse spiders (Actinopodidae: Missulena spp).

    Science.gov (United States)

    Isbister, Geoffrey K; Gray, Mike R

    2004-02-01

    A number of mygalomorph spiders cause bites in Australia, including the funnel-web spiders (Hexathelidae, Atracinae: Hadronyche and Atrax) and mouse spiders (Actinopodidae: Missulena). There is ongoing debate about the significance of bites by mouse spiders and the frequency of severe envenoming by funnel-web spiders. We conducted a prospective cohort study of definite spider bites with expert spider identification and include the analysis of mygalomorph spiders here. Subjects were recruited prospectively from February 1999 to April 2003 from patients presenting to participating hospitals or contacting a state poison information centre. Forty-nine cases of bites by mygalomorph spiders were included: 16 were by funnel-web spiders, 13 by mouse spiders and 20 by other trapdoor spiders (Families Idiopidae and Nemesiidae). Of the 49 bites, 45 (92%) occurred on distal limbs (hands and feet). Local effects included severe pain (53%), puncture marks (61%) and bleeding (27%), local redness (33%). Itchiness did not occur. The following were highly statistically associated with mygalomorph spider bites compared to all other spiders (pweb spider bites, there were 10 cases with minor local effects, four with moderate envenoming (non-specific systemic or local neurotoxicity) and two with severe envenoming requiring antivenom. In addition to local effects, mouse spider bites caused local paraesthesia in three cases, local diaphoresis in one case and non-specific systemic effects in five cases, but not severe envenoming. True trapdoor spider bites caused only minor effects. The data from a mixed species sample of funnel-web spiders confirms previous observations suggesting that only a small proportion of funnel-web bites cause severe effects. Mouse spider bites are unlikely to cause major envenoming but the clinical effects are consistent with neurotoxic venom and are more severe than the trapdoor spiders.

  2. Back in Europe: Quamtana spiders (Araneae: Pholcidae in Germany

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    Huber, Bernhard

    2015-11-01

    Full Text Available Two undescribed species of the African pholcid spider genus Quamtana have been found in German greenhouses and plant markets since 2012. Both species seem to have established stable populations. This genus has not been previously recorded from Europe, except for a fossil specimen in Eocene amber from the Paris Basin that was tentatively assigned to Quamtana and that is estimated to date from 53 million years ago. Since the actual geographic origins of the two species (probably South and/or tropical Africa are unknown, we do not formally describe them.

  3. Loxosceles spider bite in Turkey (Loxosceles rufescens, Sicariidae, Araneae

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    N. Yigit

    2008-01-01

    Full Text Available Loxoscelism is caused by envenomation by spiders that belong to the Loxosceles genus. In loxoscelism, a local necrotic lesion appears and, in many cases, loxoscelism or necrotic araneism is considered a serious public health problem. There is no diagnostic test available to help the physician make a diagnostic or therapeutic decision. Here, we report the case of a severe dermonecrotic araneism (loxoscelism in Turkey probably due to the bite of Loxosceles rufescens. There was little erythema at the beginning, followed by severe necrosis after 20 days, and skin grafting was needed although the case was treated.

  4. Descripción de la hembra de Dendryphantes melanomerus (Araneae: Salticidae y nuevos registros para México de arañas saltadoras Description of the female of Dendryphantes melanomerus (Araneae: Salticidae and new records of jumping spiders from Mexico

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    María Luisa Jiménez-Jiménez

    2007-06-01

    Full Text Available Se describe la hembra y se redescribe el macho de Dendryphantes melanomerus Chamberlin, 1924 de la vegetación hidrófita y matorral xerófilo de Baja California Sur, México. Se proporcionan nuevos registros para México de Habronattus divaricatus (Banks, 1898, Habronattus hallani (Richman, 1973, Metacyrba taeniola (Hentz, 1846,Paramarpissa griswoldi Logunov y Cutler, 1999, Peckhamia picata (Hentz, 1846, Salticus palpalis (Banks, 1904, Sitticus concolor (Banks, 1895 y Thiodina hespera Richman y Vetter, 2004.The first known female of the spider Dendryphantes melanomerus Chamberlin, 1924 is described and the male is redescribed from the wetland vegetation and xeric shrubland of Baja California Sur, México. New records of Habronattus divaricatus (Banks, 1898, Habronattus hallani (Richman, 1973 Metacyrba taeniola (Hentz, 1846, Paramarpissa griswoldi Logunov and Cutler, 1999, Peckhamia picata (Hentz, 1846, Salticus palpalis (Banks, 1904, Sitticus concolor (Banks, 1895, and Thiodina hespera Richman and Vetter, 2004, from Mexico, are provided.

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

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    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.

  6. Revision of the Neotropical spider genus Berlandiella (Araneae, Philodromidae

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    Arno Antonio Lise

    2011-12-01

    Full Text Available The spider genus Berlandiella Mello-Leitão, 1929 is revised and the three known species, Berlandiella insignis Mello-Leitão, 1929 (Rio de Janeiro, B. magna Mello-Leitão, 1929 (Pernambuco, Minas Gerais, Rio Grande do Sul, and B. polyacantha Mello-Leitão, 1929 (Rio de Janeiro, São Paulo, are redescribed and illustrated. Lectotypes for Berlandiella insignis, B. magna and B. polyacantha are designated. Descriptions and illustrations of three new species are presented: B. robertae sp. nov. (Brazil and Argentina, B. meridionalis sp. nov. (Brazil and B. querencia sp. nov. (Brazil. The geographical distribution of the representatives of the genus is presented.

  7. Spiders (Araneae of stony debris in North Bohemia

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    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.

  8. Chromosome mapping of dragline silk genes in the genomes of widow spiders (Araneae, Theridiidae.

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    Yonghui Zhao

    Full Text Available With its incredible strength and toughness, spider dragline silk is widely lauded for its impressive material properties. Dragline silk is composed of two structural proteins, MaSp1 and MaSp2, which are encoded by members of the spidroin gene family. While previous studies have characterized the genes that encode the constituent proteins of spider silks, nothing is known about the physical location of these genes. We determined karyotypes and sex chromosome organization for the widow spiders, Latrodectus hesperus and L. geometricus (Araneae, Theridiidae. We then used fluorescence in situ hybridization to map the genomic locations of the genes for the silk proteins that compose the remarkable spider dragline. These genes included three loci for the MaSp1 protein and the single locus for the MaSp2 protein. In addition, we mapped a MaSp1 pseudogene. All the MaSp1 gene copies and pseudogene localized to a single chromosomal region while MaSp2 was located on a different chromosome of L. hesperus. Using probes derived from L. hesperus, we comparatively mapped all three MaSp1 loci to a single region of a L. geometricus chromosome. As with L. hesperus, MaSp2 was found on a separate L. geometricus chromosome, thus again unlinked to the MaSp1 loci. These results indicate orthology of the corresponding chromosomal regions in the two widow genomes. Moreover, the occurrence of multiple MaSp1 loci in a conserved gene cluster across species suggests that MaSp1 proliferated by tandem duplication in a common ancestor of L. geometricus and L. hesperus. Unequal crossover events during recombination could have given rise to the gene copies and could also maintain sequence similarity among gene copies over time. Further comparative mapping with taxa of increasing divergence from Latrodectus will pinpoint when the MaSp1 duplication events occurred and the phylogenetic distribution of silk gene linkage patterns.

  9. La araneofauna (Araneae reciente y fósil de Chiapas, México The extant and fossil spider fauna (Araneae from Chiapas, Mexico

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    Miguel Ángel García-Villafuerte

    2009-12-01

    Full Text Available Se presenta una lista de las especies actuales y fósiles de arañas (Araneae registradas para Chiapas. Hasta el momento se registran 464 especies actuales, distribuidas en 281 géneros y 56 familias. Las familias con mayor diversidad son Salticidae, Theridiidae, Araneidae, Tetragnathidae y Gnaphosidae. Se proporcionan los géneros y especies en sinonimia, así como los géneros y especies que han sido transferidos a otras familias, y las especies transferidas a otros géneros dentro de la misma familia. Se han registrado 36 especies fósiles incluidas en ámbar. La taxonomía de arañas actuales y la de fósiles no son disciplinas completamente independientes. El género Hemirrhagus (Teraphosidae es un nuevo registro para Chiapas.A list of the recent and extinct species of spiders (Araneae that have been recorded from Chiapas is presented. To date 464 recent species have been registered, distributed in 281 genera and 56 families. The most diverse families are Salticidae, Theridiidae, Araneidae, Tetragnathidae and Gnaphosidae. The genera and species in synonymy are listed, as are the genera and species that have been transferred to other families, and the species transferred to other genera within the same family. 36 fossil species included in amber have also been recorded. The taxonomy of recent and fossil spiders should not be independent. Genus Hemirrhagus (Teraphosidae is newly recorded from Chiapas.

  10. The spider family Selenopidae (Arachnida, Araneae in Australia and Asia

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    Sarah Crews

    2011-05-01

    Full Text Available The spider family Selenopidae Simon occurs worldwide in tropical and subtropical regions, currently containing nearly 200 species in five genera. We relimit and revise the family to include four new genera and 27 new species from Australia and Asia. The family Selenopidae is redefined, as are the genera Anyphops Benoit, Garcorops Corronca, Hovops Benoit, Selenops Latreille, and Siamspinops Dankittipakul and Corronca, to accommodate the new genera and to correct previous errors in the definition. The species of Selenops that occur throughout India and China are also reviewed. Three species occur in China: S. bursarius Karsch, also known from Japan, Korea and Taiwan, S. ollarius Zhu, Sha, and Chen, and S. radiatus Latreille, the type of the genus and most widespread selenopid. Selenops cordatus Zhu, Sha, and Chen is recognized as a junior synonym of S. radiatus, syn. n. Amamanganops gen. n. is monotypic, with A. baginawa sp. n., and is known only from the Philippine island of Mindoro. Godumops gen. n. is monotypic, with G. careus sp. n., and is known only from Papua New Guinea. Karaops gen. n. occurs throughout Australia and has 24 species: K. australiensis (L. Koch comb. n., K. gangarie sp. n., K. monteithi sp. n., K. alanlongbottomi sp. n., K. keithlongbottomi sp. n., K. larryoo sp. n., K. jarrit sp. n., K. marrayagong sp. n., K. raveni sp. n., K. badgeradda sp. n., K. burbidgei sp. n., K. karrawarla sp. n., K. julianneae sp. n., K. martamarta sp. n., K. manaayn sp. n., K. vadlaadambara sp. n., K. pilkingtoni sp. n., K. deserticola sp. n., K. ngarutjaranya sp. n., K. francesae sp. n., K. toolbrunup sp. n., the type species K. ellenae sp. n., K. jenniferae sp. n., and K. dawara sp. n. The genus Makdiops gen. n. contains five species from India and Nepal: M. agumbensis (Tikader, comb. n., the type of the genus M. mahishasura sp. n., M. montigenus (Simon, comb. n., M. nilgirensis (Reimoser comb. n., and M. shiva sp. n. The genus Pakawops gen. n. is

  11. SPIDER DIVERSITY (ARACHNIDA: ARANEAE OF THE TEA PLANTATION AT SERANG VILLAGE, KARANGREJA SUB-DISTRICT, DISTRICT OF PURBALINGGA

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    Gianti Sibarani

    2017-06-01

    Full Text Available Spiders are crucial in controlling insect pest population. The various cultivation managements such as fertilizer and pesticide application, weeding, pruning, harvesting, and cropping system affect their diversity. In the plantation, vegetation diversification has applied various practices, including monoculture, and intercropping, which influence the spider community. Thus, this study was intended to determine the spider abundance and diversity of the tea plantation, and the intercropping field (tea and strawberry at Serang village, Karangreja Sub-District, District of Purbalingga. A survey and purposive sampling techniques were conducted, then the spiders were hand collected. Shannon-Wiener diversity (H’, Evenness (E, Simpson’s dominance (D, and Sorensen’s similarity (IS indices were used to measure the spider diversity. The results revealed a total number of 575 individual spiders from 10 families, i.e., Araneae, Araneidae, Clubionidae, Linyphiidae, Lycosidae, Nephilidae, Oxyopidae, Salticidae, Tetragnathidae, Theridiidae, and Thomisidae. Araneidae was the most abundant in both fields. The total abundance of spiders in tea plantation (379 individuals, however, was greater than that in the intercropping field (196 individuals. Shannon-Wiener diversity reached H’= 1.873 in the plantation, and H’= 1.975 in the intercropping field.

  12. A new species of Hortipes (Araneae, Corinnidae, the first spider with an insertable retrolateral tibial apophysis on the male palp

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    Arnaud Henrard

    2012-10-01

    Full Text Available Hortipes gigapophysalis (Araneae, Corinnidae is a new species described from both sexes from montane forest on Mt Nimba, eastern Guinea. The species is remarkable for its long, whip-shaped retrolateral tibial apophysis (RTA on the male palp. The structure apparently has an insertable function as the epigyne of the female contains a separate set of ducts starting from a central concavity that is unique in the genus. This duct system is apparently meant to receive the supple RTA. This type of structural arrangement has never previously been found in spiders.

  13. Intersexual variations in the pharmacological properties of Coremiocnemis tropix (Araneae, Theraphosidae) spider venom.

    Science.gov (United States)

    Herzig, Volker; Hodgson, Wayne C

    2009-02-01

    This study aimed to determine the biochemical, insecticidal and neurotoxic properties of venom from both sexes of the Australian spider Coremiocnemis tropix (Araneae, Theraphosidae). Insecticidal properties were tested in crickets, while in vitro neurotoxicity was determined in an avian skeletal muscle preparation. Some intersexual differences in venom composition were identified by rp-HPLC and by LC-MS, but the majority of components were found in venoms of both sexes. Injecting the venom into crickets revealed that venom from male specimens was slightly more potent, while female venom induced more prominent effects in the chick biventer cervicis nerve-muscle preparation. The results from the chick assay suggest the presence of at least two vertebrate-active neurotoxins. A pre-synaptic neurotoxin may explain the reversible inhibition of muscle twitches and the unaffected response to nicotinic agonists at medium concentrations of female and medium to high concentrations of male venom. In addition, the presence of a neurotoxin that blocks post-synaptic nicotinic receptors might explain the irreversible inhibition of muscle twitches and the reduced response to nicotinic agonists at high concentrations (5-10 microg/ml) of venom from female specimens only.

  14. Co-segregation of sex chromosomes in the male black widow spider Latrodectus mactans (Araneae, Theridiidae).

    Science.gov (United States)

    Ault, Jeffrey G; Felt, Kristen D; Doan, Ryan N; Nedo, Alexander O; Ellison, Cassondra A; Paliulis, Leocadia V

    2017-02-23

    During meiosis I, homologous chromosomes join together to form bivalents. Through trial and error, bivalents achieve stable bipolar orientations (attachments) on the spindle that eventually allow the segregation of homologous chromosomes to opposite poles. Bipolar orientations are stable through tension generated by poleward forces to opposite poles. Unipolar orientations lack tension and are stereotypically not stable. The behavior of sex chromosomes during meiosis I in the male black widow spider Latrodectus mactans (Araneae, Theridiidae) challenges the principles governing such a scenario. We found that male L. mactans has two distinct X chromosomes, X1 and X2. The X chromosomes join together to form a connection that is present in prometaphase I but is lost during metaphase I, before the autosomes disjoin at anaphase I. We found that both X chromosomes form stable unipolar orientations to the same pole that assure their co-segregation at anaphase I. Using micromanipulation, immunofluorescence microscopy, and electron microscopy, we studied this unusual chromosome behavior to explain how it may fit the current dogma of chromosome distribution during cell division.

  15. Dispatch from the field: ecology of ground-web-building spiders with description of a new species (Araneae, Symphytognathidae

    Directory of Open Access Journals (Sweden)

    Jeremy Miller

    2014-03-01

    Full Text Available Crassignatha danaugirangensis sp. n. (Araneae: Symphytognathidae was discovered during a tropical ecology field course held at the Danau Girang Field Centre in Sabah, Malaysia. A taxonomic description and accompanying ecological study were completed as course activities. To assess the ecology of this species, which belongs to the ground-web-building spider community, three habitat types were surveyed: riparian forest, recently inundated riverine forest, and oil palm plantation. Crassignatha danaugirangensis sp. n. is the most abundant ground-web-building spider species in riparian forest; it is rare or absent from the recently inundated forest and was not found in a nearby oil palm plantation. The availability of this taxonomic description may help facilitate the accumulation of data about this species and the role of inundated riverine forest in shaping invertebrate communities.

  16. Secondary eyes mediate the response to looming objects in jumping spiders (Phidippus audax, Salticidae).

    Science.gov (United States)

    Spano, Lauren; Long, Skye M; Jakob, Elizabeth M

    2012-12-23

    Some species have sensory systems divided into subsystems with morphologically different sense organs that acquire different types of information within the same modality. Jumping spiders (family Salticidae) have eight eyes. Four eyes are directed anteriorly to view objects in front of the spider: a pair of principal eyes track targets with their movable retinae, while the immobile anterior lateral (AL) eyes have a larger field of view and lower resolution. To test whether the principal eyes, the AL eyes, or both together mediate the response to looming stimuli, we presented spiders with a video of a solid black circle that rapidly expanded (loomed) or contracted (receded). Control spiders and spiders with their principal eyes masked were significantly more likely to back away from the looming stimulus than were spiders with their AL eyes masked. Almost no individuals backed away from the receding stimulus. Our results show that the AL eyes alone mediate the loom response to objects anterior to the spider.

  17. Spider assemblage (Arachnida: Araneae associated with canopies of Vochysia divergens (Vochysiaceae in the northern region of the Brazilian Pantanal

    Directory of Open Access Journals (Sweden)

    Leandro D. Battirola

    Full Text Available ABSTRACT This study describes the composition and temporal variation of the spider assemblage (Arachnida: Araneae associated with canopies of Vochysia divergens Pohl. (Vochysiaceae in the northern region of the Brazilian Pantanal. Three V. divergens plants were sampled in 2004, at each seasonal period of the northern Pantanal (high water, receding water, dry season and rising water, using thermonebulization of the canopies with insecticide, totaling 396 m2 of sampled canopies. Analysis of abundance and richness of spider families were based on Non-Metric Multidimensional Scaling (NMDS and Variance Analysis (ANOVA and MANOVA. A total of 7,193 spiders were collected (6,330 immatures; 88.0%; 863 adults, 12.0% distributed in 30 families. Araneidae (1,676 individuals, Anyphaenidae (1,631 individuals, Salticidae (1,542 individuals and Pisauridae (906 individuals, were predominant, representing 80.0% of the sample. Ten different guilds were registered: aerial hunters, orb-weavers, nocturnal aerial runners and diurnal space web weavers dominated, sharing most ecological niches. The spider assemblage is affected by changes in the habitat structure, especially by the seasonal hydrological regime and variations in the phenology of V. divergens . The assemblage is composed of different groups of spiders. The dominant taxa and behavioral guilds differ in the different seasonal periods. Spiders were more abundant during the dry and rising water seasons, most likely reflecting a greater supply of potential prey, associated with new foliage and flowering at the canopy. The displacement of soil dwelling spiders to the trunks and canopies before and during the seasonal floods can change the structure and composition of the canopy assemblages. Oonopidae, Gnaphosidae and Caponiidae, were more frequent during the rising and high water seasons, which indicates that these taxa use the canopies of V. divergens as a refuge during the seasonal flooding in the Pantanal.

  18. Neuropeptide discovery in the Araneae (Arthropoda, Chelicerata, Arachnida): elucidation of true spider peptidomes using that of the Western black widow as a reference.

    Science.gov (United States)

    Christie, Andrew E; Chi, Megan

    2015-03-01

    The public deposition of large transcriptome shotgun assembly (TSA) datasets for the Araneae (true spiders) provides a resource for determining the structures of the native neuropeptides present in members of this chelicerate order. Here, the Araneae TSA data were mined for putative peptide-encoding transcripts using the recently deduced neuropeptide precursors from the Western black widow Latrodectus hesperus as query templates. Neuropeptide-encoding transcripts from five spiders, Latrodectus tredecimguttatus, Stegodyphus mimosarum, Stegodyphus lineatus, Stegodyphus tentoriicola and Acanthoscurria geniculata, were identified, including ones encoding members of the allatostatin A, allatostatin B, allatostatin C, allatotropin, CAPA/periviscerokinin/pyrokinin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/ion transport peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FMRFamide-like peptide (FLP), GSEFLamide, insulin-like peptide, orcokinin, proctolin, short neuropeptide F, SIFamide, sulfakinin and tachykinin-related peptide (TRP) families. A total of 156 distinct peptides were predicted from the precursor proteins deduced from the S. mimosarum transcripts, with 65, 26, 21 and 12 peptides predicted from those deduced from the A. geniculata, L. tredecimguttatus, S. lineatus and S. tentoriicola sequences, respectively. Among the peptides identified were variant isoforms of FLP, orcokinin and TRP, peptides whose structures are similar to ones previously identified from L. hesperus. The prediction of these atypical peptides from multiple spiders suggests that they may be broadly conserved within the Araneae rather than being species-specific variants. Taken collectively, the data described here greatly expand the number of known Araneae neuropeptides, providing a foundation for future functional studies of peptidergic signaling in this important Chelicerate order.

  19. Aeromechanics of the Spider Cricket Jump: How to Jump 60+ Times Your Body Length and Still Land on Your Feet

    Science.gov (United States)

    Palmer, Emily; Deshler, Nicolas; Gorman, David; Neves, Catarina; Mittal, Rajat

    2015-11-01

    Flapping, gliding, running, crawling and swimming have all been studied extensively in the past and have served as a source of inspiration for engineering designs. In the current project, we explore a mode of locomotion that straddles ground and air: jumping. The subject of our study is among the most proficient of long-jumpers in Nature: the spider cricket of the family Rhaphidophoridae, which can jump more than 60 times its body length. Despite jumping this immense distance, these crickets usually land on their feet, indicating an ability to control their posture during ``flight.'' We employ high-speed videogrammetry, to examine the jumps and to track the crickets' posture and appendage orientation throughout their jumps. Simple aerodynamic models are developed to predict the aerodynamic forces and moment on the crickets during `flight`. The analysis shows that these wingless insects employ carefully controlled and coordinated positioning of the limbs during flight so as to increase jump distance and to stabilize body posture during flight. The principles distilled from this study could serve as an inspiration for small jumping robots that can traverse complex terrains.

  20. Spiders (Araneae) Found in Bananas and Other International Cargo Submitted to North American Arachnologists for Identification.

    Science.gov (United States)

    Vetter, Richard S; Crawford, Rodney L; Buckle, Donald J

    2014-11-01

    Spiders found in international cargo brought into North America are sometimes submitted to arachnologists for identification. Often, these spiders are presumed to be of medical importance because of size or a submitter's familiarity with a toxic spider genus from the continent of origin. Starting in 2006, requests were made for spiders found in international cargo brought into North America, in addition to the specimens from similar cargo shipments already in our museum collections. This was an ad hoc study that allowed us to focus on spiders of concern to the discoverer. We identified 135 spiders found in international cargo. A key for the most common species is provided. The most frequently submitted spiders were the pantropical huntsman spider, Heteropoda venatoria (L.) (Sparassidae), and the redfaced banana spider, Cupiennius chiapanensis Medina Soriano (Ctenidae). Spiders of medical importance were rare. The most common cargo from which spiders were submitted was bananas with most specimens coming from Central America, Ecuador, or Colombia. Lack of experience with nonnative fauna caused several experienced American arachnologists to misidentify harmless ctenid spiders (C. chiapanensis, spotlegged banana spider, Cupiennius getazi Simon) as highly toxic Phoneutria spiders. These misidentifications could have led to costly, unwarranted prophylactic eradication measures, unnecessary employee health education, heightened employee anxiety and spoilage when perishable goods are left unloaded due to safety concerns. © 2014 Entomological Society of America.

  1. The complete mitochondrial genomes of two orb-weaving spider Cyrtarachne nagasakiensis (Strand, 1918) and Hypsosinga pygmaea (Sundevall, 1831) (Araneae: Araneidae).

    Science.gov (United States)

    Li, Chao; Wang, Zheng-Liang; Fang, Wen-Yuan; Yu, Xiao-Ping

    2016-07-01

    The complete mitogenomes of Cyrtarachne nagasakiensis and Hypsosinga pygmaea are determined to be 14,402 and 14,193 bp in length, with the A + T content of 75.7% and 76.1%, respectively. All protein-coding genes in both spiders start with the initiation codons (ATT, ATA, TTA or TTG) that are usually used in Araneae mitogenomes, and terminate with canonical stop codon TAA or TAG except for ND5 in both spiders and ND4L in H. pygmaea, which end with the incomplete codon TA or T instead. Most of the tRNAs lack the potential to form the typically cloverleaf-shaped secondary structures and none of tandem repeats are present in the control regions of both spider mitogenomes. The phylogenetic analysis based on the Bayesian inference dataset shows a good resolution of relationship of C. nagasakiensis and H. pygmaea in Araneidae.

  2. Spiders from the Island of Fernando de Noronha, Brazil: Part III: Gnaphosidae (Araneae: Arachnida Aranhas da Ilha de Fernando de Noronha, Brasil: Parte III: Gnaphosidae (Araneae: Arachnida

    Directory of Open Access Journals (Sweden)

    Antonio D. Brescovit

    2008-06-01

    Full Text Available The female of Zimiromus hortenciae Buckup & Brescovit, 1993 is described for the first time and Trachyzelotes kulczynskii (Bösemberg, 1902, a species introduced from Europe, is recorded for the first time on the island of Fernando de Noronha, state of Pernambuco. The latter, along with T. lyonneti (Audouim, 1826 recorded from the state of Rio Grande do Sul, is the second species of this genus to be reported from Brazil. The spiders were collected with pitfall traps in five points of the island. Ecological data showed that Gnaphosidae was the fifth best sampled spider family, with 179 specimens, belonging to two species, T. kulczynskii and Z. hortenciae. Trachyzelotes kulczynskii was the most abundant with 118 adults while Z. hortenciae was represented by only 21 adults. Both species were collected during the dry and wet seasons but T. kulczynskii was more abundant during the wet season while Z. hortenciae was more abundant during the dry season. The male:female ratio for the dry season was similar for both species but in the wet season it was three times higher for T. kulczynskii.A fêmea de Zimiromus hortenciae Buckup & Brescovit, 1993 é descrita pela primeira vez. Trachyzelotes kulczynskii (Bösemberg, 1902, uma espécie de origem européia, é registrada pela primeira vez na Ilha de Fernando de Noronha, no estado de Pernambuco. Junto com T. lyonneti (Audouin, 1826, já registrado para o estado do Rio Grande do Sul, Brasil, é a segunda espécie do gênero introduzida no Brasil. As aranhas foram coletadas com armadilhas de solo em cinco pontos da ilha e os dados ecológicos detectados para Gnaphosidae foram de que esta foi a quinta família melhor amostrada dentre Araneae, com 179 espécimes de duas espécies, T. kulczynskii e Z. hortenciae. Trachyzelotes kulczynskii foi mais abundante com 118 adultos enquanto Z. hortenciae teve 21 adultos coletados. Ambas foram coletadas nas estações seca e chuvosa, sendo que T. kulczynskii foi mais

  3. Molecular phylogenetics of the spider family Micropholcommatidae (Arachnida: Araneae) using nuclear rRNA genes (18S and 28S).

    Science.gov (United States)

    Rix, Michael G; Harvey, Mark S; Roberts, J Dale

    2008-03-01

    The spider family Micropholcommatidae is an enigmatic taxon of uncertain limits and uncertain affinities. Various phylogenetic hypotheses have been proposed for the family, but these hypotheses have never been tested with a robust phylogenetic analysis. The existence of similar Australasian and New World taxa, the possibility of morphological convergence associated with extreme 'smallness', and the apparent paucity of synapomorphic morphological characters, have all clouded generic relationships in this group. We used fragments from two nuclear ribosomal RNA genes (18S and 28S) to test the monophyly and phylogenetic position of the Micropholcommatidae. The analyses incorporated 50 ingroup spider species, including 23 micropholcommatid species and representatives from 14 other spider families. Ribosomal RNA secondary structures were inferred for the V3-V5 region of the 18S rRNA gene, and Domain II of the 28S rRNA gene of Hickmania troglodytes [Higgins, E.T., Petterd, W.F., 1883. Description of a new cave-inhabiting spider, together with notes on mammalian remains from a recently discovered cave in the Chudleigh district. Pap. Proc. R. Soc. Tasman. 1882, 191-192]. These secondary structures were used to guide multiple sequence alignments, and determine the position and nature of indels in different taxa. Secondary structure information was also incorporated into a structurally partitioned rRNA analysis in MrBayes Version 3.1.2, using a doublet model of nucleotide substitution. This structurally partitioned rRNA analysis provided a less resolved but more conservative and informative estimate of phylogeny than an otherwise identical, unpartitioned rDNA analysis. With the exception of the Chilean species Teutoniella cekalovici [Platnick, N.I., Forster, R.R., 1986. On Teutoniella, an American genus of the spider family Micropholcommatidae (Araneae, Palpimanoidea). Am. Mus. Novit. 2854, 1-9], the family Micropholcommatidae was found to be monophyletic with three

  4. Social makes smart: rearing conditions affect learning and social behaviour in jumping spiders.

    Science.gov (United States)

    Liedtke, J; Schneider, J M

    2017-08-22

    There is a long-standing debate as to whether social or physical environmental aspects drive the evolution and development of cognitive abilities. Surprisingly few studies make use of developmental plasticity to compare the effects of these two domains during development on behaviour later in life. Here, we present rearing effects on the development of learning abilities and social behaviour in the jumping spider Marpissa muscosa. These spiders are ideally suited for this purpose because they possess the ability to learn and can be reared in groups but also in isolation without added stress. This is a critical but rarely met requirement for experimentally varying the social environment to test its impact on cognition. We split broods of spiders and reared them either in a physically or in a socially enriched environment. A third group kept under completely deprived conditions served as a 'no-enrichment' control. We tested the spiders' learning abilities by using a modified T-maze. Social behaviour was investigated by confronting spiders with their own mirror image. Results show that spiders reared in groups outperform their conspecifics from the control, i.e. 'no-enrichment', group in both tasks. Physical enrichment did not lead to such an increased performance. We therefore tentatively suggest that growing up in contact with conspecifics induces the development of cognitive abilities in this species.

  5. Bourgeois behavior and freeloading in the colonial orb web spider Parawixia bistriata (Araneae, Araneidae).

    Science.gov (United States)

    Wenseleers, Tom; Bacon, Jonathan P; Alves, Denise A; Couvillon, Margaret J; Kärcher, Martin; Nascimento, Fabio S; Nogueira-Neto, Paulo; Ribeiro, Marcia; Robinson, Elva J H; Tofilski, Adam; Ratnieks, Francis L W

    2013-07-01

    Spiders of the tropical American colonial orb weaver Parawixia bistriata form a communal bivouac in daytime. At sunset, they leave the bivouac and construct individual, defended webs within a large, communally built scaffolding of permanent, thick silk lines between trees and bushes. Once spiders started building a web, they repelled other spiders walking on nearby scaffolding with a "bounce" behavior. In nearly all cases (93%), this resulted in the intruder leaving without a fight, akin to the "bourgeois strategy," in which residents win and intruders retreat without escalated contests. However, a few spiders (6.5%) did not build a web due to lack of available space. Webless spiders were less likely to leave when bounced (only 42% left) and instead attempted to "freeload," awaiting the capture of prey items in nearby webs. Our simple model shows that webless spiders should change their strategy from bourgeois to freeloading satellite as potential web sites become increasingly occupied.

  6. Sperm Dynamics in Spiders (Araneae): Ultrastructural Analysis of the Sperm Activation Process in the Garden Spider Argiope bruennichi (Scopoli, 1772)

    OpenAIRE

    Oliver Vöcking; Gabriele Uhl; Peter Michalik

    2013-01-01

    Storage of sperm inside the female genital tract is an integral phase of reproduction in many animal species. The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. Here, we focus on sperm activation in spiders. Male spiders produce sperm whose cell components are coiled within the sperm cell and that...

  7. Previous experience and site tenacity in the orb spider Nephila (Araneae, Araneidae).

    Science.gov (United States)

    Vollrath, F; Houston, A

    1986-09-01

    The tenacity of the orb spider Nephila clavipes to a web site was studied in the laboratory. No differences were found between the giving-up-times and the site tenacity of spiders reared in the laboratory or those caught in the field, nor between spiders raised under a poor or a richt diet. The animals left sites at random and seemed to ignore experiences gained at previous sites.

  8. 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......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...... was also detected and its conservation implications are discussed....

  9. Determining with SEM, structure of the venom apparatus in the tube web spider, Segestria florentina (Araneae: Segestriidae

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    Suna Cebesoy

    2013-08-01

    Full Text Available The objective of the present study was to describe functional morphological features of venom apparatus in the tube web spider, Segestria florentina (Rossi, 1790 (Araneae: Segestriidae by using scanning electron microscope (SEM. The venom apparatus is situated in the anterior part of the prosoma, and is composed of a pair of venom glands and chelicerae. The chelicera of S. florentina has two parts: basal segment and a movable articulated apical segment (fang. The cheliceral fang rests in a groove on the basal segment of chelicerae. A venom hole is located on the subterminal part of each fang. A pair of venom glands is completely separate but similar to each other within the prosoma. Each venom gland is surrounded by striated muscle bundles, such as with the capsules. The venom, produced in the venom glands, is carried by venom ducts passing throughout the chelicerae. Each venom gland has its own venom duct, chelicera and fang. The venom is excreted from the venom pore on the subterminal part of the fang by means of muscular contractions covering the venom gland.

  10. 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

    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...

  11. 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...

  12. Nukuhiva Berland, 1935 is a troglobitic wolf spider (Araneae: Lycosidae), not a nursery-web spider (Pisauridae).

    Science.gov (United States)

    Framenau, Volker W; Lehtinen, Pekka T

    2015-10-07

    The monotypic genus Nukuhiva Berland, 1935 with N. adamsoni (Berland, 1933) as type species, is re-described and transferred from the Pisauridae Simon, 1890 (fishing or nursery-web spiders) to the Lycosidae Sundevall, 1833 (wolf spiders) based on genitalic and somatic characters. Nukuhiva adamsoni, originally described from French Polynesia, appears to inhabit mountainous habitats of volcanic origin. Its troglobitic morphology--comparatively small eyes and pale, uniform coloration--suggest it to be associated with subterranean habitats such as caves or lava tubes, similar to the Hawaiian troglobitic species Lycosa howarthi Gertsch, 1973 and Adelocosa anops Gertsch, 1973.

  13. The ability of spiderlings of the widow spider Latrodectus hesperus (Araneae: Theridiidae) to pass through different size mesh screen: implications for exclusion from air intake ducts and greenhouses.

    Science.gov (United States)

    Vetter, Richard S; Flanders, Christopher P; Rust, Michael K

    2009-06-01

    Experiments tested the ability of newly emerged spiderlings of a black widow spider, Latrodectus hesperus Chamberlin & Ivie (Araneae: Theridiidae), to crawl through brass screen of various mesh size. The purpose was to determine whether immatures of these medically important spiders could be excluded from buildings. In horizontal orientation, black widow spiderlings were able to easily pass through mesh with openings of 0.83 mm and were prevented from passing in four of five tests with mesh of 0.59-mm openings. Spiderlings also readily pass through 0.83-mm mesh in vertical orientation. Our laboratory studies indicate that the mesh size sufficient for exclusion is too small for practical use in most cases, although there are some specialized situations where such small mesh might be useful. The results are discussed in regard to actual conditions found in typical commercial building situations.

  14. 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.

  15. A check list of the spiders of the Kruger National Park, South Africa (Arachnida: Araneae

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    A.S. Dippenaar-Schoeman

    2003-12-01

    Full Text Available As part of the South African National Survey of Arachnida (SANSA, projects are underway to determine the biodiversity of arachnids present in protected areas in South Africa. Spiders have been collected over a period of 16 years from the Kruger National Park, South Africa. A check list is provided consisting of 152 species, 116 genera and 40 families. This represents about 7.6 % of the total known South African spider fauna. Of the 152 species, 103 are new records for the park. The ground dwelling spiders comprise 58 species from 25 families. Of these, 21 % are web dwellers and 62 % free living, while 17 % live in burrows. From the plant layer, 94 species have been collected of which 53 % were web builders and 47 % free living wandering spiders.

  16. Annotated Check List of the Spiders (Araneae) of the Mountain Zebra National Park

    OpenAIRE

    Anna S. Dippenaar-Schoeman

    1988-01-01

    A preliminary check list of the spider fauna of the Mountain Zebra National Park is given. Sixteen families, comprising 29 genera and 32 species, are recorded. Observations on the distribution, diagnostic morphology and behaviour of 15 species are given.

  17. Spiders (Araneae) of the Moosehorn National Wildlife Refuge, Washington County, Maine

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes my identifications of spiders for graduate student Matthew Vander Haegen, College of Forest Resources, Department of Wildlife, University of...

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

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    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.

  19. Sperm dynamics in spiders (Araneae: ultrastructural analysis of the sperm activation process in the garden spider Argiope bruennichi (Scopoli, 1772.

    Directory of Open Access Journals (Sweden)

    Oliver Vöcking

    Full Text Available Storage of sperm inside the female genital tract is an integral phase of reproduction in many animal species. The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. Here, we focus on sperm activation in spiders. Male spiders produce sperm whose cell components are coiled within the sperm cell and that are surrounded by a proteinaceous sheath. These inactive and encapsulated sperm are transferred to the female spermathecae where they are stored for later fertilization. We analyzed the ultrastructural changes of sperm cells during residency time in the female genital system of the orb-web spider Argiope bruennichi. We found three clearly distinguishable sperm conditions: encapsulated sperm (secretion sheath present, decapsulated (secretion sheath absent and uncoiled sperm (cell components uncoiled, presumably activated. After insemination, sperm remain in the encapsulated condition for several days and become decapsulated after variable periods of time. A variable portion of the decapsulated sperm transforms rapidly to the uncoiled condition resulting in a simultaneous occurrence of decapsulated and uncoiled sperm. After oviposition, only decapsulated and uncoiled sperm are left in the spermathecae, strongly suggesting that the activation process is not reversible. Furthermore, we found four different types of secretion in the spermathecae which might play a role in the decapsulation and activation process.

  20. Distribution of the brown recluse spider (Araneae: Sicariidae) in Illinois and Iowa.

    Science.gov (United States)

    Cramer, Kenneth L; Vetter, Richard S

    2014-01-01

    The medical importance of the brown recluse spider, Loxosceles reclusa Gertsch and Mulaik, is well known, but there is a need for more accurate information about the distribution of the spider in North America. We gathered information via an Internet offer to identify spiders in Illinois and Iowa that were thought to be brown recluses. We also mined brown recluse locality information from other agencies that kept such records. In Iowa, the brown recluse is unknown from its northern counties and rare in southern counties. In Illinois, brown recluse spiders are common in the southern portion of the state and dwindle to almost nonexistence in a transition to the northern counties. Although there were a few finds in the Chicago, IL area and its suburbs, these are surmised to be human-transported specimens and not part of naturally occurring populations. Considering the great human population density and paucity of brown recluses in the Chicago area, medical personnel therein should obtain patient geographic information and be conservative when diagnosing loxoscelism in comparison with southern Illinois, where the spiders are plentiful and bites are more likely.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    Background Divergence in trophic niche between the sexes may function to reduce competition between the sexes (“intersexual niche partitioning hypothesis”), or may be result from differential selection among the sexes on maximizing reproductive output (“sexual selection hypothesis”). The latter may...... 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...... 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...

  2. INSECTICIDE RESISTANCE IN THE GROUND SPIDER, Pardosa sumatrana (THORELL, 1890; ARANEAE: LYCOSIDAE).

    Science.gov (United States)

    Tahir, Hafiz Muhammad; Khizar, Farva; Naseem, Sajida; Yaqoob, Rabia; Samiullah, Khizar

    2016-09-01

    Elevated levels of insecticides detoxifying enzymes, such as esterases, glutathione S-transferases (GSTs), and cytochrome P-450 monooxygenases, act in the resistance mechanisms in insects. In the present study, levels of these enzymes in the insecticide-resistant ground spider Pardosa sumatrana (Thorell, 1890) were compared with a susceptible population (control) of the same species. Standard protocols were used for biochemical estimation of enzymes. The results showed significantly higher levels of nonspecific esterases and monooxygenases in resistant spiders compared to controls. The activity of GSTs was lower in the resistant spiders. Elevated levels of nonspecific esterases and monooxygenases suggest their role in metabolic resistance in P. sumatrana. The reduced levels of total protein contents revealed its possible consumption to meet energy demands.

  3. A check list of the spider fauna of the Karoo National Park, South Africa (Arachnida: Araneae

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    Anna S. Dippenaar-Schoeman

    1999-01-01

    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. A faunistic study on ground-dwelling spiders (Araneae in the Tirana district, Albania

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    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.

  5. The spider fauna of Scragh Bog in Co Westmeath, Ireland (Arachnida: Araneae)

    NARCIS (Netherlands)

    Helsdingen, van P.J.

    1998-01-01

    The spider fauna of Scragh Bog, a quacking bog in Co Westmeath, Ireland, was investigated for the first time. The presence of 53 species could be established, two of which are new to Ireland (Carorita limnaea (Crosby & Bishop), Porrhomma oblitum (O.P.-Cambridge)), while 30 represent new county recor

  6. Functional morphology of the respiratory organs in the cellar spider Pholcus phalangioides (Arachnida, Araneae, Pholcidae).

    Science.gov (United States)

    Schmitz, Anke

    2015-08-01

    Morphometric evaluation of the lungs of male and female cellar spiders (Pholcus phalangioideus) was carried out in 2 test groups with different body masses (mean value 10.8, males, and 26.6 mg, females). Males have significant higher lung volume to body mass ratios (2.49 vs. 2.13 × 10(-3) cm(3) g(-1)), which might result from the differences in body mass between sexes. Moreover, males have slightly more respiratory surface area per body mass (8.2 vs. 7.7 cm(2) g(-1)) and a little bit larger morphological diffusing capacities for oxygen (9.3 vs. 8.2 nmol s(-1) g(-1) kPa(-1)) than females, but both values were not significant. Metabolic rates were measured using flow through respirometry under video tracking: the CO2 release of male and female spiders was measured. Resting rates were 1.7 (males) and 1.5 nmol s(-1) g(-1) (females). Gluing of one spiracle did not influence the resting metabolic rate. Factorial scopes during stimulation to maximum metabolic rates were about 12 in intact animals, while elimination of one spiracle reduced the factorial scope to 5.2. Comparison with other araneomorph spiders strengthens the hypothesis that tracheae in spiders increase the metabolic rates of the tracheated species and do not only replace reduced lung capacity.

  7. 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...

  8. Two new species of the orb-weaving spider genus Alpaida (Araneae, Araneidae) from Peru.

    Science.gov (United States)

    Deza, Mariajosé; Andía, Juan Manuel

    2014-07-02

    Two new species of the orb-weaving spider genus Alpaida O. P.-Cambridge, 1889 are described and illustrated; Alpaida losamigos n. sp. based on females from Madre de Dios, and Alpaida penca n. sp. based on females and males from Cajamarca.

  9. Annotated Check List of the Spiders (Araneae of the Mountain Zebra National Park

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    Anna S. Dippenaar-Schoeman

    1988-10-01

    Full Text Available A preliminary check list of the spider fauna of the Mountain Zebra National Park is given. Sixteen families, comprising 29 genera and 32 species, are recorded. Observations on the distribution, diagnostic morphology and behaviour of 15 species are given.

  10. Phylogeny of pholcid spiders (Araneae: Pholcidae): combined analysis using morphology and molecules.

    Science.gov (United States)

    Bruvo-Madarić, Branka; Huber, Bernhard A; Steinacher, Arno; Pass, Günther

    2005-12-01

    The spider family Pholcidae comprises a large number of mainly tropical, web-weaving spiders, and is among the most diverse and dominant spider groups in the world. The phylogeny of this family has so far been investigated exclusively using morphological data. Here, we present the first molecular data for the family analyzed in a phylogenetic context. Four different gene regions (12S rRNA, 16S rRNA, cytochrome c oxidase subunit I, 28S rRNA) and 45 morphological characters were scored for 31 pholcid and three outgroup taxa. The data were analyzed both for individual genes, combined molecular data, and molecular plus morphological data, using parsimony, maximum likelihood, and Bayesian methods. Some of the phylogenetic hypotheses obtained previously using morphology alone were also supported by our results, like the monophyly of pholcines and of the New World clade. On the other hand, some of the previous hypotheses could be discarded with some confidence (monophyly of holocnemines, the position of Priscula), and still others need further investigation (the position of holocnemines, ninetines, and Metagonia). The data obtained provide an excellent basis for future investigations of phylogenetic patterns both within the family and among spider families.

  11. The spiders of the Swartberg Nature Reserve in South Africa (Arachnida: Araneae

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    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. 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 asse

  13. Ninetis russellsmithi n. sp., an unusual new pholcid spider species from Malawi (Araneae: Pholcidae

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    Bernhard A. Huber

    2002-03-01

    Full Text Available A new species Ninetis russellsmithi n. sp. is described from Malawi. It lacks the most prominent autapomorphy of pholcid spiders, the retrolateral projection of the cymbium (procursus. Biogeographically this species marks the first record for the genus in a 3000 km gap between its African congeners in Namibia and Tanzania.

  14. Palpimanid spiders from Guyana: new species of the genera Fernandezina and Otiothops (Araneae, Palpimanidae, Otiothopinae

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    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.

  15. 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.

  16. On the diversity of some soil and cave spiders (Aranea: Arachnida from Serbia

    Directory of Open Access Journals (Sweden)

    Ćurčić Božidar P.

    2004-01-01

    Full Text Available A total of 46 species from 14 families: Pholcidae (2, Dysderidae (3 Eresidae (1, Linyphiidae (11, Tetragnathidae (3, Araneidae (4, Lycosidae (5, Agelenidae (4, Amaurobiidae (2, Liocranidae (1, Gnaphosidae (2 Philodromidae (1, Thomisidae (2 and Salticidae (5 were established from 29 localities in Serbia. Five species: Dysderocrates silvestris Deeleman-Reinhold (Dysderidae, Centromerus obenbergeri (Kulczyński, 1897 (Linyphiidae, Trochosa hispanica Simon, 1870, Trochosa spinipalpis (O. P.-Cambridge (Lycosidae and Philodromus praedatus O. P.-Cambridge are new to the Serbian spider fauna; the most diverse is the family Linyphiidae which is represented by 11 species. At the time, the spiders of Serbia are represented by 633 species, belonging to 224 genera and 36 families.

  17. Complex genital structures indicate cryptic female choice in a haplogyne spider (Arachnida, Araneae, Oonopidae, Gamasomorphinae).

    Science.gov (United States)

    Burger, Matthias; Nentwig, Wolfgang; Kropf, Christian

    2003-01-01

    Female genital structures with their allied muscles of the haplogyne spider Opopaea fosuma are described. A functional explanation of this system is given, which indicates that cryptic female choice may occur in these spiders: the anterior wall of their spermatheca is strongly sclerotized and possesses a cone-shaped hole in its upper part. A transverse sclerite that serves as muscle attachment bears a nail-like structure and lies in a chitinized area of the anterior wall of the uterus externus. Muscle contraction presses this nail into the hole of the spermatheca. In this way, the uterus externus gets both locked and fixed. Furthermore, as this occurs the copulatory orifice is enlarged and the resulting suction probably leads to previously deposited sperm being drawn from the spermatheca and dumped. This is a common mechanism used by females to influence a male's chances of fathering their offspring in a process known as cryptic female choice.

  18. Ground-living spiders (Araneae at polluted sites in the Subarctic

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    Koponen, Seppo

    2011-01-01

    Full Text Available Spiders were studied around the Pechenganikel smelter combine, Kola Peninsula, north-western Russia. The average spider density was 6-fold greater and the density of Linyphiidae specimens 11.5-fold higher at slightly polluted sites, compared with heavily polluted sites. Altogether, 18 species from 10 families were found at heavily polluted sites, the theridiid Robertus scoticus clearly dominating (23.3 % of identifiable specimens, also Neon reticulatus (9.6 %, Thanatus formicinus (9.6 % and Xysticus audax (8.2 % were abundant. The most numerous among 58 species found at slightly polluted sites were Tapinocyba pallens (18.5 %, Robertus scoticus (13.7 %, Maso sundevalli (9.5 % and Alopecosa aculeata (8.2 %. The family Linyphiidae dominated at slightly polluted sites, 64 % of species and 60 % of individuals; compared with heavily polluted sites, 23 % and 38 % respectively.

  19. Bats in cobwebs of the giant-spider Nephilingis cruentata (Fabricius, 1775 (Araneae: Nephilidae in Brazil

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    Fábio André Facco Jacomassa

    2015-12-01

    Full Text Available Bats throughout the world are preyed upon primarily by vertebrates, but some are also attacked by invertebrates. We report two cases of bats entangled in webs of the giant-spider Nephilingis cruentata in southeastern Brazil. The first incidence occurred in December 2012, on which a female Eptesicus diminutus was found dead. The second occurred in March 2013, in which a male Tadarida brasiliensis was removed from the web alive, and later released. The animals showed no predation marks on the body, and both events were recorded after heavy rains. We suspect that the bats may have become entangled in the webs while seeking shelter from rain, or while foraging for insects. Even though the bats were not preyed upon, this spider cannot be ruled out as an opportunistic predator of small bats, as has been observed outside of Brazil.

  20. Spiders (Araneae of Hůrka u Hranic National Nature Reserve (Moravia, Czech Republic

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    Ondřej Machač

    2015-01-01

    Full Text Available Spiders of Hůrka u Hranic National Nature Reserve were investigated during the year 2011. Several capture methods were used during the vegetation season (from April to November in many various habitats of this territory. Altogether, 92 species from 27 families were recorded, including very rare and remarcable species. Majority of such species prefer thermophilous habitats: Atypus affinis Eichwald, 1830, Dysdera czechica Řezáč, in prep., Theridion melanurum Hahn, 1831, Agroeca cuprea Menge, 1873, Drassyllus villicus (Thorell, 1875, Zodarion germanicum (C. L. Koch, 1837 and Dipoena melanogaster (C. L. Koch, 1837. Some species are also listed in the Red List of threatened species in the Czech Republic: Cheiracanthium elegans Thorell, 1875 in category endangered (EN, Cozyptila blackwalli (Simon, 1875 and Leptorchestes berolinensis (C. L. Koch, 1846 in category vulnerable (VU. Altogether, 144 spider species are now known from the reserve; they represent 16.6% of araneofauna of the Czech Republic.

  1. Four new spider species of the family Theridiosomatidae (Arachnida, Araneae from caves in Laos

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    Yucheng Lin

    2014-03-01

    Full Text Available Four new species of the spider family Theridiosomatidae are described from caves in Laos: Alaria cavernicola sp. n. (♂♀, A. navicularis sp. n., (♂♀ A. bicornis sp. n. (♂♀, Chthonopes thakekensis sp. n. (♀. Diagnoses and illustrations for all new taxa are given. All holotypes are deposited in the Senckenberg Research Institute in Frankfurt am Main, Germany (SMF.

  2. The first report of the widow spider Latrodectus elegant (Araneae: Theridiidae from India

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    A. Kananbala

    2012-07-01

    Full Text Available The widow spider genus Latrodectus Walckenaer, 1805, in India is represented by three species L. erythromelas Schmidt & Klaas, 1991, L. geometricus C.L. Koch, 1841 and L. hasselti Thorell, 1870. In this paper, we report the occurrence of Lactrodectus elegans Thorell, 1898 for the first time from India. We provide additional information on taxonomy and natural history based on the specimens collected from Manipur.

  3. The Holarctic Hacklemesh Spider Genus Callobius (Araneae: Amaurobiidae): Morphology, Systematics, and Population Biology

    OpenAIRE

    Lew, Stephen Ellis

    2011-01-01

    Interest in the California Floristic Province as a study region for scientists interested in biodiversity, evolution, systematics, and phylogeography has been increasing over the last several years. The amaurobiid spider genus Callobius (Chamberlin) occurs throughout the Northern Hemisphere, but is particularly common in western North America and particularly diverse in the California Floristic Province. An understanding of the evolutionary history of Callobius would contribute a great deal...

  4. Intersexual trophic niche partitioning in an ant-eating spider (Araneae: Zodariidae.

    Directory of Open Access Journals (Sweden)

    Stano Pekár

    Full Text Available BACKGROUND: Divergence in trophic niche between the sexes may function to reduce competition between the sexes ("intersexual niche partitioning hypothesis", or may be result from differential selection among the sexes on maximizing reproductive output ("sexual selection hypothesis". The latter may 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, and larger than ants captured by juveniles and males. Female fecundity was highly positively correlated with female body mass, which reflects foraging success during the adult stage. Females in laboratory experiments preferred the large ant sub-castes and displayed higher capture efficiency. In contrast, males occupied a different trophic niche and showed reduced foraging effort and reduced prey capture and feeding efficiency compared with females and juveniles. CONCLUSIONS/SIGNIFICANCE: Our data indicate that female-biased dimorphism in trophic morphology and body size correlate with sex-specific reproductive strategies. We propose that intersexual trophic niche partitioning is shaped primarily by fecundity selection in females, and results from sex

  5. Regional variations in agrobiont composition and agrobiont life history of spiders (Araneae within Hungary

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    Samu, Ferenc

    2011-01-01

    Full Text Available Agrobiont spider species are well adapted to arable systems, which have fairly uniform vegetation structure and pest assemblages over continent-wide areas. We wanted to study, whether agrobiont spider subassemblages and the life history of the most prominent agrobiont, Pardosa agrestis, show any regional variation within Hungary, where only modest climatic differences exist between the NW and SE parts of the country. We studied agrobiont species of spider assemblages in 27 alfalfa and 21 cereal fields with suction sampling and pitfalls. The similarity structure of these agrobiont sub-assemblages (Sørensen distance measure was congruent with the geographic distance matrices (Eucledian distance, as tested by Mantel tests. However, if we considered sub-assemblages consisting of the non-agrobiont species, this congruency was always higher. Thus, agrobionts responded only moderately to geographical variation if we compare them to non-agrobiont species. We studied the generation numbers and the occurrence of the first adult individuals in P. agrestis; the most common agrobiont spider in Hungary. This comparison involved comparing fields along a NW – SE gradient during 6 sampling years in pairwise comparisons, where in each year a northern and a southern population was compared with a minimum distance of 126 km in between. In generation numbers there was no difference; we found two generations across Hungary. In contrast, the first occurrence of adult individuals was on average 15 days earlier in both generations in the more southern populations. Thus, it can be concluded that agrobionts show a fairly stable and relatively low magnitude response over country-sized geographical ranges.

  6. A golden orb-weaver spider (Araneae: Nephilidae: Nephila) from the Middle Jurassic of China

    OpenAIRE

    Paul A Selden; Shih, Chungkun; Ren, Dong

    2011-01-01

    Nephila are large, conspicuous weavers of orb webs composed of golden silk, in tropical and subtropical regions. Nephilids have a sparse fossil record, the oldest described hitherto being Cretaraneus vilaltae from the Cretaceous of Spain. Five species from Neogene Dominican amber and one from the Eocene of Florissant, CO, USA, have been referred to the extant genus Nephila. Here, we report the largest known fossil spider, Nephila jurassica sp. nov., from Middle Jurassic (approx. 165 Ma) strat...

  7. Phenotypic integration in a series of trophic traits: tracing the evolution of myrmecophagy in spiders (Araneae).

    Science.gov (United States)

    Pekár, Stano; Michalko, Radek; Korenko, Stanislav; Sedo, Ondřej; Líznarová, Eva; Sentenská, Lenka; Zdráhal, Zbyněk

    2013-02-01

    Several hypotheses have been put forward to explain the evolution of prey specificity (stenophagy). Yet little light has so far been shed on the process of evolution of stenophagy in carnivorous predators. We performed a detailed analysis of a variety of trophic adaptations in one species. Our aim was to determine whether a specific form of stenophagy, myrmecophagy, has evolved from euryphagy via parallel changes in several traits from pre-existing characters. For that purpose, we studied the trophic niche and morphological, behavioural, venomic and physiological adaptations in a euryphagous spider, Selamia reticulata. It is a species that is branching off earlier in phylogeny than stenophagous ant-eating spiders of the genus Zodarion (both Zodariidae). The natural diet was wide and included ants. Laboratory feeding trials revealed versatile prey capture strategies that are effective on ants and other prey types. The performance of spiders on two different diets - ants only and mixed insects - failed to reveal differences in most fitness components (survival and developmental rate). However, the weight increase was significantly higher in spiders on the mixed diet. As a result, females on a mixed diet had higher fecundity and oviposited earlier. No differences were found in incubation period, hatching success or spiderling size. S. reticulata possesses a more diverse venom composition than Zodarion. Its venom is more effective for the immobilisation of beetle larvae than of ants. Comparative analysis of morphological traits related to myrmecophagy in the family Zodariidae revealed that their apomorphic states appeared gradually along the phylogeny to derived prey-specialised genera. Our results suggest that myrmecophagy has evolved gradually from the ancestral euryphagous strategy by integrating a series of trophic traits. Copyright © 2012 Elsevier GmbH. All rights reserved.

  8. Maro lehtineni (Araneae: Linyphiidae – a spider species new to the fauna of Poland

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    Wiśniewski, Konrad

    2015-11-01

    Full Text Available The rare linyphiid spider species Maro lehtineni Saaristo, 1971 was recorded in the Polish part of the Sudetes, in the Giant Mountains (in Polish Karkonosze. Five males were found on one of the sloping transition mires in the spring and early summer of 2011 and 2012. We provide new figures for identification of this species, and summarize and discuss data on its distribution, characteristic habitats and phenology.

  9. Transcriptome Profiling Analysis of Wolf Spider Pardosa pseudoannulata (Araneae: Lycosidae after Cadmium Exposure

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    Chang-Chun Li

    2016-12-01

    Full Text Available Pardosa pseudoannulata is one of the most common wandering spiders in agricultural fields and a potentially good bioindicator for heavy metal contamination. However, little is known about the mechanisms by which spiders respond to heavy metals at the molecular level. In the present study, high-throughput transcriptome sequencing was employed to characterize the de novo transcriptome of the spiders and to identify differentially expressed genes (DEGs after cadmium exposure. We obtained 60,489 assembled unigenes, 18,773 of which were annotated in the public databases. A total of 2939 and 2491 DEGs were detected between the libraries of two Cd-treated groups and the control. Functional enrichment analysis revealed that metabolism processes and digestive system function were predominately enriched in response to Cd stress. At the cellular and molecular levels, significantly enriched pathways in lysosomes and phagosomes as well as replication, recombination and repair demonstrated that oxidative damage resulted from Cd exposure. Based on the selected DEGs, certain critical genes involved in defence and detoxification were analysed. These results may elucidate the molecular mechanisms underlying spiders’ responses to heavy metal stress.

  10. First evidence of neurons in the male copulatory organ of a spider (Arachnida, Araneae).

    Science.gov (United States)

    Lipke, Elisabeth; Hammel, Jörg U; Michalik, Peter

    2015-07-01

    Spider males have evolved a remarkable way of transferring sperm by using a modified part of their pedipalps, the so-called palpal organ. The palpal organ is ontogenetically derived from tarsal claws; however, no nerves, sensory organs or muscles have been detected in the palpal bulb so far, suggesting that the spider male copulatory organ is numb and sensorily blind. Here, we document the presence of neurons and a nerve inside the male palpal organ of a spider for the first time. Several neurons that are located in the embolus are attached to the surrounding cuticle where stresses and strains lead to a deformation (stretching) of the palpal cuticle on a local scale, suggesting a putative proprioreceptive function. Consequently, the male copulatory organ of this species is not just a numb structure but likely able to directly perceive sensory input during sperm transfer. In addition, we identified two glands in the palpal organ, one of which is located in the embolus (embolus gland). The embolus gland appears to be directly innervated, which could allow for rapid modulation of secretory activity. Thus, we hypothesize that the transferred seminal fluid can be modulated to influence female processes.

  11. Characterization of the venom from the Brazilian Brown Spider Loxosceles similis Moenkhaus, 1898 (Araneae, Sicariidae).

    Science.gov (United States)

    Silvestre, F G; de Castro, C S; de Moura, J F; Giusta, M S; De Maria, M; Alvares, E S S; Lobato, F C F; Assis, R A; Gonçalves, L A; Gubert, I C; Chávez-Olórtegui, C; Kalapothakis, E

    2005-12-15

    Accidents caused by brown spiders (Loxosceles genus) are frequent in Brazil and are associated with dermonecrotic lesions and, eventually, systemic reactions that may be lethal. The major species implicated with human envenoming have been: L. intermedia, L. gaucho and L. laeta. In this study we characterized the venom from Loxosceles similis, a species of spider normally found inside caves. L. similis venom was characterized by two-dimensional gel electrophoresis and enzymatic activity (dermonecrosis and haemolysis). The lethal dose to mice and the capacity of commercial anti-serum to neutralize this venom were also analysed. The cross-reactivity with anti-venoms against L. intermedia, L. laeta and L. gaucho were studied. Our results showed that this venom was able to induce severe dermonecrotic lesions and showed the presence of the bacteria Clostridium septicum in association with the fangs. In addition, we have cloned the DNA coding for a dermonecrotic protein (LsD1), using the genomic DNA of L. similis. The deduced amino acid sequence showed a toxin of approximately 31.2 kDa with an estimated pI of 7.37 and sequence similar to LiD1, a protein from the dermonecrotic family of Loxosceles intermedia spider venom, a synanthropic species of medical importance.

  12. Comparative transcriptomics of Entelegyne spiders (Araneae, Entelegynae), with emphasis on molecular evolution of orphan genes.

    Science.gov (United States)

    Carlson, David E; Hedin, Marshal

    2017-01-01

    Next-generation sequencing technology is rapidly transforming the landscape of evolutionary biology, and has become a cost-effective and efficient means of collecting exome information for non-model organisms. Due to their taxonomic diversity, production of interesting venom and silk proteins, and the relative scarcity of existing genomic resources, spiders in particular are excellent targets for next-generation sequencing (NGS) methods. In this study, the transcriptomes of six entelegyne spider species from three genera (Cicurina travisae, C. vibora, Habronattus signatus, H. ustulatus, Nesticus bishopi, and N. cooperi) were sequenced and de novo assembled. Each assembly was assessed for quality and completeness and functionally annotated using gene ontology information. Approximately 100 transcripts with evidence of homology to venom proteins were discovered. After identifying more than 3,000 putatively orthologous genes across all six taxa, we used comparative analyses to identify 24 instances of positively selected genes. In addition, between ~ 550 and 1,100 unique orphan genes were found in each genus. These unique, uncharacterized genes exhibited elevated rates of amino acid substitution, potentially consistent with lineage-specific adaptive evolution. The data generated for this study represent a valuable resource for future phylogenetic and molecular evolutionary research, and our results provide new insight into the forces driving genome evolution in taxa that span the root of entelegyne spider phylogeny.

  13. Electric shock for aversion training of jumping spiders: towards an arachnid model of avoidance learning.

    Science.gov (United States)

    Peckmezian, Tina; Taylor, Phillip W

    2015-04-01

    Electric shock is used widely as an aversive stimulus in conditioning experiments, yet little attention has been given to its physiological effects and their consequences for bioassays. In the present study, we provide a detailed characterization of how electric shock affects the mobility and behaviour of Servaea incana, a jumping spider. We begin with four mobility assays and then narrow our focus to a single effective assay with which we assess performance and behaviour. Based on our findings, we suggest a voltage range that may be employed as an aversive stimulus while minimizing decrements in physical performance and other aspects of behaviour. Additionally, we outline a novel method for constructing electric shock platforms that overcome some of the constraints of traditional methods while being highly effective and easily modifiable to suit the study animal and experimental context. Finally, as a demonstration of the viability of our aversive stimulus in a passive avoidance conditioning task, we successfully train spiders to associate a dark compartment with electric shock. Future research using electric shock as an aversive stimulus with terrestrial invertebrates such as spiders and insects may benefit from the flexible and reliable methods outlined in the present study.

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

    Science.gov (United States)

    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

  15. Taxonomic revision of the Trapdoor spider genus Eucteniza Ausserer (Araneae, Mygalomorphae, Euctenizidae).

    Science.gov (United States)

    Bond, Jason E; Godwin, Rebecca L

    2013-01-01

    The mygalomorph spider genus Eucteniza Ausserer, 1875 comprises 15 nominal species known only from the southwestern United States (Texas) and Mexico (Northern, Central, and the Baja Peninsula). Eucteniza atoyacensis Bond & Opell, 2002 is considered a nomen dubium; E. rex (Chamberlin, 1940) and E. stolida (Gertsch & Mulaik, 1940) are both considered junior synonyms of E. relata (O.P.-Cambridge, 1895). Twelve new species are described: E. caprica, E. coylei, E. diablo, E. cabowabo, E. huasteca, E. zapatista, E. chichimeca, E. ronnewtoni, E. hidalgo, E. golondrina, E. panchovillai and E. rosalia.

  16. Taxonomic revision of the Trapdoor spider genus Eucteniza Ausserer (Araneae, Mygalomorphae, Euctenizidae

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    Jason Bond

    2013-11-01

    Full Text Available The mygalomorph spider genus Eucteniza Ausserer, 1875 comprises 15 nominal species known only from the southwestern United States (Texas and Mexico (Northern, Central, and the Baja Peninsula. Eucteniza atoyacensis Bond & Opell, 2002 is considered a nomen dubium; E. rex (Chamberlin, 1940 and E. stolida (Gertsch & Mulaik, 1940 are both considered junior synonyms of E. relata (O.P.-Cambridge, 1895. Twelve new species are described: E. caprica, E. coylei, E. diablo, E. cabowabo, E. huasteca, E. zapatista, E. chichimeca, E. ronnewtoni, E. hidalgo, E. golondrina, E. panchovillai and E. rosalia.

  17. Modeling distribution of Phoneutria bahiensis (Araneae: Ctenidae: an endemic and threatened spider from Brazil

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    Marcelo A Dias

    2011-08-01

    Full Text Available Phoneutria bahiensis Simó & Brescovit, 2001 is a large ctenid spider inhabiting the states of Bahia and Espírito Santo, Brazil. Considering that it is probably endemic, this species was included in the Brazilian red book of threatened species. Here, we predict the distribution range of P. bahiensis using 19 bioclimatic variables in the model design. The most septentrional record for this spider was indicated for northern Bahia. The model predicts that the distribution range covers the Atlantic Forest from the state of Paraíba to Rio de Janeiro, with the best suitable area in the Atlantic Forest of the state of Bahia. The bioclimatic variable with the best contribution to the model was precipitation in the driest quarter. Based on collected data, the species inhabits Ombrophilous Forests and Restinga vegetation, two ecosystems of the Atlantic Forest biome. In the best-predicted area of distribution, eleven Conservation Units were included. This information could be considered for future conservation plans of this species.

  18. Transcriptome analysis of Loxosceles laeta (Araneae, Sicariidae spider venomous gland using expressed sequence tags

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    Almeida Diego D

    2008-06-01

    Full Text Available Abstract Background The bite of spiders belonging to the genus Loxosceles can induce a variety of clinical symptoms, including dermonecrosis, thrombosis, vascular leakage, haemolysis, and persistent inflammation. In order to examine the transcripts expressed in venom gland of Loxosceles laeta spider and to unveil the potential of its products on cellular structure and functional aspects, we generated 3,008 expressed sequence tags (ESTs from a cDNA library. Results All ESTs were clustered into 1,357 clusters, of which 16.4% of the total ESTs belong to recognized toxin-coding sequences, being the Sphingomyelinases D the most abundant transcript; 14.5% include "possible toxins", whose transcripts correspond to metalloproteinases, serinoproteinases, hyaluronidases, lipases, C-lectins, cystein peptidases and inhibitors. Thirty three percent of the ESTs are similar to cellular transcripts, being the major part represented by molecules involved in gene and protein expression, reflecting the specialization of this tissue for protein synthesis. In addition, a considerable number of sequences, 25%, has no significant similarity to any known sequence. Conclusion This study provides a first global view of the gene expression scenario of the venom gland of L. laeta described so far, indicating the molecular bases of its venom composition.

  19. Complex female genitalia indicate sperm dumping in armored goblin spiders (Arachnida, Araneae, Oonopidae).

    Science.gov (United States)

    Burger, Matthias

    2010-01-01

    In promiscuous females, sperm ejection from the sperm storage site can be a strong mechanism to influence sperm priority patterns. Sperm dumping is reported from different animals including birds, insects, and humans. In spiders, it has been documented for four species including the oonopid Silhouettella loricatula. Oonopidae are a diverse spider family comprising many species with peculiar female genitalia. Especially in species where studies of mating behavior are difficult, morphological investigations of the genitalia help to understand their function and evolution. In the present study, the genitalia of the oonopids Myrmopopaea sp., Grymeus sp., and Lionneta sp. are investigated by means of histological serial sections and scanning electron microscopy (SEM). The results are compared with previous findings on S. loricatula. In Myrmopopaea sp. and Grymeus sp., the same morphological components are present that are involved in sperm dumping in S. loricatula. Inside the receptaculum, sperm are enclosed in a secretory sac which can be moved to the genital opening and dumped during copulation by muscle contractions. The female genitalia of Lionneta sp. are asymmetric. They show the same characteristics as S. loricatula but all the investigated females were unmated. The results strongly suggest that sperm dumping occurs in Myrmopopaea sp., Grymeus sp., and Lionneta sp. and happens by the same mechanism as in S. loricatula. Sperm dumping might even be common within a clade of oonopids. As in S. loricatula, the sperm transfer forms in the investigated species consist of several spermatozoa. Papillae with unknown function occur on the receptacula of all females.

  20. Redescription of the orb-weaving spider Gasteracantha geminata (Fabricius, 1798) (Araneae, Araneidae).

    Science.gov (United States)

    Sankaran, Pradeep M; Jobi, Malamel J; Sebastian, Pothalil A

    2015-02-02

    The orb-weaving spider genus Gasteracantha Sundevall, 1833 (Araneidae) is notable for its pronounced sexual size dimorphism. Gasteracantha females are characterized by having a highly sclerotized "spiny" abdomen varying in relative size and number of spines, as well as abdomen dorsally and ventrally provided with varying numbers of sigillae (Cambridge 1879). The genus currently includes 70 described species and 31 subspecies (World Spider Catalog 2014). The Oriental species Gasteracantha geminata (Fabricius, 1798) was originally described from Ramnad (now known as Ramanathapuram) in Tamilnadu State of Southern India based on an unspecified number of female specimen(s). The female of this species has been described and illustrated several times by various authors. Its male is only known from the description of Simon (1895). Simon's original description of the male of G. geminata was supported by two simple but beautiful and informative illustrations: a retrolateral view of the cephalothorax and a dorsal view of the abdomen (Simon 1895, figs. 886, 887). However we lack a clear and detailed description of the male genitalia. The present paper provides detailed redescription of G. geminata and illustrations of the male pedipalp. 

  1. A golden orb-weaver spider (Araneae: Nephilidae: Nephila) from the Middle Jurassic of China.

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    Selden, Paul A; Shih, ChungKun; Ren, Dong

    2011-10-23

    Nephila are large, conspicuous weavers of orb webs composed of golden silk, in tropical and subtropical regions. Nephilids have a sparse fossil record, the oldest described hitherto being Cretaraneus vilaltae from the Cretaceous of Spain. Five species from Neogene Dominican amber and one from the Eocene of Florissant, CO, USA, have been referred to the extant genus Nephila. Here, we report the largest known fossil spider, Nephila jurassica sp. nov., from Middle Jurassic (approx. 165 Ma) strata of Daohugou, Inner Mongolia, China. The new species extends the fossil record of the family by approximately 35 Ma and of the genus Nephila by approximately 130 Ma, making it the longest ranging spider genus known. Nephilidae originated somewhere on Pangaea, possibly the North China block, followed by dispersal almost worldwide before the break-up of the supercontinent later in the Mesozoic. The find suggests that the palaeoclimate was warm and humid at this time. This giant fossil orb-weaver provides evidence of predation on medium to large insects, well known from the Daohugou beds, and would have played an important role in the evolution of these insects.

  2. A check list of the spider fauna of the Western Soutpansberg, South Africa (Arachnida: Araneae

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    S.H. Foord

    2002-12-01

    Full Text Available By virtue of its geological history and geographical location the Soutpansberg constitutes a refuge for a high diversity of organisms. The Western Soutpansberg forms part of the Savanna Biome and is presently the area with the highest concentration of Natural Heritage Sites in South Africa. A unique private initiative is under way to improve its national and international conservation status in a bid to conserve the mountain. A checklist of the spider species of the Western Soutpansberg collected over a five-year period is presented. Forty-six families, represented by 109 genera and 127 species have been collected. Of the species collected, 81 (64 % were wandering spiders and 46 (36 % web builders. The Thomisidae have the highest number of species (15 followed by the Araneidae and the Salticidae with 10 species each. Ninety-six genera are represented by a single species. Ninety six percent of the species collected are new records for the area. This survey is the first for the area and forms part of the South African National Survey of Arachnida (SANSA.

  3. Evolution of genital asymmetry, exaggerated eye stalks, and extreme palpal elongation in Panjange spiders (Araneae: Pholcidae

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    Bernhard Huber

    2015-12-01

    Full Text Available We describe several new species of the previously monotypic Panjange lanthana species group from the Philippines and document their extraordinary morphology. Some species show strong male genital asymmetry, a phenomenon that seems to be exceedingly rare in spiders. Males of most species have eye stalks, and in two species these eye stalks are among the longest ever recorded in spiders. Some species show a tendency for male genital (pedipalp elongation, and one species has the longest and thinnest palps ever recorded in Pholcidae. A cladistic analysis is performed including all described and several undescribed species of Panjange (except for one “problem species”, supporting the lanthana group and its close relationship with members of the possibly paraphyletic cavicola group. The following eight new species are described: Panjange malagos Huber sp. nov.; Pa. casaroro Huber sp. nov.; Pa. camiguin Huber sp. nov.; Pa. hamiguitan Huber sp. nov.; Pa. isarog Huber sp. nov.; Pa. dinagat Huber sp. nov.; Pa. marilog Huber sp. nov.; Pa. bukidnon Huber sp. nov.

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

    Science.gov (United States)

    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

  5. New records of 43 spider species from the Mountain Zebra National Park, South Africa (Arachnida: Araneae

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    A.S. Dippenaar-Schoeman

    2006-12-01

    Full Text Available This study forms part of the South African National Survey of Arachnida (SANSA, initiated in 1997 with the main aim to create an inventory of the arachnid fauna of South Africa (Dippenaar-Schoeman & Craemer 2000. One of the objectives of SANSA is to assess the number of arachnid species presently protected in conserved areas in the country. Check lists of spiders are now available for three national parks, three nature reserves and a conservancy. These areas include: Mountain Zebra National Park (Dippenaar-Schoeman 1988; Karoo National Park (Dippenaar-Schoeman et al. 1999; Kruger National Park (Dippenaar- Schoeman & Leroy 2002; Roodeplaatdam Nature Reserve (Dippenaar-Schoeman et al. 1989; Makelali Nature Reserve (Whitmore et al. 2001, 2002; Swartberg Nature Reserve (Dippenaar-Schoeman et al. 2005; and the Soutpansberg Conservancy (Foord et al. 2002.

  6. On the new monotypic wolf spider genus Ovia gen. nov. (Araneae: Lycosidae, Lycosinae).

    Science.gov (United States)

    Sankaran, Pradeep M; Malamel, Jobi J; Sebastian, Pothalil A

    2017-01-17

    A new monotypic wolf spider genus, Ovia gen. nov. is proposed to accommodate a misplaced species: Pardosa procurva Yu & Song, 1988. Ovia procurva comb. nov. is redescribed, illustrated and designated as the type species for the genus. The subfamily placement of the new genus is discussed and it is considered as a member of Lycosinae Sundevall, 1833 and possibly closely related to Alopecosa Simon, 1885. The presence of an apical process (spur) on the median apophysis is proposed as the putative synapomorphy of Ovia gen. nov. The possible sister-taxon relationship of Ovia gen. nov. with Alopecosa is discussed and evidence on the occurrence of sexual dimorphism and mating plug within the genus are presented. Ovia gen. nov. is assumed to be of Holarctic origin, from which it has migrated to the Indomalayan region. Additionally, a current distribution map for the genus is provided.

  7. The Amazonian Goblin Spiders of the New Genus Gradunguloonops (Araneae: Oonopidae).

    Science.gov (United States)

    Grismado, Cristian J; Izquierdo, Matías A; González Márquez, María E; Ramírez, Martín J

    2015-03-29

    A new genus of soft-bodied oonopids, Gradunguloonops, is established for a group of goblin spiders found in the Amazonian rainforests of northern South America. Members of this genus differ from other oonopids in that the proclaw of tarsi I and II is notably larger than the corresponding retroclaw, a putative synapomorphy of the group. Gradunguloonops comprises twelve species, all new and described in this contribution: G. mutum (type species) from Brazil and Peru, G. bonaldoi, G. amazonicus, G. urucu, G. pacanari, G. juruti from Brazil, G. erwini from Peru, G. orellana and G. nadineae from Ecuador, G. benavidesae and G. florezi from Colombia, and G. raptor from Venezuela. Two preliminary intrageneric groups are proposed on the basis of their female genital morphology: the bonaldoi group, to which are assigned the species with the anterior section comprising only a single anterior sclerite, and the mutum group, with a more complex, tripartite anterior section.

  8. Four new Mouse Spider species (Araneae, Mygalomorphae, Actinopodidae, Missulena from Western Australia

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    Laura Miglio

    2014-05-01

    Full Text Available Four new species of the Mouse Spider genus Missulena Walckenaer, 1805 (family Actinopodidae are described from Western Australia based on morphological features of adult males. Missulena leniae sp. n. (from the Carnarvon and Yalgoo biogeographic regions, Missulena mainae sp. n. (Carnarvon, Missulena melissae sp. n. (Pilbara and Missulena pinguipes sp. n. (Mallee represent a broad spectrum of morphological diversity found in this genus and differ from other congeners by details of the male copulatory bulb, colour patterns, eye sizes, leg morphology and leg spination. Two of the species, M. pinguipes sp. n. and M. mainae sp. n., are characterised by swollen metatarsi of the fourth legs in males, a feature not previously recorded in the family. A key to males of all named Missulena species from Australia is presented and allows their identification based on external morphology.

  9. Frequent misdirected courtship in a natural community of colorful Habronattus jumping spiders.

    Science.gov (United States)

    Taylor, Lisa A; Powell, Erin C; McGraw, Kevin J

    2017-01-01

    Male courtship display is common in many animals; in some cases, males engage in courtship indiscriminately, spending significant time and energy courting heterospecifics with whom they have no chance of mating or producing viable offspring. Due to high costs and few if any benefits, we might expect mechanisms to evolve to reduce such misdirected courtship (or 'reproductive interference'). In Habronattus jumping spiders, males frequently court heterospecifics with whom they do not mate or hybridize; females are larger and are voracious predators, posing a severe risk to males who court indiscriminately. In this study, we examined patterns of misdirected courtship in a natural community of four sympatric Habronattus species (H. clypeatus, H. hallani, H. hirsutus, and H. pyrrithrix). We used direct field observations to weigh support for two hypotheses (differential microhabitat use and species recognition signaling) to explain how these species reduce the costs associated with misdirected courtship. We show that, while the four species of Habronattus do show some differences in microhabitat use, all four species still overlap substantially, and in three of the four species individuals equally encountered heterospecifics and conspecifics. Males courted females at every opportunity, regardless of species, and in some cases, this led to aggression and predation by the female. These results suggest that, while differences in microhabitat use might reduce misdirected courtship to some extent, co-existence of these four species may be possible due to complex communication (i.e. species-specific elements of a male's courtship display). This study is the first to examine misdirected courtship in jumping spiders. Studies of misdirected courtship and its consequences in the field are limited and may broaden our understanding of how biodiversity is maintained within a community.

  10. Spatial variation in the strength of mutualism between a jumping spider and a terrestrial bromeliad: Evidence from the stable isotope 15N

    Science.gov (United States)

    Romero, Gustavo Q.; Vasconcellos-Neto, João; Trivelin, Paulo C. O.

    2008-05-01

    Psecas chapoda, a neotropical jumping spider strictly associated with the terrestrial bromeliad Bromelia balansae in cerrados and semi-deciduous forests in South America, effectively contributes to plant nutrition and growth. In this study, our goal was to investigate if spider density caused spatial variations in the strength of this spider-plant mutualism. We found a positive significant relationship between spider density and δ15N values for bromeliad leaves in different forest fragments. Open grassland Bromeliads were associated with spiders and had higher δ15N values compared to forest bromeliads. Although forest bromeliads had no association with spiders their total N concentrations were higher. These results suggest that bromeliad nutrition is likely more litter-based in forests and more spider-based in open grasslands. This study is one of the few to show nutrient provisioning and conditionality in a spider-plant system.

  11. The synganglion of the jumping spider Marpissa muscosa (Arachnida: Salticidae): Insights from histology, immunohistochemistry and microCT analysis.

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    Steinhoff, Philip O M; Sombke, Andy; Liedtke, Jannis; Schneider, Jutta M; Harzsch, Steffen; Uhl, Gabriele

    2017-03-01

    Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-dimensional reconstruction. In the prosoma, the CNS is a clearly demarcated mass that surrounds the esophagus. The anteriormost neuromere, the protocerebrum, comprises nine bilaterally paired neuropils, including the mushroom bodies and one unpaired midline neuropil, the arcuate body. Further ventrally, the synganglion comprises the cheliceral (deutocerebrum) and pedipalpal neuropils (tritocerebrum). Synapsin-immunoreactivity in all neuropils is generally strong, while allatostatin-immunoreactivity is mostly present in association with the arcuate body and the stomodeal bridge. The most prominent neuropils in the spider brain, the mushroom bodies and the arcuate body, were suggested to be higher integrating centers of the arthropod brain. The mushroom body in M. muscosa is connected to first and second order visual neuropils of the lateral eyes, and the arcuate body to the second order neuropils of the anterior median eyes (primary eyes) through a visual tract. The connection of both, visual neuropils and eyes and arcuate body, as well as their large size corroborates the hypothesis that these neuropils play an important role in cognition and locomotion control of jumping spiders. In addition, we show that the architecture of the brain of M. muscosa and some previously investigated salticids differs significantly from that of the wandering spider Cupiennius salei, especially with regard to structure and arrangement of visual neuropils and mushroom body. Thus, we need to explore the anatomical conformities and specificities of the brains of different spider taxa in order to understand evolutionary transformations of the

  12. Why is Madagascar special? The extraordinarily slow evolution of pelican spiders (Araneae, Archaeidae).

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    Wood, Hannah M; Gillespie, Rosemary G; Griswold, Charles E; Wainwright, Peter C

    2015-02-01

    Although Madagascar is an ancient fragment of Gondwana, the majority of taxa studied thus far appear to have reached the island through dispersal from Cenozoic times. Ancient lineages may have experienced a different history compared to more recent Cenozoic arrivals, as such lineages would have encountered geoclimatic shifts over an extended time period. The motivation for this study was to unravel the signature of diversification in an ancient lineage by comparing an area known for major geoclimatic upheavals (Madagascar) versus other areas where the environment has been relatively stable. Archaeid spiders are an ancient paleoendemic group with unusual predatory behaviors and spectacular trophic morphology that likely have been on Madagascar since its isolation. We examined disparities between Madagascan archaeids and their non-Madagascan relatives regarding timing of divergence, rates of trait evolution, and distribution patterns. Results reveal an increased rate of adaptive trait diversification in Madagascan archaeids. Furthermore, geoclimatic events in Madagascar over long periods of time may have facilitated high species richness due to montane refugia and stability, rainforest refugia, and also ecogeographic shifts, allowing for the accumulation of adaptive traits. This research suggests that time alone, coupled with more ancient geoclimatic events allowed for the different patterns in Madagascar. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  13. The first lowland species of the Holarctic alpine ground spider genus Parasyrisca (Araneae, Gnaphosidae from Hungary

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    Csaba Szinetár

    2009-07-01

    Full Text Available The first lowland species of the alpine genus Parasyrisca, Parasyrisca arrabonica Szinetár & Eichardt, sp. n., is described from the sandy grasslands of Hungary. The genus was hitherto known only from Western Europe (Pyrenees and Western Alps and Eastern Europe (Crimea, and although records from Slovenia and Romania were known, these are listed in check-lists in both cases as doubtful since no voucher specimens are available. Thus this species is not only the first representative of Parasyrisca in the Hungarian fauna and in the Pannonian region, but is the first verified record of the genus in Central Europe too. Parasyrisca arrabonica seems to belong to the speciose potanini group (of which this is the first European record and the westernmost occurrence to date, and is especially similar to P. turkenica Ovtsharenko, Platnick & Marusik, 1995 and P. songi Marusik & Fritzén, 2009. Detailed descriptions of the species’ ecological characteristics (habitat, co-occurring species are provided, as its habitat preference is unusual and unique within the genus. This species is quite rare: only eight specimens have been found among 20700 captured spiders. Adult specimens have been collected exclusively in late autumn and early spring (so practically outside the major collecting period, which might explain why this species was not discovered earlier.

  14. The complete mitochondrial genome of orb-weaving spider Araneus ventricosus (Araneae: Araneidae).

    Science.gov (United States)

    Wang, Zheng-Liang; Li, Chao; Fang, Wen-Yuan; Yu, Xiao-Ping

    2016-05-01

    The complete mitochondrial genome of an orb-weaving spider Araneus ventricosus was determined. It is a circular molecule of 14,617 bp in length and contains a standard set of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a control region. The A + T content of the overall base composition of majority strand (J-strand) is 73.4% (T: 38.5%; C: 10.1%; A: 34.9%; G: 16.5%). Among protein-coding genes, one gene (COI) begins with TTA, two (ATP6 and ND4) start with ATA, three (COII, COIII and ND6) begin with ATT and other seven genes use ATT as initiation codon. COIII and ND3 end with an incomplete stop codon (T), and ND1, ND2 and Cytb are terminated with TAG, while all other genes end with TAA as stop codon. Two regions including tandem repeats were found in the control region (D-loop): a 106 bp sequence tandemly repeated twice and a 195 bp sequence tandemly repeated twice with a partial third (120 bp).

  15. Revision, phylogeny, and microhabitat shifts in the Southeast Asian spider genus Aetana (Araneae, Pholcidae

    Directory of Open Access Journals (Sweden)

    Bernhard A. Huber

    2015-12-01

    Full Text Available The previously poorly known Southeast Asian spider genus Aetana Huber, 2005 is revised. Fifteen species are newly described, and the first SEM data and a first phylogenetic analysis of the genus are presented. Four species groups are well supported, one restricted to Borneo, two restricted to the Philippines, and one ranging from the Philippines to Fiji. The cladistic analysis and field observations suggest that the ancestor of Aetana built its web close to the ground, in confined spaces among and under rocks and logs. In at least two cases, evolutionary shifts of microhabitat resulted in species being adapted to life in higher forest strata, with correlated morphological and behavioral changes (lighter coloration; longer abdomen; additional sheet in web or more strongly domed web. The following species are newly described: A. abadae Huber, sp. nov., A. baganihan Huber, sp. nov., A. banahaw Huber, sp. nov., A. kiukoki Huber, sp. nov., A. libjo Huber, sp. nov., A. loboc Huber, sp. nov., A. lozadae Huber, sp. nov., A. manansalai Huber, sp. nov., A. ocampoi Huber, sp. nov., A. paragua Huber, sp. nov. and A. pasambai Huber, sp. nov. from the Philippines; A. gaya Huber, sp. nov., A. indah Huber, sp. nov., A. lambir Huber, sp. nov. and A. poring Huber, sp. nov. from northern Borneo. The female of A. kinabalu Huber, 2005 is newly described. A potential case of female genital dimorphism is documented in A. ocampoi Huber, sp. nov.

  16. Multiple bradykinin-related peptides from the capture web of the spider Nephila clavipes (Araneae, Tetragnatidae).

    Science.gov (United States)

    Volsi, Evelyn C F R; Mendes, Maria Anita; Marques, Maurício Ribeiro; dos Santos, Lucilene Delazari; Santos, Keity Souza; de Souza, Bibiana Monson; Babieri, Eduardo Feltran; Palma, Mario Sergio

    2006-04-01

    Three bradykinin-related peptides (nephilakinins-I to -III) and bradykinin itself were isolated from the aqueous washing extract of the capture web of the spider Nephila clavipes by gel permeation chromatography on a Sephacryl S-100 column, followed by chromatography in a Hi-Trap Sephadex-G25 Superfine column. The novel peptides occurred in low concentrations and were sequenced through ESI-MS/MS analysis: nephilakinin-I (G-P-N-P-G-F-S-P-F-R-NH2), nephilakinin-II (E-A-P-P-G-F-S-P-F-R-NH2) and nephilakinin-III (P-S-P-P-G-F-S-P-F-R-NH2). Synthetic peptides replicated the novel bradykinin-related peptides, which were submitted to biological characterizations. Nephilakinins were shown to cause constriction on isolated rat ileum preparations and relaxation on rat duodenum muscle preparations at amounts higher than bradykinin; apparently these peptides constitute B2-type agonists of ileal and duodenal smooth muscles. All peptides including the bradykinin were moderately lethal to honeybees. These bradykinin peptides may be related to the predation of insects by the webs of N. clavipes.

  17. Biogeography and speciation patterns of the golden orb spider genus Nephila (Araneae: Nephilidae) in Asia.

    Science.gov (United States)

    Su, Yong-Chao; Chang, Yung-Hau; Smith, Deborah; Zhu, Ming-Sheng; Kuntner, Matjaž; Tso, I-Min

    2011-01-01

    The molecular phylogeny of the globally distributed golden orb spider genus Nephila (Nephilidae) was reconstructed to infer its speciation history, with a focus on SE Asian/W Pacific species. Five Asian, two Australian, four African, and one American species were included in the phylogenetic analyses. Other species in Nephilidae, Araneidae, and Tetragnathidae were included to assess their relationships with the genus Nephila, and one species from Uloboridae was used as the outgroup. Phylogenetic trees were reconstructed from one nuclear (18S) and two mitochondrial (COI and 16S) markers. Our molecular phylogeny shows that the widely distributed Asian/Australian species, N. pilipes, and an African species, N. constricta, form a clade that is sister to all other Nephila species. Nested in this Nephila clade are one clade with tropical and subtropical/temperate Asian/Australian species, and the other containing African and American species. The estimated divergence times suggest that diversification events within Nephila occurred during mid-Miocene to Pliocene (16 Mya-2 Mya), and these time periods were characterized by cyclic global warming/cooling events. According to Dispersal and Vicariance Analysis (DIVA), the ancestral range of the Asian/Australian clade was tropical Asia, and the ancestral range of the genus Nephila was either tropical Asia or Africa. We conclude that the speciation of the Asian/Australian Nephila species was driven by Neogene global cyclic climate changes. However, further population level studies comparing diversification patterns of sister species are needed to determine the mode of speciation of these species.

  18. Resolving the phylogeny of a speciose spider group, the family Linyphiidae (Araneae).

    Science.gov (United States)

    Wang, Fang; Ballesteros, Jesus A; Hormiga, Gustavo; Chesters, Douglas; Zhan, Yongjia; Sun, Ning; Zhu, Chaodong; Chen, Wei; Tu, Lihong

    2015-10-01

    For high-level molecular phylogenies, a comprehensive sampling design is a key factor for not only improving inferential accuracy, but also for maximizing the explanatory power of the resulting phylogeny. Two standing problems in molecular phylogenies are the unstable placements of some deep and long branches, and the phylogenetic relationships shown by robust supported clades conflict with recognized knowledge. Empirical and theoretical studies suggest that increasing taxon sampling is expected to ameliorate, if not resolve, both problems; however, sometimes neither the current taxonomic system nor the established phylogeny can provide sufficient information to guide additional sampling design. We examined the phylogeny of the spider family Linyphiidae, and selected ingroup species based on epigynal morphology, which can be reconstructed in a phylogenetic context. Our analyses resulted in seven robustly supported clades within linyphiids. The placements of four deep and long branches are sensitive to variations in both outgroup and ingroup sampling, suggesting the possibility of long branch attraction artifacts. Results of ancestral state reconstruction indicate that successive state transformations of the epigynal plate are associated with early cladogenetic events in linyphiid diversification. Representatives of different subfamilies were mixed together within well supported clades and examination revealed that their defining characters, as per traditional taxonomy, are homoplastic. Furthermore, our results demonstrated that increasing taxon sampling produced a more informative framework, which in turn helps to study character evolution and interpret the relationships among linyphiid lineages. Additional defining characters are needed to revise the linyphiid taxonomic system based on our phylogenetic hypothesis. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Revision of the orb-weaving spider genus Verrucosa McCook, 1888 (Araneae, Araneidae).

    Science.gov (United States)

    Lise, Arno A; Kesster, Cynara C; Da Silva, Estevam L Cruz

    2015-02-25

    The araneid spider genus Verrucosa McCook, 1888 is revised. Five of the seven previously known species, V. arenata (Walckenaer, 1841), V. lampra Soares & Camargo, 1948, V. meridionalis (Keyserling, 1892), V. undecimvariolata (O. Pickard-Cambridge, 1889) and V. zebra (Keyserling, 1892), are redescribed and illustrated. In addition, 37 new species of Verrucosa from the Neotropical region are described and illustrated: V. cachimbo n. sp., V. tarapoa n. sp., V. scapofracta n. sp., V. carara n. sp., V. latigastra n. sp., V. guatopo n. sp., V. cuyuni n. sp., V. benavidesae n. sp., V. rancho n. sp., V. excavata n. sp., V. meta n. sp., V. levii n. sp., V. chanchamayo n. sp., V. manauara n. sp., V. brachiscapa n. sp., V. macarena n. sp., V. pedrera n. sp., V. lata n. sp., V. galianoae n. sp., V. suaita n. sp., V. coroico n. sp., V. florezi n. sp., V. hoferi n. sp., V. caninde n. sp., V. opon n. sp., V. silvae n. sp., V. avilesae n. sp., V. tuberculata n. sp., V. alvarengai n. sp., V. apuela n. sp., V. bartica n. sp., V. cajamarca n. sp., V. canje n. sp., V. cuyabenoensis n. sp., V. sergipana n. sp., V. simla n. sp. and V. rhea n. sp. Mahadiva reticulata O. P.-Cambridge, 1889 is removed from the synonymy of Verrucosa arenata (Walckenaer, 1841) and is recognized as a valid species, Verrucosa reticulata. Araneus cylicophorus Badcock, 1932 is transferred to Verrucosa by Mello-Leitão (1946) removed from the synonymy of Verrucosa meridionalis (Keyserling, 1892) and recognized as a valid species. The male of Verrucosa meridionalis (Keyserling, 1892) is described for the first time. Distributional maps are provided for all species.

  20. Revision and phylogenetic analysis of the orb-weaving spider genus Glenognatha Simon, 1887 (Araneae, Tetragnathidae).

    Science.gov (United States)

    Cabra-García, Jimmy; Brescovit, Antonio D

    2016-01-27

    A taxonomic revision and phylogenetic analysis of the spider genus Glenognatha Simon, 1887 is presented. This analysis is based on a data set including 24 Glenognatha species plus eight outgroups representing three related tetragnathine genera and one metaine as the root. These taxa were scored for 78 morphological characters. Parsimony was used as the optimality criterion and a sensitivity analysis was performed using different character weighting concavities. Seven unambiguous synapomorphies support the monophyly of Glenognatha. Some internal clades within the genus are well-supported and its relationships are discussed. Glenognatha as recovered includes 27 species, four of them only known from males. A species identification key and distribution maps are provided for all. New morphological data are also presented for thirteen previously described species. Glenognatha has a broad distribution occupying the Neartic, Afrotropic, Indo-Malaya, Oceania and Paleartic regions, but is more diverse in the Neotropics. The following eleven new species are described: G. vivianae n. sp., G. caaguara n. sp., G. boraceia n. sp. and G. timbira n. sp. from southeast Brazil, G. caparu n. sp., G. januari n. sp. and G. camisea n. sp. from the Amazonian region, G. mendezi n. sp., G. florezi n. sp. and G. patriceae n. sp. from northern Andes and G. gouldi n. sp. from Southern United States and central Mexico. Females of G. minuta Banks, 1898, G. gaujoni Simon, 1895 and G. gloriae (Petrunkevitch, 1930) and males of G. globosa (Petrunkevitch, 1925) and G. hirsutissima (Berland, 1935) are described for the first time. Three new combinations are proposed in congruence with the phylogenetic results: G. argyrostilba (O. P.-Cambridge, 1876) n. comb., G. dentata (Zhu & Wen, 1978) n. comb. and G. tangi (Zhu, Song & Zhang, 2003) n. comb., all previously included in Dyschiriognatha Simon, 1893. The following taxa are newly synonymized: Dyschiriognatha montana Simon, 1897, Glenognatha mira Bryant

  1. Systematics, conservation and morphology of the spider genus Tayshaneta (Araneae, Leptonetidae) in Central Texas Caves

    Science.gov (United States)

    Ledford, Joel; Paquin, Pierre; Cokendolpher, James; Campbell, Josh; Griswold, Charles

    2012-01-01

    Abstract The spider genus Tayshaneta is revised based on results from a three gene phylogenetic analysis (Ledford et al. 2011) and a comprehensive morphological survey using scanning electron (SEM) and compound light microscopy. The morphology and relationships within Tayshaneta are discussed and five species-groups are supported by phylogenetic analyses: the anopica group, the coeca group, the myopica group, the microps group and the sandersi group. Short branch lengths within Tayshaneta contrast sharply with the remaining North American genera and are viewed as evidence for a relatively recent radiation of species. Variation in troglomorphic morphology is discussed and compared to patterns found in other Texas cave invertebrates. Several species previously known as single cave endemics have wider ranges than expected, suggesting that some caves are not isolated habitats but instead form part of interconnected karst networks. Distribution maps are compared with karst faunal regions (KFR’s) in Central Texas and the implications for the conservation and recovery of Tayshaneta species are discussed. Ten new species are described: Tayshaneta archambaulti sp. n., Tayshaneta emeraldae sp. n., Tayshaneta fawcetti sp. n., Tayshaneta grubbsi sp. n., Tayshaneta madla sp. n., Tayshaneta oconnorae sp. n., Tayshaneta sandersi sp. n., Tayshaneta sprousei sp. n., Tayshaneta vidrio sp. n. and Tayshaneta whitei sp. n. The males for three species, Tayshaneta anopica (Gertsch, 1974), Tayshaneta devia (Gertsch, 1974) and Tayshaneta microps (Gertsch, 1974) are described for the first time. Tayshaneta furtiva (Gertsch, 1974) and Tayshaneta uvaldea (Gertsch, 1974) are declared nomina dubia as the female holotypes are not diagnosable and efforts to locate specimens at the type localities were unsuccessful. All Tayshaneta species are thoroughly illustrated, diagnosed and keyed. Distribution maps are also provided highlighting areas of taxonomic ambiguity in need of additional sampling

  2. The black widow spider genus Latrodectus (Araneae: Theridiidae): phylogeny, biogeography, and invasion history.

    Science.gov (United States)

    Garb, Jessica E; González, Alda; Gillespie, Rosemary G

    2004-06-01

    The spider genus Latrodectus includes the widely known black widows, notorious because of the extreme potency of their neurotoxic venom. The genus has a worldwide distribution and comprises 30 currently recognized species, the phylogenetic relationships of which were previously unknown. Several members of the genus are synanthropic, and are increasingly being detected in new localities, an occurrence attributed to human mediated movement. In particular, the nearly cosmopolitan range of the brown widow, Latrodectus geometricus, is a suspected consequence of human transport. Although the taxonomy of the genus has been examined repeatedly, the recognition of taxa within Latrodectus has long been considered problematic due to the difficulty associated with identifying morphological features exhibiting discrete geographic boundaries. This paper presents, to our knowledge, the first phylogenetic hypothesis for the Latrodectus genus and is generated from DNA sequences of the mitochondrial gene cytochrome c oxidase subunit I. We recover two well-supported reciprocally monophyletic clades within the genus: (1) the geometricus clade, consisting of Latrodectus rhodesiensis from Africa, and its is sister species, the cosmopolitan L. geometricus, and (2) the mactans clade containing all other Latrodectus species sampled, including taxa occurring in Africa, the Middle East, Iberian Peninsula, Australia, New Zealand, and North and South America. Recovery of the geometricus and mactans clades is consistent with previous designations of species groups within the genus based on female genitalic morphology. All L. geometricus sampled, consisting of specimens from Africa, Argentina, North America, and Hawaii, were recovered as a strongly supported monophyletic group with minimal amounts of genetic divergence, corroborating the hypothesis that human transport has recently expanded the range of this species.

  3. Systematics, conservation and morphology of the spider genus Tayshaneta (Araneae, Leptonetidae in Central Texas Caves

    Directory of Open Access Journals (Sweden)

    Joel Ledford

    2012-01-01

    Full Text Available The spider genus Tayshaneta is revised based on results from a three gene phylogenetic analysis (Ledford et al. 2011 and a comprehensive morphological survey using scanning electron (SEM and compound light microscopy. The morphology and relationships within Tayshaneta are discussed and five species-groups are supported by phylogenetic analyses: the anopica group, the coeca group, the myopica group, the microps group and the sandersi group. Short branch lengths within Tayshaneta contrast sharply with the remaining North American genera and are viewed as evidence for a relatively recent radiation of species. Variation in troglomorphic morphology is discussed and compared to patterns found in other Texas cave invertebrates. Several species previously known as single cave endemics have wider ranges than expected, suggesting that some caves are not isolated habitats but instead form part of interconnected karst networks. Distribution maps are compared with karst faunal regions (KFR’s in Central Texas and the implications for the conservation and recovery of Tayshaneta species are discussed. Ten new species are described: T. archambaulti sp. n., T. emeraldae sp. n., T. fawcetti sp. n., T. grubbsi sp. n., T. madla sp. n., T. oconnorae sp. n., T. sandersi sp. n., T. sprousei sp. n., T. vidrio sp. n. and T. whitei sp. n. The males for three species, T. anopica (Gertsch, 1974, T. devia (Gertsch, 1974 and T. microps (Gertsch, 1974 are described for the first time. Tayshaneta furtiva (Gertsch, 1974 and T. uvaldea (Gertsch, 1974 are declared nomina dubia as the female holotypes are not diagnosable and efforts to locate specimens at the type localities were unsuccessful. All Tayshaneta species are thoroughly illustrated, diagnosed and keyed. Distribution maps are also provided highlighting areas of taxonomic ambiguity in need of additional sampling.

  4. Misdiagnosis of spider bites: bacterial associates, mechanical pathogen transfer, and hemolytic potential of venom from the hobo spider, Tegenaria agrestis (Araneae: Agelenidae).

    Science.gov (United States)

    Gaver-Wainwright, Melissa M; Zack, Richard S; Foradori, Matthew J; Lavine, Laura Corley

    2011-03-01

    The European spider Tegenaria agrestis (Walckenaer) (hobo spider) has been implicated as a spider of medical importance in the Pacific Northwest since its introduction in the late 1980s. Studies have indicated that the hobo spider causes necrotic tissue lesions through hemolytic venom or through the transfer of pathogenic bacteria introduced by its bite. Bacterial infections are often diagnosed as spider bites, in particular the pathogenic bacteria methicillin-resistant Staphylococcus aureus (MRSA). This study examines three aspects of the potential medical importance of hobo spiders in part of its introduced range, Washington State. First, the bacterial diversity of the spider was surveyed using a polymerase chain reaction-based assay to determine whether the spider carries any pathogenic bacteria. Second, an experiment was conducted to determine the ability of the spiders to transfer MRSA. Third, the venom was evaluated to assess the hemolytic activity. We found 10 genera of ubiquitous bacteria on the exterior surface of the spiders. In addition, none of the spiders exposed to MRSA transferred this pathogen. Finally, the hemolytic venom assay corroborates previous studies that found hobo spider venom was not deleterious to vertebrate red blood cells.

  5. Can ant-eating Zodarion spiders (Araneae: Zodariidae) develop on a diet optimal for euryphagous arthropod predators?

    DEFF Research Database (Denmark)

    Pekar, Stano; Toft, Søren

    2009-01-01

    . Such adaptations may then entail trade-offs in handling and utilization of alternative prey. To investigate behavioural as well as nutritional adaptations and the occurrence of the corresponding trade-offs in two ant-eating spiders of the genus Zodarion [Zodarion atlanticum Pekár & Cardoso and Zodarion germanicum...... (C. L. Koch)], spiders are reared on two diets: ants (i.e. their preferred prey) and fruit flies (i.e. an alternative prey that is nutritionally optimal for euryphagous spiders). Food consumption is observed and several fitness-related life-history parameters are measured. Although spiders readily...... accept ants, more than one-third of 35 spiders refuse to consume fruit flies and starve. Furthermore, severe hunger does not induce these individuals to accept fruit flies. Starving spiders die before moulting to the second stadium. Spiders that eat fruit flies increase only little and slowly in weight...

  6. The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea: a relimitation and revision at the generic level

    Directory of Open Access Journals (Sweden)

    Michael Rix

    2010-02-01

    Full Text Available The araneoid spider family Micropholcommatidae Hickman, previously containing 34 southern-temperate species in eight genera, is relimited and revised at the generic level to include 18 genera from Australia, Lord Howe Island, New Caledonia, New Zealand, Papua New Guinea and Chile. Three subfamilies are proposed, and a new phylogenetic hypothesis for the family is presented as a result of two morphological cladistic analyses, used to test the phylogenetic position and phylogeny of the known micropholcommatid taxa. These cladistic analyses inferred a monophyletic Micropholcommatidae, belonging to the diverse araneoid symphytognathidan lineage, with the families Anapidae, Symphytognathidae and Micropholcommatidae further united by the newly proposed 'EbCY' clade. The genus Teutoniella Brignoli, previously included in the Micropholcommatidae, was found to be most closely related to an undescribed genus from South Africa, together forming a distinctive ‘teutoniellid’ lineage within the EbCY clade. The subfamily Micropholcommatinae Hickman, new rank contains the bulk of micropholcommatid diversity, with three tribes, 15 genera and 45 described species. The micropholcommatine tribe Micropholcommatini Hickman, new rank includes the nominate genus Micropholcomma Crosby & Bishop, along with three additional genera from Australasia and Chile: Micropholcomma has eight species, including the type, M. caeligenum Crosby & Bishop, and M. junee sp. n.; Pua Forster is monotypic, with P. novaezealandiae Forster; Tricellina Forster & Platnick is also monotypic, with T. gertschi (Forster & Platnick; and Austropholcomma gen. n. has two species, including the type A. florentine sp. n., and A. walpole sp. n. The micropholcommatine tribe Textricellini Hickman, new rank is a diverse and distinctive lineage, including all species previously described in the genus Textricella Hickman, which is hereby recognised as a junior generic synonym of Eterosonycha Butler syn. n

  7. FAUNISTICAL DATA REGARDING SPIDERS (ARACHNIDA: ARANEAE FROM SOUTH-EASTERN ROMANIA WITH MENTION OF SOME RARE SPECIES

    Directory of Open Access Journals (Sweden)

    I. DUMA

    2005-01-01

    Full Text Available In this paper we present the results of the faunistical study made in the south-eastern Romania in the summers of 2004 and 2006. We found 118 species of araneae belonging to 21 families. Among them there were some rare species: Argiope lobata (Pallas, 1772 mentioned for the third time in Romania, Hariaeus melloteei (Simon, 1886 mentioned for the second time in our country and Latrodectus tredecimguttatus (Rossi, 1890.

  8. First report of clinical presentation of a bite by a running spider, Philodromus sp. (Araneae: Philodromidae), with recommendations for spider bite management

    OpenAIRE

    Maureen Coetzee; Ansie Dippenaar; John Frean; Hunt, Richard H

    2017-01-01

    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 showing cytotoxic envenomation. Management of the bites should be as recommended for other cytotoxic spider bites.

  9. First report of clinical presentation of a bite by a running spider, Philodromus sp. (Araneae: Philodromidae, with recommendations for spider bite management

    Directory of Open Access Journals (Sweden)

    Maureen Coetzee

    2017-07-01

    Full Text Available 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 showing cytotoxic envenomation. Management of the bites should be as recommended for other cytotoxic spider bites.

  10. 华模蛛科——采自中国的蜘蛛目一新科(蛛形纲,蜘蛛目)%SINOPIMOIDAE, A NEW SPIDER FAMILY FROM CHINA (ARACHNIDA, ARANEAE)

    Institute of Scientific and Technical Information of China (English)

    李枢强; WUNDERLICH J(o)rg

    2008-01-01

    The new spider family Sinopimoidae fam. nov. (Araneae, Araneoidea), with inopimoa bicolor gen. nov. et sp. nov., is described from a tropical rainforest in Southwest China.%记述了采自我国云南西双版纳雨林的1新科,华模蛛科Sinopimoidae fam.nov.,1新属,华模蛛属Sinopimoa gen.nov.,1新种,双色华模蛛Sinopimoa bicolor sp.nov..模式标本保存在中国科学院动物研究所.

  11. 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.

  12. Can long-range PCR be used to amplify genetically divergent mitochondrial genomes for comparative phylogenetics? A case study within spiders (Arthropoda: Araneae).

    Science.gov (United States)

    Briscoe, Andrew G; Goodacre, Sara; Masta, Susan E; Taylor, Martin I; Arnedo, Miquel A; Penney, David; Kenny, John; Creer, Simon

    2013-01-01

    The development of second generation sequencing technology has resulted in the rapid production of large volumes of sequence data for relatively little cost, thereby substantially increasing the quantity of data available for phylogenetic studies. Despite these technological advances, assembling longer sequences, such as that of entire mitochondrial genomes, has not been straightforward. Existing studies have been limited to using only incomplete or nominally intra-specific datasets resulting in a bottleneck between mitogenome amplification and downstream high-throughput sequencing. Here we assess the effectiveness of a wide range of targeted long-range PCR strategies, encapsulating single and dual fragment primer design approaches to provide full mitogenomic coverage within the Araneae (Spiders). Despite extensive rounds of optimisation, full mitochondrial genome PCR amplifications were stochastic in most taxa, although 454 Roche sequencing confirmed the successful amplification of 10 mitochondrial genomes out of the 33 trialled species. The low success rates of amplification using long-Range PCR highlights the difficulties in consistently obtaining genomic amplifications using currently available DNA polymerases optimised for large genomic amplifications and suggests that there may be opportunities for the use of alternative amplification methods.

  13. Can long-range PCR be used to amplify genetically divergent mitochondrial genomes for comparative phylogenetics? A case study within spiders (Arthropoda: Araneae.

    Directory of Open Access Journals (Sweden)

    Andrew G Briscoe

    Full Text Available The development of second generation sequencing technology has resulted in the rapid production of large volumes of sequence data for relatively little cost, thereby substantially increasing the quantity of data available for phylogenetic studies. Despite these technological advances, assembling longer sequences, such as that of entire mitochondrial genomes, has not been straightforward. Existing studies have been limited to using only incomplete or nominally intra-specific datasets resulting in a bottleneck between mitogenome amplification and downstream high-throughput sequencing. Here we assess the effectiveness of a wide range of targeted long-range PCR strategies, encapsulating single and dual fragment primer design approaches to provide full mitogenomic coverage within the Araneae (Spiders. Despite extensive rounds of optimisation, full mitochondrial genome PCR amplifications were stochastic in most taxa, although 454 Roche sequencing confirmed the successful amplification of 10 mitochondrial genomes out of the 33 trialled species. The low success rates of amplification using long-Range PCR highlights the difficulties in consistently obtaining genomic amplifications using currently available DNA polymerases optimised for large genomic amplifications and suggests that there may be opportunities for the use of alternative amplification methods.

  14. Diversidad de arañas (Arachnida: Araneae en hábitats antropogénicos Diversity of spiders (Arachnida: Araneae in anthropogenic habitats

    Directory of Open Access Journals (Sweden)

    Marco Antonio Desales-Lara

    2013-03-01

    Full Text Available La construcción de ciudades constituye la transformación más drástica, fundamental e irreversible de los sistemas naturales, reemplazando todo componente biótico y abiótico original del lugar. Entre los artrópodos que han podido adaptarse a los ambientes urbanos se encuentran las arañas. Se encontraron 41 especies en el interior de 12 casas de 2 niveles de la ciudad de Toluca, ubicadas en 4 ambientes con diferente grado de urbanización, durante el periodo de septiembre del 2009 a agosto del 2010. Por primera vez se empleó un método sistematizado para recolecta de arañas en el interior de las viviendas. La diversidad de arañas fue diferente en cada uno de los ambientes muestreados; el índice de Shannon (H' mostró que la diversidad de arañas es mayor en las casas que presentan jardín en el ambiente urbano, por lo que no se apoya la hipótesis del disturbio intermedio. El número de arañas encontradas fue mayor en el primer nivel de las viviendas que en el segundo, por lo que se proponen 3 hipótesis para explicar esta diferencia. Se propone la prueba de Olmstead-Tukey para determinar los 4 niveles de sinantropismo (N. S., ya que la prueba engloba valores utilizados en los índices de densidad e infestación (ocupación.City-building is the most drastic, fundamental and irreversible transformation of natural environments, replacing all original biotic and abiotic components of the site. Spiders are among the arthropods that have become adapted to urban environments. We found 41 species within 12 two-story houses of the city of Toluca, located in 4 environments with different degrees of urbanization, during the period September 2009-August 2010. For the first time a systematic method was used to collect spiders inside houses with even collecting efforts. The diversity of spiders is different in each of the sampled environments, the Shannon index (H ' indicated that the diversity of spiders was higher in houses with gardens in the

  15. Voracious male spiders that kill adult females of their own species (genera Walckenaeria, Diplostyla, Neriene, Meta, Araneae)

    NARCIS (Netherlands)

    Heuts, B.; Brunt, T.

    2008-01-01

    In contrast to the popular belief that adult female spiders often kill and eat their adult male partners in the context of copulation, we present a few instances of adult male spiders killing and eating adult females of their own species in the laboratory. However, in line with the popular belief,

  16. Toxicity of the venom of Latrodectus (Araneae: Theridiidae) spiders from different regions of Argentina and neutralization by therapeutic antivenoms.

    Science.gov (United States)

    de Roodt, Adolfo Rafael; Lanari, Laura Cecilia; Laskowicz, Rodrigo Daniel; Costa de Oliveira, Vanessa; Irazu, Lucia Elvira; González, Alda; Giambelluca, Luis; Nicolai, Néstor; Barragán, Javier Hugo; Ramallo, Leticia; López, Raúl Alfredo; Lopardo, Jorge; Jensen, Oscar; Larrieu, Edmundo; Calabró, Arnoldo; Vurcharchuc, Miriam Guadalupe; Lago, Néstor Rubén; García, Susana Isabel; de Titto, Ernesto Horacio; Damín, Carlos Fabián

    2017-05-01

    "Black widow" spiders belong to the genus Latrodectus and are one of the few spiders in the world whose bite can cause severe envenomation in humans and domestic animals. In Argentina, these spiders are distributed throughout the country and are responsible for the highest number of bites by spiders of toxicological sanitary interest. Here, we studied the toxicity and some biochemical and immunochemical characteristics of eighteen venom samples from Latrodectus spiders from eight different provinces of Argentina, and the neutralization of some of these samples by two therapeutic antivenoms used in the country for the treatment of envenomation and by a anti-Latrodectus antivenom prepared against the venom of Latrodectus mactans from Mexico. We observed important toxicity in all the samples studied and a variation in the toxicity of samples, even in those from the same region and province and even in the same Latrodectus species from the same region. The therapeutic antivenoms efficiently neutralized all the venoms studied.

  17. Exposure of Brown Recluse and Brown Widow Spiders (Araneae: Sicariidae, Theridiidae) to a Commercial Sulfuryl Fluoride Fumigation.

    Science.gov (United States)

    Vetter, Richard S; Hoddle, Mark S; Choe, Dong-Hwan; Thoms, Ellen

    2014-10-01

    The body of pesticide research on spiders is sparse with most studies using topical or residual applications to assess efficacy. Data on the effects of fumigation on spider survivorship are scarce in the scientific literature. In this study, we exposed adult male and female brown recluse spiders, Loxosceles reclusa Gertsch & Mulaik, and female brown widow spiders, Latrodectus geometricus C. L. Koch, to a commercial fumigation event using sulfuryl fluoride directed at termite control. General consensus from the pest control industry is that fumigation is not always effective for control of spiders for a variety of reasons, including insufficient fumigant dosage, particularly, for contents of egg sacs that require a higher fumigant dosage for control. We demonstrated that a sulfuryl fluoride fumigation with an accumulated dosage of 162 oz-h per 1,000 ft(3) at 21°C over 25 h (≈1.7 × the drywood termite dosage) directed at termites was sufficient to kill adult brown recluse and brown widow spiders. The effectiveness of commercial fumigation practices to control spiders, and particularly their egg sacs, warrants further study. © 2014 Entomological Society of America.

  18. How did the spider cross the river? Behavioral adaptations for river-bridging webs in Caerostris darwini (Araneae: Araneidae.

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    Matjaž Gregorič

    Full Text Available BACKGROUND: 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. METHODOLOGY: 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. CONCLUSIONS: 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.

  19. 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.

  20. Do really all wolf spiders carry spiderlings on their opisthosomas? The case of Hygrolycosa rubrofasciata (Araneae: Lycosidae

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    Dolejš, Petr

    2013-06-01

    Full Text Available Wolf spider females are characterised by carrying cocoons attached to their spinnerets. Emerged spiderlings are carried on the females’ opisthosomas, with the exception of three Japanese lycosid species who carry spiderlings on empty cocoons. Here, the same behaviour is recorded in a European spider: the drumming wolf spider Hygrolycosa rubrofasciata. Spiderlings of this species do not try to climb on the female’s opisthosoma, even when they are adopted by a female of a species with a normal pulli-carrying behaviour. This behaviour occurs in Trechaleidae and four unrelated species of Lycosidae inhabiting wet habitats and is therefore regarded as an adaptation to the unsuitable environment.

  1. A new orb-weaving spider from the Argentinean flooding pampas grasses: Aculepeira morenoae new species (Araneae, Araneidae).

    Science.gov (United States)

    Rubio, Gonzalo D; Izquierdo, Matías A; Piacentini, Luis N

    2013-02-14

    A new species of the orb-weaving spider genus Aculepeira Chamberling & Ivie 1942, A. morenoae new species, is described and illustrated based on male and female specimens from the Argentinean natural flooding pampas grasses.

  2. The biodiversity and species composition of the spider community of Marion Island, a recent survey (Arachnida: Araneae

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    T.T. Khoza

    2005-12-01

    Full Text Available Marion Island, the larger of the Prince Edward Islands, lies in the sub-Antarctic biogeographic region in the southern Indian Ocean. From previous surveys, four spider species are known from Marion. The last survey was undertaken in 1968. During this study a survey was undertaken over a period of four weeks on the island to determine the present spider diversity and to record information about the habitat preferences and general behaviour of the species present. Three collection methods (active search, Tullgren funnels and pitfall traps were used, and spiders were sampled from six habitat sites. A total of 430 spiders represented by four families were collected, Myro kerguelenesis crozetensis Enderlein, 1909 and M. paucispinosus Berland, 1947 (Desidae, Prinerigone vagans (Audouin, 1826 (Linyphiidae, Cheiracanthium furculatum Karsch, 1879 (Miturgidae and an immature Salticidae. The miturgid and salticid are first records. Neomaso antarticus (Hickman, 1939 (Linyphiidae was absent from samples, confirming that the species might have been an erroneous record.

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

    Science.gov (United States)

    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.

  4. The Occurrence of Red-Back Spider Latrodectus Hasselti (Araneae: Theridiidae in Bandar Abbas, Southern Port of Iran

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    M Shahi

    2011-06-01

    Full Text Available Background: Due to importance and fatal affect of Red-back spiders, Latrodectus hasselti, a faunistic survey for presence of this spider in Bandar Abbas has been conducted. This animal is considerably the most medically importance spiders all over the world.Methods: Live adult spider specimens were collected from Bandar Abbas town using hand catch conventional method and transferred to the laboratory throughout the summer of 2008. They were identified based on mor­phological characteristics and taxonomic keys and confirmed by some external experts.Results: Results showed the occurrence of the red-back spider, L. hasselti from Bandar Abbas, southern port of Iran. Two female specimens were found. The spider had specific morphological characters including black color with an obvious orange to red longitudinal strip on its upper parts of abdomen. Conclusion: Although the specimens were collected from south of the country, however since the region is an important harbor and port and goods come form different parts of world we assume the possibility of arrival from its origin and native breeding sites of the world. Therefore further investigation is needed to clarify the presence of this species in different parts of Iran.

  5. Community structure and composition of litter spiders (Arachnida: Araneae and influence of macro-climatic factors on Parque Ecológico Jatobá Centenário, Morrinhos, Goiás, Brazil

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    Renan Castro Santana

    2015-08-01

    Full Text Available Spiders are a diverse group and are considered to be good bioindicators due to their sensitivity to variation in biotic and abiotic factors.  Despite this the taxonomy of the Araneae is poorly known, particularly in the tropical and subtropical regions.  The use of spider guilds can improve our understanding of the dynamics of spider communities, and in this paper we analyse the influence of climatic factors on guilds and species dominance of spiders within the leaf litter layer of a semi-deciduous forest in the tropical savanna Cerrado, Brazil. The study site was Parque Ecológico Jatobá Centenário, a fragment of 90ha, in Morrinhos, Goiás, Brazil.  Spiders were sampled from November 2006 to August 2007 using pitfall traps that remained open for seven days on each of four occasions.  Overall 4139 spiders from 35 families and 118 species were collected. The main families were Salticidae (28%, Linyphiidae (27%, Lycosidae (12% and Theridiidae (11%.  In terms of richness the main families were: Theridiidae, Salticidae, Corinnidae and Araneidae, with 18, 16, 15 and 13 species respectively. The overall Shannon-Wiener (H’ diversity was 3.6. The rainy season showed higher values than the dry season for abundance (2,868 and 1,271 respectively, richness (100 and 71 and diversity (3,296 and 3,237.  The families Theridiidae, Corinnidae and Salticidae presented more species in both dry and wet seasons.  Observed climatic variation (rainfall, humidity and temperature between seasons influenced the community structure of ground-dwelling spiders

  6. The six-eyed sand spiders of the genus Sicarius (Araneae: Haplogynae: Sicariidae) from the Brazilian Caatinga.

    Science.gov (United States)

    Magalhães, Ivan L F; Brescovit, Antonio D; Santos, Adalberto J

    2013-01-04

    In this paper we revise the species of Sicarius (Araneae: Sicariidae) from the Brazilian Caatinga, the largest tropical dry forest nucleus in the world. We redescribe, designate a neotype and provide new records for Sicarius tropicus (Mello- Leitão, 1936), the only species previously known from the region, and describe three new species: S. cariri n. sp., S. diadorim n. sp. and S. ornatus n. sp. We report high intraspecific variation in the genitalic morphology of these species, especially in females. We also provide anecdotal observations on natural history and behavior of these species, including diet, mating behavior and clutch size. We include an identification key for Brazilian Caatinga species of Sicarius.

  7. Spinning gland transcriptomics from two main clades of spiders (order: Araneae--insights on their molecular, anatomical and behavioral evolution.

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    Francisco Prosdocimi

    Full Text Available Characterized by distinctive evolutionary adaptations, spiders provide a comprehensive system for evolutionary and developmental studies of anatomical organs, including silk and venom production. Here we performed cDNA sequencing using massively parallel sequencers (454 GS-FLX Titanium to generate ∼80,000 reads from the spinning gland of Actinopus spp. (infraorder: Mygalomorphae and Gasteracantha cancriformis (infraorder: Araneomorphae, Orbiculariae clade. Actinopus spp. retains primitive characteristics on web usage and presents a single undifferentiated spinning gland while the orbiculariae spiders have seven differentiated spinning glands and complex patterns of web usage. MIRA, Celera Assembler and CAP3 software were used to cluster NGS reads for each spider. CAP3 unigenes passed through a pipeline for automatic annotation, classification by biological function, and comparative transcriptomics. Genes related to spider silks were manually curated and analyzed. Although a single spidroin gene family was found in Actinopus spp., a vast repertoire of specialized spider silk proteins was encountered in orbiculariae. Astacin-like metalloproteases (meprin subfamily were shown to be some of the most sampled unigenes and duplicated gene families in G. cancriformis since its evolutionary split from mygalomorphs. Our results confirm that the evolution of the molecular repertoire of silk proteins was accompanied by the (i anatomical differentiation of spinning glands and (ii behavioral complexification in the web usage. Finally, a phylogenetic tree was constructed to cluster most of the known spidroins in gene clades. This is the first large-scale, multi-organism transcriptome for spider spinning glands and a first step into a broad understanding of spider web systems biology and evolution.

  8. Spinning Gland Transcriptomics from Two Main Clades of Spiders (Order: Araneae) - Insights on Their Molecular, Anatomical and Behavioral Evolution

    Science.gov (United States)

    Prosdocimi, Francisco; Bittencourt, Daniela; da Silva, Felipe Rodrigues; Kirst, Matias; Motta, Paulo C.; Rech, Elibio L.

    2011-01-01

    Characterized by distinctive evolutionary adaptations, spiders provide a comprehensive system for evolutionary and developmental studies of anatomical organs, including silk and venom production. Here we performed cDNA sequencing using massively parallel sequencers (454 GS-FLX Titanium) to generate ∼80,000 reads from the spinning gland of Actinopus spp. (infraorder: Mygalomorphae) and Gasteracantha cancriformis (infraorder: Araneomorphae, Orbiculariae clade). Actinopus spp. retains primitive characteristics on web usage and presents a single undifferentiated spinning gland while the orbiculariae spiders have seven differentiated spinning glands and complex patterns of web usage. MIRA, Celera Assembler and CAP3 software were used to cluster NGS reads for each spider. CAP3 unigenes passed through a pipeline for automatic annotation, classification by biological function, and comparative transcriptomics. Genes related to spider silks were manually curated and analyzed. Although a single spidroin gene family was found in Actinopus spp., a vast repertoire of specialized spider silk proteins was encountered in orbiculariae. Astacin-like metalloproteases (meprin subfamily) were shown to be some of the most sampled unigenes and duplicated gene families in G. cancriformis since its evolutionary split from mygalomorphs. Our results confirm that the evolution of the molecular repertoire of silk proteins was accompanied by the (i) anatomical differentiation of spinning glands and (ii) behavioral complexification in the web usage. Finally, a phylogenetic tree was constructed to cluster most of the known spidroins in gene clades. This is the first large-scale, multi-organism transcriptome for spider spinning glands and a first step into a broad understanding of spider web systems biology and evolution. PMID:21738742

  9. Venom of the Brazilian spider Sicarius ornatus (Araneae, Sicariidae contains active sphingomyelinase D: potential for toxicity after envenomation.

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    Priscila Hess Lopes

    Full Text Available BACKGROUND: The spider family Sicariidae includes two genera, Sicarius and Loxosceles. Bites by Sicarius are uncommon in humans and, in Brazil, a single report is known of a 17-year old man bitten by a Sicarius species that developed a necrotic lesion similar to that caused by Loxosceles. Envenomation by Loxosceles spiders can result in dermonecrosis and severe ulceration. Sicarius and Loxosceles spider venoms share a common characteristic, i.e., the presence of Sphingomyelinases D (SMase D. We have previously shown that Loxosceles SMase D is the enzyme responsible for the main pathological effects of the venom. Recently, it was demonstrated that Sicarius species from Africa, like Loxosceles spiders from the Americas, present high venom SMase D activity. However, despite the presence of SMase D like proteins in venoms of several New World Sicarius species, they had reduced or no detectable SMase D activity. In order to contribute to a better understanding about the toxicity of New World Sicarius venoms, the aim of this study was to characterize the toxic properties of male and female venoms from the Brazilian Sicarius ornatus spider and compare these with venoms from Loxosceles species of medical importance in Brazil. METHODOLOGY/PRINCIPAL FINDINGS: SDS-PAGE analysis showed variations in the composition of Loxosceles spp. and Sicarius ornatus venoms. Differences in the electrophoretic profiles of male and female venoms were also observed, indicating a possible intraspecific variation in the composition of the venom of Sicarius spider. The major component in all tested venoms had a Mr of 32-35 kDa, which was recognized by antiserum raised against Loxosceles SMases D. Moreover, male and female Sicarius ornatus spiders' venoms were able to hydrolyze sphingomyelin, thus showing an enzymatic activity similar to that determined for Loxosceles venoms. Sicarius ornatus venoms, as well as Loxosceles venoms, were able to render erythrocytes susceptible to

  10. Venom of the Brazilian spider Sicarius ornatus (Araneae, Sicariidae) contains active sphingomyelinase D: potential for toxicity after envenomation.

    Science.gov (United States)

    Lopes, Priscila Hess; Bertani, Rogério; Gonçalves-de-Andrade, Rute M; Nagahama, Roberto H; van den Berg, Carmen W; Tambourgi, Denise V

    2013-01-01

    The spider family Sicariidae includes two genera, Sicarius and Loxosceles. Bites by Sicarius are uncommon in humans and, in Brazil, a single report is known of a 17-year old man bitten by a Sicarius species that developed a necrotic lesion similar to that caused by Loxosceles. Envenomation by Loxosceles spiders can result in dermonecrosis and severe ulceration. Sicarius and Loxosceles spider venoms share a common characteristic, i.e., the presence of Sphingomyelinases D (SMase D). We have previously shown that Loxosceles SMase D is the enzyme responsible for the main pathological effects of the venom. Recently, it was demonstrated that Sicarius species from Africa, like Loxosceles spiders from the Americas, present high venom SMase D activity. However, despite the presence of SMase D like proteins in venoms of several New World Sicarius species, they had reduced or no detectable SMase D activity. In order to contribute to a better understanding about the toxicity of New World Sicarius venoms, the aim of this study was to characterize the toxic properties of male and female venoms from the Brazilian Sicarius ornatus spider and compare these with venoms from Loxosceles species of medical importance in Brazil. SDS-PAGE analysis showed variations in the composition of Loxosceles spp. and Sicarius ornatus venoms. Differences in the electrophoretic profiles of male and female venoms were also observed, indicating a possible intraspecific variation in the composition of the venom of Sicarius spider. The major component in all tested venoms had a Mr of 32-35 kDa, which was recognized by antiserum raised against Loxosceles SMases D. Moreover, male and female Sicarius ornatus spiders' venoms were able to hydrolyze sphingomyelin, thus showing an enzymatic activity similar to that determined for Loxosceles venoms. Sicarius ornatus venoms, as well as Loxosceles venoms, were able to render erythrocytes susceptible to lysis by autologous serum and to induce a significant loss of

  11. Spiders (Araneae) of Churchill, Manitoba: DNA barcodes and morphology reveal high species diversity and new Canadian records.

    Science.gov (United States)

    Blagoev, Gergin A; Nikolova, Nadya I; Sobel, Crystal N; Hebert, Paul D N; Adamowicz, Sarah J

    2013-11-26

    Arctic ecosystems, especially those near transition zones, are expected to be strongly impacted by climate change. Because it is positioned on the ecotone between tundra and boreal forest, the Churchill area is a strategic locality for the analysis of shifts in faunal composition. This fact has motivated the effort to develop a comprehensive biodiversity inventory for the Churchill region by coupling DNA barcoding with morphological studies. The present study represents one element of this effort; it focuses on analysis of the spider fauna at Churchill. 198 species were detected among 2704 spiders analyzed, tripling the count for the Churchill region. Estimates of overall diversity suggest that another 10-20 species await detection. Most species displayed little intraspecific sequence variation (maximum spider fauna of any region. Few cryptic species of spiders were detected, a result contrasting with the prevalence of undescribed species in several other terrestrial arthropod groups at Churchill. Because most (97.5%) sequence clusters at COI corresponded with a named taxon, DNA barcoding reliably identifies spiders in the Churchill fauna. The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

  12. The orb-weaving spider genus Chrysometa in Uruguay: distribution and description of a new species (Araneae, Tetragnathidae).

    Science.gov (United States)

    Simó, Miguel; Álvarez, Luis; Laborda, Álvaro

    2016-01-26

    The spider genus Chrysometa Simon, 1895 comprises 138 species of small (3-5 mm) Neotropical orb-weavers spiders (Nogueira et al. 2011; World Spider Catalogue 2015) mainly associated with arboreal vegetation from intermediate to low altitude forests (Levi 1986). Males of Chrysometa differ from other tetragnathids by having the palpal tibial length approximately as long as its widest point; paracymbium articulated and with several apophyses located at both ends; male cephalic region narrower than in the female and having cymbial ectobasal and ectomedian processes. Females are diagnosed by having femora without trichobothria; abdomen covered with silver guanine patches; a flat epigynum and also by their fertilization ducts originating anteriorly and crossing over the spermathecae (Levi 1986; Alvarez-Padilla & Hormiga 2011).

  13. Optimal foraging or predator avoidance: why does the Amazon spider Hingstepeira folisecens (Araneae: Araneidae adopt alternative foraging behaviors?

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    Kátia F. Rito

    Full Text Available ABSTRACT Strategies that increase foraging efficiency may also increase predation risk. We investigated how individuals of Hingstepeira folisecens Hingston, 1932, which build shelters at the orb hub, modulate their foraging behaviors in response to the trade-off between capturing prey and becoming exposed by leaving their shelters. We evaluated whether the position of the prey on the web alters the frequency at which spiders leave their shelters. Hingstepeira folisecens spiders were more likely to capture prey positioned below than above the entrance of the shelter. Moreover, when the prey was near the entrance of the shelter, the spider pulled the threads with the entangled prey without leaving the shelter. Conversely, when the prey was distant from the entrance of the shelter, an "attack" behavior (leaving the shelter was favored. We argue that the "pulling behavior" may be an adaptation to reduce exposure to predators.

  14. Spiders (Arachnida: Araneae of Gujarat University Campus, Ahmedabad, India with additional description of Eilica tikaderi (Platnick, 1976

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    Dhruv A. Prajapati

    2016-09-01

    Full Text Available We report a checklist of spiders based on a survey made from August 2013 to July 2014 in Gujarat University Campus, an urban area located in the middle of Ahmadabad City, Gujarat State. A total of 77 species of spiders belonging to 53 genera and 20 families of spiders were recorded from the study area represented by 31.74% of the total 63 families reported from India. Salticidae was found to be the most dominant family with 18 species from 14 genera. Guild structure analysis revealed six feeding guilds, namely stalkers, orb-web builders, space-web builders, ambushers, foliage hunters and ground runners. Stalkers and orb-web builders were the most dominant feeding guilds representing 28.58% and 20.78% respectively among all studied guilds. Species Eilica tikaderi (Platnick, 1976 is reported for the first time from Gujarat with additional description and detailed genitalic illustrations.

  15. Spiders in dermatology.

    Science.gov (United States)

    Kang, Jun K; Bhate, Chinmoy; Schwartz, Robert A

    2014-09-01

    Spider bites represent an unusual and potentially over-represented clinical diagnosis. Despite a common fear of spiders, known as arachnophobia, current knowledge suggests that only a small number of families within the order Araneae are medically relevant. Moreover, most cutaneous spider reactions, including both evenomations and physical trauma, produce mild, local symptoms which may be managed with supportive care alone. The differential diagnosis for spider bites may be broad, especially if the offending arachnid is not seen or found. We describe a series of spiders relevant to the dermatologist in the United States.

  16. Seasonal patterns of parasitism of the tropical spiders Theridion evexum (Araneae, Theridiidae and Allocyclosa bifurca (Araneae, Araneidae by the wasps Zatypota petronae and Polysphincta gutfreundi (Hymenoptera, Ichneumonidae

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    Gilbert Barrantes

    2008-06-01

    Full Text Available The rates of parasitism of Theridion evexum by the parasitoid wasp Zatypota petronae, and Allocyclosa bifurca by Polysphincta gutfreundi, were followed for two years. Parasitism of T. evexum was very low (mean 1.39+1.8%, and restricted to nearly seven months of the year. Parasitism of A. bifurca was higher (mean 7.8+7.6%, and did not show a seasonal pattern. Reproduction of the host spider T. evexum was highly seasonal, with only one, highly coordinated generation per year, while adults of A. bifurca were present year round. Short-term autocorrelation on parasitism rates over time at different sites suggest that P. gutfreundi tend to return to the same sites to hunt hosts over periods of a few weeks. Rev. Biol. Trop. 56 (2: 749-754. Epub 2008 June 30.Las tasas de parasitismo de Theridion evexum por la avispa parasitoide Zatypota petronae y de Allocyclosa bifurca por Polysphincta gutfreundi fueron estudiadas durante dos años. El parasitismo en T. evexum fue muy bajo (promedio 1.39+1.8% y restringido a aproximadamente siete meses del año. El parasitismo en A. bifurca fue más alto (promedio 7.8+7.6% y no mostró un claro patrón estacional. La reproducción de la araña hospedera T. evexum fue muy estacional, con solamente una generación por año, mientras que los adultos de A. bifurca estuvieron presentes todo el año. Autocorrelaciones de las tasas de parasitismo entre censos consecutivos en diferentes sitios sugiere que P. gutfreundi tiende a retornar a los mismos sitios para parasitar las arañas hospederas durante algunas semanas.

  17. Pheromones exert top-down effects on visual recognition in the jumping spider Lyssomanes viridis.

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    Tedore, Cynthia; Johnsen, Sönke

    2013-05-01

    In diverse and productive habitats, predaceous arthropods are expected to frequently encounter dangerous conspecifics and heterospecifics. This should make quick and accurate discriminations between species and sexes adaptive. By simultaneously sampling both visual cues and pheromones, and by utilizing stringent species- and sex-specific visual recognition templates, an individual should be able to increase both its speed and accuracy in making such discriminations. We tested for the use and stringency of visual recognition templates in the jumping spider Lyssomanes viridis by presenting males with animated images of conspecifics, heterospecifics and composite images that combined the facial coloration and morphology of one sex or species with the leg coloration of another. Males' courtship versus threat displays indicated whether a stimulus was perceived as a potential mate or a threat. By comparing males' visual inspection times of, and display types towards, the various images in the presence versus absence of female pheromones, we were able to deduce whether males tend to inspect a subset of the color pattern and morphological features that make up their conspecific recognition templates (i.e. those on just the face or just the legs), or all features, and whether this changes in the presence of pheromones. We found that the male recognition template for conspecific female was surprisingly coarse, whereas the recognition template for conspecific male, and especially the male face, was more specific. Pheromones hastened the recognition of images with coloration and morphology closely matching those of conspecifics, presumably by activating conspecific visual recognition templates. When males were presented with an image that was, overall, a poor match to a conspecific female, but that contained a subset of female or female-like features, female pheromones usually did not hasten recognition, but did increase the likelihood that the image would be identified as a

  18. Formation of primary sperm conjugates in a haplogyne spider (Caponiidae, Araneae) with remarks on the evolution of sperm conjugation in spiders.

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    Lipke, Elisabeth; Michalik, Peter

    2012-11-01

    Sperm conjugation, where two or more sperm are physically united, is a rare but widespread pheno-menon across the animal kingdom. One group well known for its different types of sperm conjugation are spiders. Particularly, haplogyne spiders show a high diversity of sperm traits. Besides individual cleistospermia, primary (synspermia) and secondary (coenospermia, "spermatophore") sperm conjugation occurs. However, the evolution of sperm conjugates and sperm is not understood in this group. Here, we look at how sperm are transferred in Caponiidae (Haplogynae) in pursuit of additional information about the evolution of sperm transfer forms in spiders. Additionally, we investigated the male reproductive system and spermatozoa using light- and transmission electron-microscopy and provide a 3D reconstruction of individual as of well as conjugated spermatozoa. Mature spermatozoa are characterized by an extremely elongated, helical nucleus resulting in the longest spider sperm known to date. At the end of spermiogenesis, synspermia are formed by complete fusion of four spermatids. Thus, synspermia might have evolved early within ecribellate Haplogynae. The fused sperm cells are surrounded by a prominent vesicular area. The function of the vesicular area remains still unknown but might be correlated with the capacitation process inside the female. Further phylogenetic and functional implications of the spermatozoa and sperm conjugation are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. The symphytognathoid spiders of the Gaoligongshan, Yunnan, China (Araneae, Araneoidea): Systematics and diversity of micro-orbweavers

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    Miller, J.A.; Griswold, C.E.; Yin, C.M.

    2009-01-01

    A ten-year inventory of the Gaoligongshan in western Yunnan Province, China, yielded more than 1000 adult spider specimens belonging to the symphytognathoid families Theridiosomatidae, Mysmenidae, Anapidae, and Symphytognathidae. These specimens belong to 36 species, all herein described as new. In

  20. Ecological preference of the diving bell spider Argyroneta aquatica in a resurgence of the Po plain (Northern Italy (Araneae: Cybaeidae

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    Stefano Mammola

    2016-06-01

    Full Text Available The diving bell spider Argyroneta aquatica is the only known spider to conduct a wholly aquatic life. For this reason, it has been the object of an array of studies concerning different aspects of its peculiar biology such as reproductive behavior and sexual dimorphism, physiology, genetic and silk. On the other hand, besides some empirical observations, the autoecology of this spider is widely understudied. We conducted an ecological study in a resurgence located in the Po Plain (Northern Italy, Province of Vercelli hosting a relatively rich population of Argyroneta aquatica, aiming at identifying the ecological factors driving its presence at the micro-habitat level. By means of a specific sampling methodology, we acquired distributional data of the spiders in the study area and monitored physical-chemical and habitat structure parameters at each plot. We analyzed the data through Bernoulli Generalized Linear Models (GLM. Results pointed out a significant positive effect of the presence of aquatic vegetation in the plot. In addition, the presence of A. aquatica was significantly associated with areas of the resurgence characterized at the same time by high prey availability and low density of predators. Considering the ecological importance and rarity of this species, we update and revise the data on the distribution of A. aquatica in Italy.

  1. The symphytognathoid spiders of the Gaoligongshan, Yunnan, China (Araneae, Araneoidea): Systematics and diversity of micro-orbweavers

    NARCIS (Netherlands)

    Miller, J.A.; Griswold, C.E.; Yin, C.M.

    2009-01-01

    A ten-year inventory of the Gaoligongshan in western Yunnan Province, China, yielded more than 1000 adult spider specimens belonging to the symphytognathoid families Theridiosomatidae, Mysmenidae, Anapidae, and Symphytognathidae. These specimens belong to 36 species, all herein described as new. In

  2. A checklist of spiders from Sovenga Hill, an inselberg in the Savanna Biome, Limpopo Province, South Africa (Arachnida: Araneae

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    M.A. Modiba

    2005-12-01

    Full Text Available The South African National Survey of Arachnida (SANSA was initiated to make an inventory of the arachnid fauna of South Africa. Various projects are underway to prepare inventories of the spider fauna of the different floral biomes and provinces of South Africa. During April and May 2004 five different collecting methods were sed to sample spiders from four slopes on Sovenga Hill, an inselberg situated in the Savanna Biome, near Polokwane, in the Limpopo Province of South Africa. A total of 793 specimens represented by 29 families, 62 genera and 76 species were recorded over the twomonth period. The Thomisidae was the most abundant (n = 167 representing 21.1 % of all spiders sampled, followed by the Gnaphosidae (n = 101 with 12.7 % and the Lycosidae (n = 77 with 9.7 %. The most abundant species was a thomisid Tmarus comellini Garcia-Neto (n = 82, representing 10.3 % of the total, followed by a clubionid Clubiona godfreyi Lessert (n = 66 with 8.3 %. The Thomisidae was the most species-rich family with 12 species, followed by the Gnaphosidae with 11 species and the Araneidae with 10 species. Of the species collected 83.9 % were wandering spiders and 16.1 % web builders. This is the first quantitative survey of the Savanna Biome in the Polokwane area.

  3. A Check-List of the Spiders (Araneae) of the Bolshekhekhtsyrski Nature Reserve, Khabarovsk Province, the Russian Far East

    Institute of Scientific and Technical Information of China (English)

    Yuri M. Marusik; Andrei V. Tanasevitch; Dmitri K. Kurenshchikov; Dmitri V. Logunov

    2007-01-01

    326 species of spiders belonging to 26 families are recorded from the Bolshekhekhtsyrski State Nature Reserve, of them 70 are new records for the reserve and six are new to the fauna of Russia: Asperthorox boreolis Ono et Saito, 2001; Cyclosa kumadai Tanikawa, 1992; Cyclosa okumae Tanikawa, 1992(earlier it was identified as C. argenteoalba Bbsenberg et Strand, 1906); Haplodrassus taepaikensis Paik, 1992; Hypselistes fossilobus Fei et Zhu, 1993; and Pachygnatha gaoi Zhu et al., 2003. The name Pronous minutus (S. Saito, 1939) is synonymized with Pronoides brunneus Schenkel, 1936. The male of H. taepaikensis is illustrated for the first time. Composition of the fauna is briefly discussed; 41% of the recorded species have their ranges confined to the SE Palaearctics. By its species diversity, the reserve' s fauna is the second largest local fauna eastward of the Urals. An expected spider diversity of this reserve is likely to be over 400 species.

  4. Spider (Arachnida, Araneae) diversity in secondary and old-growth southern Atlantic forests of Paraná state, Brazil.

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    Raub, Florian; Höfer, Hubert; Scheuermann, Ludger

    2017-07-01

    The data presented here have been collected in the southern part of the Atlantic Forest (Mata Atlântica) in the state of Paraná, Brazil within a bilateral scientific project (SOLOBIOMA). The project aimed to assess the quality of secondary forests of different regeneration stages in comparison with old-growth forests with regard to diversity of soil animals and related functions. The Atlantic Forest is a hotspot of biological diversity with an exceptionally high degree of endemic species, extending over a range of 3,500 km along the coast of Brazil. The anthropogenic pressure in the region is very high with three of the biggest cities of Brazil (São Paulo, Rio de Janeiro, and Curitiba) lying in its extension. An evaluation of the value of secondary forests for biodiversity conservation is becoming more and more important due to the complete disappearance of primary forests. In 2005, we sampled spiders in 12 sites of three successional stages (5-8, 10-15, 35-50 yr old, three replicates of each forest stage) and old-growth forests (> 100 yr untouched, also three replicates). All sites were inside a private nature reserve (Rio Cachoeira Nature Reserve). We repeated the sampling design and procedure in 2007 in a second private reserve (Itaqui Nature Reserve). The two nature reserves are within about 25 km of each other within a well preserved region of the Mata Atlântica, where the matrix of the landscape mosaic is still forest. A widely accepted standard protocol was used in a replicated sampling design to apply statistical analyses to the resulting data set and allow for comparison with other studies in Brazil. Spiders were sorted to family level and counted; the adult spiders further identified to species if possible or classified as morphospecies with the help of several spider specialists. © 2017 by the Ecological Society of America.

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

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    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

  6. Behavioural analysis of web building anomalies in the orb-weaving spider Zygiella x-notata (Araneae, Araneidae

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    Toscani, Camille

    2012-07-01

    Full Text Available Among animal constructions, spider’s orb webs represent regular geometrical architecture models. Their construction is the result of successive, simple and reproducible behavioural patterns, often considered as stereotyped. It has recently been shown that spider’s building behaviours vary, which can alter web regularity. The final capture spiral results from the laying of successive threads between two radii, here termed ‘spiral units’. We defined a theoretical normal web, as a web in which each turn of the final spiral should be parallel to the preceding one. Weaving of the spiral units sometimes leads to anomalies in the orb web. Anomalies were identified and analysed in the orb-weaving spider Zygiella x-notata (Clerck, 1757. From video recordings of web construction, we noted the displacements of the legs and of the abdomen of the spider. We compared the frequency of displacements, and their duration, between the construction of spiral units that produce a normal turn and ones that produce an anomalous turn. The position of the legs on the web’s threads was also analysed. Results showed that anomalies were not the consequences of a modification in activity but more likely the result of the position on the radii of the fourth leg. These results suggest that spiders use local information to build the final capture spiral.

  7. Short and long-term effects of three neurotoxic insecticides on biological and behavioural attributes of the orb-web spider Alpaida veniliae (Araneae, Araneidae): implications for IPM programs.

    Science.gov (United States)

    Benamú, Marco A; Schneider, Marcela I; González, Alda; Sánchez, Norma E

    2013-09-01

    Soybean pest control in Argentina is done just by chemical control using broad-spectrum pesticides. Alpaida veniliae (Araneae, Araneidae) is one of the most abundant spider species of the orb web weaver guild in soybean, and it is considered a very important polyphagous predator, attacking different insects' families. The objective of this study was to determine if neurotoxic insecticides commonly used in soybean crops and a new active ingredient registered in Argentina (spinosad) adversely affected survival, prey consumption, mating behaviour, web building and reproductive capacity of A. veniliae females, under standard laboratory conditions. Spinosad was the most harmful insecticide due to high acute toxicity, even at lower concentrations than those registered for its field use and for its sublethal effects also. Cypermethrin caused several sublethal effects although its acute toxicity on spider was lower than other insecticides. It reduced prey consumption, affected web building, caused abnormalities in eggs sacs and decreased drastically the fecundity and fertility at sublethal concentrations. Endosulfan did not reduce prey consumption but it affected web building, caused abnormalities in eggs sacs and egg masses, and decreased the fecundity and fertility. Spinosad was also the compound with the most drastic effect on web building, it did not reduce prey consumption and fecundity, but fertility was reduced and abnormalities in egg sacs and egg masses were observed. The use of these insecticides in IPM programs according to their potential toxicity on spider communities is discussed.

  8. Spiders on a Hot Volcanic Roof: Colonisation Pathways and Phylogeography of the Canary Islands Endemic Trap-Door Spider Titanidiops canariensis (Araneae, Idiopidae.

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    Vera Opatova

    Full Text Available Studies conducted on volcanic islands have greatly contributed to our current understanding of how organisms diversify. The Canary Islands archipelago, located northwest of the coast of northern Africa, harbours a large number of endemic taxa. Because of their low vagility, mygalomorph spiders are usually absent from oceanic islands. The spider Titanidiops canariensis, which inhabits the easternmost islands of the archipelago, constitutes an exception to this rule. Here, we use a multi-locus approach that combines three mitochondrial and four nuclear genes to investigate the origins and phylogeography of this remarkable trap-door spider. We provide a timeframe for the colonisation of the Canary Islands using two alternative approaches: concatenation and species tree inference in a Bayesian relaxed clock framework. Additionally, we investigate the existence of cryptic species on the islands by means of a Bayesian multi-locus species delimitation method. Our results indicate that T. canariensis colonised the Canary Islands once, most likely during the Miocene, although discrepancies between the timeframes from different approaches make the exact timing uncertain. A complex evolutionary history for the species in the archipelago is revealed, which involves two independent colonisations of Fuerteventura from the ancestral range of T. canariensis in northern Lanzarote and a possible back colonisation of southern Lanzarote. The data further corroborate a previously proposed volcanic refugium, highlighting the impact of the dynamic volcanic history of the island on the phylogeographic patterns of the endemic taxa. T. canariensis includes at least two different species, one inhabiting the Jandia peninsula and central Fuerteventura and one spanning from central Fuerteventura to Lanzarote. Our data suggest that the extant northern African Titanidiops lineages may have expanded to the region after the islands were colonised and, hence, are not the source

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

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    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

  10. The male genital system of the cellar spider Pholcus phalangioides (Fuesslin, 1775 (Pholcidae, Araneae: development of spermatozoa and seminal secretion

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    Uhl Gabriele

    2005-06-01

    Full Text Available Abstract Background Most arthropods pass through several molting stages (instars before reaching sexual maturity. In spiders, very little is known about the male genital system, its development and seminal secretions. For example, it is unknown whether spermatozoa exist prior to-, or only after the final molt. Likewise, it is unclear whether sperm are produced throughout male adulthood or only once in a lifetime, as is whether seminal secretions contain factors capable of manipulating female behavior. In order to shed light on these aspects of the reproductive biology of spiders, we investigated the male genital system of the common cellar spider Pholcus phalangioides, with special emphasis on its development and seminal secretions. Results Testes already display all stages of spermatogenesis in subadult males (about four weeks before the final molt. Their vasa deferentia possess proximally a very voluminous lumen containing dense seminal fluid and few spermatozoa, whereas the distal part is seemingly devoid of contents. Spermatoza of P. phalangioides are typical cleistospermia with individual secretion sheaths. In male stages approximately two weeks prior to the final molt, the lumina of the testes are wider and filled with a dense secretion. The wide, proximal portion of the vasa deferentia is filled with secretion and a large number of spermatozoa, and the narrow distal part also contains secretion. In adult males, the wide lumina of the testes are packed with spermatozoa and secretions. The latter are produced by the somatic cells that bear microvilli and contain many vesicles. The lumina of the vasa deferentia are narrow and filled with spermatozoa and secretions. We could identify a dense matrix of secretion consisting of mucosubstances and at least three types of secretion droplets, likely consisting of proteinaceous substances. Conclusion This study reveals that spermatogenesis begins weeks before maturity and takes place continuously in

  11. Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae).

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    Ruhland, Fanny; Chiara, Violette; Trabalon, Marie

    2016-11-01

    Wolf spiders' (Lycosidae) maternal behaviour includes a specific phase called "egg brooding" which consists of guarding and carrying an egg-sac throughout the incubation period. The transport of an egg-sac can restrict mothers' exploratory and locomotor activity, in particular when foraging. The present study details the ontogeny of maternal behaviour and assesses the influence of age of egg-sac (or embryos' developmental stage) on vagrant wolf spider Pardosa saltans females' exploration and locomotion. We observed these spiders' maternal behaviour in the laboratory and evaluated their locomotor activity using a digital activity recording device. Our subjects were virgin females (without egg-sac) and first time mothers (with her egg-sac) who were divided into three groups. The first group of mothers were tested on the day the egg-sac was built (day 0), and the females of the other two groups were tested 10 or 15days after they had built their egg-sac. We evaluated the effects of the presence and the loss of egg-sac on mothers' activity. Pardosa saltans females' behaviour depended on mothers' physiological state and/or age of egg-sac (developmental stage of embryos). Virgin females' behaviour was not modified by the presence of an egg-sac in their environment. Mothers' reactions to the presence, the loss and the recovery of their egg-sac varied during the maternal cycle. Maternal behaviour changed with age of egg-sac, but the levels of locomotor activity of mothers with egg-sacs was similar to those of virgin females. Loss of egg-sac modified the maternal behaviour and locomotor activity of all mothers; these modifications were greater on "day 15" when embryos had emerged from eggs. All mothers were able to retrieve their egg-sacs and to re-attach them to their spinnerets. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Activities against hemostatic proteins and adrenal gland ultrastructural changes caused by the brown widow spider Latrodectus geometricus (Araneae: Theridiidae) venom.

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    Guerrero, Belsy; Finol, Hector J; Reyes-Lugo, Matias; Salazar, Ana M; Sánchez, Elda E; Estrella, Amalid; Roschman-González, Antonio; Ibarra, Carlos; Salvi, Ivan; Rodríguez-Acosta, Alexis

    2010-01-01

    Brown widow spider (BrWS) (Latrodectus geometricus) venom produces intense systemic reactions such as cramps, harsh muscle nociceptive, nauseas, vomiting and hypertension. The proposed pathogenic mechanisms resulting in these accidents have principally been damages occurring at the nervous system. However, it is suspected that there is also damage of the adrenal glands, as a result of the experimental animal's clinical manifestations, which developed symptoms compatible with acute adrenal insufficiency. We have currently found that the adrenal gland is damaged by this venom gland homogenates (VGH) producing severe alterations on cortex cells resulting in death by acute adrenal insufficiency. In general, the ultrastructural study on the glands of mice under transmission electronic microscopy observations showed alterations in the majority of the intracellular membranes within 3 to 24h. BrWSVGH also showed specific actions on extracellular matrix proteins such as fibronectin, laminin and fibrinogen. In addition, zymogram experiments using gelatin as substrates detected gelatinolytic activity. The molecular exclusion fractionation of crude BrWSVGH resulted in 15 fractions, of which F1 and F2 presented alpha/beta-fibrinogenase and fibronectinolytic activities. Fractions F6, F14 and F15 showed only alpha-fibrinogenase activity; in contrast, the gelatinolytic action was only observed in fraction F11. Only metalloproteinase inhibitors abolished all these proteolytic activities. Our results suggest that adrenal cortex lesions may be relevant in the etiopathogenesis of severe brown widow spider envenoming. To our knowledge, this is the first report on adrenal gland damages, fibrinogenolytic activity and interrelations with cell-matrix adhesion proteins caused by L.geometricus VGH. The venom of this spider could be inducing hemostatic system damages on envenomed patients.

  13. Notes on the Venezuelan jumping spiders described by Caporiacco (Araneae, Salticidae Notas sobre as aranhas papa-mosca venezuelanas descritas por Caporiacco (Araneae, Salticidae

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    Gustavo R. S. Ruiz

    2005-09-01

    Full Text Available The type specimens of 15 nominal salticid species from Venezuela described by Lodovico di Caporiacco were examined. In this paper we present brief redescriptions when deemed necessary as well as three new synonymies: Aculeobreda Caporiacco, 1955 = Pachomius Peckham & Peckham, 1896; Sidusa variegata Caporiacco, 1955 = Simonurius quadratarius (Simon, 1901; Sitticus cabellensis Prószynski, 1971 = Pseudattulus incertus Caporiacco, 1955; and five new transferences: Aculeobreda hadzji Caporiacco, 1955 = Pachomius hadzji (Caporiacco, 1955 comb. nov.; Dendryphantes franganilloi Caporiacco, 1955 = Metacyrba franganilloi (Caporiacco, 1955 comb. nov.; Evarcha venezuelica Caporiacco, 1955 = Asaracus venezuelicus (Caporiacco, 1955 comb. nov.; Pseudamphidraus femellus Caporiacco, 1955 = Marma femella (Caporiacco, 1955 comb. nov.; Scopocira sexspinosa Caporiacco, 1955 = Sassacus sexspinosus (Caporiacco, 1955 comb. nov. Phintodes craneae Caporiacco, 1955, described based on a juvenile, must be treated as species inquirenda.Os exemplares-tipo de 15 espécies nominais de Salticidae da Venezuela descritas por Lodovico di Caporiacco são examinados. Neste trabalho são apresentadas breves redescrições quando necessário, e três novas sinonímias: Aculeobreda Caporiacco, 1955 = Pachomius Peckham & Peckham, 1896; Sidusa variegata Caporiacco, 1955 = Simonurius quadratarius (Simon, 1901; Sitticus cabellensis Prószynski, 1971 = Pseudattulus incertus Caporiacco, 1955; e cinco novas transferências: Aculeobreda hadzji Caporiacco, 1955 = Pachomius hadzji (Caporiacco, 1955 comb. nov.; Dendryphantes franganilloi Caporiacco, 1955 = Metacyrba franganilloi (Caporiacco, 1955 comb. nov.; Evarcha venezuelica Caporiacco, 1955 = Asaracus venezuelicus (Caporiacco, 1955 comb. nov.; Pseudamphidraus femellus Caporiacco, 1955 = Marma femella (Caporiacco, 1955 comb. nov.; Scopocira sexspinosa Caporiacco, 1955 = Sassacus sexspinosus (Caporiacco, 1955 comb. nov. Phintodes craneae Caporiacco, 1955, descrita a partir de um jovem, é tratada como species inquirenda.

  14. Nephila clavata L Koch, the Joro Spider of East Asia, newly recorded from North America (Araneae: Nephilidae

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    E. Richard Hoebeke

    2015-02-01

    Full Text Available Nephila clavata L Koch, known as the Joro spider and native to East Asia (Japan, China, Korea, and Taiwan, is newly reported from North America. Specimens from several locations in northeast Georgia were collected from around residential properties in Barrow, Jackson, and Madison counties in late October and early November 2014. These are the first confirmed records of the species in the New World. Our collections, along with confirmed images provided by private citizens, suggest that the Joro spider is established in northeast Georgia. Genomic sequence data for the COI gene obtained from two specimens conforms to published sequences for N. clavata, providing additional confirmation of species identity. Known collection records are listed and mapped using geocoding. Our observations are summarized along with published background information on biology in Asia and we hypothesize on the invasion history and mode of introduction into North America. Recognition features are given and photographic images of the male and female are provided to aid in their differentiation from the one native species of the genus (Nephila clavipes in North America.

  15. Nephila clavata L Koch, the Joro Spider of East Asia, newly recorded from North America (Araneae: Nephilidae).

    Science.gov (United States)

    Hoebeke, E Richard; Huffmaster, Wesley; Freeman, Byron J

    2015-01-01

    Nephila clavata L Koch, known as the Joro spider and native to East Asia (Japan, China, Korea, and Taiwan), is newly reported from North America. Specimens from several locations in northeast Georgia were collected from around residential properties in Barrow, Jackson, and Madison counties in late October and early November 2014. These are the first confirmed records of the species in the New World. Our collections, along with confirmed images provided by private citizens, suggest that the Joro spider is established in northeast Georgia. Genomic sequence data for the COI gene obtained from two specimens conforms to published sequences for N. clavata, providing additional confirmation of species identity. Known collection records are listed and mapped using geocoding. Our observations are summarized along with published background information on biology in Asia and we hypothesize on the invasion history and mode of introduction into North America. Recognition features are given and photographic images of the male and female are provided to aid in their differentiation from the one native species of the genus (Nephila clavipes) in North America.

  16. Influence of long-period pesticide force on genetic polymorphism of wolf spider Pardosa pseudoannulata (Lycosidae: Araneae)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Wolf spiders are predators in large quantities in the fields. How wolf spiders keep their dominant species status under long-period pesticide force? To answer this question, eight geographical populations of Pardosa pseudoannulata were used as materials to test the influence of geographical habitats on their genomic DNA polymorphism. The RAPD pattern showed polymorphic variations among and within different populations. Total 84 bands amplified by 10 random primers, of which 62 (73.81% ) are polymorphic, were generated from 55 individuals of eight geographical populations. Meanwhile, Shannon's index (Ho = 0.5177) showed a rich genetic diversity of P. pseudoannulata, and most of the genetic variation (64.24%) was found within populations. Multiple regression analysis suggested that it is the climatic variation (such as annual average temperature etc. ) that results in adaptive eco-geographic differentiation, and it is the long-period pesticide force that speeds up the genetic differentiation of P. pseudoannulata which changed the genetic diversity of the population.

  17. Multilocus sequence data reveal dozens of putative cryptic species in a radiation of endemic Californian mygalomorph spiders (Araneae, Mygalomorphae, Nemesiidae).

    Science.gov (United States)

    Leavitt, Dean H; Starrett, James; Westphal, Michael F; Hedin, Marshal

    2015-10-01

    We use mitochondrial and multi-locus nuclear DNA sequence data to infer both species boundaries and species relationships within California nemesiid spiders. Higher-level phylogenetic data show that the California radiation is monophyletic and distantly related to European members of the genus Brachythele. As such, we consider all California nemesiid taxa to belong to the genus Calisoga Chamberlin, 1937. Rather than find support for one or two taxa as previously hypothesized, genetic data reveal Calisoga to be a species-rich radiation of spiders, including perhaps dozens of species. This conclusion is supported by multiple mitochondrial barcoding analyses, and also independent analyses of nuclear data that reveal general genealogical congruence. We discovered three instances of sympatry, and genetic data indicate reproductive isolation when in sympatry. An examination of female reproductive morphology does not reveal species-specific characters, and observed male morphological differences for a subset of putative species are subtle. Our coalescent species tree analysis of putative species lays the groundwork for future research on the taxonomy and biogeographic history of this remarkable endemic radiation. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Comparative analysis of tissue-specific transcriptomes in the funnel-web spider Macrothele calpeiana (Araneae, Hexathelidae

    Directory of Open Access Journals (Sweden)

    Cristina Frías-López

    2015-06-01

    Full Text Available The funnel-web spider Macrothele calpeiana is a charismatic Mygalomorph with a great interest in basic, applied and translational research. Nevertheless, current scarcity of genomic and transcriptomic data of this species clearly limits the research in this non-model organism. To overcome this limitation, we launched the first tissue-specific enriched RNA-seq analysis in this species using a subtractive hybridization approach, with two main objectives, to characterize the specific transcriptome of the putative chemosensory appendages (palps and first pair of legs, and to provide a new set of DNA markers for further phylogenetic studies. We have characterized the set of transcripts specifically expressed in putative chemosensory tissues of this species, much of them showing features shared by chemosensory system genes. Among specific candidates, we have identified some members of the iGluR and NPC2 families. Moreover, we have demonstrated the utility of these newly generated data as molecular markers by inferring the phylogenetic position M. calpeina in the phylogenetic tree of Mygalomorphs. Our results provide novel resources for researchers interested in spider molecular biology and systematics, which can help to expand our knowledge on the evolutionary processes underlying fundamental biological questions, as species invasion or biodiversity origin and maintenance.

  19. Evarcha culicivora chooses blood-fed Anopheles mosquitoes but other East African jumping spiders do not.

    Science.gov (United States)

    Jackson, R R; Nelson, X J

    2012-06-01

    Previous research using computer animation and lures made from dead prey has demonstrated that the East African salticid Evarcha culicivora Wesolowska & Jackson (Araneae: Salticidae) feeds indirectly on vertebrate blood by actively choosing blood-carrying female mosquitoes as prey, and also that it singles out mosquitoes of the genus Anopheles (Diptera: Culicidae) by preference. Here, we demonstrate that E. culicivora's preference is expressed when the species is tested with living prey and that it is unique to E. culicivora. As an alternative hypothesis, we considered the possibility that the preference for blood-fed female anopheline mosquitoes might be widespread in East African salticids. When live-prey choice tests were carried out in 19 additional species, there were no instances in which blood-carrying mosquitoes were chosen significantly more often than other prey. Combined with the findings of previous work, these results suggest that it is possible that specialized predators play a role in the biological control of disease vectors. © 2011 The Authors. Medical and Veterinary Entomology © 2011 The Royal Entomological Society.

  20. A revision of the purse-web spider genus Calommata Lucas, 1837 (Araneae, Atypidae in the Afrotropical Region

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    Rene Fourie

    2011-05-01

    Full Text Available The purse-web spider genus Calommata Lucas, 1837 is revised in the Afrotropical Region. Following examination of the female type material, C. transvaalica Hewitt, 1916 is removed from synonymy with C. simoni Pocock, 1903 and revalidated. The females of both species are redescribed and their males described for the first time. While C. simoni is very widespread across tropical Africa, C. transvaalica is endemic to northern South Africa. Four new species are described, all known only from males: C. megae sp. n. (Zimbabwe, C. meridionalis sp. n. (South Africa, C. namibica sp. n. (Namibia and C. tibialis sp. n. (Ivory Coast and Togo. Notes are presented on the biology of each species.

  1. Around the World in Eight Million Years: Historical Biogeography and Evolution of the Spray Zone Spider Amaurobioides (Araneae: Anyphaenidae)

    Science.gov (United States)

    Opell, Brent D.; Haddad, Charles R.; Raven, Robert J.; Soto, Eduardo M.; Ramírez, Martín J.

    2016-01-01

    Closely related organisms with transoceanic distributions have long been the focus of historical biogeography, prompting the question of whether long-distance dispersal, or tectonic-driven vicariance shaped their current distribution. Regarding the Southern Hemisphere continents, this question deals with the break-up of the Gondwanan landmass, which has also affected global wind and oceanic current patterns since the Miocene. With the advent of phylogenetic node age estimation and parametric bioinformatic advances, researchers have been able to disentangle historical evolutionary processes of taxa with greater accuracy. In this study, we used the coastal spider genus Amaurobioides to investigate the historical biogeographical and evolutionary processes that shaped the modern-day distribution of species of this exceptional genus of spiders. As the only genus of the subfamily Amaurobioidinae found on three Southern Hemisphere continents, its distribution is well-suited to study in the context of Gondwanic vicariance versus long-distance, transoceanic dispersal. Ancestral species of the genus Amaurobioides appear to have undergone several long-distance dispersal events followed by successful establishments and speciation, starting from the mid-Miocene through to the Pleistocene. The most recent common ancestor of all present-day Amaurobioides species is estimated to have originated in Africa after arriving from South America during the Miocene. From Africa the subsequent dispersals are likely to have taken place predominantly in an eastward direction. The long-distance dispersal events by Amaurobioides mostly involved transoceanic crossings, which we propose occurred by rafting, aided by the Antarctic Circumpolar Current and the West Wind Drift. PMID:27732621

  2. Combining morphology, DNA sequences, and morphometrics: revising closely related species in the orb-weaving spider genus Araniella (Araneae, Araneidae).

    Science.gov (United States)

    Spasojevic, Tamara; Kropf, Christian; Nentwig, Wolfgang; Lasut, Liana

    2016-05-17

    The integration of independent data sets could solve problems in both traditional and DNA-based taxonomy. The aim of this study is to investigate the power of CO1 sequences and of morphometrics to distinguish closely related species in the spider genus Araniella. We put special emphasis on the species pair A. cucurbitina (Clerck, 1757) and A. opisthographa (Kulczyński, 1905) since the females are morphologically difficult to distinguish and often misidentified. A total of 216 sequences of eight Araniella species from seven European countries, North America and Asia were included in the molecular analysis. The results from both maximum likelihood and Bayesian phylogenetic inference indicate successful separation of six out of eight Araniella species, including A. cucurbitina and A. opisthographa. For the same six species, we detect no overlap of intra- and interspecific genetic divergence, leading to successful species identification with a threshold approach. In addition, morphometric analysis of the epigyna of A. cucurbitina and A. opisthographa supports species separation by two best explanatory ratios: receptaculum length and distance between receptaculum and copulatory duct. Although a small overlap in the ratios exists, the species identification rate increases when combining morphometric and molecular data, which demonstrates the efficiency of integrative approaches for distinguishing closely related species. However, none of the molecular approaches was able to separate closely related A. alpica (L. Koch, 1869) and A. inconspicua (Simon, 1874) due to shared CO1 haplotypes. Considering the clear morphological separation of the males and different habitat preferences, incomplete lineage sorting or introgressive hybridization could have led to identical CO1 sequences. Therefore, DNA-barcoding must be thoroughly tested even within small homogenous genera of spiders.

  3. Australian Assassins, Part II: A review of the new assassin spider genus Zephyrarchaea (Araneae, Archaeidae) from southern Australia

    Science.gov (United States)

    Rix, Michael G.; Harvey, Mark S.

    2012-01-01

    Abstract The Assassin Spiders of the family Archaeidae from southern Australia are revised, with a new genus (Zephyrarchaea gen. n.) and nine new species described from temperate, mesic habitats in southern Victoria, South Australia and south-western Western Australia: Zephyrarchaea austini sp. n., Zephyrarchaea barrettae sp. n., Zephyrarchaea grayi sp. n., Zephyrarchaea janineae sp. n., Zephyrarchaea marae sp. n., Zephyrarchaea marki sp. n., Zephyrarchaea melindae sp. n., Zephyrarchaea porchi sp. n. and Zephyrarchaea vichickmani sp. n. Specimens of the type species, Zephyrarchaea mainae (Platnick, 1991), comb. n., are redescribed from the Albany region of Western Australia, along with the holotype female of Zephyrarchaea robinsi (Harvey, 2002) comb. n. from the Stirling Range National Park. The previously described species Archaea hickmani Butler, 1929 from Victoria is here recognised as a nomen dubium. A key to species and multi-locus molecular phylogeny complement the species-level taxonomy, with maps, habitat photos, natural history information and conservation assessments provided for all species. PMID:22639534

  4. The symphytognathoid spiders of the Gaoligongshan, Yunnan, China (Araneae: Araneoidea: Systematics and diversity of micro-orbweavers

    Directory of Open Access Journals (Sweden)

    Jeremy Miller

    2009-05-01

    Full Text Available A ten-year inventory of the Gaoligongshan in western Yunnan Province, China, yielded more than 1000 adult spider specimens belonging to the symphytognathoid families Theridiosomatidae, Mysmenidae, Anapidae, and Symphytognathidae. These specimens belong to 36 species, all newly described here. In the Theridiosomatidae: Epeirotypus dalong n. sp., Ogulnius barbandrewsi n. sp., Baalzebub nemesis n. sp., Theridiosoma diwang n. sp., Theridiosoma shuangbi n. sp., Zoma dibaiyin n. sp., Wendilgarda muji n. sp., Coddingtonia euryopoides n. gen., n. sp.; in the Mysmenidae: Mysmena changouzi n. sp., Mysmena jinlong n. sp., Mysmena bizi n. sp., Mysmena goudao n. sp., Mysmena haban n. sp., Mysmena shibali n. sp., Simaoa yaojia n. gen., n. sp., Simaoa kavanaugh n. sp., Simaoa maku n. sp., Simaoa bianjing n. sp., Gaoligonga changya n. gen., n. sp., Gaoligonga zhusun n. sp., Mosu nujiang n. gen., n. sp., Mosu huogou n. sp., Chanea suukyii n. gen., n. sp., Maymena paquini n. sp., Maymena kehen n. sp.; in the Anapidae: Gaiziapis zhizhuba n. gen., n. sp.; in the Symphytognathidae: Patu jidanweishi n. sp., Patu qiqi n. sp., Patu xiaoxiao n. sp., Crassignatha pianma n. sp., Crassignatha yinzhi n. sp., Crassignatha quanqu n. sp., Crassignatha yamu n. sp., Crassignatha ertou n. sp., Crassignatha gudu n. sp., Crassignatha longtou n. sp. The first species of Zoma Saaristo, 1996 (previously monotypic, known from the Seychelles and Maymena Gertsch, 1960 (previously known from the Americas are reported from China. The genus Crassignatha Wunderlich, 1995 (previously known from a single male from Malaysia is represented by seven new Chinese species and is transferred to Symphytognathidae. The first Epeirotypus O. Pickard-Cambridge, 1894 species from beyond the Neotropics is described, although the presence of the genus in Asia was previously noted. Notes on morphological characters exhibited by this fauna and implications for the limits and diagnosis of some symphytognathoid

  5. An infestation of 2,055 brown recluse spiders (Araneae: Sicariidae) and no envenomations in a Kansas home: implications for bite diagnoses in nonendemic areas.

    Science.gov (United States)

    Vetter, Richard S; Barger, Diane K

    2002-11-01

    During a 6-mo period, 2,055 brown recluse spiders, Loxosceles reclusa Gertsch and Mulaik, were collected in a 19th-century-built, currently occupied home in Lenexa, KS. We conservatively estimate that at least 400 of these spiders were large enough to cause envenomation. Additional collections from more typically infested homes in Missouri and Oklahoma in 2001 yielded 45 and 30 brown recluse spiders, respectively. Despite these infestations, no envenomations of the inhabitants of these three homes occurred. Considering the levels of infestations with no bites in the homes presented here, nonendemic areas in the United States, which typically lack recluse spider populations and have had zero to few verified specimens of the spider, do not have sufficient numbers of brown recluse spiders to make envenomation a likely scenario. Despite this, physicians from nonendemic recluse areas often diagnose brown recluse bites which, therefore, are unlikely to be correct.

  6. Web architecture alteration of the orb web weaving spider Metellina merianae (Araneae, Tetragnathidae induced by the parasitoid Megaetaira madida (Ichneumonidae, Polysphincta group

    Directory of Open Access Journals (Sweden)

    Korenko, Stanislav

    2016-09-01

    Full Text Available The polysphinctine wasp Megaetaira madida (Haliday, 1838 is a koinobiont ecto-parasitoid of spiders of the genus Metellina. Under the influence of the parasitoid’s final instar larva, the spider host M. merianae (Scopoli, 1763 built a three-dimensional web architecture, which differed considerably from the capturing orb web. The alteration of spider web behaviour induced by a parasitoid larva in this host-parasitoid pair is described for the first time.

  7. Comunidades de aranhas (Araneae em cultivos de seringueira (Hevea brasiliensis Muell. Arg. no Estado de São Paulo Spider communities (Araneae on rubber tree (Hevea brasiliensis Muell. Arg. plantations in São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Isabela Maria Piovesan Rinaldi

    2002-09-01

    Full Text Available The spider fauna composition of three rubber tree commercial plantations in the Northwest part of São Paulo State, Brazil, was characterized for both canopy and litter strata. On seven occasions from April 2000 to October 2001, samples were taken by beating sheet and hand capture, resulting in a total of 946 individuals, belonging to 24 families and 119 species. The most common species were Italaman santamaria Brescovit, 1997 and Teudis sp. (Anyphaenidae, Castianeira sp. and Falconina aff. gracilis (Corinnidae, Paracleocnemis sp. (Philodromidae, Ibotyporanga naideae Mello-Leitão, 1944 (Pholcidae, Chira spinipes (Taczanowiski, 1871 and Rudra sp. (Salticidae, Achaearanea hirta (Taczanowiski, 1873 and Coleosoma floridanum (Banks, 1900 (Theridiidae and Goeldia sp. (Titanoecidae. Anyphaenidae, Theridiidae and Salticidae were the most abundant families in the canopy, while Pholcidae and Corinnidae in the litter. Spider abundance was found to be, in general, positively correlated to the litter volume and density of branches in the trees. The use of acaricides and insecticides for one plantation resulted in a decrease in spider abundance for both strata. Abundance values among the samples suggest that the canopy spider abundance decreases with the loss of leaves in the dry season. Simultaneously, litter spider abundance increased in this season, because of the increase in litter volume. The most active canopy spiders, like runners and stalkers, should be investigated for their potential as pest control agents.

  8. Studies on Tropical Pholcidae I Panjange, a new genus of Indo-Australian Leaf- and rock-dwelling Pholcid spiders (Araneae)

    NARCIS (Netherlands)

    Deeleman-Reinhold, C.L.; Deeleman, P.R.

    1983-01-01

    The study of tropical spiders was taken up in the last part of the nineteenth century by Thorell, Simon and others, but since then passed through a long dormant stage. Only during the last few decades there was some revival. In particular numerous spider species from leaf-litter, ground debris, etc.

  9. The strange case of Laetesia raveni n. sp., a green linyphiid spider from Eastern Australia with a preference for thorny plants (Araneae, Linyphiidae)

    DEFF Research Database (Denmark)

    Hormiga, Gustavo; Scharff, Nikolaj

    2014-01-01

    Laetesia raveni n. sp. (Araneae, Linyphiidae), is described based on specimens collected in New South Wales and Queensland (Australia). This new linyphiid species is of bright green colour, and it seems to have a preference to build its webs almost exclusively on two plant species, namely Calamus...... muelleri Wendland (Arecaceae) and Solanum inaequilaterum Domin, (Solanaceae), both of them densely covered with thorns. The epigynal morphology of Laetesia raveni n. sp. varies intraspecifically. Live individuals and several of their dome-shaped sheet webs are illustrated....

  10. A spider population in flux: selection and abandonment of artificial web-sites and the importance of intraspecific interactions in Lephthyphantes tenuis (Araneae: Linyphiidae) in wheat.

    Science.gov (United States)

    Samu, Ferenc; Sunderland, Keith D; Topping, Chris J; Fenlon, John S

    1996-04-01

    Lepthyphantes tenuis, a small sheet-webbuilding linyphiid spider is one of the most abundant spider species of cereal fields in Europe. In the present study we examined the process of web-site selection and web-site tenacity by adult females of this species in a winter wheat field. Spiders were selective in their choice of web-site. Different immigration rates into various manipulated web-sites, in field and laboratory, suggested that structural support and suitable micro-climate (high humidity) are the most important factors in the selection. Small holes dug in the ground were the most favoured web-sites. Web-site occupation was influenced by the presence of other conspecific spiders. Territorial contests occurred between spiders attempting to occupy the same web, these almost invariably led to the take-over of the web when the intruder was heavier. Interference, but also a certain level of tolerance, between spiders within the same web-site but in different webs was suggested by direct and indirect evidence. Many holes supported two or even three spiders in vertically stratified webs. Leaving probability of marked spiders was significantly higher in multiply occupied holes than in holes with a single web. Comparison with the results of a no-interference stochastic model showed that multiple occupancy in nature is less frequent than predicted by the model. There was further evidence for weak extra-web-interference between spiders in that multiple occupancy was even less frequent and overall occupancy was lower in web-sites which were packed close to each other. However, a level of tolerance for crowding is shown by the fact that closely packed hole colonies supported a spider density 13 times higher than in natural web-sites in the field. A marking experiment was carried out to gain information on web-site tenacity (i.e. the length of time a spider spends in a web-site) and abandonment. The average duration of tenacity was less than 2 days. A random loss function

  11. Bioaccumulation of mercury and its effects on survival, development and web-weaving in the funnel-web spider Agelena labyrinthica (Araneae: Agelenidae).

    Science.gov (United States)

    Liu, Jin; Gao, Jin; Yun, Yueli; Hu, Zhiyong; Peng, Yu

    2013-05-01

    This study investigated the bioaccumulation and effects of mercury (Hg) in funnel-web spiders, Agelena labyrinthica, following exposure to sublethal concentrations of Hg(NO3)2 in their drinking water. The results showed that the Hg content in adult A. labyrinthica increased rapidly with the number of days exposed to the Hg(NO3)2 solution, and the mortality of adult spiders within 30 days increased with increased concentrations of Hg(NO3)2 in the drinking water. The total developmental duration of A. labyrinthica exposed to Hg(NO3)2 was significantly longer than in the control spiders, but there were no significant differences in the total developmental duration of spiders among the three treatment groups (exposed to 10, 20 and 50 mg/L Hg(NO3)2 solution). We also compared the web-weaving of the control and treated spiders, and found no significant differences in shape, structure, color, or size of the webs between the control and treated spiders; however, there was a significant difference in web placement between the treatment and control groups. The spiders in the control group appeared to have an episodic-like memory, choosing to weave their five webs in the same corner in the five time periods allowed.

  12. Nephila clavipes spiders (Araneae: Nephilidae) keep track of captured prey counts: testing for a sense of numerosity in an orb-weaver.

    Science.gov (United States)

    Rodríguez, Rafael L; Briceño, R D; Briceño-Aguilar, Eduardo; Höbel, Gerlinde

    2015-01-01

    Nephila clavipes golden orb-web spiders accumulate prey larders on their webs and search for them if they are removed from their web. Spiders that lose larger larders (i.e., spiders that lose larders consisting of more prey items) search for longer intervals, indicating that the spiders form memories of the size of the prey larders they have accumulated, and use those memories to regulate recovery efforts when the larders are pilfered. Here, we ask whether the spiders represent prey counts (i.e., numerosity) or a continuous integration of prey quantity (mass) in their memories. We manipulated larder sizes in treatments that varied in either prey size or prey numbers but were equivalent in total prey quantity (mass). We then removed the larders to elicit searching and used the spiders' searching behavior as an assay of their representations in memory. Searching increased with prey quantity (larder size) and did so more steeply with higher prey counts than with single prey of larger sizes. Thus, Nephila spiders seem to track prey quantity in two ways, but to attend more to prey numerosity. We discuss alternatives for continuous accumulator mechanisms that remain to be tested against the numerosity hypothesis, and the evolutionary and adaptive significance of evidence suggestive of numerosity in a sit-and-wait invertebrate predator.

  13. The response of spider (Araneae assemblages to structural heterogeneity and prey abundance in sub-montane vegetation modified by conservation grazing

    Directory of Open Access Journals (Sweden)

    Peter Dennis

    2015-01-01

    Full Text Available The effect of experimental livestock grazing regimens (4 treatments×6 replicates on spiders via habitat structure and prey abundance was investigated on sub-montane habitats in the Southern Highlands of Scotland. The study, 2002–2004 included a baseline survey under the prior, commercial sheep grazing regimen and two assessments of spider assemblages post-treatment: commercial stocking density of sheep; 1/3 stocking density with sheep; 1/3 stocking density cattle with sheep; and no grazing. Spiders were sampled with a suction sampler, five sucks at each of 25 sample units by 24 plots (600 samples in 2003 and 2004, ca. 320 in 2002. Spider abundance and species richness increased under reduced stocking density, mixed herbivore and ungrazed treatments indirectly via changes in vegetation structure and prey abundance. The results refuted a meta-analysis that concluded species richness of spiders is unaffected by grazing. Grazing regimens caused turnover in species composition more than the net difference in species richness suggested, implying that no single, optimal grazing regimen will support as many species as a patchwork under varied grazing management. Conservation grazing benefits spiders and will have significant benefits for food webs in sub-montane ecosystems but the period to equilibrium after changes to grazing requires further investigation.

  14. Efficacy of Several Pesticide Products on Brown Widow Spider (Araneae: Theridiidae) Egg Sacs and Their Penetration Through the Egg Sac Silk.

    Science.gov (United States)

    Vetter, Richard S; Tarango, Jacob; Campbell, Kathleen A; Tham, Christine; Hayashi, Cheryl Y; Choe, Dong-Hwan

    2016-02-01

    Information on pesticide effects on spiders is less common than for insects; similar information for spider egg sacs is scarcer in the open literature. Spider egg sacs are typically covered with a protective silk layer. When pesticides are directly applied to egg sacs, the silk might prevent active ingredients from reaching the eggs, blocking their insecticidal effect. We investigated the impact of six water-based pesticide sprays and four oil-based aerosol products against egg sacs of brown widow spiders, Latrodectus geometricus C. L. Koch. All water-based spray products except one failed to provide significant mortality to egg sacs, resulting in successful spiderling emergence from treated egg sacs at a similar rate to untreated egg sacs. In contrast to water-based sprays, oil-based aerosols provided almost complete control, with 94-100% prevention of spiderling emergence. Penetration studies using colored pesticide products indicated that oil-based aerosols were significantly more effective in penetrating egg sac silk than were the water-based sprays, delivering the active ingredients on most (>99%) of the eggs inside the sac. The ability of pesticides to penetrate spider egg sac silk and deliver lethal doses of active ingredients to the eggs is discussed in relation to the chemical nature of egg sac silk proteins. Our study suggests that pest management procedures primarily relying on perimeter application of water-based sprays might not provide satisfactory control of brown widow spider eggs. Determination of the most effective active ingredients and carrier characteristics warrant further research to provide more effective control options for spider egg sacs. © 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. Transgenic Cabbage Expressing Cry1Ac1 Does Not Affect the Survival and Growth of the Wolf Spider, Pardosa astrigera L. Koch (Araneae: Lycosidae)

    Science.gov (United States)

    Kim, Young-Joong; Lee, Joon-Ho; Harn, Chee Hark; Kim, Chang-Gi

    2016-01-01

    Both herbivores that consume transgenic crops and their predators can be exposed to insecticidal proteins expressed in those crops. We conducted a tritrophic bioassay to evaluate the ecotoxicological impacts that Bt cabbage (Brassica oleracea var. capitata) expressing Cry1Ac1 protein might have on the wolf spider (Pardosa astrigera), a non-target generalist predator. Enzyme-Linked Immunosorbent Assays indicated that protein levels were 4.61 ng g-1 dry weight in fruit flies (Drosophila melanogaster) fed with the transgenic cabbage and 1.86 ng g-1 dry weight in the wolf spiders that preyed upon them. We also compared the life history traits of spiders collected from Bt versus non-Bt cabbage and found no significant differences in their growth, survival, and developmental rates. Because Bt cabbage did not affect the growth of fruit flies, we conclude that any indirect effects that this crop had on the wolf spider were probably not mediated by prey quality. Therefore, exposure to Cry1Ac1 protein when feeding upon prey containing that substance from transgenic cabbage has only a negligible influence on those non-target predatory spiders. PMID:27055120

  16. Establishment of the Brown Widow Spider (Araneae: Theridiidae) and Infestation of its Egg Sacs by a Parasitoid, Philolema latrodecti (Hymenoptera: Eurytomidae), in French Polynesia and the Cook Islands.

    Science.gov (United States)

    Marie, Jérôme; Vetter, Richard S

    2015-11-01

    This paper presents two newly established species for French Polynesia: the invasive brown widow spider, Latrodectus geometricus C. L. Koch, and its potential biocontrol agent, the parasitoid wasp, Philolema latrodecti (Fullaway). The brown widow spider was recorded from the island of Moorea in 2006 and, since that discovery, the occurrence of this species has expanded to two of the five archipelagos of French Polynesia including the main island of Tahiti and four of the Cook Islands. Although the tropical climate contributes to the establishment of L. geometricus, a biotic factor, P. latrodecti, may restrain population from demographic explosion. This eurytomid wasp is present in French Polynesia and is a parasitoid that has been used in biological control of the southern black widow Latrodectus mactans (F.) in Hawaii. This wasp could become a significant limiting factor for L. geometricus distribution on these islands, as it was found in 31% of the Tahitian brown widow spider egg sacs that were dissected. However, thus far, the wasp was only found on Tahiti in association with the brown widow spider. Although the brown widow is generally considered to be less toxic than its black widow relatives, it remains of medical concern in French Polynesia because reactions to its bites can, at times, be severe. The spider remains of public concern because it is a novel species; it has the word widow in its name and dark morphs are mistaken as black widows.

  17. The Effect of Organic Fertilizers and Flowering Plants on Sheet-Web and Wolf Spider Populations (Araneae: Lycosidae and Linyphiidae) and Its Importance for Pest Control.

    Science.gov (United States)

    El-Nabawy, El-Said M; Tsuda, Katsuo; Sakamaki, Yositaka; Oda, Asahi; Ushijima, Yurie

    2016-01-01

    The main goal of this study was to identify the treatment that increases the populations of spiders, which are effective predators in agroecosystems. In 2013 and 2014 the experimental eggplant (Solanum melongena L.) field was two different treatments, organic fertilizers and chemical fertilizer treatment, and in 2014 we surrounded organic fertilizer plots with the flowering plants mealy cup sage (Salvia farinacea Benth.), spearmint (Mentha spicata L.), and basil (Ocimum basilicum L.). Analysis using repeated measures ANOVA revealed significant influences of fertilizer type on the numbers of linyphiid spiders and Collembola in 2013. In 2014, the numbers of Collembola, thrips, and lycosid and linyphiid spider were higher in organic fertilizer with flowering plants treatment comparing with the chemical fertilizer treatment. Moreover, the numbers of Henosepilachna vigintioctopunctata (F.) were significantly lower in the organic fertilizer with flowering plants treatment than in chemical fertilizers treatment. Finally, we expect that Thysanoptera and Collembola were important alternative prey for linyphiid and lycosid spiders and the use of organic fertilizer and flowering plants enhanced the density of these spiders, and may increase their effectiveness in suppressing the populations of H. vigintioctopunctata (F.).

  18. Phylogenetic reconstruction of the wolf spiders (Araneae: Lycosidae) using sequences from the 12S rRNA, 28S rRNA, and NADH1 genes: implications for classification, biogeography, and the evolution of web building behavior.

    Science.gov (United States)

    Murphy, Nicholas P; Framenau, Volker W; Donnellan, Stephen C; Harvey, Mark S; Park, Yung-Chul; Austin, Andrew D

    2006-03-01

    Current knowledge of the evolutionary relationships amongst the wolf spiders (Araneae: Lycosidae) is based on assessment of morphological similarity or phylogenetic analysis of a small number of taxa. In order to enhance the current understanding of lycosid relationships, phylogenies of 70 lycosid species were reconstructed by parsimony and Bayesian methods using three molecular markers; the mitochondrial genes 12S rRNA, NADH1, and the nuclear gene 28S rRNA. The resultant trees from the mitochondrial markers were used to assess the current taxonomic status of the Lycosidae and to assess the evolutionary history of sheet-web construction in the group. The results suggest that a number of genera are not monophyletic, including Lycosa, Arctosa, Alopecosa, and Artoria. At the subfamilial level, the status of Pardosinae needs to be re-assessed, and the position of a number of genera within their respective subfamilies is in doubt (e.g., Hippasa and Arctosa in Lycosinae and Xerolycosa, Aulonia and Hygrolycosa in Venoniinae). In addition, a major clade of strictly Australasian taxa may require the creation of a new subfamily. The analysis of sheet-web building in Lycosidae revealed that the interpretation of this trait as an ancestral state relies on two factors: (1) an asymmetrical model favoring the loss of sheet-webs and (2) that the suspended silken tube of Pirata is directly descended from sheet-web building. Paralogous copies of the nuclear 28S rRNA gene were sequenced, confounding the interpretation of the phylogenetic analysis and suggesting that a cautionary approach should be taken to the further use of this gene for lycosid phylogenetic analysis.

  19. Trap and soil monolith sampled edaphic spiders (arachnida: araneae in Araucaria angustifolia forest Aranhas (arachnida: araneae edáficas amostradas por armadilhas e monólitos de solo em florestas com Araucaria angustifolia

    Directory of Open Access Journals (Sweden)

    Dilmar Baretta

    2007-08-01

    Full Text Available Forests with Araucaria angustifolia (Bert. O. Kuntze trees are endangered in Brazil, and information on the diversity of soil spider families associated to these environments is practically inexistent. The present study was set up to evaluate the abundance and diversity of soil spider families in natural and reforested Araucaria forests, impacted or not by fire, and to identify the most efficient method to collect these organisms. The study was conducted in four areas: native forest with predominance of Araucaria (NF; Araucaria reforestation (R; Araucaria reforestation submitted to an accidental fire (RF; and native grass pasture with native Araucaria and submitted to an intense accidental fire (NPF. Considering both sampling methods (Monolith and Pitfall traps, 20 spider families were identified. The pitfall trap method was more effective as it captured 19 out of the 20 recorded families, while the Monolith method extracted only ten spider families. Spider family abundance and Shannon's diversity index (H were affected by the employed collection method; the values for these attributes were always higher for the NF and lower for the NPF. Correspondence analysis (CA showed a spatial separation among spider familiy assemblages from the different studied areas. It is suggested that changes in the abundance of soil spider families in Araucaria forests are mainly caused by recurrent human intervention over the last few years.As florestas com Araucaria angustifolia (Bert. O. Kuntze estão ameaçadas de extinção no Brasil, e são praticamente inexistentes as informações sobre a diversidade de famílias de aranhas de solo associadas nestes ambientes. O estudo teve o objetivo de avaliar, em florestas com araucária naturais e reflorestadas, impactadas ou não pela queima acidental, a abundância e diversidade de famílias de aranhas, além de identificar o método mais eficiente para coletar estes organismos. O estudo foi conduzido em quatro

  20. Small-scale spatial pattern of web-building spiders (Araneae) in alfalfa: relationship to disturbance from cutting, prey availability, and intraguild interactions.

    Science.gov (United States)

    Birkhofer, Klaus; Scheu, Stefan; Wise, David H

    2007-08-01

    Understanding the development of spatial patterns in generalist predators will improve our ability to incorporate them into biological control programs. We studied the small-scale spatial patterns of spider webs in alfalfa by analyzing the relationship between web locations over distances ranging from 4 to 66 cm. Using a coordinate-based spatial statistic (O-ring) and assuming a heterogeneous distribution of suitable web sites, we analyzed the impact of cutting and changes in spider abundance on web distribution. We analyzed the influence of small-scale variation in prey availability by comparing web distributions to the pattern of sticky-trap captures of Aphididae and Diptera described by a count-based spatial statistic (SADIE). Cutting of alfalfa reduced the overall density of web-building spiders but had no immediate impact on the spatial distribution of their webs. Availability of aphids was highest before the alfalfa was cut and was clumped at a scale of 66 cm. Spider webs, however, were not clumped at any scale or date. In contrast, webs were regularly distributed at smaller distances (web-building spiders were most active during this period, we hypothesize that the development of small-scale regularity in web locations was driven by intraguild interactions. Our results suggest that intraguild interactions contribute to the development of small-scale spatial patterns of spider webs in alfalfa. Variation in prey availability may have more of an influence on web distribution in crops with a different vegetation structure or if patterns are studied at larger spatial scales.

  1. 越南蜘蛛区系的初步研究(蛛形纲:蜘蛛目)%A Preliminary Note on Spider Fauna of Vietnam (Arachnida: Araneae)

    Institute of Scientific and Technical Information of China (English)

    范鼎飒; 徐湘; 李枢强

    2007-01-01

    The spider fauna of Vietnam are studied based on the examined specimens and related publications.A total of 320 spider species and one subspecies belonging to 32 families and 159 genera are known from Vietnam,including 21 species that are newly recorded to Vietnam in this study.%依据镜检标本和已知文献,初步研究了越南的蜘蛛区系.包括本文报道的21种新记录在内,越南蜘蛛目前已知320种及1亚种.

  2. Diversidad de arañas (Arachnida: Araneae asociadas con viviendas de la ciudad de México (Zona Metropolitana Spider diversity (Arachnida: Araneae associated with houses in México city (Metropolitan area

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    César Gabriel Durán-Barrón

    2009-04-01

    Full Text Available La ecología urbana es un área de investigación relativamente reciente. Los ecosistemas urbanos son aquellos definidos como ambientes dominados por el hombre. Con el proceso de urbanización, insectos y arácnidos silvestres aprovechan los nuevos microhábitats que las viviendas humanas ofrecen. Se revisaron arañas recolectadas dentro de 109 viviendas durante los años de 1985 a 1986, 1996 a 2001 y 2002 a 2003. Se cuantificaron 1 196 organismos , los cuales se determinaron hasta especie. Se obtuvo una lista de 25 familias, 52 géneros y 63 especies de arañas sinantrópicas. Se utilizaron 3 índices (ocupación, densidad y estacionalidad y un análisis de intervalos para sustentar la siguiente clasificación: accidentales (índice de densidad de 0-0.9, ocasionales (1-2.9, frecuentes (3.0-9.9 y comunes (10 en adelante. Se comparan las faunas de arañas sinantrópicas de 5 países del Nuevo Mundo.Urban ecology is a relatively new area of research, with urban ecosystems being defined as environments dominated by humans. Insects and arachnids are 2 groups that successfully exploit the habitats offered by human habitations. We analyzed the occurrence and densities of spiders found in houses in México City. We used material collected between 1985 and 2003. We recorded 1 196 spiders from 109 houses. The list includes 25 families, 52 genera and 63 species of synanthropic spiders. Indices of ocupation, density and seasonality, as well as rank analyses were used to make the following classification of synanthropism: accidental (density index 0-0.9, occasional (1-2.9, frequent (3.0-9.9 and common (10 or more. The synanthropic spider faunas of 5 New World countries are compared.

  3. Dietary and prey-capture adaptations by which Zodarion germanicum, an ant-eating spider (Araneae: Zodariidae), specialises on the Formicinae

    DEFF Research Database (Denmark)

    Pekár, S.; Toft, Søren; Hrusková, M.

    2008-01-01

    , and we found that the spiders on the formicine-only diet lived longer and grew at a faster rate. Lipid, carbon and nitrogen compositions of ants were analysed, but we found no evidence of formicines differing from myrmicines in macro-nutrient content. This suggests that effects on longevity and growth...

  4. Dietary and prey-capture adaptations by which Zodarion germanicum, an ant-eating spider (Araneae: Zodariidae), specialises on the Formicinae

    Science.gov (United States)

    Pekár, S.; Toft, S.; Hrušková, M.; Mayntz, D.

    2008-03-01

    There has been considerable recent interest in the biology of spiders that specialise on ants as prey, but previous studies have tended to envisage the level of adaptation as being to ants as a group. In this paper, we provide evidence that Zodarion germanicum is a spider that has dietary and venom adaptations by which it targets a particular subset of ants, the subfamily Formicinae. We reared spiders from first instar in the laboratory on three different diets: formicine ants only, myrmicine ants only and mixed (both formicine and myrmicine ants). Fitness-related life-history parameters were determined, and we found that the spiders on the formicine-only diet lived longer and grew at a faster rate. Lipid, carbon and nitrogen compositions of ants were analysed, but we found no evidence of formicines differing from myrmicines in macro-nutrient content. This suggests that effects on longevity and growth depended on more specific nutrients or on compounds the prey uses for defence. We investigated how efficient Z. germanicum was at paralysing different ants and our findings suggest that the spider’s venom is especially effective against formicines. Taken together, our findings suggest that Z. germanicum has evolved specialisation at the level of targeting a particular ant subfamily, the Formicinae.

  5. Evolutionary morphology of the male reproductive system, spermatozoa and seminal fluid of spiders (Araneae, Arachnida)--current knowledge and future directions.

    Science.gov (United States)

    Michalik, Peter; Ramírez, Martín J

    2014-07-01

    The male reproductive system and spermatozoa of spiders are known for their high structural diversity. Spider spermatozoa are flagellate and males transfer them to females in a coiled and encapsulated state using their modified pedipalps. Here, we provide a detailed overview of the present state of knowledge of the primary male reproductive system, sperm morphology and the structural diversity of seminal fluids with a focus on functional and evolutionary implications. Secondly, we conceptualized characters for the male genital system, spermiogenesis and spermatozoa for the first time based on published and new data. In total, we scored 40 characters for 129 species from 56 families representing all main spider clades. We obtained synapomorphies for several taxa including Opisthothelae, Araneomorphae, Dysderoidea, Scytodoidea, Telemidae, Linyphioidea, Mimetidae, Synotaxidae and the Divided Cribellum Clade. Furthermore, we recovered synspermia as a synapomorphy for ecribellate Haplogynae and thus propose Synspermiata as new name for this clade. We hope that these data will not only contribute to future phylogenetic studies but will also stimulate much needed evolutionary studies of reproductive systems in spiders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Description of a new species of the spider genus Syntrechalea (Araneae: Lycosoidea: Trechaleidae from Colombia Descrição de uma nova espécie de Syntrechalea (Araneae: Lycosoidea: Trechaleidae da Colômbia

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    Estevam L. C. da Silva

    2008-09-01

    Full Text Available A new species of the spider genus Syntrechalea F.O.P.-Cambridge, 1902 is described and illustrated based on material collected in Loreto Mocagua, Colombia. Representatives of this spider genus exhibit an arboreal foraging behavior and are distinguished from the other genera of Trechaleidae by the flattened carapace, long legs and flexible metatarsi and tarsi. New records on the distribution of Syntrechalea tenuis F.O.P.Cambridge, 1902 in Colombia are presented.Uma espécie nova do gênero Syntrechalea F.O.P.-Cambridge, 1902 é descrita e ilustrada, a partir de material coletado em Loreto Mocagua, Colômbia. Os representantes deste gênero apresentam o hábito arbóreo de forragear e são distinguidos dos demais gêneros de Trechaleidae pela carapaça achatada,pernas longas e metatarsos e tarsos flexíveis. Novos registros de distribuição de Syntrechalea tenuis F.O.P.-Cambridge, 1902 na Colômbia são apresentados.

  7. A revised and dated phylogeny of cobweb spiders (Araneae, Araneoidea, Theridiidae): A predatory Cretaceous lineage diversifying in the era of the ants (Hymenoptera, Formicidae).

    Science.gov (United States)

    Liu, Jie; May-Collado, Laura J; Pekár, Stano; Agnarsson, Ingi

    2016-01-01

    Cobweb spiders (Theridiidae) are highly diverse from the perspective of species richness, morphological diversity, variety of web architecture, and behavioral repertoires. The family includes over 50% of social spiders, a behavioral rarity among the order, and members of the family are furthermore the subject of research on venom, silk biomechanics, kleptoparasitism and web building, among other traits. Theridiidae is one of the most abundant groups of spiders, and thus key insect predators in many different ecosystems and is among relatively few spider families that show high degree of myrmecophagy. Modern comparative studies on all these fronts are best buttressed on a phylogenetic foundation. Our goal here is to offer a revised, dated, phylogenetic hypothesis for the family by summarizing previously published data from multiple molecular and morphological studies through data-mining, and adding novel data from several genera. We also test the hypothesis that the origin and diversification of cobweb spiders coincides with that of ants on which many species specialize as prey. The new phylogeny is largely congruent with prior studies and current taxonomy and should provide a useful tool for theridiid classification and for comparative analyses. Nevertheless, we also highlight the limitations of currently available data-the state of the art in Theridiidae phylogenetics-offering weak support for most of the deeper nodes in the phylogeny. Thus the need is clear for modern phylogenomic approaches to obtain a more solid understanding, especially of relationships among subfamilies. We recover the monophyly of currently recognized theridiid subfamilies with the exception of some enigmatic 'pholcommatines' (Styposis, Phoroncidia) and putative 'hadrotarsines' (Audifia, Tekellina) whose placement is uncertain in our analyses. Theridiidae dates back some 100 mya to the Cretaceous, a period of diversification in flowering plants and many groups of insects, including ants. The

  8. Neuroarchitecture of the arcuate body in the brain of the spider Cupiennius salei (Araneae, Chelicerata) revealed by allatostatin-, proctolin-, and CCAP-immunocytochemistry and its evolutionary implications.

    Science.gov (United States)

    Loesel, Rudi; Seyfarth, Ernst-August; Bräunig, Peter; Agricola, Hans-Jürgen

    2011-05-01

    Here we describe the neuronal organization of the arcuate body in the brain of the wandering spider Cupiennius salei. The internal anatomy of this major brain center is analyzed in detail based on allatostatin-, proctolin-, and crustacean cardioactive peptide (CCAP)-immunohistochemistry. Prominent neuronal features are demonstrated in graphic reconstructions. The stainings revealed that the neuroarchitecture of the arcuate body is characterized by several distinct layers some of which comprise nerve terminals that are organized in columnar, palisade-like arrays. The anatomy of the spider's arcuate body exhibits similarities as well as differences when compared to the central complex in the protocerebrum of the Tetraconata. Arguments for and against a possible homology of the arcuate body of the Chelicerata and the central complex of the Tetraconata and their consequences for the understanding of arthropod brain evolution are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. On the new record of the sheet-web spider Erigonoplus foveatus comb. nov. from Slovakia, with comments on Erigonoplus simplex (Araneae: Linyphiidae

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    Hollá, Katarína

    2016-04-01

    Full Text Available Mecynargus foveatus (Dahl, 1912 was recorded in the territory of Slovakia for the first time. Within two years of spider research, a single adult male was collected by beating branches of Scots pine (Pinus sylvestris in the Borská nížina lowland. We also discovered that specimens of Erigonoplus simplex Millidge, 1979 from Bulgaria were misidentified as M. foveatus. Therefore, we suggest to consider E. simplex as a new record for Bulgaria and to exclude M. foveatus from the spider fauna of Bulgaria. A revised distribution of both species is presented and discussed. Based on the high similarity to Erigonoplus, M. foveatus is transferred to this genus as Erigonoplus foveatus (Dahl, 1912 comb. nov.

  10. South African National Survey of Arachnida: A checklist of the spiders (Arachnida, Araneae) of the Lekgalameetse Nature Reserve, Limpopo province, South Africa

    OpenAIRE

    Foord, Stefan H.; Anna S. Dippenaar-Schoeman; Rudy Jocqué; Charles R. Haddad; Robin Lyle; Peter Webb

    2016-01-01

    The aim of the South African National Survey of Arachnida (SANSA) is to document the Arachnida fauna of South Africa. One of the focus areas of SANSA is to survey protected areas to obtain species-specific information, and species distribution patterns for Red Data assessments. Here, we provide the first checklist of the spider species of Lekgalameetse Nature Reserve (LNR) in the Limpopo province of South Africa collected during five surveys between 2009 and 2016 using methods targeting both ...

  11. 蒙新区平腹蛛科蜘蛛区系分析%Fauna Analysis of Spiders of the Family Gnaphosidae in Mengxin Area(Arachnida: Araneae)

    Institute of Scientific and Technical Information of China (English)

    范玉香; 唐贵明

    2011-01-01

    分析了蒙新区94种平腹蛛科蜘蛛在世界、中国以及蒙新区动物区系中的分布情况和分布特征.结果表明,在世界动物区系中古北界占明显优势,在中国动物区系中蒙新区与华北区、青藏区以及西南区的共有种较多,蒙新区以东部草原亚区的区系分布为主.%The distribution and the distributive characteristics in Mengxin Area,China,and the world fauna of 94 spider species of the family Gnaphosidae in Mengxin area were elaborately analyzed. The result revealed that the Palaearctic element was dominated obviously in the world spider fauna. Many common species exist in Mengxin area and Northern China,Qingzang area,Southwest area. The Gnaphosidae spiders in Mengxin area are mainly in east plain subregion.

  12. Fauna de aranhas (Arachnida, Araneae em diferentes estágios do cultivo do arroz irrigado em Cachoeirinha, RS, Brasil Spider fauna (Arachnida, Araneae in differents stages of the irrigated rice culture in Cachoeirinha, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Everton N. L. Rodrigues

    2008-09-01

    o arroz é semeado e colhido altera a estrutura ambiental brutalmente, conduzindo a uma mudança na diversidade de aranhas em termos de riqueza e composição de espécies. Os resultados sugerem a importância de estudos da biodiversidade nos agroecossistemas.The spider diversity associated to a rice field was surveyed along different stages of the culture. The studied area belongs to the Estação Experimental do Arroz (EEA, Instituto Rio Grandense do Arroz (IRGA, Cachoeirinha, state of Rio Grande do Sul, Brazil (50º58'21"W; 29º55'30"S. Between October 2004 and June 2005, 17 samples were taken, distributed in three periods: before seeding, during the development of the rice plants and after the harvest. Samples were done in the morning using sweeping nets (35 cm diameter, 50 sweeps in each of four randomly chosen transects. A total of 918 spiders were sampled, distributed in 14 families, mostly Araneidae, Anyphaenidae, Oxyopidae and Tetragnathidae. Among the adults, 38 morphospecies were found, the most abundant were Alpaida veniliae (Keyserling, 1865, Tetragnatha nitens (Audouin, 1826, Ashtabula sp.1 and Tetragnatha aff. jaculator, the four together comprising more than 45% of the adult specimens. Of the species richness estimators used, Chao 1 was closer to the observed richness; 87,4% of the potentially present species were effectively sampled. Both abundance and species richness showed an increasing trend, accompanying rice development (and thus increasing habitat complexity, with a stern decrease after harvesting. A constant colonization of the habitat is thus postulated, also given the high number of young spiders found at all times. There were no significant correlations between climatic factors (temperature and rainfall and neither abundance nor species richness, except a positive one between rainfall and richness. Among the functional groups, ambushing hunters dominated, followed by orb-web builders. An analysis of similarity (ANOSIM found significant

  13. Storage buildings and greenhouses as stepping stones for non-native, potentially invasive spiders (Araneae – a baseline study in Basel, Switzerland

    Directory of Open Access Journals (Sweden)

    Hänggi, Ambros

    2016-04-01

    Full Text Available Transportation of goods via land, sea or air causes a dissemination of species on a global scale. In central Europe species that are associated with fruit, vegetables and/or buildings are suspected to be imported and potentially build up populations in the following four categories of buildings: I greenhouses, garden centres, flower shops and flower wholesale stores, II storage buildings and logistic centres, III botanical gardens and zoos and IV touristic hotspots. During this research 20 such localities in and around Basel were investigated by means of visual searching. 340 adult spider individuals were collected, representing 37 species and 15 families. Three were first records for Switzerland. Eight species were not published before for the region of Basel even if six of these were already known in private, not published collections – partly going back to the 1930s. Our investigation shows that the interpretation of the spread and invasion of species needs good published knowledge about the actual status of our fauna which, especially for synanthropic spiders, is not the case. We therefore urge everybody to publish all knowledge about faunistics even for so-called common species.

  14. Genital structures in the entelegyne widow spider Latrodectus revivensis (Arachnida; Araneae; Theridiidae) indicate a low ability for cryptic female choice by sperm manipulation.

    Science.gov (United States)

    Berendonck, Bettina; Greven, Hartmut

    2005-01-01

    The female genital structures of the entelegyne spider Latrodectus revivensis are described using semithin sections and scanning electron microscopy. Apart from the tactile hairs overhanging the opening of the atrium, the contact zones of the female epigynum are devoid of any sensilla, indicating that the female does not discriminate in favor or against males due to their genital size or stimulation through copulatory courtship. The dumb-bell shape and the spatial separation of the entrance and the exit of the paired spermathecae suggest that they are functionally of the conduit type. Not described for other entelegyne spiders so far, the small fertilization ducts originating from the spermathecae of each side lead to a common fertilization duct that connects the spermathecae to the uterus externus. During oviposition, it is most likely that spermatozoa are indiscriminately sucked out of the spermathecal lumina by the low pressure produced by the contraction of the muscle extending from the epigynal plate to the common fertilization duct. As no greater amounts of secretion are produced by the female during oviposition, and no activated sperm are present within the female genital tract, the secretion produced by the spermathecal epithelium does not serve in displacement or (selective) activation of spermatozoa. These findings suggest that female L. revivensis are not able to exert cryptic female choice by selectively choosing spermatozoa of certain males.

  15. Neuroprotective activity of parawixin 10, a compound isolated from Parawixia bistriata spider venom (Araneidae: Araneae in rats undergoing intrahippocampal NMDA microinjection

    Directory of Open Access Journals (Sweden)

    Helene Aparecida Fachim

    2015-01-01

    Full Text Available Background: Parawixia bistriata is a semi colonial spider found mainly in southeastern of Brazil. Parawixin 10 (Pwx 10 a compound isolated from this spider venom has been demonstrated to act as neuroprotective in models of injury regulating the glutamatergic neurotransmission through glutamate transporters. Objectives: The aim of this work was to evaluate the neuroprotective effect of Pwx 10 in a rat model of excitotoxic brain injury by N methyl D aspartate (NMDA injection. Material and Methods: Male Wistar rats have been used, submitted to stereotaxic surgery for saline or NMDA microinjection into dorsal hippocampus. Two groups of animals were treated with Pwx 10. These treated groups received a daily injection of the Pwx 10 (2.5 mg/μL in the right lateral ventricle into rats pretreated with NMDA, always at the same time, each one starting the treatment 1 h or 24 h. Nissl staining was performed for evaluating the extension and efficacy of the NMDA injury and the neuroprotective effect of Pwx 10. Results: The treatment with Pwx 10 showed neuroprotective effect, being most pronounced when the compound was administrated from 1 h after NMDA in all hippocampal subfields analyzed (CA1, CA3 and hilus. Conclusion: These results indicated that Pwx 10 may be a good template to develop therapeutic drugs for treating neurodegenerative diseases, reinforcing the importance of continuing studies on its effects in the central nervous system.

  16. Phylogenetic placement of the spider genus Nephila (Araneae: Araneoidea) inferred from rRNA and MaSp1 gene sequences.

    Science.gov (United States)

    Pan, Hong-Chun; Zhou, Kai-Ya; Song, Da-Xiang; Qiu, Yang

    2004-03-01

    The family status of the genus Nephila, which belongs to Tetragnathidae currently but Araneidae formerly, was reexamined based on molecular phylogenetic analyses. In the present study, 12S and 18S rRNA gene fragments of eight species of spiders were amplified and sequenced. In addition, 3'-end partial cDNA of major ampullate spidroin-1 (MaSp1) gene of Argiope amoena was cloned and sequenced, and the 3'-end non-repetitive region's cDNA sequence of MaSp1 gene and the predicted amino acid sequence of C-terminal non-repetitive region of MaSp1 were aligned with some previously known sequences. The resulting phylogeny showed that Araneidae and Tetragnathidae are not a sister group in the superfamily Araneoidea, and the genus Nephila is closer to the genera of the family Araneidae rather than to those of Tetragnathidae. We suggest that the genus Nephila should be transferred back to Araneidae. Or the subfamily Nephilinae might be elevated to family level after it was redefined and redelimited. Furthermore, the study showed that 3'-end non-repetitive region's cDNA sequence of MaSp1 gene and C-terminal non-repetitive region's amino acid sequence of MaSp1 are useful molecular markers for phylogenetic analysis of spiders.

  17. The life and adventures of an eight-legged castaway: Colonization and diversification of Philisca ghost spiders on Robinson Crusoe Island (Araneae, Anyphaenidae).

    Science.gov (United States)

    Soto, Eduardo M; Labarque, Facundo M; Ceccarelli, F Sara; Arnedo, Miquel A; Pizarro-Araya, Jaime; Ramírez, Martín J

    2017-02-01

    Oceanic archipelagoes, by their young origin and isolation, provide privileged settings to study the origin and diversification of species. Here, we study the anyphaenid spider genus Philisca, endemic to the Valdivian temperate rainforest, which includes species living both on the mainland as well as on the Robison Crusoe Island in the Juan Fernández archipelago. Anyphaenids, as many spiders, are potentially good colonizers due their ability for ballooning, an airborne dispersal mediated by strands of silk that are caught in the wind. We use a molecular approach to estimate both the phylogenetic relationships and the timeframe of species diversification of Philisca, with the aim to infer its evolutionary history. We further estimate the rates of speciation on both the insular and continental Philisca species and score the microhabitat used by each species and their sizes as a proxy to evaluate ecological niche diversification within the island. Most analyses support the monophyly of Philisca, with the exclusion of Philisca tripunctata. Our results reveal colonization from a single lineage that postdated the origin of the island, followed by rapid (∼2Ma) diversification. The ancestral microhabitat was most likely leaf-dwelling but we identify two independent microhabitat shifts. Our data provides evidence that Philisca has undergone an adaptive radiation on the Robison Crusoe Island. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Colonization and diversification of the spider genus Pholcus Walckenaer, 1805 (Araneae, Pholcidae) in the Macaronesian archipelagos: evidence for long-term occupancy yet rapid recent speciation.

    Science.gov (United States)

    Dimitrov, Dimitar; Arnedo, Miquel A; Ribera, Carles

    2008-08-01

    Macaronesian archipelagos stand apart from other oceanic islands reputed as laboratories for the study of evolution by their proximity to the mainland, lack of subsidence, and steep ecological gradients. The genus Pholcus Walckenaer, 1805, commonly known as daddy-long-leg spiders, is one of the most speciose arthropod groups in the region, with 25 endemic species. In the present study, we use information from four mitochondrial genes, along with morphological data, to examine the phylogenetic relationships and diversification patterns of the genus in the region. Phylogenetic analyses support monophyly of Macaronesian Pholcus including the Moroccan species Pholcus vachoni and hence a single colonization event in the archipelagos. Madeira colonizers most likely originated from the Canaries, and a back-colonization of the nearby mainland receives further support. Estimated lineage divergence times suggest a long-time presence of Pholcus in the region, but also reveal that most present-day species are the result of recent, and probably rapid, speciation events. Diagnostic characters among Macaronesian Pholcus are confined to structures involved in copulation. Coupled with the extremely high diversification rate, the highest recorded for spiders, these copulatory characters suggest that sexual selection has played a key role in the local diversification of Pholcus in Macaronesia.

  19. On the males of the orb-weaving spiders Alpaida nigrofrenata (Simon, 1895), A. machala Levi, 1988, and A. cisneros Levi, 1988 (Araneae, Araneidae) and a new synonymy.

    Science.gov (United States)

    Poeta, Maria Rita Muniz; Lise, Arno Antonio

    2015-08-17

    The araneid spider genus Alpaida O.P.-Cambridge, 1889 has, until now, 148 described species (WSC 2015). The males of A. nigrofrenata (Simon, 1895), A. machala Levi, 1988, and A. cisneros Levi, 1988 are described here for the first time. A. moka Levi, 1988, based on female specimens, is synonymized with A. xavantina Levi, 1988, based on the study of specimens of both sexes. I.L.F. de Magalhães (MACN) is thanked for reviewing an early revision of this manuscript. We also thank to M. Machado (PUCRS) for the pictures of A. moka, and M. Kolmann (University of Toronto) and A. Londoño Burbano (PUCRS) for review the English. We are grateful to G. Hormiga for helping to improve this manuscript. M.R.M. Poeta was financially supported by CAPES at PPG-Zoo, PUCRS.

  20. Redescription of the Jamaican orb-weaving spider Chrysometa pecki Levi, 1986 (Araneae, Tetragnathidae), including the first description of the male.

    Science.gov (United States)

    Kallal, Robert J; Hormiga, Gustavo

    2016-01-12

    The tetragnathid genus Chrysometa Simon, 1894 includes 138 species found in the Americas, ranging from the Caribbean to Chile (World Spider Catalog 2015). This genus was revised by Levi (1986), with more recent publications adding to the genus (Álvarez-Padilla 2007, Nogueira et al. 2011, Simó et al., in press). Following Álvarez-Padilla & Hormiga (2011), Chrysometa is differentially diagnosed from other American tetragnathids based on the male palp with a cymbial ectobasal process, cymbial ectomedian process, and embolic basal process, and a paracymbium articulated with a membrane. The epigynum is flat, with fertilization ducts present. Both sexes have guanine crystals in their abdomen and femora lacking trichobothria. Three Jamaican Chrysometa are known: C. pecki Levi, 1986, C. fuscolimbata (Archer, 1958) and C. linguiformis (Franganillo, 1930); all of them known from females only (Levi 1986).

  1. More on the spider genus Xeropigo O.P.-Cambridge (Araneae, Corinnidae, Corinninae): seven new species and new records from Brazil.

    Science.gov (United States)

    Carvalho, Leonardo S; Shimano, Yulie; Candiani, David F; Bonaldo, Alexandre B

    2016-05-17

    Seven new species of the spider genus Xeropigo O. P.-Cambridge are described from Brazil, increasing the genus member list up to 16 species. X. piripiri n. sp., X. aitatu n. sp., and X. cajuina n. sp. are described from the state of Piauí. X. crispim n. sp. is described from the states of Ceará, Piauí, and Maranhão. X. oxente n. sp. is described from the state of Rio Grande do Norte. X. canga n. sp. is described from the state of Minas Gerais. X. ufo n. sp. is described from the state of Mato Grosso. The geographical distribution of X. tridentiger, X. camilae, X. pachitea, and X. perene is updated. A key to all species of Xeropigo is presented and possible relationships among all species of the genus are discussed.

  2. The spider collection (Arachnida: Araneae of the Zoological Museum of the Iranian Research Institute of Plant Protection, with new species records for Iran

    Directory of Open Access Journals (Sweden)

    Zamani, Alireza

    2015-11-01

    Full Text Available The spider collection of the Zoological Museum of the Iranian Research Institute of Plant Protection was studied during the summer of 2014. A total of 180 specimens, belonging to 25 families, 60 genera and 77 species were documented. Of these, the following nine species could be recorded from Iran for the first time: Alopecosa schmidti (Hahn, 1835, Anyphaena accentuata (Walckenaer, 1802, Crustulina sticta (O. P.-Cambridge, 1861, Enoplognatha mordax (Thorell, 1875, Ero tuberculata (De Geer, 1778, Salticus zebraneus (C. L. Koch, 1837, Pardosa aenigmatica Tongiorgi, 1966, Pardosa nebulosa (Thorell, 1872 and Tmarus piochardi (Simon, 1866. Morphological and geographical data are provided for the newly recorded species. Two species (P. aenigmatica and T. piochardi are illustrated and a map of localities is given.

  3. The jumping spider genus Thiodina Simon, 1900 reinterpreted, and revalidation of Colonus F.O.P-Cambridge, 1901 and Nilakantha Peckham & Peckham, 1901 (Araneae: Salticidae: Amycoida).

    Science.gov (United States)

    Bustamante, Abel A; Maddison, Wayne P; Ruiz, Gustavo R S

    2015-09-02

    In this paper we call attention to the identity of the type species of Thiodina Simon, 1900, T. nicoleti Roewer, 1951. When Simon proposed the genus, he characterized it based on morphological features found in species he described, but not found in the type species he designated, and whose type specimens, apparently, he had not examined. Nicolet's original description makes it clear that the type species is not closely related to the more familiar species placed in the genus. This misinterpretation was followed by contemporary researchers and survives until today. Here we designate and describe a neotype for T. nicoleti. We revalidate Colonus F.O.P.-Cambridge, 1901 and Nilakantha Peckham & Peckham, 1901 to transfer most species formerly placed in Thiodina. The combinations Colonus puerperus (Hentz, 1846), Nilakantha cockerelli Peckham & Peckham, 1901 and N. peckhami Bryant, 1940 are restored. The following new combinations are established: Colonus branicki (Taczanowski, 1871) new comb., C. candidus (Mello-Leitão, 1922) new comb., C. germaini (Simon, 1900) new comb., C. hesperus (Richman & Vetter, 2004) new comb., C. melanogaster (Mello-Leitão, 1917) new comb., C. pallidus (C.L. Koch, 1846) new comb., C. pseustes (Chamberlin & Ivie, 1936) new comb., C. punctulatus (Mello-Leitão, 1917) new comb., C. rishwani (Makhan, 2006) new comb., C. robustus (Mello-Leitão, 1945) new comb., C. sylvanus (Hentz, 1846) new comb., C. vaccula (Simon, 1900) new comb., C. vellardi (Soares & Camargo, 1948) new comb., Nilakantha beugelorum (Wolff, 1990) new comb., N. crucifera (F.O.P.-Cambridge, 1901) new comb., and N. inerma (Bryant, 1940) new comb. Thiodina setosa Mello-Leitão, 1947 is tentatively transferred to Cotinusa Simon, 1900.

  4. Descriptions of two new genera of the spider family Caponiidae (Arachnida, Araneae) and an update of Tisentnops and Taintnops from Brazil and Chile

    Science.gov (United States)

    Brescovit, Antonio D.; Sánchez-Ruiz, Alexander

    2016-01-01

    Abstract New members of the spider family Caponiidae from Brazil and Chile are presented. Three new species in previously known genera are described: Taintnops paposo sp. n. from Chile, and the Brazilian Tisentnops mineiro sp. n. and Tisentnops onix sp. n., both belonging to a genus known only from its damaged type. Additionally, two new non–nopine Brazilian genera are proposed: Nasutonops gen. n. including three new species: Nasutonops chapeu sp. n., Nasutonops sincora sp. n. and Nasutonops xaxado sp. n.; and Carajas gen. n., known only from the type species Carajas paraua sp. n. Both new genera have entire, rather than sub-segmented tarsi. Therefore, they are not included in the caponiid subfamily Nopinae. Nasutonops gen. n. is characterized by the presence of a projected clypeal horn, unique among caponiids. Additionally, the first blind caponiids are described: Tisentnops mineiro sp. n. from the state of Minas Gerais and Carajas paraua sp. n. from the state of Pará. Both of these species are found only in caves and completely lack eyes. PMID:27843380

  5. Descriptions of two new genera of the spider family Caponiidae (Arachnida, Araneae and an update of Tisentnops and Taintnops from Brazil and Chile

    Directory of Open Access Journals (Sweden)

    Antonio D. Brescovit

    2016-10-01

    Full Text Available New members of the spider family Caponiidae from Brazil and Chile are presented. Three new species in previously known genera are described: Taintnops paposo sp. n. from Chile, and the Brazilian Tisentnops mineiro sp. n. and Tisentnops onix sp. n., both belonging to a genus known only from its damaged type. Additionally, two new non–nopine Brazilian genera are proposed: Nasutonops gen. n. including three new species: N. chapeu sp. n., N. sincora sp. n. and N. xaxado sp. n.; and Carajas gen. n., known only from the type species C. paraua sp. n. Both new genera have entire, rather than sub-segmented tarsi. Therefore, they are not included in the caponiid subfamily Nopinae. Nasutonops gen. n. is characterized by the presence of a projected clypeal horn, unique among caponiids. Additionally, the first blind caponiids are described: Tisentnops mineiro sp. n. from the state of Minas Gerais and Carajas paraua sp. n. from the state of Pará. Both of these species are found only in caves and completely lack eyes.

  6. Structure, composition and mechanical properties of the silk fibres of the egg case of the Joro spider, Nephila clavata (Araneae, Nephilidae)

    Indian Academy of Sciences (India)

    Ping Jiang; Cong Guo; Taiyong Lv; Yonghong Xiao; Xinjun Liao; Bing Zhou

    2011-12-01

    The silk egg case and orb web of spiders are elaborate structures that are assembled from a number of components. We analysed the structure, the amino acid and fibre compositions, and the tensile properties of the silk fibres of the egg case of Nephila clavata. SEM shows that the outer and inner covers of the egg case consist of thick, medium and thin silk fibres. The silk fibres of the outer cover of the egg case are probably produced by the major and minor ampullate glands. The silk fibres of the inner cover of the egg case from cylindrical glands appears to be distinct from the silk fibres of the major ampullate glands based on their micro-morphology, mole percent amino acid composition and types, and tensile behaviour and properties. Collectively, our investigations show that N. clavata uses silk fibres from relatively few glands in varying combinations to achieve different physical and chemical properties (e.g., color, diameter, morphology and amino acid composition) and functional and mechanical properties in the different layers of the egg case.

  7. Structure, composition and mechanical properties of the silk fibres of the egg case of the Joro spider, Nephila clavata (Araneae, Nephilidae).

    Science.gov (United States)

    Jiang, Ping; Guo, Cong; Lv, Taiyong; Xiao, Yonghong; Liao, Xinjun; Zhou, Bing

    2011-12-01

    The silk egg case and orb web of spiders are elaborate structures that are assembled from a number of components. We analysed the structure, the amino acid and fibre compositions, and the tensile properties of the silk fibres of the egg case of Nephila clavata. SEM shows that the outer and inner covers of the egg case consist of thick, medium and thin silk fibres. The silk fibres of the outer cover of the egg case are probably produced by the major and minor ampullate glands. The silk fibres of the inner cover of the egg case from cylindrical glands appears to be distinct from the silk fibres of the major ampullate glands based on their micro-morphology, mole percent amino acid composition and types, and tensile behaviour and properties. Collectively, our investigations show that N. clavata uses silk fibres from relatively few glands in varying combinations to achieve different physical and chemical properties (e.g., color, diameter, morphology and amino acid composition) and functional and mechanical properties in the different layers of the egg case.

  8. The venomous secrets of the web droplets from the viscid spiral of the orb-weaver spider Nephila clavipes (Araneae, Tetragnatidae).

    Science.gov (United States)

    Salles, Heliana C; Volsi, Evelyn Cristina F R; Marques, Maurício R; Souza, Bibiana M; dos Santos, Lucilene D; Tormena, Cláudio F; Mendes, Maria A; Palma, Mario S

    2006-07-01

    The capture web of N. clavipes presents viscous droplets, which play important roles in web mechanics and prey capture. By using scanning and transmission electron microscopy, it was demonstrated that the web droplets are constituted of different chemical environments, provided by the existence both of an aqueous and a lipid layer, which, in turn, present a suspension of tenths of vesicles containing polypeptides and/or lipids. GC/EI-MS Analysis of the contents of these vesicles led to the identification of some saturated fatty acids, such as decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, octadecanoic acid, and icosanoic acid, while other components were unsaturated fatty acids, such as (Z)-tetradec-9-enoic acid, (Z)-octadec-9-enoic acid, and (Z)-icosa-11-enoic acid; and polyunsaturated fatty acids like (9Z,12Z)-octadeca-9,12-dienoic acid, (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid, and (11Z,14Z)-icosa-11,14-dienoic acid. Toxic proteins such as calcium-activated proteinase and metalloproteinase jararhagin-like precursor were also identified by using a proteomic approach, indicating the possible involvement of these enzymes in the pre-digestion of spiders' preys web-captured. Apparently, the mixture of fatty acids are relatively toxic to insects by topical application (LD50 64.3+/-7.6 ng mg(-1) honeybee), while the proteins alone present no topical effect; however, when injected into the prey-insects, these proteins presented a moderate toxicity (LD50 40.3+/-4.8 ng mg(-1) honeybee); the mixture of fatty acids and proteins is very toxic to the preys captured by the web droplets of the viscid spiral of Nephila clavipes when topically applied on them (LD50 14.3+/-1.8 ng mg(-1) honeybee).

  9. On the trapdoor spiders of Mexico: description of the first new species of the spider genus Aptostichus from Mexico and the description of the female of Eucteniza zapatista (Araneae, Mygalomorphae, Euctenizidae)

    Science.gov (United States)

    Valdez-Mondragón, Alejandro; Cortez-Roldán, Mayra R.

    2016-01-01

    Abstract A new species of the spider genus Aptostichus Simon, 1891 is described from a cave in Huautla de Jiménez, Oaxaca, Mexico: Aptostichus sabinae sp. n. This species represents the first new species described from Mexico and the southernmost record in North America for the genus so far. Aptostichus sabinae sp. n. represents the forty-first species described for the genus, which has the highest species diversity in the family Euctenizidae. Eucteniza zapatista is redescribed based on five new males and the first known female from the Parque Nacional La Malinche (PNLM), Tlaxcala Mexico. Eucteniza zapatista is the fourth species of the genus where a female is known, and one of fourteen species described for the genus to date. PMID:28138292

  10. On the trapdoor spiders of Mexico: description of the first new species of the spider genus Aptostichus from Mexico and the description of the female of Eucteniza zapatista (Araneae, Mygalomorphae, Euctenizidae).

    Science.gov (United States)

    Valdez-Mondragón, Alejandro; Cortez-Roldán, Mayra R

    2016-01-01

    A new species of the spider genus Aptostichus Simon, 1891 is described from a cave in Huautla de Jiménez, Oaxaca, Mexico: Aptostichus sabinaesp. n. This species represents the first new species described from Mexico and the southernmost record in North America for the genus so far. Aptostichus sabinaesp. n. represents the forty-first species described for the genus, which has the highest species diversity in the family Euctenizidae. Eucteniza zapatista is redescribed based on five new males and the first known female from the Parque Nacional La Malinche (PNLM), Tlaxcala Mexico. Eucteniza zapatista is the fourth species of the genus where a female is known, and one of fourteen species described for the genus to date.

  11. On the taxonomy of some neotropical species of jumping spiders described by Caporiacco (Araneae, Salticidae Sobre a taxonomia de algumas espécies neotropicais de aranhas papa-moscas descritas por Caporiacco (Araneae, Salticidae

    Directory of Open Access Journals (Sweden)

    Gustavo R.S. Ruiz

    2007-06-01

    Full Text Available Pseudattulus incertus Caporiacco, 1955 is synonymized with P. kratochvili Caporiacco, 1947 and the male of this species is redescribed. The genus Uspachus Galiano, 1995 is synonymized with Romitia Caporiacco, 1947 and the male of its type species, R. nigra Caporiacco, 1947, is redescribed. The following new combinations are established for the species formerly included in Uspachus: Romitia albipalpis (Taczanowski, 1878, Romitia andina (Taczanowski, 1878, Romitia bahiensis (Galiano, 1995, Romitia colombiana (Galiano, 1995, Romitia juquiaensis (Galiano, 1995, Romitia ministerialis (C.L. Koch, 1846, Romitia misionensis (Galiano, 1995 and Romitia patellaris (Galiano, 1995. The genus Pseudamphidraus Caporiacco, 1947 is synonymized with Noegus Simon, 1900 by transfer of its type species, Noegus niger (Caporiacco, 1947 comb. nov., whose male is herein redescribed. The species Pseudamphidraus variegatus Caporiacco, 1947 and Marma trifidocarinata Caporiacco, 1947 are synonymized with Marma nigritarsis (Simon, 1900.Pseudattulus incertus Caporiacco, 1955 é sinonimizada com P. kratochvili Caporiacco, 1947 e o macho desta espécie é redescrito. O gênero Uspachus Galiano, 1995 é sinonimizado com Romitia Caporiacco, 1947 e o macho de sua espécie-tipo, R. nigra Caporiacco, 1947, é redescrito.As seguintes combinações novas são estabelecidas para as espécies até o momento incluídas em Uspachus: Romitia albipalpis (Taczanowski, 1878, Romitia andina (Taczanowski, 1878, Romitia bahiensis (Galiano, 1995, Romitia colombiana (Galiano, 1995, Romitia juquiaensis (Galiano, 1995, Romitia ministerialis (C.L. Koch, 1846, Romitia misionensis (Galiano, 1995 e Romitia patellaris (Galiano, 1995. O gênero Pseudamphidraus Caporiacco, 1947 é sinonimizado com Noegus Simon, 1900 pela transferência de sua espécie-tipo, Noegus niger (Caporiacco, 1947 comb. nov., cujo macho é redescrito. As espécies Pseudamphidraus variegatus Caporiacco, 1947 e Marma trifidocarinata Caporiacco, 1947 são sinonimizadas com Marma nigritarsis (Simon, 1900.

  12. 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

  13. Erster Nachweis der Springspinne Evarcha jucunda (Araneae: Salticidae in Deutschland

    Directory of Open Access Journals (Sweden)

    Ludy, Claudia

    2005-06-01

    Full Text Available One specimen of the jumping spider Evarcha jucunda was discovered in the fruit department of a general store in Gießen, Germany. The species has obviously been introduced with transported fruit from mediterranean countries.

  14. Contribution to the knowledge of pathogenic fungi of spiders in Argentina. Southernmost record in the world.

    Science.gov (United States)

    Manfrino, Romina G; González, Alda; Barneche, Jorge; Tornesello Galván, Julieta; Hywell-Jones, Nigel; López Lastra, Claudia C

    The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Spiders in random environment

    CERN Document Server

    Gallesco, Christophe; Popov, Serguei; Vachkovskaia, Marina

    2010-01-01

    A spider consists of several, say $N$, particles. Particles can jump independently according to a random walk if the movement does not violate some given restriction rules. If the movement violates a rule it is not carried out. We consider random walk in random environment (RWRE) on $\\Z$ as underlying random walk. We suppose the environment $\\omega=(\\omega_x)_{x \\in \\Z}$ to be elliptic, with positive drift and nestling, so that there exists a unique positive constant $\\kappa$ such that $\\E[((1-\\omega_0)/\\omega_0)^{\\kappa}]=1$. The restriction rules are kept very general; we only assume transitivity and irreducibility of the spider. The main result is that the speed of a spider is positive if $\\kappa/N>1$ and null if $\\kappa/N<1$. In particular, if $\\kappa/N <1$ a spider has null speed but the speed of a (single) RWRE is positive.

  16. 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 abu

  17. 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 abu

  18. 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

  19. Spider Veins

    Science.gov (United States)

    ... How to Choose the Best Skin Care Products Spider Veins Treatment Options Learn more about treatment options ... severe venous disease. What you should know about spider veins The exact cause of spider veins is ...

  20. The complete mitochondrial genome sequence of the spider habronattus oregonensis reveals rearranged and extremely truncated tRNAs

    Energy Technology Data Exchange (ETDEWEB)

    Masta, Susan E.; Boore, Jeffrey L.

    2004-01-31

    We sequenced the entire mitochondrial genome of the jumping spider Habronattus oregonensis of the arachnid order Araneae (Arthropoda: Chelicerata). A number of unusual features distinguish this genome from other chelicerate and arthropod mitochondrial genomes. Most of the transfer RNA gene sequences are greatly reduced in size and cannot be folded into typical cloverleaf-shaped secondary structures. At least nine of the tRNA sequences lack the potential to form TYC arm stem pairings, and instead are inferred to have TV-replacement loops. Furthermore, sequences that could encode the 3' aminoacyl acceptor stems in at least 10 tRNAs appear to be lacking, because fully paired acceptor stems are not possible and because the downstream sequences instead encode adjacent genes. Hence, these appear to be among the smallest known tRNA genes. We postulate that an RNA editing mechanism must exist to restore the 3' aminoacyl acceptor stems in order to allow the tRNAs to function. At least seven tRN As are rearranged with respect to the chelicerate Limulus polyphemus, although the arrangement of the protein-coding genes is identical. Most mitochondrial protein-coding genes of H. oregonensis have ATN as initiation codons, as commonly found in arthropod mtDNAs, but cytochrome oxidase subunit 2 and 3 genes apparently use UUG as an initiation codon. Finally, many of the gene sequences overlap one another and are truncated. This 14,381 bp genome, the first mitochondrial genome of a spider yet sequenced, is one of the smallest arthropod mitochondrial genomes known. We suggest that post transcriptional RNA editing can likely maintain function of the tRNAs while permitting the accumulation of mutations that would otherwise be deleterious. Such mechanisms may have allowed for the minimization of the spider mitochondrial genome.

  1. Summary statistics for fossil spider species taxonomy

    Directory of Open Access Journals (Sweden)

    David Penney

    2012-05-01

    Full Text Available 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 taxonomic catalogues. Data for extant taxa showed a steady linear increase of approximately 500 new species per year over the last decade, reflecting a rather constant research activity in this area by a large number of scientists, which can be expected to continue. The results for fossil species were very different, with peaks of new species descriptions followed by long troughs, indicating minimal new published research activity for most years. This pattern is indicative of short bursts of research by a limited number of authors. Given the frequent discovery of new fossil deposits containing spiders, a wealth of new material coming to light from previously worked deposits, and the application of new imaging techniques in palaeoarachnology that allow us to extract additional data from historical specimens, e.g. X-ray computed tomography, it is important not only to ensure a sustained research activity on fossil spiders (and other arachnids through training and enthusing the next generation of palaeoarachnologists, but preferably to promote increased research and expertise in this field.

  2. Response of ground-dwelling spider assemblages to prescribed fire following stand structure manipulation in the southern Cascade Range

    Science.gov (United States)

    Nancy E. Gillette; Richard S. Vetter; Sylvia R. Mori; Carline R. Rudolph; Dessa R. Welty

    2008-01-01

    We assessed spider (Arachnida: Araneae) responses to prescribed fire following stand s tructure treatments in ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) stands in the Cascade Range of California. Stands were logged or left untreated to create three levels of structural diversity. We logged one treatment to minimize old-growth...

  3. 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

  4. Spider phylogenomics: untangling the Spider Tree of Life.

    Science.gov (United States)

    Garrison, Nicole L; Rodriguez, Juanita; Agnarsson, Ingi; Coddington, Jonathan A; Griswold, Charles E; Hamilton, Christopher A; Hedin, Marshal; Kocot, Kevin M; Ledford, Joel M; Bond, Jason E

    2016-01-01

    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 challenge the monophyly of

  5. Spiders from Fernando de Noronha, Brazil: part II. proposal of a new genus and description of three new species of jumping spiders (Araneae, Salticidae Aranhas de Fernando de Noronha, Brasil: parte II. proposição de um gênero novo e descrição de três espécies novas de papa-moscas (Araneae, Salticidae

    Directory of Open Access Journals (Sweden)

    Gustavo R. S. Ruiz

    2007-01-01

    Full Text Available The new genus Matagaia is proposed to include the newly described M. chromatopus sp. nov. from Fernando de Noronha Archipelago, state of Pernambuco, Brazil. In addition, Corythalia insularis sp. nov. and Neonella noronha sp. nov. are also described from this locality. The synanthropic Hasarius adansoni (Audouin, 1826 and Menemerus bivittatus (Dufour, 1831 are also recorded from the Archipelago.O novo gênero Matagaia é proposto para incluir M. chromatopus sp. nov., aqui descrita, do Arquipélago de Fernando de Noronha, Pernambuco, Brasil. Além desta espécie, Corythalia insularis sp. nov. e Neonella noronha sp. nov. também são descritas para a mesma localidade. As espécies sinantrópicas Hasarius adansoni (Audouin, 1826 e Menemerus bivittatus (Dufour, 1831 também são registradas para o arquipélago.

  6. Two new Thiratoscirtus species from Gabon (Araneae, Salticidae, Thiratoscirtinae

    Directory of Open Access Journals (Sweden)

    Michael Seiter

    2015-05-01

    Full Text Available Two new species of jumping spiders, Thiratoscirtus oberleuthneri (♂ and Th. lamboji (♀, are described from Gabon, one of the least explored areas of the Afrotropics. Both species live in rainforest, at the forest floor. They are members of a very poorly known subfamily of salticids, the Thiratoscirtinae.

  7. A checklist of spiders of Baishi Mountain National Geopark of Hebei province (Arachnida: Araneae)%河北省白石山国家地质公园蜘蛛名录

    Institute of Scientific and Technical Information of China (English)

    邱宏远; 卢红显; 张锋; 闫寅磊

    2009-01-01

    We conduct a survey on the spiders fauna of Baishi Mountain National Geopark. After studying the 2 671 collected specimens and reading up the related literatures, 123 species belonging to 68 genera,23 families have been identified and listed in this checklist.%本项研究通过对河北省涞源县白石山国家地质公园2 671头蜘蛛标本的采集、整理、鉴定及分析,基本弄清了该地区的蜘蛛组成,目前白石山蜘蛛共计23科、68属、123种.

  8. Rounding up the usual suspects: a standard target-gene approach for resolving the interfamilial phylogenetic relationships of ecribellate orb-weaving spiders with a new family-rank classification (Araneae, Araneoidea)

    DEFF Research Database (Denmark)

    Dimitrov, Dimitar; Benevidas, Ligia R.; Arnedo, Miquel A.;

    2017-01-01

    We test the limits of the spider superfamily Araneoidea and reconstruct its interfamilial relationships using standard molecular markers. The taxon sample (363 terminals) comprises for the first time representatives of all araneoid families, including the first molecular data of the family...... Synaphridae. We use the resulting phylogenetic framework to study web evolution in araneoids. Araneoidea is monophyletic and sister to Nicodamoidea rank. n. Orbiculariae are not monophyletic and also include the RTA clade, Oecobiidae and Hersiliidae. Deinopoidea is paraphyletic with respect to a lineage...... holarchaeids but the family remains diphyletic even if Holarchaea is considered an anapid. The orb-web is ancient, having evolved by the early Jurassic; a single origin of the orb with multiple “losses” is implied by our analyses. By the late Jurassic, the orb-web had already been transformed into different...

  9. Tarantula spider

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002855.htm Tarantula spider bite To use the sharing features on this ... This article describes the effects of a tarantula spider bite. This article is for information only. DO ...

  10. Venomous Spiders

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH VENOMOUS SPIDERS Recommend on Facebook Tweet Share Compartir Photo courtesy of University of Missouri Venomous spiders found in the United States include the black ...

  11. Erstnachweis von Evarcha michailovi in Deutschland (Araneae: Salticidae sowie weitere für Mecklenburg-Vorpommern neue Spinnenarten

    Directory of Open Access Journals (Sweden)

    Martin, Dieter

    2014-12-01

    Full Text Available The jumping spider Evarcha michailovi Logunov 1992 was recorded as new to Germany from a nature reserve in the south of Mecklenburg-Western Pomerania in a dry heathland habitat. Furthermore, the first records of the jumping spiders Evarcha laetabunda (C. L. Koch, 1846, Philaeus chrysops (Poda, 1761 and Sitticus inexpectus Logunov & Kronestedt, 1997, the comb-footed spider Crustulina sticta (O. P.-Cambridge, 1861 and the crab spider Heriaeus graminicola (Doleschall, 1852 in Mecklenburg-Western Pomerania are reported.

  12. Hymenoepimecis neotropica (Brues & Richardson (Hymenoptera, Ichneumonidae, Pimplinae parasitoid of Araneus omnicolor (Keyserling (Araneae, Araneidae: first host record and new occurrence to Brazil Hymenoepimecis neotropica (Brues & Richardson (Hymenoptera, Ichneumonidae parasitoide de Araneus omnicolor (Keyserling (Araneae, Araneidae: primeiro registro do hospedeiro e nova ocorrência para o Brasil

    Directory of Open Access Journals (Sweden)

    Jober Fernando Sobczak

    2012-09-01

    Full Text Available Hymenoepimecis neotropica (Brues & Richardson (Hymenoptera, Ichneumonidae, Pimplinae parasitoid of Araneus omnicolor (Keyserling (Araneae, Araneidae: first host record and new occurrence to Brazil. The species of the genus Hymenoepimecis occur only in Neotropical region, being recognized for using as their hosts spiders which build orbicular webs. That wasp was described occurring only in the Guyana. This work expands the geographical distribution of the species to Brazil and records the spider Araneus omnicolor (Araneae, Araneidae as its host. Furthermore, it provides information about the natural history of this interaction.Hymenoepimecis neotropica (Brues & Richardson (Hymenoptera, Ichneumonidae parasitoide de Araneus omnicolor (Keyserling (Araneae, Araneidae: primeiro registro do hospedeiro e nova ocorrência para o Brasil. Espécies do gênero Hymenoepimecis ocorrem somente na região Neotropical, sendo reconhecidas por utilizarem, como hospedeiras, aranhas que constroem teias orbiculares. Essa vespa foi descrita ocorrendo somente na Guiana. Este trabalho amplia a distribuição geográfica da espécie para o Brasil e registra a aranha Araneus omnicolor (Araneae, Araneidae como sua hospedeira. Além disso, fornece informações sobre a história natural desta interação.

  13. Spider orientation and hub position in orb webs

    Science.gov (United States)

    Zschokke, Samuel; Nakata, Kensuke

    2010-01-01

    Orb-web building spiders (Araneae: Araneoidea, Uloboridae) can be considered as territorial central place foragers. In territorial central place foragers, the optimal foraging arena is circular, with the forager sitting in its centre. In orb webs, the spider’s orientation (head up or head down) whilst waiting for prey on the hub of its web and the downwards-upwards asymmetry of its running speeds are the probable causes for the observed deviation of the hub from the web’s centre. Here, we present an analytical model and a more refined simulation model to analyse the relationships amongst the spider’s running speeds, its orientation whilst waiting for prey and the vertical asymmetry of orb webs. The results of our models suggest that (a) waiting for prey head down is generally favourable because it allows the spider to reach the prey in its web on average quicker than spiders waiting head up, (b) the downwards-upwards running speed asymmetry, together with the head-down orientation of most spiders, are likely causes for the observed vertical asymmetry of orb webs, (c) waiting head up can be advantageous for spiders whose downwards-upwards running speed asymmetry is small and who experience high prey tumbling rates and (d) spiders waiting head up should place their hub lower than similar spiders waiting head down.

  14. Spider bite.

    Science.gov (United States)

    Isbister, Geoffrey K; Fan, Hui Wen

    2011-12-10

    Spiders are a source of intrigue and fear, and several myths exist about their medical effects. Many people believe that bites from various spider species cause necrotic ulceration, despite evidence that most suspected cases of necrotic arachnidism are caused by something other than a spider bite. Latrodectism and loxoscelism are the most important clinical syndromes resulting from spider bite. Latrodectism results from bites by widow spiders (Latrodectus spp) and causes local, regional, or generalised pain associated with non-specific symptoms and autonomic effects. Loxoscelism is caused by Loxosceles spp, and the cutaneous form manifests as pain and erythema that can develop into a necrotic ulcer. Systemic loxoscelism is characterised by intravascular haemolysis and renal failure on occasion. Other important spiders include the Australian funnel-web spider (Atrax spp and Hadronyche spp) and the armed spider (Phoneutria spp) from Brazil. Antivenoms are an important treatment for spider envenomation but have been less successful than have those for snake envenomation, with concerns about their effectiveness for both latrodectism and loxoscelism. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. A structured inventory of spiders (Arachnida, Araneae in natural and artificial forest gaps at Porto Urucu, Western Brazilian Amazonia Inventário estruturado de aranhas (Arachnida, Araneae em clareiras naturais e artificiais em Porto Urucu, Amazônia Ocidental Brasileira

    Directory of Open Access Journals (Sweden)

    Alexandre B. Bonaldo

    2010-01-01

    Full Text Available A preliminary survey of the spider fauna in natural and artificial forest gap formations at “Porto Urucu”, a petroleum/natural gas production facility in the Urucu river basin, Coari, Amazonas, Brazil is presented. Sampling was conducted both occasionally and using a protocol composed of a suite of techniques: beating trays (32 samples, nocturnal manual samplings (48, sweeping nets (16, Winkler extractors (24, and pitfall traps (120. A total of 4201 spiders, belonging to 43 families and 393 morphospecies, were collected during the dry season, in July, 2003. Excluding the occasional samples, the observed richness was 357 species. In a performance test of seven species richness estimators, the Incidence Based Coverage Estimator (ICE was the best fit estimator, with 639 estimated species. To evaluate differences in species richness associated with natural and artificial gaps, samples from between the center of the gaps up to 300 meters inside the adjacent forest matrix were compared through the inspection of the confidence intervals of individual-based rarefaction curves for each treatment. The observed species richness was significantly higher in natural gaps combined with adjacent forest than in the artificial gaps combined with adjacent forest. Moreover, a community similarity analysis between the fauna collected under both treatments demonstrated that there were considerable differences in species composition. The significantly higher abundance of Lycosidae in artificial gap forest is explained by the presence of herbaceous vegetation in the gaps themselves. Ctenidae was significantly more abundant in the natural gap forest, probable due to the increase of shelter availability provided by the fallen trees in the gaps themselves. Both families are identified as potential indicators of environmental change related to the establishment or recovery of artificial gaps in the study area.Apresenta-se um inventário preliminar da fauna de aranhas

  16. High throughput techniques to reveal the molecular physiology and evolution of digestion in spiders.

    Science.gov (United States)

    Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Verhaert, Peter D E M; Lopes, Adriana R

    2016-09-07

    Spiders are known for their predatory efficiency and for their high capacity of digesting relatively large prey. They do this by combining both extracorporeal and intracellular digestion. Whereas many high throughput ("-omics") techniques focus on biomolecules in spider venom, so far this approach has not yet been applied to investigate the protein composition of spider midgut diverticula (MD) and digestive fluid (DF). We here report on our investigations of both MD and DF of the spider Nephilingis (Nephilengys) cruentata through the use of next generation sequencing and shotgun proteomics. This shows that the DF is composed of a variety of hydrolases including peptidases, carbohydrases, lipases and nuclease, as well as of toxins and regulatory proteins. We detect 25 astacins in the DF. Phylogenetic analysis of the corresponding transcript(s) in Arachnida suggests that astacins have acquired an unprecedented role for extracorporeal digestion in Araneae, with different orthologs used by each family. The results of a comparative study of spiders in distinct physiological conditions allow us to propose some digestion mechanisms in this interesting animal taxon. All the high throughput data allowed the demonstration that DF is a secretion originating from the MD. We identified enzymes involved in the extracellular and intracellular phases of digestion. Besides that, data analyses show a large gene duplication event in Araneae digestive process evolution, mainly of astacin genes. We were also able to identify proteins expressed and translated in the digestive system, which until now had been exclusively associated to venom glands.

  17. Low-Tech, Pilot Scale Purification of a Recombinant Spider Silk Protein Analog from Tobacco Leaves

    Directory of Open Access Journals (Sweden)

    René Heppner

    2016-10-01

    Full Text Available Spider dragline is used by many members of the Araneae family not only as a proteinogenic safety thread but also for web construction. Spider dragline has been shown to possess high tensile strength in combination with elastic behavior. This high tensile strength can be attributed to the presence of antiparallel β-sheets within the thread; these antiparallel β-sheets are why the protein is classified as a silk. Due to the properties of spider silk and its technical and medical uses, including its use as a suture material and as a scaffold for tissue regeneration, spider dragline is a focus of the biotechnology industry. The production of sufficient amounts of spider silk is challenging, as it is difficult to produce large quantities of fibers because of the cannibalistic behavior of spiders and their large spatial requirements. In recent years, the heterologous expression of genes coding for spider silk analogs in various hosts, including plants such as Nicotiana tabacum, has been established. We developed a simple and scalable method for the purification of a recombinant spider silk protein elastin-like peptide fusion protein (Q-/K-MaSp1-100× ELP after heterologous production in tobacco leaves involving heat and acetone precipitation. Further purification was performed using centrifugal Inverse Transition Cycling (cITC. Up to 400 mg of highly pure spider silk protein derivatives can be isolated from six kilograms of tobacco leaves, which is the highest amount of silk protein derivatives purified from plants thus far.

  18. 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.

  19. Low-Tech, Pilot Scale Purification of a Recombinant Spider Silk Protein Analog from Tobacco Leaves.

    Science.gov (United States)

    Heppner, René; Weichert, Nicola; Schierhorn, Angelika; Conrad, Udo; Pietzsch, Markus

    2016-10-09

    Spider dragline is used by many members of the Araneae family not only as a proteinogenic safety thread but also for web construction. Spider dragline has been shown to possess high tensile strength in combination with elastic behavior. This high tensile strength can be attributed to the presence of antiparallel β-sheets within the thread; these antiparallel β-sheets are why the protein is classified as a silk. Due to the properties of spider silk and its technical and medical uses, including its use as a suture material and as a scaffold for tissue regeneration, spider dragline is a focus of the biotechnology industry. The production of sufficient amounts of spider silk is challenging, as it is difficult to produce large quantities of fibers because of the cannibalistic behavior of spiders and their large spatial requirements. In recent years, the heterologous expression of genes coding for spider silk analogs in various hosts, including plants such as Nicotiana tabacum, has been established. We developed a simple and scalable method for the purification of a recombinant spider silk protein elastin-like peptide fusion protein (Q-/K-MaSp1-100× ELP) after heterologous production in tobacco leaves involving heat and acetone precipitation. Further purification was performed using centrifugal Inverse Transition Cycling (cITC). Up to 400 mg of highly pure spider silk protein derivatives can be isolated from six kilograms of tobacco leaves, which is the highest amount of silk protein derivatives purified from plants thus far.

  20. Ecotoxicological effects of buprofezin on fecundity, growth, development, and predation of the wolf spider Pirata piratoides (Schenkel).

    Science.gov (United States)

    Deng, Lingling; Xu, Muqi; Cao, Hong; Dai, Jiayin

    2008-11-01

    The toxicological effects of buprofezin, an insect growth regulator, on the fecundity, development, and pest control potential of the wolf spider Pirata piratoides (Schenkel) (Araneae: Lycosidae) were investigated in the laboratory. It was shown that buprofezin had low toxicity to P. piratoides and that the median lethal dosage (LD(50)) 48 h and 10% lethal dosage (LD(10)) after topical application for female spiders were 653 and 316 mg buprofezin/mg fresh weight of spider, respectively. Buprofezin significantly reduced the percent hatching of spiders' eggs but had only a slight effect on egg production. No negative effects on the development and growth were observed. However, spider predation rates were strongly affected: Insecticide-treated females predated on fewer prey than the controls, and their predation rate did not recover even 5 days after insecticide application. This indicated that their pest control potential might be influenced by buprofezin, and the use of buprofezin in biological control of insects is discussed.

  1. The Effect of Wind Exposure on the Web Characteristics of a Tetragnathid Orb Spider.

    Science.gov (United States)

    Tew, Nicholas; Hesselberg, Thomas

    2017-01-01

    Studies on spiders in their natural habitats are necessary for determining the full range of plasticity in their web-building behaviour. Plasticity in web design is hypothesised to be important for spiders building in habitats where environmental conditions cause considerable web damage. Here we compared web characteristics of the orb spider Metellina mengei (Araneae, Tetragnathidae) in two different forest habitats differing in their wind exposure. We found a notable lack of differences in web geometry, orientation and inclination between webs built along an exposed forest edge and those built inside the forest, despite marked differences in wind speed. This suggests that M. mengei did not exhibit web-building plasticity in response to wind in the field, contrasting with the findings of laboratory studies on other species of orb spiders. Instead, differences in prey capture and wind damage trade-offs between habitats may provide an explanation for our results, indicating that different species employ different strategies to cope with environmental constraints.

  2. Jumping Dynamics

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new...... paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one...... without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking....

  3. Endosymbiont dominated bacterial communities in a dwarf spider.

    Directory of Open Access Journals (Sweden)

    Bram Vanthournout

    Full Text Available The microbial community of spiders is little known, with previous studies focussing primarily on the medical importance of spiders as vectors of pathogenic bacteria and on the screening of known cytoplasmic endosymbiont bacteria. These screening studies have been performed by means of specific primers that only amplify a selective set of endosymbionts, hampering the detection of unreported species in spiders. In order to have a more complete overview of the bacterial species that can be present in spiders, we applied a combination of a cloning assay, DGGE profiling and high-throughput sequencing on multiple individuals of the dwarf spider Oedothorax gibbosus. This revealed a co-infection of at least three known (Wolbachia, Rickettsia and Cardinium and the detection of a previously unreported endosymbiont bacterium (Rhabdochlamydia in spiders. 16S rRNA gene sequences of Rhabdochlamydia matched closely with those of Candidatus R. porcellionis, which is currently only reported as a pathogen from a woodlouse and with Candidatus R. crassificans reported from a cockroach. Remarkably, this bacterium appears to present in very high proportions in one of the two populations only, with all investigated females being infected. We also recovered Acinetobacter in high abundance in one individual. In total, more than 99% of approximately 4.5M high-throughput sequencing reads were restricted to these five bacterial species. In contrast to previously reported screening studies of terrestrial arthropods, our results suggest that the bacterial communities in this spider species are dominated by, or even restricted to endosymbiont bacteria. Given the high prevalence of endosymbiont species in spiders, this bacterial community pattern could be widespread in the Araneae order.

  4. 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

    in the posterior and anteriomedian eyes, and at approximately 540 nm in the anteriolateral eyes. Theoretical calculations of photon catches showed that the eyes are likely to employ a combination of spatial and temporal pooling in order to function at night. Under starlit conditions, the raw spatial and temporal...

  5. Interactions of transgenic Bacillus thuringiensis insecticidal crops with spiders (Araneae)

    Science.gov (United States)

    Genetically modified crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) have dramatically increased in acreage since their introduction in the mid-1990’s. Although the insecticidal mechanisms of Bt target specific pests, concerns persist regarding direct and indirect effects on...

  6. Nopyllus, a new South American Drassodinae spider genus (Araneae, Gnaphosidae

    Directory of Open Access Journals (Sweden)

    Ricardo Ott

    2014-06-01

    Full Text Available Nopyllus gen. nov. is proposed to include Apopyllus isabelae Brescovit & Lise, 1993 and Nopyllus vicente sp. nov. from southern Brazil. Nopyllus gen. nov. is close to Apodrassodes Vellard, 1924 and Apopyllus Platnick & Shadab, 1984, can be distinguished from both genera by the absence of a dorsal abdominal scutum in males, the absence of a median apophysis on bulb, the curved, narrow and reniform cymbium, and by the presence of a very conspicuous cymbial basal projection.

  7. 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.

  8. Long Jump

    CERN Document Server

    Dorobantu, V

    2012-01-01

    When the laws of Physics are taken seriously, the sports can benefit in getting better results, as was the case of the high jump in Flop style, so that the athlete sprints diagonally towards the bar,then curve and leap backwards over it. The jumper, in this case, has the center of mass under the bar, fact which allows improvement of the performance.

  9. Spider Vein Removal

    Science.gov (United States)

    Spider veins: How are they removed? I have spider veins on my legs. What options are available ... M.D. Several options are available to remove spider veins — thin red lines or weblike networks of ...

  10. Spider Bites (For Parents)

    Science.gov (United States)

    ... TV, Video Games, and the Internet First Aid: Spider Bites KidsHealth > For Parents > First Aid: Spider Bites ... rare. Signs and Symptoms Of a brown recluse spider bite: red blister in the center with surrounding ...

  11. 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.

  12. 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.

  13. Spider Webs and Silks.

    Science.gov (United States)

    Vollrath, Fritz

    1992-01-01

    Compares the attributes of the silk from spiders with those of the commercially harvested silk from silkworms. Discusses the evolution, design, and effectiveness of spider webs; the functional mechanics of the varieties of silk that can be produced by the same spider; and the composite, as well as molecular, structure of spider silk thread. (JJK)

  14. Spider Webs and Silks.

    Science.gov (United States)

    Vollrath, Fritz

    1992-01-01

    Compares the attributes of the silk from spiders with those of the commercially harvested silk from silkworms. Discusses the evolution, design, and effectiveness of spider webs; the functional mechanics of the varieties of silk that can be produced by the same spider; and the composite, as well as molecular, structure of spider silk thread. (JJK)

  15. Herbivory in a spider through exploitation of an ant-plant mutualism.

    Science.gov (United States)

    Meehan, Christopher J; Olson, Eric J; Reudink, Matthew W; Kyser, T Kurt; Curry, Robert L

    2009-10-13

    Spiders are thought to be strict predators. We describe a novel exception: Bagheera kiplingi, a Neotropical jumping spider (Salticidae) that exploits a well-studied ant-plant mutualism, is predominantly herbivorous. From behavioral field observations and stable-isotope analyses, we show that the main diet of this host-specific spider comprises specialized leaf tips (Beltian food bodies; Figure 1A) from Vachellia spp. ant-acacias (formerly Acacia spp.), structures traded for protection in the plant's coevolved mutualism with Pseudomyrmex spp. ants that inhabit its hollow thorns. This is the first report of a spider that feeds primarily and deliberately on plants.

  16. Spider Bite in Iran.

    Science.gov (United States)

    Sanaei-Zadeh, Hossein

    2017-07-01

    Some of the world's most dangerous spiders have been certified in some areas of Iran. Spider bites are common in some geographical areas, and are sporadic in some regions. Spider bites can be classified as latrodectism or loxoscelism. If the patient had not seen the spider, the clinical manifestations of latrodectism could be easily mistaken for other types of bite or sting; or an infectious disease, and withdrawal symptoms, and also loxoscelism could be mistaken for cellulitis, various types of skin infection, or even a sting from a Gadim scorpion (Hemiscorpius lepturus). Given the nonspecific presentation of spider bites, one must keep the diagnosis in mind, and question patients, regarding possible exposure to spiders. Physicians recommend becoming familiar with the geographical distribution of Iranian dangerous spiders, clinical manifestations, and management of their bites. The most useful treatment for spider bite is anti-venom administration. Producing spider bite anti-venom in the Razi Vaccine and Serum Research Institute is under investigation.

  17. 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.

  18. Response of the Gypsy Moth, Lymantria dispar to Transgenic Poplar, Populus simonii x P. nigra, Expressing Fusion Protein Gene of the Spider Insecticidal Peptide and Bt-toxin C-peptide

    OpenAIRE

    Cao, Chuan-Wang; Liu, Gui-Feng; Wang, Zhi-Ying; Yan, Shan-Chun; Ma, Ling; Yang, Chuan-Ping

    2010-01-01

    The response of the Asian gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae) to a fusion gene consisting of the spider, Atrax robustus Simon (Araneae: Hexanthelidae) ω?-ACTX-Ar1 sequence coding for an ω?-atracotoxin and a sequence coding for the Bt-toxin C-peptide, expressed in transgenic poplar Populus simonii x P. nigra L. (Malphigiales: Salicaceae) was investigated. Individual performance, feeding selection, midgut proteinase activity and nutrition utilization were monitored. The...

  19. 新加坡的2种卵形蛛科蜘蛛的雌性新发现蛛形纲:蜘蛛目)%First discoveries of the females of two oonopid spider species from Singapore (Arachnida, Araneae)

    Institute of Scientific and Technical Information of China (English)

    佟秀娇; 王瑞; 佟艳丰

    2016-01-01

    首次发现了采自于新加坡的2种卵形蛛的雌性:Aposphragisma salewskii Thoma和Prethopal-pus pahang Baehr,并提供了详细的形态描述及特征图。%The females of two oonopid spider species from Singapore were firstly discovered: Aposphragisma salewskii Thoma and Prethopalpus pahang Baehr. Descriptions and figures were provided for females of both species.

  20. Tracking a medically important spider: climate change, ecological niche modeling, and the brown recluse (Loxosceles reclusa.

    Directory of Open Access Journals (Sweden)

    Erin E Saupe

    Full Text Available Most spiders use venom to paralyze their prey and are commonly feared for their potential to cause injury to humans. In North America, one species in particular, Loxosceles reclusa (brown recluse spider, Sicariidae, causes the majority of necrotic wounds induced by the Araneae. However, its distributional limitations are poorly understood and, as a result, medical professionals routinely misdiagnose brown recluse bites outside endemic areas, confusing putative spider bites for other serious conditions. To address the issue of brown recluse distribution, we employ ecological niche modeling to investigate the present and future distributional potential of this species. We delineate range boundaries and demonstrate that under future climate change scenarios, the spider's distribution may expand northward, invading previously unaffected regions of the USA. At present, the spider's range is centered in the USA, from Kansas east to Kentucky and from southern Iowa south to Louisiana. Newly influenced areas may include parts of Nebraska, Minnesota, Wisconsin, Michigan, South Dakota, Ohio, and Pennsylvania. These results illustrate a potential negative consequence of climate change on humans and will aid medical professionals in proper bite identification/treatment, potentially reducing bite misdiagnoses.

  1. Diversity and distribution of spiders from Gibbon Wildlife Sanctuary, Assam, India

    Directory of Open Access Journals (Sweden)

    Dilip Kumar Kalita

    2012-07-01

    Full Text Available The study describes the identification of the spider assemblages with respect to their diversity and distribution in the semi evergreen forest, Gibbon Wildlife Sanctuary, Assam, India. The paper aims to introduce this neglected Order- Araneae which is primarily unknown to Science particularly in Northeast India. A total of 95 species of spiders belonging to 56 genera and 18 families were recorded during the study from June-August and October-December, 2011. The species were identified using keys for Indian spiders from (Tikader, 1987; Platnick , 2011. Methodology included active searching at all layers from ground level to tree canopy layer accessible easily for hand collecting and visual surveys. This is the first attempt to report the spider assemblages and their microhabitat preferences from Assam, India. Such surveys are vital for conservation of these creatures and building a biodiversity database of this mega diverse group from a fragmented semi-evergreen forest ecosystem in Assam, India. This study is focused on the neglected diversity of spider fauna representing this semi evergreen forest.

  2. Morphological characterization of the venom apparatus in the wolf spider Lycosa singoriensis (Laxmann, 1770

    Directory of Open Access Journals (Sweden)

    N Yigit

    2009-01-01

    Full Text Available The wolf spider Lycosa singoriensis (Laxmann, 1770 (Lycosidae: Araneae is distributed throughout central and eastern Europe, including Russia, Kazakhistan and Turkey. This study describes the venom apparatus morphology of L. singoriensis through scanning electron microscopy (SEM. Its structure follows the general architecture observed in other spiders. Generally, a venom apparatus is composed by a pair of venom glands and chelicerae. L. singoriensis chelicerae are robust and consist of a stout basis and a movable apical segment (fang. The fang rests in a groove on the basal segment that is covered by different types of hair. L. singoriensis venom glands present equal size and measure about 4 mm in length. Each gland is enclosed by irregular muscular layers.

  3. Ctenus medius and Phoneutria nigriventer spiders venoms share noxious proinflammatory activities.

    Science.gov (United States)

    Okamoto, Cinthya Kimori; Gonçalves-De-Andrade, Rute M; Queiroz, Giselle Pidde; Gutierez, Vanessa P; De Almeida, Daniel Manzoni; Cury, Yara; Bertani, Rogério; Portaro, Fernanda C V; Tambourgi, Denise V

    2009-01-01

    Ctenus medius Keyserling, 1891 (Araneae: Ctenidae) co-occurs in various microhabitats of the Brazilian Atlantic Forest and can be easily misidentified as the medically important spider Phoneutria nigriventer Keyserling, 1981 (Ctenidae). Despite being phylogenetically close to Phoneutria, no data are available about the toxic potential of Ctenus medius venom. Here we show that, although presenting different profile of protein composition, C. medius venom displays some of the toxic properties exhibited by P. nigriventer venom, including proteolytic, hyaluronidasic and phospholipasic activities, as well as the ability of causing hyperalgesia and edema. Moreover, C. medius venom interferes in the activation of the complement system in concentrations that P. nigriventer venom is inactive. Thus, these data show that venoms of spiders from Ctenidae family share important proinflammatory properties and suggest that the C. medius bite may have an important noxious effect in human accidents.

  4. Bromeliad-living spiders improve host plant nutrition and growth.

    Science.gov (United States)

    Romero, Gustavo Q; Mazzafera, Paulo; Vasconcellos-Neto, Joao; Trivelin, Paulo C O

    2006-04-01

    Although bromeliads are believed to obtain nutrients from debris deposited by animals in their rosettes, there is little evidence to support this assumption. Using stable isotope methods, we found that the Neotropical jumping spider Psecas chapoda (Salticidae), which lives strictly associated with the terrestrial bromeliad Bromelia balansae, contributed 18% of the total nitrogen of its host plant in a greenhouse experiment. In a one-year field experiment, plants with spiders produced leaves 15% longer than plants from which the spiders were excluded. This is the first study to show nutrient provisioning in a spider-plant system. Because several animal species live strictly associated with bromeliad rosettes, this type of facultative mutualism involving the Bromeliaceae may be more common than previously thought.

  5. Bird-eating Spiders

    Institute of Scientific and Technical Information of China (English)

    梁小明

    2002-01-01

    Many people are frightened by spiders (蜘蛛). They are especially afraid of large, hairyones. The largest and most frightening of all is thebird-eating spider, which lives in the hot, thickrain forests of northern South America.

  6. Nature Study Tips. Spiders.

    Science.gov (United States)

    Mulaik, Stanley B.

    1990-01-01

    Different types of spiders, their ranges and habits are discussed. Activities associated with the study of spiders are suggested. Four references are listed which may be of interest to beginners. (CW)

  7. Did You Say Spiders?

    Science.gov (United States)

    Campbell, Alene

    This spider unit focuses on students' development of cooperative learning and inquiry-based skills. Students read "The Very Busy Spider" by Eric Carle, and then work in cooperative groups using the Internet to research and synthesize important information about spiders. Technology is used for vocabulary instruction and to create a…

  8. Die epigäische Spinnenzönose (Araneae auf Schotterbänken der Mittelgebirgsbäche und -flüsse im Rheinischen Schiefergebirge

    Directory of Open Access Journals (Sweden)

    Smit, Janna

    1997-07-01

    Full Text Available The spider communities on gravel bars along streams in lower montainous areas of Northern Hess were investigated. Eight streams differently altered by human impact were studied: four small streams without weirs and impoundments, two regulated small streams and two larger regulated streams. The sampling sites were located in one kilometer streches of the upper, middle and lower reach of each small stream, respectively. In addition the gravel bars in several floodplain sections of larger streams were investigated. Altogether 592 quantitative samples of spiders were made. 7027 spiders (Araneae comprising 77 species were encountered. Only two species (Oedothorax agrestis, Pirata knorri make up more than 70 percent of all spiders captured. Erigone atra and Erigone dentipalpis were frequently foung along all streams investigated. While Diplocephalus permixtus and Diplocephalus protuberans were only encountered along the small streams, Oedothorax retusus and Pardosa amentata were predominantly recorded on gravelbars of large streams. Diplocephalus protuberans was recorded for the first time in Hesse. The mean abundances (median ranged between 4 and 28 individuals/m2. 198 individuals/m2 have been the maximum of abundance.

  9. The Spiders of China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Sevaral books about Chinese spider systematics and biology have been published,mostly since the later 1970s and the majority of then are designed as classification guides to the spider fauna of a particular area of China,or focused on a particular group ,for example Fauna of Zhejiang Province ,Araneida and Salticids of China. The newly published book "The Spiders of China",in English,differs from all others by including all 2361 described Chinese spider species and by reviewing literature of over 200 years of work on Chinese spider classification.

  10. Risk, Jumps, and Diversification

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Law, Tzuo Hann; Tauchen, George

    We test for price discontinuities, or jumps, in a panel of high-frequency intraday returns for forty large-cap stocks and an equiweighted index from these same stocks. Jumps are naturally classified into two types: common and idiosyncratic. Common jumps affect all stocks, albeit to varying degree...

  11. Jumping in Arithmetic

    NARCIS (Netherlands)

    Visser, Albert

    2014-01-01

    In this paper we study a new relation between sentences: the jump relation. The idea of the jump relation is based on an analysis of Feferman's Theorem that the inconsistency of a theory U is interpretable over U. The jump relation is based on a converse of Feferman's Theorem: if a sentence is inter

  12. Orb-weaving spider diversity in the Iberá Marshlands, Argentina.

    Science.gov (United States)

    Rubio, Gonzalo D; Moreno, Claudia E

    2010-01-01

    The Iberá Marshlands RAMSAR reserve, in the northeast of Argentina, is one of the largest and most important wetlands of America. In this study we assess orb-weaving spider (Araneae: Orbiculariae) diversity in this reserve, analyzing different facets of local diversity (species richness, diversity, evenness and taxonomic distinctness), and the contribution of species differentiation (beta diversity) among localities and habitat types to the composition of regional diversity. We found 1657 individuals of 59 orb-weaving spider species/morphospecies. Local diversity differs among the three sampled localities. At the habitat level, the different facets of biodiversity followed a clear pattern, where woodlands have higher species richness, diversity, evenness and taxonomic distinctness than savannas. Savanna sites shared a common spider species composition, while woodland communities have high values of complementarity. Thus, beta diversity has a very high contribution to the regional diversity of the orb-weaving spiders in the Iberá Marshlands. We suggest that conservation management in the reserve should be directed towards promoting natural spatial heterogeneity, giving special protection to habitat mosaics in different localities.

  13. Spiders in caves

    Science.gov (United States)

    2017-01-01

    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. PMID:28446696

  14. Spider-man

    Institute of Scientific and Technical Information of China (English)

    路遇

    2002-01-01

    Spider-Man was first introduced in the comic(连环画) Amazing Fantasy #15(August 1962).Peter Parker,a Senior at Midtown High School,receives his powers when bitten by a exhibition(转基因) spider in a science demonstration(展览).This bite endowed(赋予) him with the proportional(相应的) strength and agility(敏捷) of a spider along with a keen “spider sense”.

  15. Effects of toxin huwentoxin-Ⅲ from the venom of the Chinese bird spider, Ornithoctonus huwena (Araneae: Theraphosidae) on neuronal voltage-gated ion channels in cockroach Periplaneta americana%虎纹捕鸟蛛毒素虎纹毒素-Ⅲ对美洲蜚蠊神经细胞电压门控离子通道的影响

    Institute of Scientific and Technical Information of China (English)

    王瑞兰; 梁宋平

    2009-01-01

    Huwentoxin-Ⅲ purified from the venom of the Chinese bird spider, Ornithoctonus huwena (Wang et al.), is an insect neurotoxic peptide. The effects of huwentoxin-Ⅲ on neuronal voltage-gated ion channels were studied by using whole-cell patch clamp technique. Huwentoxin-Ⅲ specifically inhibited voltage-gated sodium channels in dorsal unpaired median neurons of adult cockroach Periplaneta americana (IC50≈1.106 μmol/L) while having no evident effect on voltage-gated potassium channels. HWTX-Ⅲ inhibited insect voltage-gated sodium channels through a novel mechanism distinctive from other spider toxins, did not affect the activation and inactivation kinetics, and not evidently shift the steady-state inactivation curve. Thus, its specificity and novel mechanism on insect neuronal voltage-gated sodium channels make it an interesting tool for investigating the multiple molecular forms of voltage-gated sodium channels and exploiting new and safe insecticides.%HWTX-Ⅲ是从中国虎纹捕鸟蛛Ornithoctonus huwena粗毒中分离纯化到的一种昆虫神经多肽.通过应用全细胞膜片钳技术研究了HWTX-Ⅲ对美洲蜚蠊Periplaneta americana神经细胞电压门控离子通道的影响.发现HWTX-Ⅲ特异性地抑制美洲蜚蠊背侧不成对中间(dorsal unpaired median,DUM)神经细胞的电压门控钠通道(IC50≈1.106μmol/L),而对电压门控钾通道没有明显的影响.HWTX-Ⅲ通过一种新型的不同于其他蜘蛛毒素的机制抑制昆虫电压门控钠通道,它不影响通道的激活与失活动力学,也不明显地漂移稳态失活曲线.HWTX-Ⅲ对昆虫神经细胞电压门控钠通道的特异性与新型作用机制为研究电压门控钠通道分子结构的多样性以及开发新的安全的杀虫剂提供有用的工具.

  16. Short-term response of soil spiders to cover-crop removal in an organic olive orchard in a Mediterranean setting.

    Science.gov (United States)

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity.

  17. Short-Term Response of Soil Spiders to Cover-Crop Removal in an Organic Olive Orchard in a Mediterranean Setting

    Science.gov (United States)

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity. PMID:22938154

  18. Four new species of the spider genus Nesticella Lehtinen & Saaristo, 1980 from Laos, Thailand and Myanmar and the first description of the male of Nesticella yui Wunderlich & Song, 1995 with a proposed new diagnostic character for the family Nesticidae Simon, 1894 (Arachnida, Araneae).

    Science.gov (United States)

    Grall, Elena; Jäger, Peter

    2016-03-02

    During various expeditions to Laos between 2003 and 2012 and one expedition to Myanmar in 2014, spiders of the family Nesticidae were collected inside and outside of caves. This was the first time this family was encountered in Laos. All specimens belong to the genus Nesticella Lehtinen & Saaristo, 1980. Four species have been recognized as being new to science, which are described in this paper: Nesticella beccus n. sp. (male, female; LAOS: Bolikhamsay Province, Luang Prabang Province, Huaphan Province, Khammouan Province, THAILAND: Mae Hong Son Province), Nesticella laotica n. sp. (male, female; LAOS: Vientiane Province, Huaphan Province, Luang Prabang Province, Bolikhamsay Province), Nesticella foelixi n. sp. (male; LAOS: Bolikhamsay Province) and Nesticella michaliki n. sp. (male, female; MYANMAR: Chin State). The male of Nesticella yui Wunderlich & Song, 1995 is described for the first time and it is the first record for Laos. Results from a first micro-computed tomography analysis of a female copulatory organ for this genus are provided. This analysis proves that female Nesticella exhibit a complex functional receptaculum, which is highly complex within the genus. The presence of a special type of leg setae (pipette setae) in males is proposed as diagnostic for the family Nesticidae.

  19. Spiders and Silk

    Institute of Scientific and Technical Information of China (English)

    熊世民

    2004-01-01

    Spiders are very small, so it is easy to think that they do not make anything strong. However, a scientist at Oxford University in Britain has discovered this is not true. David Knight says that eight-legged spiders create a material called silk that could be as strong as rope.

  20. Disgust and spider phobia

    NARCIS (Netherlands)

    Mulkens, SAN; de Jong, Peter; Merckelbach, H

    1996-01-01

    Twenty-four women with spider phobia and 45 nonphobic women completed the Disgust Questionnaire(DQ; P. Rozin, A. E. Fallen, & R. Mandell, 1984) and the Spider Phobia Questionnaire (SPQ; R. Klorman, T. C. Weerts, J. E. Hastings, B. G. Melamed, gr P. J. Lang, 1974). Participants also underwent behavio

  1. Disgust and spider phobia

    NARCIS (Netherlands)

    Mulkens, SAN; de Jong, Peter; Merckelbach, H

    1996-01-01

    Twenty-four women with spider phobia and 45 nonphobic women completed the Disgust Questionnaire(DQ; P. Rozin, A. E. Fallen, & R. Mandell, 1984) and the Spider Phobia Questionnaire (SPQ; R. Klorman, T. C. Weerts, J. E. Hastings, B. G. Melamed, gr P. J. Lang, 1974). Participants also underwent behavio

  2. Becoming a Spider Scientist

    Science.gov (United States)

    Patrick, Patricia; Getz, Angela

    2008-01-01

    In this integrated unit, third grade students become spider scientists as they observe spiders in their classroom to debunk some common misconceptions about these intimidating creatures. "Charlotte's Web" is used to capture students' interest. In addition to addressing philosophical topics such as growing-up, death, and friendship; E.B. White's…

  3. Steerable Miniature Jumping Robot

    OpenAIRE

    Kovac, Mirko; Schlegel, Manuel; Zufferey, Jean-Christophe; Floreano, Dario

    2010-01-01

    Jumping is used in nature by many small animals to locomote in cluttered environments or in rough terrain. It offers small systems the benefit of overcoming relatively large obstacles at a low energetic cost. In order to be able to perform repetitive jumps in a given direction, it is important to be able to upright after landing, steer and jump again. In this article, we review and evaluate the uprighting and steering principles of existing jumping robots and present a novel spherical robot w...

  4. Potential distribution of the endangered spider Macrothele calpeiana(Araneae, Hexathelidae) and the impact of climate warming%一种濒危大疣蛛的潜在分布区域以及气候变暖的影响

    Institute of Scientific and Technical Information of China (English)

    Alberto JIMENEZ-VALVERDE; Jorge M. LOBO

    2007-01-01

    本研究的目的是 i)确定伊比利亚半岛一种大疣蛛(Macrothele calpeiana)分布的气候相关性以预测其潜在分布,ii) 详细阐述该物种在伊比利亚半岛的分布假说,iii) 通过推断模型预测确认该物种在北非和整个地中海地区的适合区域,iv) 预测气候变暖对蜘蛛潜在分布区的影响.基于物种的存在、远离目前环境条件下的可能缺失以及其它的气候参数,使用广义线性模型发展了潜在分布的可预测模型.蜘蛛在伊比利亚半岛上的潜在分布远大于目前已知的分布区,延伸到尚未发现蜘蛛分布的葡萄牙广大地区.本文提出了该种大疣蛛在适合分布区域内没有分布的历史因素.北非具有适合该物种的条件但却没有该属物种的分布支持了大疣蛛(Macrothele)祖先的东方起源假说.对地中海地区蜘蛛分布的推断突出显示了阿根廷地区有合适的分布区,该地区也发现有另一种欧洲大疣蛛.气候变暖将对现存于伊比利亚的M.calpeiana种群产生负面影响,因为气候变暖将减少并破碎化蜘蛛在北非的潜在栖息地.目前,急需确认在葡萄牙广大地区是否存在蜘蛛物种,发展对该属的系统发育研究以确定大疣蛛属起源和扩散史的理论.%The aims of this contribution are i) to identify major climate correlates of the distribution of Macrothele calpeiana(Walckenaer, 1805) in the Iberian Peninsula in order to predict its potential distribution; ii) to elaborate a hypothesis for the distribution of the spider in the Iberian Peninsula; iii) to identify suitable places for the species in both North Africa and the entire Mediterranean region through extrapolation of model predictions; and iv) to predict the impact of climate warming on the potential spider distribution. Generalized Linear Models were used to develop a potential distribution predictive model. Potential Iberian Peninsula distribution extends through a large part of Portugal

  5. Bat predation by spiders.

    Directory of Open Access Journals (Sweden)

    Martin Nyffeler

    Full Text Available 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.

  6. 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.

  7. Optimal Ski Jump

    Science.gov (United States)

    Rebilas, Krzysztof

    2013-01-01

    Consider a skier who goes down a takeoff ramp, attains a speed "V", and jumps, attempting to land as far as possible down the hill below (Fig. 1). At the moment of takeoff the angle between the skier's velocity and the horizontal is [alpha]. What is the optimal angle [alpha] that makes the jump the longest possible for the fixed magnitude of the…

  8. Jumping Good Fun

    Science.gov (United States)

    Nye, Susan B.

    2010-01-01

    Jumping rope is an activity that can be fun and enjoyable for all students. It requires minimal activity space, can be performed individually or in small groups, and is an inexpensive way to engage students in a lifelong physical activity. Jumping rope is commonly used by coaches and athletes for training purposes to improve aerobic endurance,…

  9. Jumping Good Fun

    Science.gov (United States)

    Nye, Susan B.

    2010-01-01

    Jumping rope is an activity that can be fun and enjoyable for all students. It requires minimal activity space, can be performed individually or in small groups, and is an inexpensive way to engage students in a lifelong physical activity. Jumping rope is commonly used by coaches and athletes for training purposes to improve aerobic endurance,…

  10. Estimation of Jump Tails

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Todorov, Victor

    We propose a new and flexible non-parametric framework for estimating the jump tails of Itô semimartingale processes. The approach is based on a relatively simple-to-implement set of estimating equations associated with the compensator for the jump measure, or its "intensity", that only utilizes ...

  11. 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.

  12. Arachnid aloft: directed aerial descent in neotropical canopy spiders.

    Science.gov (United States)

    Yanoviak, Stephen P; Munk, Yonatan; Dudley, Robert

    2015-09-06

    The behaviour of directed aerial descent has been described for numerous taxa of wingless hexapods as they fall from the tropical rainforest canopy, but is not known in other terrestrial arthropods. Here, we describe similar controlled aerial behaviours for large arboreal spiders in the genus Selenops (Selenopidae). We dropped 59 such spiders from either canopy platforms or tree crowns in Panama and Peru; the majority (93%) directed their aerial trajectories towards and then landed upon nearby tree trunks. Following initial dorsoventral righting when necessary, falling spiders oriented themselves and then translated head-first towards targets; directional changes were correlated with bilaterally asymmetric motions of the anterolaterally extended forelegs. Aerial performance (i.e. the glide index) decreased with increasing body mass and wing loading, but not with projected surface area of the spider. Along with the occurrence of directed aerial descent in ants, jumping bristletails, and other wingless hexapods, this discovery of targeted gliding in selenopid spiders further indicates strong selective pressures against uncontrolled falls into the understory for arboreal taxa. © 2015 The Author(s).

  13. Computed tomography recovers data from historical amber: an example from huntsman spiders

    Science.gov (United States)

    Dunlop, Jason A.; Penney, David; Dalüge, Natalie; Jäger, Peter; McNeil, Andrew; Bradley, Robert S.; Withers, Philip J.; Preziosi, Richard F.

    2011-06-01

    Computed tomography (CT) methods were applied to a problematic fossil spider (Arachnida: Araneae) from the historical Berendt collection of Eocene (ca. 44-49 Ma) Baltic amber. The original specimens of Ocypete crassipes Koch and Berendt 1854 are in dark, oxidised amber and the published descriptions lack detail. Despite this, they were subsequently assigned to the living Pantropical genus Heteropoda Latreille, 1804 and are ostensibly the oldest records of huntsman spiders (Sparassidae) in general. Given their normally large size, and presumptive ability to free themselves more easily from resin, it would be surprising to find a sparassid in amber and traditional (optical) methods of study would likely have left O. crassipes as an equivocal record—probably a nomen dubium. However, phase contrast enhanced X-ray CT revealed exquisite morphological detail and thus `saved' this historical name by revealing characters which confirm that it's a bona fide member both of Sparassidae and the subfamily Eusparassinae. We demonstrate here that CT studies facilitate taxonomic equivalence even between recent spiders and unpromising fossils described in older monographs. In our case, fine structural details such as eye arrangement, cheliceral dentition, and leg characters like a trilobate membrane, spination and claws, allow a precise referral of this fossil to an extant genus as Eusparassus crassipes (Koch and Berendt 1854) comb. nov.

  14. Wolbachia screening in spiders and assessment of horizontal transmission between predator and prey.

    Science.gov (United States)

    Yun, Y; Peng, Y; Liu, F X; Lei, C

    2011-01-01

    Recent studies have revealed that the prevalence of Wolbachia in arthropods is attributable not only to its vertical transmission, but also to its horizontal transfer. In order to assess the horizontal transmission of Wolbachia between predator and prey, arthropods belonging to 11 spider families and six insect families were collected in the same field of rice. The distribution of Wolbachia in these arthropods was detected by diagnostic PCR amplification of the wsp (Wolbachia outer surface protein gene) and 16S rDNA genes. Nurscia albofasciata Strand (Araneae: Titanoecidae), Propylea japonica Thunberg (Coleoptera: Coccinellidae), Paederus fuscipes Curtis (Coleoptera: Staphylinidae), and Nilaparvata lugens Stal (Homoptera: Delphacidae) were infected with Wolbachia. This is the first report of infection of N. albofasciata and P. fuscipes by Wolbachia. No direct evidence indicated the existence of horizontal transmission of Wolbachia between predator and prey.

  15. The effect of ageing on the mechanical properties of the silk of the bridge spider Larinioides cornutus (Clerck, 1757)

    Science.gov (United States)

    Lepore, Emiliano; Isaia, Marco; Mammola, Stefano; Pugno, Nicola

    2016-05-01

    Spider silk is regarded as one of the best natural polymer fibers especially in terms of low density, high tensile strength and high elongation until breaking. Since only a few bio-engineering studies have been focused on spider silk ageing, we conducted nano-tensile tests on the vertical naturally spun silk fibers of the bridge spider Larinioides cornutus (Clerck, 1757) (Arachnida, Araneae) to evaluate changes in the mechanical properties of the silk (ultimate stress and strain, Young’s modulus, toughness) over time. We studied the natural process of silk ageing at different time intervals from spinning (20 seconds up to one month), comparing silk fibers spun from adult spiders collected in the field. Data were analyzed using Linear Mixed Models. We detected a positive trend versus time for the Young’s modulus, indicating that aged silks are stiffer and possibly less effective in catching prey. Moreover, we observed a negative trend for the ultimate strain versus time, attesting a general decrement of the resistance force. These trends are interpreted as being due to the drying of the silk protein chains and the reorientation among the fibers.

  16. Early Environmental Conditions Shape Personality Types in a Jumping Spider

    OpenAIRE

    Liedtke, Jannis; Redekop, Daniel; Jutta M Schneider; Schuett, Wiebke

    2015-01-01

    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 whi...

  17. Descriptions of four kleptoparasitic spiders of the genus Mysmenopsis (Araneae, Mysmenidae) and their potential host spider species in the genus Linothele (Araneae, Dipluridae) from Ecuador.

    Science.gov (United States)

    Dupérré, Nadine; Tapia, Elicio

    2015-06-12

    Four new species of the genus Mysmenopsis are described: M. onorei n. sp., M. otonga n. sp., M. fernandoi n. sp. and M. chiquita n. sp. All species were collected in diplurid webs and are therefore assumed to be kleptoparasitic. Five potential host species of the genus Linothele (Dipluridae) that were collected with the symbionts are also described: Linothele yanachanka n. sp., L. pukachumpi n. sp., L. zaia n. sp., L. tsachilas n. sp. and L. quori n. sp.

  18. Spider webs: Damage control

    Science.gov (United States)

    Omenetto, Fiorenzo G.; Kaplan, David L.

    2012-04-01

    A study reveals that spider orb webs fail in a nonlinear fashion, owing to the hierarchical organization of the silk proteins. The discovery may serve as inspiration for engineers for the design of aerial, light-weight, robust architectures.

  19. Black widow spider (image)

    Science.gov (United States)

    This is a black widow spider. Note the red "hour glass" on the abdomen. The bite of the black widow can produce severe symptoms but is seldom fatal, except in young children and older adults. (Image courtesy ...

  20. Attentional bias to moving spiders in spider fearful individuals.

    NARCIS (Netherlands)

    Vrijsen, J.N.; Fleurkens, P.F.T.; Nieuwboer, W.; Rinck, M.

    2009-01-01

    We investigated if an attentional bias for spiders in spider fearful individuals (SFs) can also be found for moving spiders, rather than static images. In Study 1, 28 SFs and 33 non-anxious controls (NACs) participated in a modified version of the dot probe paradigm: they had to react to a probe

  1. Attentional and behavioural responses of spider fearfuls to virtual spiders

    NARCIS (Netherlands)

    Rinck, M.; Kwakkenbos, C.M.C.; Dotsch, R.; Wigboldus, D.H.J.; Becker, E.S.

    2009-01-01

    This study employed an immersed virtual environment (IVE) in the Nijmegen RIVERlab to study spider fearfuls' attentional and motor reactions to virtual spiders. The participants were exposed to virtual spiders while completing an unrelated task, walking freely through a virtual museum. Compared to

  2. Spider Silk For Future Scaffolds

    OpenAIRE

    Bringhurst, Heidi; Decker, R.; Frisby, S.; Tucker, C.

    2014-01-01

    Spider silk, an ancient biomaterial, has many qualities worth replicating. With the use of genetic modification, relatively large amounts of the spider silk protein have been produced through goat milk. With access to this protein we have worked to create spider silk films and hydrogels. Through chemical and mechanical means, we are discovering treatments that maximize cell growth and cell attachment on spider silk films and hydrogels.

  3. Myocarditis following katipo spider bite.

    Science.gov (United States)

    Crook, Ruth; Harrison, Nigel; Gibbons, Derek

    2010-05-14

    We report the case of a 22-year-old man who developed severe myocarditis following a presumed katipo spider bite. Katipo spiders are thought to be one of the most poisonous native creatures in New Zealand. No deaths from katipo spider bites have been reported since the 19th Century. A literature search reveals no previously reported cases of myocarditis following a bite from a katipo spider. The clinical presentation of latrodectism is discussed.

  4. Spider Silk For Future Scaffolds

    OpenAIRE

    Bringhurst, Heidi; Decker, R.; Frisby, S.; Tucker, C

    2014-01-01

    Spider silk, an ancient biomaterial, has many qualities worth replicating. With the use of genetic modification, relatively large amounts of the spider silk protein have been produced through goat milk. With access to this protein we have worked to create spider silk films and hydrogels. Through chemical and mechanical means, we are discovering treatments that maximize cell growth and cell attachment on spider silk films and hydrogels.

  5. Quantum Walk with Jumps

    CERN Document Server

    Lavička, H; Kiss, T; Lutz, E; Jex, I

    2011-01-01

    We analyze a special class of 1-D quantum walks (QWs) realized using optical multi-ports. We assume non-perfect multi-ports showing errors in the connectivity, i.e. with a small probability the multi- ports can connect not to their nearest neighbor but to another multi-port at a fixed distance - we call this a jump. We study two cases of QW with jumps where multiple displacements can emerge at one timestep. The first case assumes time-correlated jumps (static disorder). In the second case, we choose the positions of jumps randomly in time (dynamic disorder). The probability distributions of position of the QW walker in both instances differ significantly: dynamic disorder leads to a Gaussian-like distribution, while for static disorder we find two distinct behaviors depending on the parity of jump size. In the case of even-sized jumps, the distribution exhibits a three-peak profile around the position of the initial excitation, whereas the probability distribution in the odd case follows a Laplace-like discre...

  6. Jumping on water

    Science.gov (United States)

    Kim, Ho-Young

    2016-11-01

    Water striders can jump on water as high as they can jump on land. Quick jumps allow them to avoid sudden dangers such as predators' attacks, and therefore understanding how they make such a dramatic motion for survival can shed light on the ultimate level of semi-aquatic motility achievable through evolution. However, the mechanism of their vertical jumping from a water surface has eluded hydrodynamic explanations so far. By observing movements of water strider legs and theoretically analyzing their dynamic interactions with deforming liquid-air interface, we have recently found that different species of jumping striders always tune their leg rotation speed with a force just below that required to break the water surface to reach the maximum take-off velocity. Here, we start with discussing the fundamental theories of dynamics of floating and sinking of small objects. The theories then enable us to analyze forces acting on a water strider while it presses down the water surface to fully exploit the capillary force. We further introduce a 68-milligram at-scale robotic insect capable of jumping on water without splash, strikingly similar to the real strider, by utilizing the water surface just as a trampoline.

  7. Funnel-web spider bite

    Science.gov (United States)

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

  8. Desarrollo postembrionario de Latrodectus variegatus (Araneae: Theridiidae)

    OpenAIRE

    2015-01-01

    The Iife cicle of Latrodectus variegatus from cocoons collected in Bariloche, Argentina, is described. In stage IV (first free stage) 361 individually bred spiders were isolated and fed Drosophila melanogaster in the juvenile stage and Musca domestica after wards. "Stage 1" is the stage following eclosion. For the study of survival, and average Iife expectancy, a week wa The Iife cicle of Latrodectus variegatus from cocoons collected in Bariloche, Argentina, is described. In stage IV (firs...

  9. Silk gene expression of theridiid spiders: implications for male-specific silk use.

    Science.gov (United States)

    Correa-Garhwal, Sandra M; Chaw, R Crystal; Clarke, Thomas H; Ayoub, Nadia A; Hayashi, Cheryl Y

    2017-06-01

    Spiders (order Araneae) rely on their silks for essential tasks, such as dispersal, prey capture, and reproduction. Spider silks are largely composed of spidroins, members of a protein family that are synthesized in silk glands. As needed, silk stored in silk glands is extruded through spigots on the spinnerets. Nearly all studies of spider silks have been conducted on females; thus, little is known about male silk biology. To shed light on silk use by males, we compared silk gene expression profiles of mature males to those of females from three cob-web weaving species (Theridiidae). We de novo assembled species-specific male transcriptomes from Latrodectus hesperus, Latrodectus geometricus, and Steatoda grossa followed by differential gene expression analyses. Consistent with their complement of silk spigots, male theridiid spiders express appreciable amounts of aciniform, major ampullate, minor ampullate, and pyriform spidroin genes but not tubuliform spidroin genes. The relative expression levels of particular spidroin genes varied between sexes and species. Because mature males desert their prey-capture webs and become cursorial in their search for mates, we anticipated that major ampullate (dragline) spidroin genes would be the silk genes most highly expressed by males. Indeed, major ampullate spidroin genes had the highest expression in S. grossa males. However, minor ampullate spidroin genes were the most highly expressed spidroin genes in L. geometricus and L. hesperus males. Our expression profiling results suggest species-specific adaptive divergence of silk use by male theridiids. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  10. 智能搜索蜘蛛%Intelligent Search Spiders

    Institute of Scientific and Technical Information of China (English)

    武海燕; 甘利人

    2001-01-01

    The search mechanism and the search process of the intelligent search spiders developed by the University of Arizona, which include Competitive Intelligence (CI) Spider, Meta Spider and Cancer Spider, are introduced. The characteristics of these spiders are summarized.

  11. Spinning hydraulic jump

    Science.gov (United States)

    Abderrahmane, Hamid; Kasimov, Aslan

    2013-11-01

    We report an experimental observation of a new symmetry breaking of circular hydraulic jump into a self-organized structure that consists of a spinning polygonal jump and logarithmic-spiral waves of fluid elevation downstream. The waves are strikingly similar to spiral density waves in galaxies. The fluid flow exhibits counterparts of salient morphological features of galactic flows, in particular the outflow from the center, jets, circum-nuclear rings, gas inflows toward the galactic center, and vortices. The hydrodynamic instability revealed here may have a counterpart that plays a role in the formation and sustainability of spiral arms in galaxies.

  12. Hey! A Black Widow Spider Bit Me!

    Science.gov (United States)

    ... widow spider, tell an adult immediately . Black widow spider bites rarely kill people, but it's important to get ... a medication that fights the venom in the spider's bite, if someone who has been bitten has underlying ...

  13. Spider bites - Assessment and management.

    Science.gov (United States)

    Braitberg, George; Segal, Leslie

    2009-11-01

    Spider bite is common, but most species cause minimal or no effects. Patients may be misinformed regarding the nature and consequences of a bite. Understanding the current literature can assist the physician in the management of spider bite patients. This article reviews the current literature on spider bites and describes the clinical assessment and management of the medically important spider bites. Most spider bite is minor and causes nothing more than local irritation. Some spiders can cause significant morbidity and rarely, mortality. Lay identification of the spider has not been shown to be reliable. Latrodectism (red back spider envenomation) is characterised by pain (local, radiating, and regional); systemic symptoms occur less commonly. Funnel web spider bite is a medical emergency; a pressure immobilisation bandage should be applied and the patient transferred to a hospital with available antivenom and resuscitation facilities. Clinicians must consider spider bite in the differential diagnosis of unexplained autonomic and neurological dysfunction, particularly in children. In Australia, skin ulceration is more likely to be an infective, inflammatory or traumatic cause than a case of necrotising arachnidism.

  14. PATHWAYS TO SPIDER PHOBIA

    NARCIS (Netherlands)

    MERCKELBACH, H; ARNTZ, A; ARRINDELL, WA; DEJONG, PJ

    1992-01-01

    Using a revised version of the Phobic Origin Questionnaire (POQ; Ost, L. G. & Hugdahl, K. Behaviour Research and Therapy, 19,439-477; 1981), the present study examined whether conditioning experiences, modeling experiences, and/or informational learning experiences were more often reported by spider

  15. Spider Web Pattern

    Science.gov (United States)

    2006-01-01

    A delicate pattern, like that of a spider web, appears on top of the Mars residual polar cap, after the seasonal carbon-dioxide ice slab has disappeared. Next spring, these will likely mark the sites of vents when the carbon-dioxide ice cap returns. This Mars Global Surveyor, Mars Orbiter Camera image is about 3-kilometers wide (2-miles).

  16. The Spider Files

    Science.gov (United States)

    McDonald, James; Dominguez, Lynn

    2012-01-01

    As children develop misconceptions about animals they believe are dangerous, they also adopt attitudes that are difficult to change. Changing these attitudes is challenging for teachers. One animal that is easy to find but difficult for children to understand is a spider. As with most wild animals, they are difficult to teach about because…

  17. Geographical distribution of the space-weaving spider, Chibchea salta, from northwestern Argentina: New records and bioclimatic modeling.

    Science.gov (United States)

    Rubio, Gonzalo D; Acosta, Luis E

    2011-01-01

    New records of the spider Chibchea salta Huber 2000 (Araneae, Pholcidae) from northwestern Argentina are provided, and the potential range of this species is modeled. Two presence-only methods, Maxent and Bioclim, were run using 19 bioclimatic parameters at a resolution of 30 arc seconds. The climatic profile of C. salta is described, and the relative importance of the bioclimatic variables is explored. Temperature variables proved to be more decisive to the final range shape. The range predicted with Maxent is slightly larger than with Bioclim, but the latter appears to be more sensitive to the record set bias. Both methods performed well, resulting in predictive ranges consistent with the yungas ecoregion. These results provide an initial insight into the bioclimatic tolerance of C. salta, and by identifying potential areas with no records, such as the sierras on the Salta-Jujuy border, they also help in identifying sites for future sampling efforts.

  18. Faunistic spider collections in the Museum für Naturkunde Berlin: The collection of Erich Hesse

    Directory of Open Access Journals (Sweden)

    Kielhorn, Karl-Hinrich

    2012-12-01

    Full Text Available The ‘Hesse collection’ of spiders (Araneae and harvestmen (Opiliones in the Museum für Naturkunde Berlin is documented. Biographical notes on Erich Hesse – a former arachnid curator at the museum (1921–1940 – are provided. The ‘Hesse collection’ was actually put together by other workers, and can be broadly divided into two parts. One comes from Bielinek (= Bellinchen on the Polish side of the Oder Valley (West Pommerania; now part of the ‘Unteres Odertal’ National Park. This Bielinek material includes notable records of Heriaeus oblongus Simon, 1918 and Gibbaranea ullrichi (Hahn, 1835. The other part of the collection comes from Colbitz-Letzlinger Heide in Saxony-Anhalt, Germany. Notable here are Pistius truncatus (Pallas, 1772 and Philodromus buchari Kubcová, 2004; the latter representing the first record of this species for Saxony-Anhalt.

  19. Spider-Ant Associations: An Updated Review of Myrmecomorphy, Myrmecophily, and Myrmecophagy in Spiders

    Directory of Open Access Journals (Sweden)

    Paula E. Cushing

    2012-01-01

    Full Text Available This paper provides a summary of the extensive theoretical and empirical work that has been carried out in recent years testing the adaptational significance of various spider-ant associations. Hundreds of species of spiders have evolved close relationships with ants and can be classified as myrmecomorphs, myrmecophiles, or myrmecophages. Myrmecomorphs are Batesian mimics. Their close morphological and behavioral resemblance to ants confers strong survival advantages against visually hunting predators. Some species of spiders have become integrated into the ant society as myrmecophiles or symbionts. These spider myrmecophiles gain protection against their own predators, live in an environment with a stable climate, and are typically surrounded by abundant food resources. The adaptations by which this integration is made possible are poorly known, although it is hypothesized that most spider myrmecophiles are chemical mimics and some are even phoretic on their hosts. The third type of spider-ant association discussed is myrmecophagy—or predatory specialization on ants. A table of known spider myrmecophages is provided as is information on their biology and hunting strategies. Myrmecophagy provides these predators with an essentially unlimited food supply and may even confer other protections to the spiders.

  20. Ecology of a bolas spider, Mastophora hutchinsoni: phenology, hunting tactics, and evidence for aggressive chemical mimicry.

    Science.gov (United States)

    Yeargan, Kenneth V

    1988-01-01

    Bolas spiders are relatively rare members of the large family known as orb weavers. Instead of using a typical web to capture prey, late-stadia and adult female bolas spiders swing a droplet of adhesive on a thread at flying insects. Mastophora hutchinsoni (Araneae: Araneidae) is one of five Mastophora species known from the United States and occurs over much of eastern North America. It is univoltine in Kentucky and overwinters in the egg stage. Spiderling emerged in May, the diminutive males matured in late June and early July, and females matured in early September. Eggs were produced from late September to late October or early November. This report is the first complete documentation of the population phenology of any bolas spider. Newly-emerged M. hutchinsoni spiderlings did not use a bolas, but instead hunted by positioning themselves on the underside of leaf margins where they ambushed small arthropods that crawled along the leaf margins. Subadult and adult female M. hutchinsoni used a bolas to capture moths. Only male moths were captured, specifically three species of Noctuidae (bristly cutworm, bronzed cutworm, and smoky tetanolita) and one species of Pyralidae (bluegrass webworm). Among 492 prey captured by more than twenty spiders at two sites during 1985 and 1986, smoky tetanolita moths and bristly cutworm moths accounted for 93% of the total. The flight behavior of approaching moths, the limited taxa caught from a large available moth fauna, and the fact that only males were caught support the hypothesis that the spider attracts its prey by producing chemicals which mimic the sex pheromones of these moth species. Adult female M. hutchinsoni frequently captured more than one moth species on a given night. The two most common prey species were active at different times of night, the bristly cutworm soon after nightfall and the smoky tetanolita generally between 11:00 p.m. and dawn. This pattern suggests that mating activity of these moth species may be

  1. Revisiting the taxonomy of the rare and tiny comb-footed spider Carniella brignolii (Araneae, Theridiidae

    Directory of Open Access Journals (Sweden)

    Thaler-Knoflach, Barbara

    2014-05-01

    Full Text Available Carniella brignolii Thaler & Steinberger, 1988 was first described based on a male from Austria and still belongs to the rare, scarcely studied species. Based on material from Germany and Switzerland the hitherto unknown female now can be assigned and presented. In this context a new synonymy is also proposed: The cave-dwelling, troglomorphic C. mihaili (Georgescu, 1989 from Romania, originally established as new genus Marianana, is synonymised with C. brignolii.

  2. A new genus of Neotropical spiders of the family Sparassidae (Arachnida: Araneae

    Directory of Open Access Journals (Sweden)

    Elaine Cristina Pinto

    Full Text Available ABSTRACT Nungara gen. nov. is proposed to include the type species, Nungara niveomaculata (Mello-Leitão, 1941 comb. nov., transferred from Olios Walckenaer, 1837 and two new species, described from males and females: N. anama sp. nov., from the states of Sergipe, Alagoas and Espírito Santo, and N. gaturama sp. nov., from the states of Sergipe, Bahia and Espírito Santo, all in Brazil. The new genus is distinguished from all other Neotropical sparassid genera by the presence of a deep tegular groove on the male palpal bulb and a hood-like projection on the median septum of the female epigyne. In addition, Olios fuscovariatus Mello-Leitão, 1943, Stasina koluene Mello-Leitão, 1941 and Polybetes proximus Mello-Leitão, 1943 are transferred to Nungara gen. nov. and considered junior synonyms of N. niveomaculata . All species are described and illustrated and a distribution map is provided.

  3. Redescription of the poorly known crab spider Firmicus bivittatus (Araneae: Thomisidae

    Directory of Open Access Journals (Sweden)

    Deltshev, Christo

    2017-04-01

    Full Text Available Firmicus bivittatus Simon, 1895 was described from the Edough Mt, Algeria, based on one male only. Here, a redescription and new illustrations of the species based on the existing type material is presented. The female is figured for the first time.

  4. West African pholcid spiders: an overview, with descriptions of five new species (Araneae, Pholcidae

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    Bernhard A. Huber

    2013-10-01

    Full Text Available This paper summarizes current knowledge about West African pholcids. West Africa is here defined as the area south of 17°N and west of 5°E, including mainly the Upper Guinean subregion of the Guineo-Congolian center of endemism. This includes all of Senegal, The Gambia, Guinea Bissau, Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Togo and Benin. An annotated list of the 14 genera and 38 species recorded from this area is given, together with distribution maps and an identification key to genera. Five species are newly described: Anansus atewa sp. nov., Artema bunkpurugu sp. nov., Leptopholcus kintampo sp. nov., Spermophora akwamu sp. nov., and S. ziama sp. nov. The female of Quamtana kitahurira is newly described. Additional new records are given for 16 previously described species, including 33 new country records. Distribution patterns of West African pholcids are discussed, as well as possible explanations for relatively low West African pholcid species diversity as compared to Central and East Africa.

  5. New records and geographical distribution of ctenid spiders (Araneae: Ctenidae) in Colombia.

    Science.gov (United States)

    Hazzi, Nicolás A; Valderrama-Ardila, Carlos; Brescovit, Antonio D; Polotow, Daniele; Simó, Miguel

    2013-01-01

    This study provides new records, geographical distribution extensions and a checklist of the current ctenids species in Colombia based on the review of four arachnological collections and published literature. A total of 15 new records for Ctenidae in Colombia are reported; nine of these species are new records for the country and the distribution of the remaining six is expanded. The genus Centroctenus Mello-Leitão, 1929 (C. ocelliventer Strand, 1909) is recorded for first time in Colombia and Cupiennius coccineus (F.O. Pickard-Cambridge, 1901) for South America. Due to the strategic geographic position of Colombia, which is a transition zone between Southern and Central American biotas, species inventories in different localities are important to fill distributional gaps. The number of known species of ctenids in Colombia is increased from 16 to 25 and these data will be useful for future studies in taxonomy, systematics and biogeography of this family.

  6. A new species of the spider genus Taranucnus from Ukraine (Araneae, Linyphiidae).

    Science.gov (United States)

    Gnelitsa, Valery A

    2016-04-11

    Currently the linyphiid genus Taranucnus includes four species: T. setosus (O. P.-Cambridge, 1863), the type species with Palearctic distribution, T. bihari Fage, 1931 (Eastern Europe), T. nishikii Yaginuma, 1972 (Japan) and T. ornithes (Barrows, 1940)(USA). In Ukraine Taranucnus is represented by two species, T. setosus and T. bihari. A detailed study of the male mentioned earlier as Taranucnus sp. (Chumak, Prokopenko & Tymochko 2007; Prokopenko, Chumak 2007), and several females close to T. bihari Fage, 1931 revealed a new species of this genus. Since it is hard to clarify the position of some of these females we report them below as T. cf. bihari.

  7. Phantoms of Gondwana?-phylogeny of the spider subfamily Mynogleninae (Araneae: Linyphiidae)

    DEFF Research Database (Denmark)

    Frick, Holger; Scharff, Nikolaj

    2014-01-01

    and Micronetini), and Erigoninae, and a representative of the family Pimoidae, the sister-group to Linyphiidae. No fewer than 147 of the morphological characters used in this study are new and defined for this study, and come mainly from male and female genitalia. Parsimony analysis with equal weights resulted......This is the first genus-level phylogeny of the subfamily Mynogleninae. It is based on 190 morphological characters scored for 44 taxa: 37 mynoglenine taxa (ingroup) representing 15 of the 17 known genera and seven outgroup taxa representing the subfamilies Stemonyphantinae, Linyphiinae (Linyphiini...... in three most parsimonious trees of length 871. The monophyly of the subfamily Mynogleninae and the genera Novafroneta, Parafroneta, Laminafroneta, Afroneta, Promynoglenes, Metamynoglenes, and Haplinis are supported, whereas Pseudafroneta is paraphyletic. The remaining seven mynoglenine genera are either...

  8. Taxonomic notes on the crab spider genus Tobias Simon, 1895 (Araneae, Thomisidae, Stephanopinae).

    Science.gov (United States)

    Machado, Miguel; Teixeira, Renato Augusto; Lise, Arno Antonio

    2015-10-30

    The males of Tobias caudatus Mello-Leitão, 1929 and Tobias pustulosus Simon, 1929 are described for the first time, females are redescribed and both sexes are illustrated. New distribution records are presented for both species. Tobias monstruosus Mello-Leitão, 1929 is considered a junior synonym of T. pustulosus. The types of Tobias albovittatus Caporiacco, 1954, and Tobias gradiens Mello-Leitão, 1929 are lost, and Tobias albicans Mello-Leitão, 1929 and Tobias corticatus Mello-Leitão, 1917 are known only from poorly preserved specimens, thus they all are considered nomina dubia.

  9. Trapdoor spiders of the genus Cyclocosmia Ausserer, 1871 from China and Vietnam (Araneae, Ctenizidae)

    Science.gov (United States)

    Xu, Xin; Xu, Chen; Li, Fan; Pham, Dinh Sac; Li, Daiqin

    2017-01-01

    Abstract A species of the genus Cyclocosmia Ausserer, 1871 collected from Guizhou Province, China is diagnosed and described as new to science: Cyclocosmia liui Xu, Xu & Li, sp. n. (♀). New records of Cyclocosmia latusicosta Zhu, Zhang & Zhang, 2006 (♀) from China (Yunnan Province) and Vietnam (Vinh Phuc Province, Ninh Binh Province), and Cyclocosmia ricketti (Pocock, 1901) collected from Jiangxi Province, China are also reported in this study. PMID:28144177

  10. Revision of the enigmatic Southeast Asian spider genus Savarna (Araneae, Pholcidae

    Directory of Open Access Journals (Sweden)

    Bernhard A. Huber

    2015-12-01

    Full Text Available The genus Savarna Huber, 2005 was previously one of the most poorly known Pholcinae genera. Less than 20 specimens (representing four nominal species were available worldwide; nothing was known about ultrastructure, natural history, or relationships. We present the first SEM data, supporting the position of the genus in Pholcinae outside the Pholcus group of genera and weakly suggesting a closer relationship with the genera Khorata Huber, 2005, Spermophorides Wunderlich, 1992, and two undescribed species of unknown affinity from Borneo. We provide the first data about microhabitat, web structure, and reaction to disturbance. We clarify the type locality of Savarna tessellata (Simon, 1901 (“Jalor, Biserat” and describe topotypical material. We describe the previously unknown male of Spermophora miser Bristowe, 1952 and transfer the species (that was previously considered incertae sedis to Savarna as Savarna miser (Bristowe, 1952 comb. nov. Savarna baso (Roewer, 1963 is newly synonymized with S. miser. We newly describe the most northern species in the genus, Savarna kaeo sp. nov., and provide amendments to the descriptions of all previously described species.

  11. A new genus of huntsman spiders (Araneae, Sparassidae, Sparianthinae) from the Neotropical region.

    Science.gov (United States)

    Rheims, Cristina A

    2013-11-06

    Uaiuara gen. nov. is described to include Sparianthis amazonica Simon from Brazil, Sparianthis barroana Chamberlin from Panama, and five new species, namely: Uaiuara quyguaba sp. nov. from the states of Amazonas, Pará and Amapá; Uaiuara ope sp. nov. from Acre and Uaiuara jirau sp. nov. from Rondônia, all in northern Brazil, Uaiuara palenque sp. nov. from Ecuador and Uaiuara dianae sp. nov. from Peru. The genus is easily distinguished from the remaining Neotropical Sparianthinae by the very recurved anterior eye row, the large number of ventral spines on tibiae of legs I-II, the retrolateral grove on the male palpal cymbium and the convoluted duct system of the female vulva. In addition, the female of S. barroana and the male of S. amazonica are described for the first time. The latter species is newly recorded from Colombia, Suriname, Ecuador and Bolivia.

  12. Some faunistical remarks on spiders of the genus Haplodrassus (Araneae: Gnaphosidae from Turkey

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    Seyyar O.

    2011-01-01

    Full Text Available The characteristic features of Haplodrassus mediterraneus Levy, 2004 and Haplodrassus silvestris (Blackwall, 1833, which are recorded for the first time in Turkey, are presented in this paper. Digital and SEM photographs of genitalia of the new recorded species are presented together with their zoogeographical distributions.

  13. Taxonomic review of the New World spider genus Elaver O. Pickard-Cambridge, 1898 (Araneae, Clubionidae).

    Science.gov (United States)

    Saturnino, Regiane; Bonaldo, Alexandre Bragio

    2015-11-23

    Elaver O. Pickard-Cambridge, 1898 is characterized and redescribed, including 49 species occurring from the United States to Argentina. Thirty seven previously known species are redescribed: Elaver achuca (Roddy, 1966) revalidated, E. balboae (Chickering, 1937), E. barroana (Chickering, 1937), E. calcarata (Kraus, 1955), E. carlota (Bryant, 1940), E. chisosa (Roddy, 1966), E. crinophora (Franganillo, 1934), E. crocota (O. Pickard-Cambridge, 1896), E. albicans (Franganillo, 1930) name restored, E. depuncta O. Pickard-Cambridge, 1898, E. elaver (Bryant, 1940), E. excepta (L. Koch, 1866), E. grandivulva (Mello-Leitão, 1930), E. hortoni (Chickering, 1937), E. implicata (Gertsch, 1941), E. juana (Bryant, 1940), E. kohlsi (Gertsch & Jellison, 1939), E. linguata (F.O. Pickard-Cambridge, 1900), E. madera (Roddy, 1966), E. mirabilis (O. Pickard-Cambridge, 1896) new. comb., E. mulaiki (Gertsch, 1935), E. multinotata (Chickering, 1937), E. orvillei (Chickering, 1937), E. placida O. Pickard-Cambridge, 1898, E. portoricensis (Petrunkevitch, 1930), E. quadrata (Kraus, 1955), E. richardi (Gertsch, 1941), E. sericea O. Pickard-Cambridge, 1898, E. sigillata (Petrunkevitch, 1925), E. simplex (O. Pickard-Cambridge, 1896), E. texana (Gertsch, 1933), E. tigrina O. Pickard-Cambridge, 1898 name restored, E. tricuspis (F.O. Pickard-Cambridge, 1900), E. tristani (Banks, 1909), E. tumivulva (Banks, 1909), E. valvula (F.O. Pickard-Cambridge, 1900) and E. wheeleri (Roewer, 1933). Ten new species are described: E. candelaria n. sp. and E. helenae n. sp. from Mexico; E. arawakan n. sp. from Haiti; E. lizae n. sp. from Costa Rica; E. darwichi n. sp. from Ecuador; E. juruti n. sp., E. tourinhoae n. sp. and E. vieirae n. sp. from Brazil; E. shinguito n. sp. from Peru and E. beni n. sp. from Bolivia. The female of E. hortoni is described for the first time. Lectotypes are designated for E. sigillata and its actual female is described for the first time. Four new synonyms are proposed: E. languida (Gertsch, 1941) is synonimized with E. multinotata; E. dorothea (Gertsch, 1935) with E. wheeleri; E. exempta (Gertsch & Davis, 1940) with E. placida and E. vulnerata (Kraus, 1955) with E. calcarata. The drawings in the original descriptions of E. kawitpaaia (Barrion & Litsinger, 1995) and E. turongdaliriana (Barrion & Litsinger, 1995) are sufficiently informative to exclude these species from Elaver but not to accurately establish its generic affiliation. Thus, until the types become available for examination, these species must remain as Clubionidae incertae sedis. Heterochemmis (F.O. Pickard-Cambridge, 1900) is synonymized with Elaver and Heterochemmis mutatus Gertsch & Davis,1940 is recognized as a junior synonym of Elaver mirabilis n. comb., the type species of Heterochemmis. New records are presented for E. valvula, E. balboae, E. brevipes (Keyserling, 1891), E. grandivulva and E. lutescens (Schmidt, 1971). Two species described by Franganillo, E. tenera (Franganillo, 1935) and E. tenuis (Franganillo, 1935), are considered species inquirendae.

  14. Two new species of the spider genus Alpaida (Araneae: Araneidae from restinga areas in Brazil

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    Gracielle F. Braga-Pereira

    2013-06-01

    Full Text Available Two new species of Alpaida O.P.-Cambridge, 1889 are described based on male and female specimens from seven restinga areas from northeastern to southern Brazil. Alpaida teresinha sp. nov., from Rio de Janeiro and Espírito Santo, differs from other species of the genus in the wider lobe of the conductor, the concave median apophysis and with the posterior lobe ventrally positioned, and the wrinkled distal projection of the terminal apophysis in males. Females can be recognized by having widely spaced epigynal lips and by the narrow epigynal notch in ventral view. Alpaida toninho sp. nov., from Bahia, Espírito Santo, Rio de Janeiro and Santa Catarina, can be distinguished by the round lobes of the terminal apophysis, and by the median apophysis with a distal lobe and a projection in males, and by the epigynum elliptical, with a short scape in females.

  15. Three spider species of the genus Mimetus Hentz, 1832 (Araneae, Mimetidae from China

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    Chen Zeng

    2016-10-01

    Full Text Available The present paper deals with three species of the genus Mimetus from China, including M. echinatus Wang, 1990, M. lamelliformis sp. n. (male, and M. wangi sp. n. (female and male. M. lamelliformis differs from the related species M. echinatus Wang, 1990 by: cymbial tip with several slender long macrosetae; cymbium boat-shaped, length/width ratio about 3/1 in retrolateral view; vexillum about 1/2 length of cymbium in retrolateral view. M. wangi sp. n. differs from the related species M. sinicus Song & Zhu, 1993 by: the opisthosoma with a pair of distinct outgrowths in the dorsum; sperm duct nearly horizontal; spermathecae kidney shaped and contiguous. Photos of body and copulatory organs, line drawings of copulatory organs, as well as the locality map are provided.

  16. More than a safety line: jump-stabilizing silk of salticids.

    Science.gov (United States)

    Chen, Yung-Kang; Liao, Chen-Pan; Tsai, Feng-Yueh; Chi, Kai-Jung

    2013-10-06

    Salticids are diurnal hunters known for acute vision, remarkable predatory strategies and jumping ability. Like other jumpers, they strive for stability and smooth landings. Instead of using inertia from swinging appendages or aerodynamic forces by flapping wings as in other organisms, we show that salticids use a different mechanism for in-air stability by using dragline silk, which was previously believed to function solely as a safety line. Analyses from high-speed images of jumps by the salticid Hasarius adansoni demonstrate that despite being subject to rearward pitch at take-off, spiders with dragline silk can change body orientation in the air. Instantaneous drag and silk forces calculated from kinematic data further suggest a comparable contribution to deceleration and energy dissipation, and reveal that adjustments by the spider to the silk force can reverse its body pitch for a predictable and optimal landing. Without silk, upright-landing spiders would slip or even tumble, deferring completion of landing. Thus, for salticids, dragline silk is critical for dynamic stability and prey-capture efficiency. The dynamic functioning of dragline silk revealed in this study can advance the understanding of silk's physiological control over material properties and its significance to spider ecology and evolution, and also provide inspiration for future manoeuvrable robot designs.

  17. Aspectos ecológicos da comunidade de Araneae (Arthropoda, Arachnida em copas da palmeira Attalea phalerata Mart. (Arecaceae no Pantanal de Poconé, Mato Grosso, Brasil

    Directory of Open Access Journals (Sweden)

    Leandro Dênis Battirola

    2004-01-01

    Full Text Available Seis palmeiras de Attalea phalerata foram amostradas durante a fase aquática (cheia no Pantanal de Mato Grosso (fevereiro/2001, utilizando-se a metodologia de nebulização de copas "canopy fogging". Este estudo objetivou avaliar a composição, distribuição espacial, guildas comportamentais, biomassa e sazonalidade da comunidade de Araneae em copas dessa palmeira que forma adensamentos monodominantes, típicos nessa região. Um total de 1326 aranhas foram coletadas em 99 m² de área amostral (13,4 + 8,2 indivíduos/m², representando 20 famílias, sendo Salticidae e Araneidae as mais abundantes. A biomassa total de 704 aranhas em três palmeiras correspondeu a 0.6172 mg de peso seco (0,0123+ 0,04 mg/m². Dez guildas comportamentais demonstraram a coexistência de diferentes espécies em um mesmo habitat. Representantes de Salticidae, Oonopidae e Ctenidae dominaram entre as caçadoras, e Araneidae e Dictynidae, dentre as tecelãs. A análise de distribuição espacial demonstrou que a maior abundância de aranhas ocorreu na região central da copa, provavelmente devido à quantidade de recursos disponíveis nesse local. A comparação desses resultados com aqueles obtidos durante o período de seca, demonstra diferenças sazonais influenciadas pelo pulso de inundação, principalmente com relação à composição das famílias amostradas entre os períodos de seca e cheia.Ecological aspects of a community of Araneae (Arthropoda, Arachnida at the canopy of the palm Attalea phalerata Mart. (Arecaceae in the Pantanal of Poconé, Mato Grosso, Brazil. Six palm trees of Attalea phalerata were sampled during the aquatic phase (high water in the Pantanal of Mato Grosso (February 2001 using canopy fogging. The objective was to evaluate the composition, spatial distribution, behavioural guilds, biomass and seasonality of the community of Araneae at the crowns of these palm trees, which form monospecific stands that are typical of this region. A total

  18. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  19. Extended spider cognition.

    Science.gov (United States)

    Japyassú, Hilton F; Laland, Kevin N

    2017-05-01

    There is a tension between the conception of cognition as a central nervous system (CNS) process and a view of cognition as extending towards the body or the contiguous environment. The centralised conception requires large or complex nervous systems to cope with complex environments. Conversely, the extended conception involves the outsourcing of information processing to the body or environment, thus making fewer demands on the processing power of the CNS. The evolution of extended cognition should be particularly favoured among small, generalist predators such as spiders, and here, we review the literature to evaluate the fit of empirical data with these contrasting models of cognition. Spiders do not seem to be cognitively limited, displaying a large diversity of learning processes, from habituation to contextual learning, including a sense of numerosity. To tease apart the central from the extended cognition, we apply the mutual manipulability criterion, testing the existence of reciprocal causal links between the putative elements of the system. We conclude that the web threads and configurations are integral parts of the cognitive systems. The extension of cognition to the web helps to explain some puzzling features of spider behaviour and seems to promote evolvability within the group, enhancing innovation through cognitive connectivity to variable habitat features. Graded changes in relative brain size could also be explained by outsourcing information processing to environmental features. More generally, niche-constructed structures emerge as prime candidates for extending animal cognition, generating the selective pressures that help to shape the evolving cognitive system.

  20. Araneofauna (Arachnida: Araneae en cultivos de algodón (Gossypium hirsutum transgénicos y convencionales en el norte de Santa Fe, Argentina

    Directory of Open Access Journals (Sweden)

    Melina Soledad Almada

    2012-06-01

    Full Text Available Las arañas tienen un valor potencial considerable por su rol depredador de insectos, estas son plagas de la agricultura. Durante la campaña agrícola 2005/06, en INTA Reconquista, Santa Fe (Argentina se estudio la composición de arañas presentes en cultivos de algodón transgénico y convencional, mediante un diseño experimental de bloques completos al azar, con tres repeticiones y tres tratamientos: algodón transgénico Bt (ALBt, algodón convencional sin control químico (ALCSC y con control químico (ALCCC. Semanalmente, se capturaron arañas, con una red entomológica de arrastre, paño vertical de 1m y trampas de caída. Asimismo se recolectaron 1 255 ejemplares (16 familias y 32 especies. Siete familias se presentaron en los tres tratamientos, donde predomino Thomisidae (n=1 051, 84.04% y Araneidae (n=83, 6.64%. El gremio cazadoras por emboscada (n=1 053, 83.91%, “Tejedoras de telas orbiculares” (n=85, 6.77% y “Cazadoras al acecho” (n=53, 4.22% fueron las más abundantes. No hubo diferencias significativas en los índices de diversidad entre tratamientos. Las arañas se presentaron durante todo el ciclo del cultivo, con picos en las semanas de floración y madurez de las capsulas, además la mayor abundancia la encontramos en el ALBt. Este trabajo constituye el primer registro sobre la comunidad de arañas en cultivos de algodón para Argentina.Arachnofauna (Araneae: Araneae in transgenic and conventional cotton crops (Gossypiumhirsutum in the North of Santa Fe, Argentina. Spiders have considerable potential importance for their role as predators to some pests in agricultural systems. The composition of spiders in transgenic and conventional cotton at the Research Station of INTA Reconquista (Santa Fe was studied during the 2005-2006 season. The experiment was a complete randomized block design with three replications and three treatments: transgenic Bt cotton (ALBt, conventional cotton without chemical control (ALCSC, and

  1. Spider Movement, UV Reflectance and Size, but Not Spider Crypsis, Affect the Response of Honeybees to Australian Crab Spiders

    Science.gov (United States)

    Llandres, Ana L.; Rodríguez-Gironés, Miguel A.

    2011-01-01

    According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees. PMID:21359183

  2. Non-pest prey do not disrupt aphid predation by a web-building spider.

    Science.gov (United States)

    Welch, K D; Whitney, T D; Harwood, J D

    2016-02-01

    A generalist predator's ability to contribute to biological control is influenced by the decisions it makes during foraging. Predators often use flexible foraging tactics, which allows them to pursue specific types of prey at the cost of reducing the likelihood of capturing other types of prey. When a pest insect has low nutritional quality or palatability for a predator, the predator is likely to reject that prey in favour of pursuing alternative, non-pest prey. This is often thought to limit the effectiveness of generalist predators in consuming aphids, which are of low nutritional quality for many generalist predators. Here, we report behavioural assays that test the hypothesis that the generalist predator, Grammonota inornata (Araneae: Linyphiidae), preferentially forages for a non-pest prey with high nutritional quality (springtails), and rejects a pest prey with low nutritional quality (aphids). In no-choice assays, molecular gut-content analysis revealed that spiders continued to feed on the low-quality aphids at high rates, even when high-quality springtails were readily available. When provided a choice between aphids and springtails in two-way choice tests, spiders did not show the expected preference for springtails. Decision-making by spiders during foraging therefore appears to be sub-optimal, possibly because of attraction to the less frequently encountered of two preys as part of a dietary diversification strategy. These results indicate that behavioural preferences alone do not necessarily compromise the pest-suppression capacity of natural enemies: even nutritionally sub-optimal pest prey can potentially be subject to predation and suppression by natural enemies.

  3. Molecular spiders on a plane

    Science.gov (United States)

    Antal, Tibor; Krapivsky, P. L.

    2012-06-01

    Synthetic biomolecular spiders with “legs” made of single-stranded segments of DNA can move on a surface covered by single-stranded segments of DNA called substrates when the substrate DNA is complementary to the leg DNA. If the motion of a spider does not affect the substrates, the spider behaves asymptotically as a random walk. We study the diffusion coefficient and the number of visited sites for spiders moving on the square lattice with a substrate in each lattice site. The spider's legs hop to nearest-neighbor sites with the constraint that the distance between any two legs cannot exceed a maximal span. We establish analytic results for bipedal spiders, and investigate multileg spiders numerically. In experimental realizations legs usually convert substrates into products (visited sites). The binding of legs to products is weaker, so the hopping rate from the substrates is smaller. This makes the problem non-Markovian and we investigate it numerically. We demonstrate the emergence of a counterintuitive behavior—the more spiders are slowed down on unvisited sites, the more motile they become.

  4. Kleptoparasites or commensals? Effects of Argyrodes antipodianus (Araneae: Theridiidae) on Nephila plumipes (Araneae: Tetragnathidae).

    Science.gov (United States)

    Grostal, Paul; Walter, David Evans

    1997-08-01

    Argyrodes antipodianus is a small kleptobiotic spider that steals prey from webs of the large orb-weaving spider Nephila plumipes, and sometimes removes the web itself. We used experiments in a greenhouse to test how the presence of the kleptobiont, differences in food availability, and web damage affected fitness of the web owner. After 49 days, N. plumipes with four A. antipodianus on their webs gained 55% less weight and relocated their webs 4.5 times as often as spiders with no kleptobionts. Increased web relocation and decreased weight gain may have resulted from reduced prey levels or from web damage by A. antipodianus. A second experiment demonstrated that hosts gained weight at the feeding rate used in the first experiment, but not at lower rates. Web relocation rate also varied with feeding rate, but in a non-linear manner. Web loss was evaluated in a separate experiment, by manually removing one-quarter of the web every 5 days for 30 days; however, neither weight gain nor rate of web relocation were affected. We conclude that A. antipodianus is a true kleptoparasite that can reduce the growth rate of its host N. plumipes, but that neither food theft nor web damage alone explain increased web relocation rates.

  5. Toward spinning artificial spider silk.

    Science.gov (United States)

    Rising, Anna; Johansson, Jan

    2015-05-01

    Spider silk is strong and extensible but still biodegradable and well tolerated when implanted, making it the ultimate biomaterial. Shortcomings that arise in replicating spider silk are due to the use of recombinant spider silk proteins (spidroins) that lack native domains, the use of denaturing conditions under purification and spinning and the fact that the understanding of how spiders control silk formation is incomplete. Recent progress has unraveled the molecular mechanisms of the spidroin N- and C-terminal nonrepetitive domains (NTs and CTs) and revealed the pH and ion gradients in spiders' silk glands, clarifying how spidroin solubility is maintained and how silk is formed in a fraction of a second. Protons and CO2, generated by carbonic anhydrase, affect the stability and structures of the NT and CT in different ways. These insights should allow the design of conditions and devices for the spinning of recombinant spidroins into native-like silk.

  6. 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.

  7. Economic analysis of spider web airline networks

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The distinct network organization, management, service and operating characteristics of US Southwest Airlines are key elements of its success compared with other airlines. As a network organization type, the spider web airline network has received more attention. In this paper, we analyzed the relation between the spider web airline network and spider web, and the structure of spider web airline network, built the assignment model of the spider web airline network,and investigated the economics concerned.

  8. Ridge jump process in Iceland

    OpenAIRE

    Garcia, Sebastian

    2010-01-01

    Eastward ridge jumps bring the volcanic zones of Iceland back to the centre of the hotspot in response to the absolute westward drift of the Mid-Atlantic Ridge. Mantellic pulses triggers these ridge jumps. One of them is occurring in Southern Iceland, whereas the exact conditions of the last ridge jump in Northern Iceland remain controversial. The diachronous evolution of these two parts of Iceland may be related to the asymmetric plume-ridge interaction when comparing Northern and Southern I...

  9. and the CMJ jump height

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2016-04-01

    Full Text Available Study aim: The elastic potential energy accumulated in the musculotendinous units during the countermovement phase of a jump adds up to the energy supplied by the contracting muscles used in the take-off phase. Consequently, the total mechanical energy used during the jump may reach higher values. Stiffness represents a quantitative measure of a body’s elastic properties. Therefore, the aim of this study was to establish the relationship between leg stiffness and the countermovement jump height.

  10. 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

  11. Exploring Lightning Jump Characteristics

    Science.gov (United States)

    Chronis, Themis; Carey, Larry D.; Schultz, Christopher J.; Schultz, Elise; Calhoun, Kristin; Goodman, Steven J.

    2014-01-01

    This study is concerned with the characteristics of storms exhibiting an abrupt temporal increase in the total lightning flash rate (i.e., lightning jump, LJ). An automated storm tracking method is used to identify storm "clusters" and total lightning activity from three different lightning detection systems over Oklahoma, northern Alabama and Washington, D.C. On average and for different employed thresholds, the clusters that encompass at least one LJ (LJ1) last longer, relate to higher Maximum Expected Size of Hail, Vertical Integrated Liquid and lightning flash rates (area-normalized) than the clusters that did not exhibit any LJ (LJ0). The respective mean values for LJ1 (LJ0) clusters are 80 min (35 min), 14 mm (8 mm), 25 kg per square meter (18 kg per square meter) and 0.05 flash per min per square kilometer (0.01 flash per min per square kilometer). Furthermore, the LJ1 clusters are also characterized by slower decaying autocorrelation functions, a result that implies a less "random" behavior in the temporal flash rate evolution. In addition, the temporal occurrence of the last LJ provides an estimate of the time remaining to the storm's dissipation. Depending of the LJ strength (i.e., varying thresholds), these values typically range between 20-60 min, with stronger jumps indicating more time until storm decay. This study's results support the hypothesis that the LJ is a proxy for the storm's kinematic and microphysical state rather than a coincidental value.

  12. More Puddle Jumping

    Science.gov (United States)

    Attari, Babak; Weislogel, Mark; Wollman, Andrew; Chen, Yongkang; Snyder, Trevor

    2016-11-01

    Large droplets and puddles jump spontaneously from sufficiently hydrophobic surfaces during routine drop tower tests. The simple low-cost passive mechanism can in turn be used as an experimental device to investigate dynamic droplet phenomena for drops up to 10,000 times larger than their normal terrestrial counterparts. We provide or confirm quick and qualitative design guides for such 'drop shooters' as employed in drop tower tests including relationships to predict droplet ejection durations and velocities as functions of drop volume, surface texture, surface contour, wettability pattern, drop volume, and fluid properties including contact angle. The latter are determined via profile image comparisons with numerical equilibrium interface computations. Water drop volumes of 0.04 to 400 mL at ejection speeds of -0.007 to 0.12 m/s are demonstrated. An example application of the puddle jump method is made to the classic problem of regime mapping for low-gravity phase change heat transfer for large impinging drops. Many other candidate problems might be identified.

  13. Notes on Mediterranean Theridiidae (Araneae – II

    Directory of Open Access Journals (Sweden)

    Barbara Knoflach

    2009-07-01

    Full Text Available Taxonomic and faunistic amendments are provided for 15 species and one subspecies of comb-footed spiders (Theridiidae of the Mediterranean region, in the genera Anatolidion, Episinus, Heterotheridion, Theridion and Theridula. The following taxonomic changes are proposed: Anatolidion osmani Wunderlich, 2008 and Theridion crinigerum Simon, 1881 are synonymised with T. gentile Simon, 1881, making it the type species of the monotypic genus Anatolidion Wunderlich, 2008. Episinus albescens Denis, 1965 is synonymised with E. algiricus Lucas, 1846, Theridion xinjiangense (Hu & Wu, 1989 with Heterotheridion nigrovariegatum (Simon, 1873. Theridion aelleni Hubert, 1970 is removed from synonymy of Theridion spinitarse O. P.-Cambridge, 1876 and transferred to Theridula. The recent transfer of Theridion pinicola Simon, 1873 and T. genistae Simon, 1873 into Paidiscura has to be rejected. Theridion genistae turanicum Charitonov, 1946 from Uzbekistan is raised to species level. New faunistic records are presented for Theridion pinicola from North Africa, Anatolidion gentile, Theridion genistae and T. hemerobium from Greece. Several poorly known (sub-species are redescribed: Anatolidion gentile, Episinus maculipes numidicus Kulczynski, 1905, Theridion genistae, T. glaucinum Simon, 1881, T. musivum Simon, 1873, T. pinicola, T. pyrenaeum Denis, 1944, T. semitinctum Simon, 1914 and T. spinitarse O. P.-Cambridge, 1876.

  14. Hydraulic jumps in a channel

    DEFF Research Database (Denmark)

    Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected...

  15. Electrostatic charging of jumping droplets

    Science.gov (United States)

    Miljkovic, Nenad; Preston, Daniel J.; Enright, Ryan; Wang, Evelyn N.

    2013-09-01

    With the broad interest in and development of superhydrophobic surfaces for self-cleaning, condensation heat transfer enhancement and anti-icing applications, more detailed insights on droplet interactions on these surfaces have emerged. Specifically, when two droplets coalesce, they can spontaneously jump away from a superhydrophobic surface due to the release of excess surface energy. Here we show that jumping droplets gain a net positive charge that causes them to repel each other mid-flight. We used electric fields to quantify the charge on the droplets and identified the mechanism for the charge accumulation, which is associated with the formation of the electric double layer at the droplet-surface interface. The observation of droplet charge accumulation provides insight into jumping droplet physics as well as processes involving charged liquid droplets. Furthermore, this work is a starting point for more advanced approaches for enhancing jumping droplet surface performance by using external electric fields to control droplet jumping.

  16. Jump conditions in transonic equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Guazzotto, L.; Betti, R. [Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States); Jardin, S. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

    2013-04-15

    In the present paper, the numerical calculation of transonic equilibria, first introduced with the FLOW code in Guazzotto et al.[Phys. Plasmas 11, 604 (2004)], is critically reviewed. In particular, the necessity and effect of imposing explicit jump conditions at the transonic discontinuity are investigated. It is found that 'standard' (low-{beta}, large aspect ratio) transonic equilibria satisfy the correct jump condition with very good approximation even if the jump condition is not explicitly imposed. On the other hand, it is also found that high-{beta}, low aspect ratio equilibria require the correct jump condition to be explicitly imposed. Various numerical approaches are described to modify FLOW to include the jump condition. It is proved that the new methods converge to the correct solution even in extreme cases of very large {beta}, while they agree with the results obtained with the old implementation of FLOW in lower-{beta} equilibria.

  17. Subunit sequences of the 4 x 6-mer hemocyanin from the golden orb-web spider, Nephila inaurata.

    Science.gov (United States)

    Averdam, Anne; Markl, Jürgen; Burmester, Thorsten

    2003-08-01

    The transport of oxygen in the hemolymph of many arthropod and mollusc species is mediated by large copper-proteins that are referred to as hemocyanins. Arthropod hemocyanins are composed of hexamers and oligomers of hexamers. Arachnid hemocyanins usually form 4 x 6-mers consisting of seven distinct subunit types (termed a-g), although in some spider taxa deviations from this standard scheme have been observed. Applying immunological and electrophoretic methods, six distinct hemocyanin subunits were identified in the red-legged golden orb-web spider Nephila inaurata madagascariensis (Araneae: Tetragnathidae). The complete cDNA sequences of six subunits were obtained that corresponded to a-, b-, d-, e-, f- and g-type subunits. No evidence for a c-type subunit was found in this species. The inclusion of the N. inaurata hemocyanins in a multiple alignment of the arthropod hemocyanins and the application of the Bayesian method of phylogenetic inference allow, for the first time, a solid reconstruction of the intramolecular evolution of the chelicerate hemocyanin subunits. The branch leading to subunit a diverged first, followed by the common branch of the dimer-forming b and c subunits, while subunits d and f, as well as subunits e and g form common branches. Assuming a clock-like evolution of the chelicerate hemocyanins, a timescale for the evolution of the Chelicerata was obtained that agrees with the fossil record.

  18. Choice of jumping strategy in two standard jumps, squat and countermovement jump--effect of training background or inherited preference?

    DEFF Research Database (Denmark)

    Ravn, Susanne; Voigt, M; Simonsen, Erik Bruun

    1999-01-01

    Six male subjects, three professional ballet dancers and three elite volleyball players, performed maximal vertical jumps from 1) a static preparatory position (squat jump), 2) starting with a countermovement (countermovement jump) and 3) a specific jump for ballet and for volleyball, respectively....... The jumps were recorded on highspeed film (500 Hz) combined with registration of ground reaction forces, and net joint moments were calculated by inverse dynamics. The purpose was to investigate the choice of strategy in two standard jumps, squat jump and countermovement jump. The volleyball jump...... was performed with a sequential strategy and the ballet jump was performed with a simultaneous strategy. In the two standard jumps, the choice of strategy was individual and not related to training background. This was additionally confirmed in a test of seven ballet dancers and seven volleyball players....

  19. Cell culture's spider silk road.

    Science.gov (United States)

    Perkel, Jeffrey

    2014-06-01

    A number of synthetic and natural materials have been tried in cell culture and tissue engineering applications in recent years. Now Jeffrey Perkel takes a look at one new culture component that might surprise you-spider silk.

  20. Composición de la fauna de Araneae (Arachnida de la Reserva provincial Iberá, Corrientes, Argentina

    Directory of Open Access Journals (Sweden)

    Gilberto Avalos

    2009-06-01

    Full Text Available Se estudió la composición y diversidad de la comunidad de arañas de la Reserva provincial iberá, Corrientes, Argentina. Se realizaron capturas en bosque y pastizal en Colonia Pellegrini, Paraje Galarza y Estancia Rincón por medio de las técnicas de muestreo: trampas "pit-fall", tamizado, golpeteo de follaje, observación directa y red de arrastre. Las arañas se agruparon en gremios y se compiló un inventario. La similitud entre localidades y unidades ambientales se midió con el índice de Jaccard, y se calcularon los índices de diversidad de Shannon, equitabilidad, dominancia de Berger-Parker, y la diversidad beta y gamma. Para estimar la riqueza de especies se utilizó Chao 1, Chao 2, Jackknife 1 y 2. En total se recolectaron 4 138 arañas, se identificaron 33 familias y 150 especies de Araneomorphae, y dos familias y dos especies de Mygalomorphae. Cinco especies son nuevos registros para Argentina y 11 para la provincia de Corrientes. Araneidae fue la familia más abundante (39.8%, seguida por Salticidae (10.9%, Anyphaenidae (7.9%, Tetragnathidae (7.4%, Lycosidae (5.5%, y las restantes familias representaron menos del 5% de la captura total. El gremio de arañas tejedoras de telas orbiculares fue el de mayor abundancia y riqueza de especies. Entre las unidades ambientales, la mayor abundancia, riqueza y diversidad se verificó en el bosque de Colonia Pellegrini y en el pastizal de Paraje Galarza. La diversidad a fue alta, representó el 89% de la diversidad gamma, y la diversidad ß constituyó el 11% restante. Según los diferentes índices se capturó entre el 67% y el 97% de las especies que están presentes en la Reserva.Composition of the Araneae (Arachnida fauna of the provincial Iberá Reserve, Corrientes, Argentina. A survey of the spider community composition and diversity was carried out in grasslands and woods in three localities: Colonia Pellegrini, Paraje Galarza and Estancia Rincón (iberá province Reserve. Pit fall

  1. Spiders from Mars?

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-426, 19 July 2003No, this is not a picture of a giant, martian spider web. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a plethora of polygonal features on the floor of a northern hemisphere impact crater near 65.6oN, 327.7oW. The picture was acquired during spring, after the seasonal carbon dioxide frost cap had largely migrated through the region. At the time the picture was taken, remnants of seasonal frost remained on the crater rim and on the edges of the troughs that bound each of the polygons. Frost often provides a helpful hint as to where polygons and patterned ground occur. The polygons, if they were on Earth, would indicate the presence of freeze-thaw cycles in ground ice. Although uncertain, the same might be true of Mars. Sunlight illuminates the scene from the lower left.

  2. [Arachnofauna (araneae: Araneae) in transgenic and conventional cotton crops (Gossypium hirsutum) in the North of Santa Fe, Argentina].

    Science.gov (United States)

    Almada, Melina Soledad; Sosa, María Ana; González, Alda

    2012-06-01

    Spiders have considerable potential importance for their role as predators to some pests in agricultural systems. The composition of spiders in transgenic and conventional cotton at the Research Station of INTA Reconquista (Santa Fe) was studied during the 2005-2006 season. The experiment was a complete randomized block design with three replications and three treatments: transgenic Bt cotton (ALBt), conventional cotton without chemical control (ALCSC), and conventional cotton with chemical control (ALCCC). Weekly, spiders were collected using nets, vertical cloth and pitfall-traps. A total of 1255 specimens (16 families, and 32 species) were collected. Seven families were found in all the treatments, mainly Thomisidae (n=1 51, 84.04%) and Araneidae (n=83, 6.64%). The Hunting spiders guild ambushers (n=1053, 83.91%), "Orb weavers" (n=85, 6.77%) and "Stalkers" (n=53, 4.22%) were more abundant. There were no significant differences in the indexes diversity between treatments. Spiders were presented during the whole crop season, with peaks about flowering and boll maturity, with the highest abundance in ALBt. This work is part of the first set of data registered in Argentina about spider's community in cotton crops.

  3. Frequency Jump Detection and Analysis

    Science.gov (United States)

    2008-12-01

    CUMULATIVE SUM JUMP DETECTION The Cumulative Sum ( CUSUM ) is a classic change-point analysis technique that uses the cumulative sum of the...sum and y is the average of the data. The CUSUM slope indicates the value of the data with respect to the overall average. A flat cumulative sum...sudden change in the CUSUM slope indicates a jump in the data. The CUSUM plot for a data set having a single jump will have a V or inverted V shape

  4. [Spider bites: araneidism of medical importance].

    Science.gov (United States)

    Pommier, Philip; Rollard, Christine; De Haro, Luc

    2005-01-15

    LIMITED RISKS: Although most species of spiders are venomous, only ten or so are able to induce human envenomations. From a systematic point of view, it is possible to distinguish the araneomorph spiders - or "true" spiders - from the mygalomorph spiders. Dangerous species for humans can be found in both groups. Regarding "true' spiders, two kinds of envenomation are frequent, ubiquitous and potentially severe: latrodectism (neurotoxic symptomatology) due to the Widow spiders of the Latrodectus species,and loxoscelism (viscero-cutaneous symptomatology). Regarding the mygalomorph spiders, the Australian species responsible for atraxism (neurotoxic symptomatology) are considered as the most dangerous. Most of the other mygalomorph spiders, when they bite, only provoke benign loco regional problems. A supplementary defensive weapon exists in certain South-American species: urticating hairs which may induce severe ocular damage.

  5. 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.

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

    OpenAIRE

    Jiang Min

    2016-01-01

    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.

  7. Decoding the secrets of spider silk

    OpenAIRE

    Lukas Eisoldt; Andrew Smith; Thomas Scheibel

    2011-01-01

    Spider silks have been employed by man for several thousands of years. Spider silks possess extraordinary mechanical properties due to a combination of strength and extensibility that are superior to most man-made fibers. Spider silk fibers are a protein-based material produced in a highly sophisticated hierarchical process under mild conditions. Here, we review the current understanding of spider silk and its assembly process, as well as discuss the application of silk-based materials to the...

  8. Realized Jump Risk and Equity Return in China

    OpenAIRE

    Guojin Chen; Xiaoqun Liu; Peilin Hsieh; Xiangqin Zhao

    2014-01-01

    We utilize the realized jump components to explore a new jump (including nonsystematic jump and systematic jump) risk factor model. After estimating daily realized jumps from high-frequency transaction data of the Chinese A-share stocks, we calculate monthly jump size, monthly jump standard deviation, and monthly jump arrival rate and then use those monthly jump factors to explain the return of the following month. Our empirical results show that the jump tail risk can explain the equity retu...

  9. Hey! A Brown Recluse Spider Bit Me!

    Science.gov (United States)

    ... can sometimes be hard to diagnose a spider bite correctly. The spider can be killed first before you bring it ... is really damaged at the area of the bite. (A skin graft is when a small amount ... getting bitten by brown recluse spiders is to be careful in areas where they ...

  10. Brown recluse spider bite on the breast.

    Science.gov (United States)

    Norris, Kori; Misra, Subhasis

    2014-05-01

    Brown recluse spiders are one of two types of spiders in the United States that can cause significant tissue damage and, in rare cases, death. Brown recluse spider bites are most often benign and self-limiting, but in a few cases can cause severe necrotic skin lesions.

  11. Rook Jumping Maze Design Considerations

    Science.gov (United States)

    Neller, Todd W.; Fisher, Adrian; Choga, Munyaradzi T.; Lalvani, Samir M.; McCarty, Kyle D.

    We define the Rook Jumping Maze, provide historical perspective, and describe a generation method for such mazes. When applying stochastic local search algorithms to maze design, most creative effort concerns the definition of an objective function that rates maze quality. We define and discuss several maze features to consider in such a function definition. Finally, we share our preferred design choices, make design process observations, and note the applicability of these techniques to variations of the Rook Jumping Maze.

  12. The Effect of Depth Jumps and Weight Training on Leg Strength and Vertical Jump.

    Science.gov (United States)

    Clutch, David; And Others

    1983-01-01

    Two experiments examined the results of depth jumping programs to determine: (1) whether certain depth jumping routines, when combined with weight training, are better than others; and (2) the effect of depth jumping on athletes already in training. Results indicated that depth jumping is effective, but no more so than regular jumping routines.…

  13. Mechanics and Energetics of Excavation by Burrowing Wolf Spiders, Geolycosa spp.

    Science.gov (United States)

    Suter, Robert B.; Stratton, Gail E.; Miller, Patricia R.

    2011-01-01

    Burrowing wolf spiders, Geolycosa sp. (Araneae:Lycosidae), excavate vertical burrows and inhabit them throughout their lives or, in the case of males, until they mature and wander in search of mates. Three species: G. fatifera Kurata, G. missouriensis Banks, and G. rogersi Wallace were studied to understand how and at what expense the burrowing is accomplished. Normal and high-speed videography coupled with scanning electron microscopy revealed (a) that the convex surfaces of the two fangs, together, constitute the digging tool, (b) that boluses of soil are transported to the burrow entrance on the anterior surfaces of the chelicerae held there by the pedipalps, and (c) that each bolus is either incorporated into the growing turret or flung away, propelled by the forelegs. To elucidate the energetics of burrow construction, burrow volumes were calculated and then the costs associated with dislodging, elevating, and throwing the known volumes of soil were measured. A typical Geolycosa burrow, at a volume of 23.6 ± 2.0 ml and a depth of 13.2 ± 0.7 cm, required the removal of 918 boluses each weighing about 34 mg. The aggregate dislodging cost was close to 1.9 Joules in sand/sandy loam and 5.6 J in clayey subsoil, the work against gravity necessary to raise all of the boluses to the surface was about 0.13 J, and the aggregate cost of flinging the boluses was close to 0.014 J. Assuming that the ratio of external work to metabolic cost of external work is between 0.20 and 0.25 in spiders, the real cost of burrow construction would be between 8 J and 29 J, depending primarily on soil type. This is a small but not negligible cost when placed in the context of reproductive effort: a single Geolycosa egg, dozens to hundreds of which are produced in a clutch, contains about 10 J. PMID:21529154

  14. Description of new species of Stenaelurillus Simon, 1886 from the Western Ghats of India with the redescription of Stenaelurillus lesserti Reimoser, 1934 and notes on mating plug in the genus (Arachnida, Araneae, Salticidae

    Directory of Open Access Journals (Sweden)

    Pothalil A. Sebastian

    2015-03-01

    Full Text Available A new species of the jumping spider genus Stenaelurillus Simon, 1886, S. albus sp. n., is described from the Western Ghats of India, one of the biodiversity hotspots of the world. Detailed morphological descriptions, diagnostic features and illustrations of copulatory organs of both sexes are given. Detailed redescription, diagnosis and illustration of S. lesserti Reimoser, 1934 are provided. The occurrence of a mating plug in the genus is reported.

  15. Male vulnerability explains the occurrence of sexual cannibalism in a moderately sexually dimorphic wolf spider.

    Science.gov (United States)

    Fernández-Montraveta, Carmen; González, José Miguel; Cuadrado, Mariano

    2014-06-01

    Sexual cannibalism is a widespread phenomenon among a few animal taxa. Its occurrence is interpreted as female and/or male optimal reproductive decisions or as a non-adaptive side effect of selection for efficiently foraging females. In spite of the amount of research addressed at understanding its evolutionary origins, we lack accurate information about the proximate causes of sexual cannibalism. In a moderately sexually dimorphic wolf spider (Hogna radiata, Araneae, Lycosidae) we assessed the factors mediating the occurrence of sexual cannibalism and its fitness benefits to females. Sexual cannibalism was a rather common outcome of laboratory mating interactions, occurring in more than a quarter percent of courtship interactions involving virgin females. Sexual cannibalism mostly followed mating. Occurrence of sexual cannibalism depended on male vulnerability to female attacks: relatively smaller males were at higher risk of being attacked and older males were less likely to avoid female attacks. Sexual cannibalism had direct and positive effects on female fitness, as sexually cannibalistic females exhibited increased fecundity irrespective of their size, condition and foraging rate. Male consumption was almost complete and represented a relevant food intake to females. We interpret sexual cannibalism as a strategic foraging decision for H. radiata females that adjust their aggressive behaviour towards males so as to limit its potential costs.

  16. Spider, bee, and bird communities in cities are shaped by environmental control and high stochasticity.

    Science.gov (United States)

    Sattler, T; Borcard, D; Arlettaz, R; Bontadina, F; Legendre, P; Obrist, M K; Moretti, M

    2010-11-01

    Spatially organized distribution patterns of species and communities are shaped by both autogenic processes (neutral mechanism theory) and exogenous processes (niche theory). In the latter, environmental variables that are themselves spatially organized induce spatial structure in the response variables. The relative importance of these processes has not yet been investigated in urban habitats. We compared the variance explained by purely spatial, spatially structured environmental, and purely environmental components for the community composition of spiders (Araneae), bees (Apidae), and birds (Aves) at 96 locations in three Swiss cities. Environmental variables (topography, climate, land cover, urban green management) were measured on four different radii around sampling points (Bee communities were weakly explained by isolated variables only. Our results suggest that the anthropogenic structuring of urban areas has disrupted the spatial organization of environmental variables and inhibited the development of biotic spatial processes. The near absence of spatial structure may therefore be a feature typical of urban species assemblages, resulting in urban community composition mainly influenced by local environmental variables. Urban environments represent a close-knit mosaic of habitats that are regularly disturbed. Species communities in urban areas are far from equilibrium. Our analysis also suggests that urban communities need to be considered as being in constant change to adapt to disturbances and changes imposed by human activities.

  17. Revisão das aranhas do gênero Lupettiana Brescovit (Araneae, Anyphaenidae, Anyphaeninae Revision of the spider genus Lupettiana Brescovit (Araneae, Anyphaenidae, Anyphaeninae

    Directory of Open Access Journals (Sweden)

    Antonio D. Brescovit

    1999-01-01

    Full Text Available The genus Luppetiana Brescovit, 1996 composed actually by nine species, from which five are herein described as new is revised: L. manauara from Brazil; L. levii from Dominican Republic; L. eberhardi from Costa Rica; L. piedra from Cuba; and L. bimini from Bahamas Islands. The species L. perpusilla (Banks, 1909 is synonymyzed with L. parvula (Banks, 1903. Lectotype and paralectotype of L. parvula are designated. The known geographical distribution of the genus ranges from United States of America to north of Brazil.

  18. Spider silk reduces insect herbivory.

    Science.gov (United States)

    Rypstra, Ann L; Buddle, Christopher M

    2013-02-23

    The role of predators in food webs extends beyond their ability to kill and consume prey. Such trait-mediated effects occur when signals of the predator influence the behaviour of other animals. Because all spiders are silk-producing carnivores, we hypothesized that silk alone would signal other arthropods and enhance non-lethal effects of spiders. We quantified the herbivory inflicted by two beetle species on green bean plants (Phaseolus vulgaris) in the presence of silkworm silk and spider silk along with no silk controls. Single leaflets were treated and enclosed with herbivores in the laboratory and field. Another set of leaflets were treated and left to experience natural herbivory in the field. Entire plants in the field were treated with silk and enclosed with herbivores or left exposed to herbivory. In all cases, the lowest levels of herbivory occurred with spider silk treatments and, in general, silkworm silk produced intermediate levels of leaf damage. These results suggest that silk may be a mechanism for the trait-mediated impacts of spiders and that it might contribute to integrated pest management programmes.

  19. Molecular phylogeny of moth-specialized spider sub-family Cyrtarachninae, which includes bolas spiders.

    Science.gov (United States)

    Tanikawa, Akio; Shinkai, Akira; Miyashita, Tadashi

    2014-11-01

    The evolutionary process of the unique web architectures of spiders of the sub-family Cyrtarachninae, which includes the triangular web weaver, bolas spider, and webless spider, is thought to be derived from reduction of orbicular 'spanning-thread webs' resembling ordinal orb webs. A molecular phylogenetic analysis was conducted to explore this hypothesis using orbicular web spiders Cyrtarachne, Paraplectana, Poecilopachys, triangular web spider Pasilobus, bolas spiders Ordgarius and Mastophora, and webless spider Celaenia. The phylogeny inferred from partial sequences of mt-COI, nuclear 18S-rRNA and 28S-rRNA showed that the common ancestor of these spiders diverged into two clades: a spanning-thread web clade and a bolas or webless clade. This finding suggests that the triangular web evolved by reduction of an orbicular spanning web, but that bolas spiders evolved in the early stage, which does not support the gradual web reduction hypothesis.

  20. Ballooning Spiders: The Case for Electrostatic Flight

    CERN Document Server

    Gorham, Peter W

    2013-01-01

    We consider general aspects of the physics underlying the flight of Gossamer spiders, also known as ballooning spiders. We show that existing observations and the physics of spider silk in the presence of the Earth's static atmospheric electric field indicate a potentially important role for electrostatic forces in the flight of Gossamer spiders. A compelling example is analyzed in detail, motivated by the observed "unaccountable rapidity" in the launching of such spiders from H.M.S. Beagle, recorded by Charles Darwin during his famous voyage.

  1. Efecto de las arañas (Arachnida: Araneae como depredadoras de insectos plaga en cultivos de alfalfa (Medicago sativa (Fabaceae en Argentina

    Directory of Open Access Journals (Sweden)

    Andrea Armendano

    2011-12-01

    Full Text Available Effect of spiders (Arachnida: Araneae as predators of insect pest in alfalfa crops (Medicago sativa (Fabaceae in Argentina. Spiders are predators that reduce insect pest populations in agroecosystems. Trials were conducted to measure the selectivity against different insect preys, the daily consumption, effect of predators alone and together with a known number of preys, and the indirect effect of predators on vegetation. For this, experimental units (1x1m were used covered with a fine plastic mesh. Misumenops pallidus, Oxyopes salticus and Araneus sp. were used as generalist predators, and aphids, weevils, locusts, chrysomelids and Lepidoptera larvae as their potential preys. Among the preys offered, the spiders preferred Lepidoptera larvae compared to the other two pests groups (weevils and aphids. The maximum consumption rate was of 93.33% for Lepidoptera larvae, 25.33% for aphids and 11.67% for weevils. The Q Index values for the three species of spiders showed a positive selectivity only for defoliating larvae. O. salticus showed the highest values of consumption rates while Rachiplusia nu was the most consumed. The maximum value of consumption in 24 hours was showed by O. salticus on R. nu (C=2.8. The association of several species of predatory spiders increased the total number of insects captured, and also showed that the addition of spiders caused a decrease in the number of leaves damaged by the effect of lepidopterous larvae. Rev. Biol. Trop. 59 (4: 1651-1662. Epub 2011 December 01Las arañas son depredadoras capaces de reducir las poblaciones de insectos plaga en agroecosistemas. Para medir la selectividad frente a distintas presas, se realizaron ensayos de consumo diario, efecto de los depredadores aisladamente y en conjunto sobre el número de presas y efecto indirecto de los depredadores sobre la vegetación; se utilizaron jaulas experimentales de 1x1m cubiertas con una fina malla plástica. Misumenops pallidus, Oxyopes salticus y

  2. A case of Spider bite localized to the eyelid.

    Science.gov (United States)

    Bilgili, Serap Gunes; Karadag, Ayse Serap; Karadag, Remzi; Cecen, Ilhan; Calka, Omer

    2013-03-01

    Loxosceles Spiders have a worldwide distribution and are considered one of the most medically important groups of Spiders. The venom from Spiders of the genus Loxosceles, the most famous being Loxosceles reclusa (brown recluse Spider), can promote severe local and systemic damages. This report describes a girl presenting with a Spider bite over her right upper eyelid.

  3. Vibration Propagation in Spider Webs

    Science.gov (United States)

    Hatton, Ross; Otto, Andrew; Elias, Damian

    Due to their poor eyesight, spiders rely on web vibrations for situational awareness. Web-borne vibrations are used to determine the location of prey, predators, and potential mates. The influence of web geometry and composition on web vibrations is important for understanding spider's behavior and ecology. Past studies on web vibrations have experimentally measured the frequency response of web geometries by removing threads from existing webs. The full influence of web structure and tension distribution on vibration transmission; however, has not been addressed in prior work. We have constructed physical artificial webs and computer models to better understand the effect of web structure on vibration transmission. These models provide insight into the propagation of vibrations through the webs, the frequency response of the bare web, and the influence of the spider's mass and stiffness on the vibration transmission patterns. Funded by NSF-1504428.

  4. Test-retest reliability of jump execution variables using mechanography: A comparison of jump protocols

    Science.gov (United States)

    Mechanography during the vertical jump test allows for evaluation of force-time variables reflecting jump execution, which may enhance screening for functional deficits that reduce physical performance and determining mechanistic causes underlying performance changes. However, utility of jump mechan...

  5. Swiss prospective study on spider bites.

    Science.gov (United States)

    Gnädinger, Markus; Nentwig, Wolfgang; Fuchs, Joan; Ceschi, Alessandro

    2013-09-04

    Knowledge of spider bites in Central Europe derives mainly from anecdotal case presentations; therefore we aimed to collect cases systematically. From June 2011 to November 2012 we prospectively collected 17 cases of alleged spider bites, and together with two spontaneous notifications later on, our database totaled 19 cases. Among them, eight cases could be verified. The causative species were: Cheiracanthium punctorium (3), Zoropsis spinimana (2), Amaurobius ferox, Tegenaria atrica and Malthonica ferruginea (1 each). Clinical presentation was generally mild, with the exception of Cheiracanthium punctorium, and patients recovered fully without sequelae. In Switzerland, spider bites generally have a benign clinical course, which is characterised by minor effects, with rapid and complete recovery. Since only verified spider bites can be regarded as spider bites, in the case of clinically important arachnidism, the spider should be sent to an expert for identification. Our study may help to diminish spider fear and reassure people who have experienced a bite.

  6. Double Deception: Ant-Mimicking Spiders Elude Both Visually- and Chemically-Oriented Predators

    Science.gov (United States)

    Uma, Divya; Durkee, Caitlin; Herzner, Gudrun; Weiss, Martha

    2013-01-01

    Biological mimicry is often multimodal, in that a mimic reinforces its resemblance to another organism via different kinds of signals that can be perceived by a specific target audience. In this paper we describe a novel scenario, in which a mimic deceives at least two distinct audiences, each of which relies primarily on a different sensory modality for decision-making. We have previously shown that Peckhamia picata, a myrmecomorphic spider that morphologically and behaviorally resembles the ant Camponotus nearcticus, experiences reduced predation by visually-oriented jumping spiders. Here we report that Peckhamia also faces reduced aggression from spider-hunting sphecid wasps as well as from its model ant, both of which use chemical cues to identify prey. We also report that Peckhamia does not chemically resemble its model ants, and that its total cuticular hydrocarbons are significantly lower than those of the ants and non-mimic spiders. Although further studies are needed to clarify the basis of Peckhamia's chemically-mediated protection, to our knowledge, such ‘double deception,’ in which a single organism sends misleading visual cues to one set of predators while chemically misleading another set, has not been reported; however, it is likely to be common among what have until now been considered purely visual mimics. PMID:24236152

  7. De corticole fauna van platanen: i. Arachniden (Arachnida: Araneae, Pseudoscorpiones, Acari)

    NARCIS (Netherlands)

    Noordijk, J.; Berg, M.P.

    2001-01-01

    The corticolous fauna of plane trees: I. Arachnids (Arachnida: Araneae, Pseudoscorpiones, Acari) From February until September 2000 an inventory was made of the bark-dwelling arthropod fauna of more than 400 plane trees (Platanus hybrida), all over the Netherlands. Arthropods were collected from bar

  8. [The "hornet spider" of Plinius].

    Science.gov (United States)

    Moog, Ferdinand Peter

    2002-01-01

    Pliny the Elder describes in his 'Natural History' XXIX 86 a species of spider dangerous for human beings and looking like a hornet without wings. This description corresponds to Solipugae of the genus Karschia, living in arid areas of Central Asia. These animals are not venomous but can cause harm by their powerful bite and in some cases by a following inflammation of the wound. On the contrary, an animal called "wasp-like", mentioned by Nikander of Kolophon ('Theriaca', v. 738-746) and often regarded to be the same creature, seems to be a typical venomous spider which causes an acute intoxication by its bite.

  9. 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.

  10. Gravity current jump conditions, revisited

    Science.gov (United States)

    Ungarish, Marius; Hogg, Andrew J.

    2016-11-01

    Consider the flow of a high-Reynolds-number gravity current of density ρc in an ambient fluid of density ρa in a horizontal channel z ∈ [ 0 , H ] , with gravity in - z direction. The motion is often modeled by a two-layer formulation which displays jumps (shocks) in the height of the interface, in particular at the leading front of the dense layer. Various theoretical models have been advanced to predict the dimensionless speed of the jump, Fr = U /√{g' h } ; g' , h are reduced gravity and jump height. We revisit this problem and using the Navier-Stokes equations, integrated over a control volume embedding the jump, derive balances of mass and momentum fluxes. We focus on understanding the closures needed to complete this model and we show the vital need to understand the pressure head losses over the jump, which we show can be related to the vorticity fluxes at the boundaries of the control volume. Our formulation leads to two governing equations for three dimensionless quantities. Closure requires one further assumption, depending on which we demonstrate that previous models for gravity current fronts and internal bores can be recovered. This analysis yield new insights into existing results, and also provides constraints for potential new formulae.

  11. Coalescence-induced nanodroplet jumping

    Science.gov (United States)

    Cha, Hyeongyun; Xu, Chenyu; Sotelo, Jesus; Chun, Jae Min; Yokoyama, Yukihiro; Enright, Ryan; Miljkovic, Nenad

    2016-10-01

    Water vapor condensation on superhydrophobic surfaces has received much attention in recent years due to the ability of such surfaces to shed microscale water droplets via coalescence-induced droplet jumping, resulting in heat transfer, anti-icing, and self-cleaning performance enhancement. Here we report the coalescence-induced removal of water nanodroplets (R ≈500 nm ) from superhydrophobic carbon nanotube (CNT) surfaces. The two-droplet coalescence time is measured for varying droplet Ohnesorge numbers, confirming that coalescence prior to jumping is governed by capillary-inertial dynamics. By varying the conformal hydrophobic coating thickness on the CNT surface, the minimum jumping droplet radius is shown to increase with increasing solid fraction and decreasing apparent advancing contact angle, allowing us to explore both hydrodynamic limitations stemming from viscous dissipation and surface adhesion limitations. We find that, even for the smallest nanostructure length scale (≤100 nm) and lowest surface adhesions, nonideal surface interactions and the evolved droplet morphology play defining roles in limiting the minimum size for jumping on real surfaces. The outcomes of this work demonstrate the ability to passively shed nanometric water droplets, which has the potential to further increase the efficiency of systems that can harness jumping droplets for a wide range of energy and water applications.

  12. How far can Tarzan jump?

    Science.gov (United States)

    Shima, Hiroyuki

    2012-11-01

    The tree-based rope swing is a popular recreational facility, often installed in outdoor areas. Hanging from a rope, users drop from a high platform and then swing at great speed like ‘Tarzan’, finally jumping ahead to land on the ground. The question naturally arises, how far can Tarzan jump using the swing? In this paper, I present an introductory analysis of the mechanics of the Tarzan swing, a large pendulum-like swing with Tarzan himself attached as weight. This enables determination of how much further forward Tarzan can jump using a given swing apparatus. The discussion is based on elementary mechanics and is, therefore, expected to provide rich opportunities for investigations using analytic and numerical methods.

  13. How far can Tarzan jump?

    CERN Document Server

    Shima, Hiroyuki

    2012-01-01

    The tree-based rope swing is a popular recreation facility, often installed in outdoor areas, giving pleasure to thrill-seekers. In the setting, one drops down from a high platform, hanging from a rope, then swings at a great speed like "Tarzan", and finally jumps ahead to land on the ground. The question now arises: How far can Tarzan jump by the swing? In this article, I present an introductory analysis of the Tarzan swing mechanics, a big pendulum-like swing with Tarzan himself attached as weight. The analysis enables determination of how farther forward Tarzan can jump using a given swing apparatus. The discussion is based on elementary mechanics and, therefore, expected to provide rich opportunities for investigations using analytic and numerical methods.

  14. Walckenaeria simplex neu für Deutschland (Araneae, Linyphiidae

    Directory of Open Access Journals (Sweden)

    Kielhorn, Karl-Hinrich

    2008-07-01

    Full Text Available The rare money spider Walckenaeria simplex Chyzer, 1894 was found in 2007 near the city of Meißen (Germany on a rock overlooking the river Elbe. This is the northernmost occurrence of the species. W. simplex is distributed from Central to South Eastern Europe. The species is thermophilous and prefers wooded slopes with a southern exposition.

  15. Two new Tegenaria species (Araneae: Agelenidae) from Portugal

    DEFF Research Database (Denmark)

    Bolzern, Angelo; Crespo, Luís; Bondoso Cardoso, Pedro Miguel

    2009-01-01

    The genera complex Tegenaria/Malthonica is a problematic spider group of the family Agelenidae. Besides taxonomical problems, new European species are described on a regular basis. Here two species from Portugal, Tegenaria barrientosi sp. n. and Tegenaria incognita sp. n., are described. Both...

  16. The Lycosidae and Pisauridae (Araneae) of the Netherlands

    NARCIS (Netherlands)

    Wiebes, J.T.

    1959-01-01

    INTRODUCTION In this paper the species of spiders belonging to the families Lycosidae and Pisauridae, known from the Netherlands, are described and figured. In addition a number of species, which possibly may occur in the Netherlands though they have not yet been found here hitherto, are mentioned i

  17. Spider pheromones - a structural perspective.

    Science.gov (United States)

    Schulz, Stefan

    2013-01-01

    Spiders use pheromones for sexual communication, as do other animals such as insects. Nevertheless, knowledge about their chemical structure, function, and biosynthesis is only now being unraveled. Many studies have shown the existence of spider pheromones, but the responsible compounds have been elucidated in only a few cases. This review focuses on a structural approach because we need to know the involved chemistry if we are to understand fully the function of a pheromonal communication system. Pheromones from members of the spider families Pholcidae, Araneidae, Linyphiidae, Agenelidae, and Ctenidae are currently being identified and will be discussed in this review. Some of these compounds belong to compound classes not known from other arthropod pheromones, such as citric acid derivatives or acylated amino acids, whereas others originate from more common fatty acid metabolism. Their putative biosynthesis, their function, and the identification methods used will be discussed. Furthermore, other semiochemicals and the chemistry of apolar surface lipids that potentially might be used by spiders for communication are described briefly.

  18. Spider silk: Webs measure up

    Science.gov (United States)

    Qin, Zhao; Buehler, Markus J.

    2013-03-01

    The complete elastic response of a spider's orb web has been quantified by non-invasive light scattering, revealing important insights into the architecture, natural material use and mechanical properties of the web. This knowledge advances our understanding of the prey-catching process and the role of supercontraction therein.

  19. The Spider and the Fly

    Science.gov (United States)

    Mellinger, Keith E.; Viglione, Raymond

    2012-01-01

    The Spider and the Fly puzzle, originally attributed to the great puzzler Henry Ernest Dudeney, and now over 100 years old, asks for the shortest path between two points on a particular square prism. We explore a generalization, find that the original solution only holds in certain cases, and suggest how this discovery might be used in the…

  20. First report of predation on floral visitors by crab spiders on Croton selowii Baill. (Euphorbiaceae Primeiro registro de predação de visitantes florais por aranhas-caranguejo em Croton selowii Baill. (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Reinaldo Rodrigo Novo

    2010-06-01

    Full Text Available In the literature it has been extensively mentioned that crab spiders (Araneae: Thomisidae prey on floral visitors of several plant species. Here we present observations of Croton selowii Baill. (Euphorbiaceae, a monoecious species harboring individuals of crab spiders in an area of coastal vegetation of Pernambuco state, Brazil. The species is visited by several invertebrate orders, and some of them were preyed upon by the spiders, mainly Diptera species. The spiders rubbed the forelimbs within the flowers, which may constitute a strategy to camouflage these structures. Croton selowii seems to represent a suitable foraging site for the spiders, because it has a generalist pollination system (thus being visited by a wide range of invertebrate species and blooms in a period of low flower resource availability in the area.Na literatura tem sido amplamente registrado que aranhas Thomisidae predam visitantes florais de várias espécies de planta. Neste estudo nós apresentamos observações de Croton selowii Baill. (Euphorbiaceae, uma espécie monóica, abrigando aranhas Thomisidae em uma área de restinga de Pernambuco, Brasil. A espécie é visitada por invertebrados de várias ordens e vários deles são predados pelas aranhas, principalmente espécies de Diptera. As aranhas apresentaram um comportamento de esfregar as pernas dianteiras dentro das flores, o que pode ser interpretado como uma estratégia de camuflagem das pernas. Croton selowii parece representar um bom sítio de forrageamento para essas aranhas, pois possui um sistema de polinização generalista, sendo visitado por ampla gama de invertebrados e floresce em um período de baixa disponibilidade de flores na área.

  1. The Legs That Rock the Cradle: Spider Mothers

    Indian Academy of Sciences (India)

    Vinayak Patil

    2017-05-01

    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.

  2. Alzheimer's Deaths Jump 55 Percent: CDC

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165941.html Alzheimer's Deaths Jump 55 Percent: CDC More patients also ... News) -- As more baby boomers age, deaths from Alzheimer's disease have jumped 55 percent, and in a ...

  3. Inherent enumerability of strong jump-traceability

    CERN Document Server

    Diamondstone, David; Turetsky, Daniel

    2011-01-01

    We show that every strongly jump-traceable set obeys every benign cost function. Moreover, we show that every strongly jump-traceable set is computable from a computably enumerable strongly jump-traceable set. This allows us to generalise properties of c.e.\\ strongly jump-traceable sets to all such sets. For example, the strongly jump-traceable sets induce an ideal in the Turing degrees; the strongly jump-traceable sets are precisely those that are computable from all superlow Martin-L\\"{o}f random sets; the strongly jump-traceable sets are precisely those that are a base for $\\text{Demuth}_{\\text{BLR}}$-randomness; and strong jump-traceability is equivalent to strong superlowness.

  4. Model for polygonal hydraulic jumps

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Watanabe, Shinya; Bohr, Tomas

    2012-01-01

    ) near the free surface in the jump region. The model consists of mass conservation and radial force balance between hydrostatic pressure and viscous stresses on the roller surface. In addition, we consider the azimuthal force balance, primarily between pressure and viscosity, but also including...

  5. Jumping property of Lyapunov values

    Institute of Scientific and Technical Information of China (English)

    毛锐; 王铎

    1996-01-01

    A sufficient condition for fcth Lyapunov value to be zero for planar polynomial vector fields is given, which extends the result of "jumping property’ of Lyapunov values obtained by Wang Duo to more general cases. A concrete example that the origin cannot be weak focus of order 1, 2, 4, 5, 8 is presented.

  6. Epidemiology of the brown recluse spider bite.

    Science.gov (United States)

    Rhoads, Jacqueline

    2007-02-01

    The purpose of this article was to provide a comprehensive epidemiological and clinical description of the brown recluse spider bite. Review of evidenced-based scientific literature and practice guidelines. A specific descriptive case study is interwoven through the article to tie in the clinical presenting figure associated with this bite. The brown recluse lives in a circumscribed area of the United States (the south central Midwest) with a few less common recluse species living in the more sparsely populated southwest United States. In these areas, where spider populations may be dense, recluse spiders may be a cause of significant morbidity. Most spider bites are asymptomatic but what makes this bite so devastating is the toxin injected by the brown recluse spider, which can cause considerable systemic symptoms as well as necrotic skin ulcers (necrotic arachnidism). The article presents process for diagnosis and stresses the importance of identifying the spider if at all possible.

  7. The evolution of sociality in spiders

    DEFF Research Database (Denmark)

    Lubin, Yael; Bilde, T.

    2007-01-01

    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....... 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...

  8. A jump forwards with mathematics and physics

    NARCIS (Netherlands)

    A. Heck; P. Uylings

    2011-01-01

    We jump on human body motions such as bouncing on a jumping stick, hopping, and making kangaroo jumps. Students can record the movements with a digital camera and use their video clips to investigate the motions with suitable video analysis and modelling software. We discuss some mathematical models

  9. Strawberry Shortcake and Other Jumping Rope Ideas.

    Science.gov (United States)

    Adams, Polly K.; Taylor, Michaell K.

    Information, guidelines, and activities for jumping rope are given. A short history of jumping rope explains how it evolved from a spring ritual for men to a play activity involving mostly young girls. Physical and cultural reasons are given as to why jumping rope has been more a sport for girls than for boys. Research studies are noted which show…

  10. Strawberry Shortcake and Other Jumping Rope Ideas.

    Science.gov (United States)

    Adams, Polly K.; Taylor, Michaell K.

    Information, guidelines, and activities for jumping rope are given. A short history of jumping rope explains how it evolved from a spring ritual for men to a play activity involving mostly young girls. Physical and cultural reasons are given as to why jumping rope has been more a sport for girls than for boys. Research studies are noted which show…

  11. Mesopause jumps at Antarctic latitudes

    Science.gov (United States)

    Lübken, Franz-Josef; Höffner, Josef; Becker, Erich; Latteck, Ralph; Murphy, Damian

    2016-04-01

    Recent high resolution temperature measurements by resonance lidar at Davis (69°S) occasionally showed a sudden mesopause altitude increase by ˜5 km and an associated mesopause temperature decrease by ˜10 K. We present further observations which are closely related to this 'mesopause jump', namely the increase of mean height of polar mesospheric summer echoes (PMSE) observed by a VHF radar, very strong westward winds in the upper mesosphere measured by an MF radar, and relatively large eastward winds in the stratosphere taken from reanalysis. We compare to similar observations in the Northern Hemisphere, namely at ALOMAR (69°N) where such mesopause jumps have never been observed. We present a detailed explanation of mesopause jumps. They occur only when stratospheric winds are moderately eastward and mesospheric winds are very large (westward). Under these conditions, gravity waves with comparatively large eastward phase Speeds can pass the stratosphere and propagate to the lower thermosphere because their vertical wavelengths in the mesosphere are rather large which implies reduced dynamical stability. When finally breaking in the lower thermosphere, these waves drive an enhanced residual circulation that causes a cold and high-altitude mesopause. The conditions for a mesopause jump occur only in the Southern Hemisphere (SH) and are associated with the late breakdown of the polar vortex. Mesopause jumps are primarily, but not only, observed prior and close to solstice. We also show that during the onset of PMSE in the SH, stratospheric zonal winds are still eastward (up to 30 m/s), and that the onset is not closely related to the Transition of the stratospheric circulation.

  12. Production of Synthetic Spider Silk Fibers

    OpenAIRE

    Copeland, Cameron G.

    2016-01-01

    Orb-weaving spiders produce six different types of silks, each with unique mechanical properties. The mechanical properties of many of these silks, in particular the dragline silk, are of interest for various biomedical applications. Spider silk does not elicit an immune response, making it an ideal material for several applications in the medical field. However, spiders cannot be farmed for their silk as they are cannibalistic and territorial. The most reasonable alternative for producing sp...

  13. Designing Spider Silk Proteins for Materials Applications

    Science.gov (United States)

    2009-10-28

    WY, 82071-3944 Agreement Number: FA9550-06-1-0368 Project Title: Designing Spider Silk Proteins for Materials Applications REPORT...From - To) 06/2006-010/2009 4. TITLE AND SUBTITLE Designing Spider Silk Proteins for Materials Applications 5a. CONTRACT NUMBER 5b...AVAILABILITY STATEMENT Approved for public release; distribution unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Spider silks have the

  14. Cytogenetic studies of three Lycosidae species from Argentina (Arachnida, Araneae

    Directory of Open Access Journals (Sweden)

    María A. Chemisquy

    2008-01-01

    Full Text Available Cytogenetic studies of the family Lycosidae (Arachnida: Araneae are scarce. Less than 4% of the described species have been analyzed and the male haploid chromosome numbers ranged from 8+X 1 X 2 to 13+X 1 X 2 . Species formerly classified as Lycosa were the most studied ones. Our aim in this work was to perform a comparative analysis of the meiosis in " Lycosa " erythrognatha Lucas, " Lycosa " pampeana Holmberg and Schizocosa malitiosa (Tullgren. We also compared male and female karyotypes and characterized the heterochromatin of " L. " erythrognatha . The males of the three species had 2n = 22, n = 10+X 1 X 2 , all the chromosomes were telocentric and there was generally a single chiasma per bivalent. In " Lycosa " pampeana , which is described cytogenetically for the first time herein, the bivalents and sex chromosomes showed a clustered arrangement at prometaphase I. The comparison of the male/female karyotypes (2n = 22/24 of " Lycosa " erythrognatha revealed that the sex chromosomes were the largest of the complement and that the autosomes decreased gradually in size. The analysis of the amount, composition and distribution of heterochromatin with C-banding and staining with DAPI- and CMA 3 - showed that " Lycosa " erythrognatha had little GC-rich heterochromatin in the pericentromeric region of all chromosomes. In addition, the actual occurrence of the genus Lycosa in the Southern Hemisphere is discussed.

  15. Carbon nanotubes on a spider silk scaffold

    Science.gov (United States)

    Steven, Eden; Saleh, Wasan R.; Lebedev, Victor; Acquah, Steve F. A.; Laukhin, Vladimir; Alamo, Rufina G.; Brooks, James S.

    2013-09-01

    Understanding the compatibility between spider silk and conducting materials is essential to advance the use of spider silk in electronic applications. Spider silk is tough, but becomes soft when exposed to water. Here we report a strong affinity of amine-functionalised multi-walled carbon nanotubes for spider silk, with coating assisted by a water and mechanical shear method. The nanotubes adhere uniformly and bond to the silk fibre surface to produce tough, custom-shaped, flexible and electrically conducting fibres after drying and contraction. The conductivity of coated silk fibres is reversibly sensitive to strain and humidity, leading to proof-of-concept sensor and actuator demonstrations.

  16. Decoding the secrets of spider silk

    Directory of Open Access Journals (Sweden)

    Lukas Eisoldt

    2011-03-01

    Full Text Available Spider silks have been employed by man for several thousands of years. Spider silks possess extraordinary mechanical properties due to a combination of strength and extensibility that are superior to most man-made fibers. Spider silk fibers are a protein-based material produced in a highly sophisticated hierarchical process under mild conditions. Here, we review the current understanding of spider silk and its assembly process, as well as discuss the application of silk-based materials to the fields of biomedicine and materials engineering.

  17. Comportamiento sexual de Alpaida veniliae (Araneae: Araneidae Sexual behavior of Alpaida veniliae (Araneae: Araneidae

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    Marco A. Benamú

    2012-09-01

    el riesgo de canibalismo, reforzaría la selectividad de éstos hacia las hembras receptivas vírgenes.Studies in transgenic soybean crops in Buenos Aires province, Argentina, revealed that Alpaida veniliae is one of the most abundant species in the guild of orb web spiders. This species is an effective natural enemy of insect pests affecting this crop. In the present study we carried out a descriptive and quantitative analysis of sexual behavior (courtship, mating and post-mating of A. veniliae. The spiders were collected in transgenic soybean crops located in Chivilcoy (35º01’ S - 60º06’ W, Buenos Aires, Argentina, and reared under laboratory conditions. Based on observations of 20 couples (with virgin females, behavioral units of male and female in terms of postures and movements, including details on duration and frequency, were described at all stages of sexual activity (courtship, mating and post-mating. Courtship exhibited the greatest number and duration of behavioral units in both sexes. Male and female had a sequence of 16 and nine units, respectively, being the frequency of repetitions of the units significantly higher in the male. Mating was brief and males used a single palp to fill only one of the female spermathecae, after which the female became unreceptive. Mating had two behavioral units in the male and only one in the female. During post-mating males had three and females two behavioral units. The average duration of the whole sexual behavior was 541.90±123.1 seconds for the male and 338.20±74.1 seconds for the female. Alpaida veniliae females rarely accept a second mating with the same or another male (remating, indicating a strict monogamy. In 46% of observed mating, the female cannibalized the male after it. Females became unattractive after mating, since stop producing sex pheromones, causing a reduction of the male vibratory courtship. The high cost of courtship, including the risk of cannibalism, would reinforce the selectivity of

  18. Species of Wadicosa (Araneae, Lycosidae): a new species from Madagascar.

    Science.gov (United States)

    Kronestedt, Torbjörn

    2017-05-10

    Since establishing the wolf spider genus Wadicosa Zyuzin, 1985 (Zyuzin 1985), eleven species have been accepted in it, either by transfer from Lycosa Latreille, 1804 or Pardosa C.L. Koch, 1847 or by original designation (WSC 2017). However, according to Kronestedt (1987), additional species wait to be formally transferred to Wadicosa. The genus is restricted to the Old World, with one species, Wadicosa jocquei Kronestedt, 2015, recently described from Madagascar and surrounding islands.

  19. Boden- und baumstammbewohnende Linyphiidae des Hienheimer Forstes (Bayern (Arachnida: Araneae

    Directory of Open Access Journals (Sweden)

    Schulz, Ulrich

    1998-12-01

    Full Text Available This paper presents some results of a forest ecology research project by the University of Munich’s faculty of Forestry, involving the comparison of forests designed to reflect varying degrees of naturalness. Spiders on the ground and on trunks in four different forests in the Hienheimer Forst were caught with 24 ground photo eclectors, 8 arboreal eclectors and with 40 pitfall traps. Habitat requirements were measured and analysed with particular attention to forest soil. Abiotic parameters and the structure of the litter layer were recorded. The most frequent spiders were the Linyphiidae, Agelenidae and Amaurobidae.63 species of the family Linyphiidae were caught. One half of the Linyphiidae-species could be found on trunks of oak and spruce (eclector fauna. In terms of the number of spider species and in the portion of rare and endangered species there were almost no differences between commercial forest areas and conservation areas. The differences are not as great as the original classification according to closeness to the natural state had led us to expect.

  20. Jumps of the eta invariant

    CERN Document Server

    Farber, M S; Farber, Michael S.; Levine, Jerome P.

    1994-01-01

    We study the eta-invariant, defined by Atiyah-Patodi-Singer a real valued invariant of an oriented odd-dimensional Riemannian manifold equipped with a unitary representation of its fundamental group. When the representation varies analytically, the corresponding eta-invariant may have an integral jump, known also as the spectral flow. The main result of the paper establishes a formula for this spectral jump in terms of the signatures of some homological forms, defined naturally by the path of representations. These signatures may also be computed by means of a spectral sequence of Hermitian forms,defined by the deformation data. Our theorem on the spectral jump has a generalization to arbitrary analytic families of self-adjoint elliptic operators. As an application we consider the problem of homotopy invariance of the rho-invariant. We give an intrinsic homotopy theoretic definition of the rho-invariant, up to indeterminacy in the form of a locally constant function on the space of unitary representations. In...

  1. Science Education Resources on the Web--Spiders.

    Science.gov (United States)

    Thirunarayanan, M. O.

    1997-01-01

    Lists Web sites containing information on spiders and offers brief descriptions of the information available at those sites. The 11 sites provide information on taxonomy of spiders, anatomy, different ways spiders use silk, Internet mailing lists, folk literature and art, bibliographies, night collection, and spiders commonly found in the state of…

  2. Resting EEG asymmetry and spider phobia

    NARCIS (Netherlands)

    Merckelbach, H; Muris, P; Pool, K; de Jong, Peter

    1998-01-01

    This study examined whether resting EEG asymmetries are related to symptom severity and treatment outcome in spider phobia. Prior to treatment, EEG was recorded in a sample of spider phobic patients (N = 16). Correlations between frontal and parietal asymmetries in alpha power, on the one hand, and

  3. Insects and Spiders. Environmental Education Curriculum.

    Science.gov (United States)

    Topeka Public Schools, KS.

    This unit is designed to provide information on insects and spiders that special education students are capable of understanding. The activities are aimed at level 2 and level 3 educable mentally retarded classes. There are four topics: (1) Characteristics and Life Cycles of Insects; (2) Characteristics of Spiders; (3) Habitats and Food Sources of…

  4. De corticole fauna van platanen: i. Arachniden (Arachnida: Araneae, Pseudoscorpiones, Acari)

    OpenAIRE

    Noordijk, J.; Berg, M.P.

    2001-01-01

    The corticolous fauna of plane trees: I. Arachnids (Arachnida: Araneae, Pseudoscorpiones, Acari) From February until September 2000 an inventory was made of the bark-dwelling arthropod fauna of more than 400 plane trees (Platanus hybrida), all over the Netherlands. Arthropods were collected from bark and under the ‘loose’ bark fragments at a height of 160-175 cm from the ground. Algae, mosses and fungi are important resources for the corticolous fauna. Crevices in the tree trunk and loose bar...

  5. A new species of Acanthoscurria (Araneae: Theraphosidae: Theraphosinae without stridulatory organ, from southern Peru

    Directory of Open Access Journals (Sweden)

    Nelson Ferretti

    2016-08-01

    Full Text Available Acanthoscurria sacsayhuaman sp. nov. (Araneae: Theraphosidae is described based on a male from Cusco, Peru. The new species is characterized by the absence of stridulatory bristles on retrolateral face of palpal trochanter. Moreover, it can be distinguished by morphology of the male palpal bulb and tibial apophysis of the first pair of legs. The genus is recorded for the first time for Peru.

  6. The ecological consequences of temperament in spiders

    Institute of Scientific and Technical Information of China (English)

    Jonathan N.PRUITT; Susan E.RIECHERT

    2012-01-01

    Ecological and evolutionary studies on spiders have been featured prominently throughout the contemporary behavioral syndromes movement.Here we review the behavioral syndromes literature devoted to spiders,and identify some ways in which behavioral syndromes can impact the function of spiders in ecological communities.We further highlight three general themes within the behavioral syndromes literature for which spiders have served as front running model systems:(1) how trait correlations beget performance trade-offs,(2) the influence that behavioral trait variants have on interspecific interactions and (3)mechanisms that aid in maintaining behavioral variation within- and among-populations.Research on behavioral syndromes continues to grow at an impressive rate,and we feel the success of behavioral syndromes studies in spiders bodes well for their continued prominence.

  7. Spider venomics: implications for drug discovery.

    Science.gov (United States)

    Pineda, Sandy S; Undheim, Eivind A B; Rupasinghe, Darshani B; Ikonomopoulou, Maria P; King, Glenn F

    2014-10-01

    Over a period of more than 300 million years, spiders have evolved complex venoms containing an extraordinary array of toxins for prey capture and defense against predators. The major components of most spider venoms are small disulfide-bridged peptides that are highly stable and resistant to proteolytic degradation. Moreover, many of these peptides have high specificity and potency toward molecular targets of therapeutic importance. This unique combination of bioactivity and stability has made spider-venom peptides valuable both as pharmacological tools and as leads for drug development. This review describes recent advances in spider-venom-based drug discovery pipelines. We discuss spider-venom-derived peptides that are currently under investigation for treatment of a diverse range of pathologies including pain, stroke and cancer.

  8. The ecological consequences of temperament in spiders

    Directory of Open Access Journals (Sweden)

    Jonathan N. PRUITT, Susan E. RIECHERT

    2012-08-01

    Full Text Available Ecological and evolutionary studies on spiders have been featured prominently throughout the contemporary behavio­ral syndromes movement. Here we review the behavioral syndromes literature devoted to spiders, and identify some ways in which behavioral syndromes can impact the function of spiders in ecological communities. We further highlight three general themes within the behavioral syndromes literature for which spiders have served as front running model systems: (1 how trait correlations beget performance trade-offs, (2 the influence that behavioral trait variants have on interspecific interactions and (3 mechanisms that aid in maintaining behavioral variation within- and among-populations. Research on behavioral syndromes continues to grow at an impressive rate, and we feel the success of behavioral syndromes studies in spiders bodes well for their continued prominence [Current Zoology 58 (4: 589–596, 2012].

  9. Price jumps on European stock markets

    Directory of Open Access Journals (Sweden)

    Jan Hanousek

    2014-03-01

    Full Text Available We analyze the dynamics of price jumps and the impact of the European debt crisis using the high-frequency data reported by selected stock exchanges on the European continent during the period January 2008 to June 2012. We employ two methods to identify price jumps: Method 1 minimizes the probability of false jump detection (the Type-II Error-Optimal price jump indicator and Method 2 maximizes the probability of successful jump detection (the Type-I Error-Optimal price jump indicator. We show that individual stock markets exhibited differences in price jump intensity before and during the crisis. We also show that in general the variance of price jump intensity could not be distinguished as different in the pre-crisis period from that during the crisis. Our results indicate that, contrary to common belief, the intensity of price jumps does not uniformly increase during a period of financial distress. However, there do exist differences in price jump dynamics across stock markets and investors have to model emerging and mature markets differently to properly reflect their individual dynamics.

  10. A review of the spider genus Haplodrassus Chamberlin, 1922 in Crimea (Ukraine) and adjacent areas (Araneae, Gnaphosidae).

    Science.gov (United States)

    Kovblyuk, Mykola M; Kastrygina, Zoya A; Omelko, Mikhail M

    2012-01-01

    Eight species of Haplodrassus are recorded from Crimea: Haplodrassus bohemicus Miller & Buchar, 1977; Haplodrassus dalmatensis (L. Koch, 1866); Haplodrassus isaevi Ponomarev & Tsvetkov, 2006; Haplodrassus minor (O. P.-Cambridge, 1879); Haplodrassus kulczynskii Lohmander, 1942; Haplodrassus pseudosignifer Marusik, Hippa & Koponen, 1996; Haplodrassus signifer (C.L. Koch, 1839) and Haplodrassus umbratilis (L. Koch, 1866). The occurrence of Haplodrassus cognatus (Westring, 1861) in Crimea has not been confirmed. Haplodrassus bohemicus is a new species record for the Crimean fauna. Haplodrassus pseudosignifer is a new species record for Crimea and Ukraine as a whole, with Crimea as the westernmost point of its distribution range. Haplodrassus invalidus is recorded for the first time for the fauna of Azerbaijan, Caucasus and the former Soviet Union. Azerbaijan is the easternmost point of its known distribution range. All Crimean Haplodrassus species have only one peak of activity of adult specimens during the year. In Crimea we found syntopically two closely related species Haplodrassus dalmatensis and Haplodrassus isaevi in two localities (Sudak Distr., 10 km W Sudak, Mezhdurechie Vill., steppe; and Feodosiya Distr., Karadag Nature Reserve, steppes). These species differ in their phenology. The reproductive period of Haplodrassus dalmatensis isin May-July, and that of Haplodrassus isaevi occurs is in October-December. These phenological differences probably represent an additional mechanism of reproductive isolation between the two species. Diagnostic drawings are provided for all mentioned species as well as for Haplodrassus deserticola Schmidt & Krause, 1996 and Haplodrassus pugnans (Simon, 1880).

  11. A review of the spider genus Haplodrassus Chamberlin, 1922 in Crimea (Ukraine and adjacent areas (Araneae, Gnaphosidae

    Directory of Open Access Journals (Sweden)

    Mykola Kovblyuk

    2012-07-01

    Full Text Available Eight species of Haplodrassus are recorded from Crimea: H. bohemicus Miller & Buchar, 1977; H. dalmatensis (L. Koch, 1866; H. isaevi Ponomarev & Tsvetkov, 2006; H. minor (O. P.-Cambridge, 1879; H. kulczynskii Lohmander, 1942; H. pseudosignifer Marusik, Hippa & Koponen, 1996; H. signifer (C.L. Koch, 1839 and H. umbratilis (L. Koch, 1866. The occurrence of H. cognatus (Westring, 1861 in Crimea has not been confirmed. Haplodrassus bohemicus is a new species record for the Crimean fauna. Haplodrassus pseudosignifer is a new species record for Crimea and Ukraine as a whole, with Crimea as the westernmost point of its distribution range. Haplodrassus invalidus is recorded for the first time for the fauna of Azerbaijan, Caucasus and the former Soviet Union. Azerbaijan is the easternmost point of its known distribution range. All Crimean Haplodrassus species have only one peak of activity of adult specimens during the year. In Crimea we found syntopically two closely related species H. dalmatensis and H. isaevi in two localities (Sudak Distr., 10 km W Sudak, Mezhdurechie Vill., steppe; and Feodosiya Distr., Karadag Nature Reserve, steppes. These species differ in their phenology. The reproductive period of H. dalmatensis is in May-July, and that of H. isaevi occurs is in October-December. These phenological differences probably represent an additional mechanism of reproductive isolation between the two species. Diagnostic drawings are provided for all mentioned species as well as for H. deserticola Schmidt & Krause, 1996 and H. pugnans (Simon, 1880.

  12. The orb-weaving spider genus Eustala Simon, 1895 (Araneae, Araneidae): eight new species, redescriptions, and new records.

    Science.gov (United States)

    Poeta, Maria Rita Muniz

    2014-10-13

    Eight new species of Eustala Simon, 1895 are described from southern Brazil. Eustala guarani n. sp., from Paraná and E. catarina n. sp., from Santa Catarina, are based on males and females. Six species are described from Rio Grande do Sul: E. ericae n. sp., E. cidae n. sp., E. lisei n. sp., E. cuia n. sp., E. farroupilha n. sp., based on males and females, and E. eldorado n. sp., based only on males. Eustala mourei Mello-Leitão, 1947, from Paraná and E. ulecebrosa (Keyserling, 1892), described from Rio Grande do Sul are redescribed and illustrated. New records are given for Eustala albiventer (Keyserling, 1884), E. taquara (Keyserling, 1892), E. minuscula (Keyserling, 1892), E. itapocuensis Strand, 1916, E. photographica Mello-Leitão, 1944, E. levii Poeta, Marques & Buckup, 2010, and E. palmares, Poeta, Marques & Buckup, 2010. Eustala perfida Mello-Leitão, 1947, described from Paraná, and E. belissima Poeta, Marques & Buckup, 2010, from Rio Grande do Sul, are newly recorded from Uruguay. Distribution maps are provided. 

  13. A new genus of Theraphosid spider from Mexico, with a particular palpal bulb structure (Araneae, Theraphosidae, Theraphosinae

    Directory of Open Access Journals (Sweden)

    Jorge I. Mendoza

    2016-09-01

    Full Text Available Magnacarina gen. nov. from Mexico is described. Hapalopus aldanus West, 2000 from Nayarit, is transferred to the new genus with an emended diagnosis creating the new combination Magnacarina aldana comb. nov. Three new species are described: Magnacarina moderata Locht, Mendoza & Medina sp. nov. from Nayarit and Sinaloa; Magnacarina primaverensis Mendoza & Locht sp. nov. and Magnacarina cancer Mendoza & Locht sp. nov., both from Jalisco. Magnacarina gen. nov. is characterized by an unusual bifid palpal bulb, and has a primary projection located in the central area of the palpal bulb and directed retrolaterally; this projection possesses the prolateral superior and retrolateral keels. Next to the primary projection is a secondary projection, which may be short or long, ending in the prolateral inferior and apical keel surrounding the sperm pore. This secondary projection may have prolateral accessory keels and is diagnosed by possessing a nodule of inwardly curled megaspines, located in the basal ventro-retrolateral region of metatarsi I in adult males. Additionally, male tibiae I possess three apophyses. Females of Magnacarina gen. nov. have a single reduced and strongly sclerotized spermatheca, with an apical lobe projecting ventrally, and with a uterus externus that is longer and wider than the spermatheca.

  14. On Levymanus, a remarkable new spider genus from Israel, with notes on the Chediminae (Araneae, Palpimanidae

    Directory of Open Access Journals (Sweden)

    Sergei Zonstein

    2013-08-01

    Full Text Available Levymanus gershomi gen. n. et sp. n., is described from southern Israel. The eye arrangement and structure of the male palp indicate that this genus belongs to Chediminae Simon, 1893. Levymanus gen. n. differs from other chedimine genera by its unusually long and slender legs, an elongate body, a unique shape of the bipartite thoracic fovea, reduced leg scopulae, smaller spinnerets, and other characters, which are presumably apomorphic. We propose two taxonomic changes: 1 based on widely spaced lateral eyes the Western African genus Badia Roewer, 1961 is transferred from Chediminae to Palpimaninae, and 2 Fernandezina gyirongensis Hu & Li, 1987 from China, based on palpal morphology, is transferred to the Asian genus Steriphopus Simon, 1887 for a new combination Steriphopus gyirongensis (Hu & Li, 1987 comb. n.

  15. 蜘蛛体内Wolbachia的快速检测%The Fast Detection of Wolbachia Infection in Spiders (Araneae)

    Institute of Scientific and Technical Information of China (English)

    杨启伟; 云月利; 彭宇; 刘凤想; 陈建

    2008-01-01

    将蜘蛛匀浆离心后的上清液直接作为PCR反应的模板,用于检测蜘蛛体内的Wolbachia.该方法简便、无污染,与常规方法提取蜘蛛总DNA的检测效果相同,可以用于快速和大量检测蜘蛛体内的Wolbachia感染情况.

  16. Pholcid spiders from the Lower Guinean region of Central Africa: an overview, with descriptions of seven new species (Araneae, Pholcidae

    Directory of Open Access Journals (Sweden)

    Bernhard A. Huber

    2014-04-01

    Full Text Available This paper summarizes current knowledge about Central African pholcids. Central Africa is here defined as the area between 10°N and 7°S and between 6°E and 18°E, including mainly the Lower Guinean subregion of the Guineo-Congolian center of endemism. This includes all of Gabon, Equatorial Guinea, São Tomé and Príncipe, most of Cameroon and Congo Republic, and parts of the neighboring countries. An annotated list of the 14 genera and 79 species recorded from this area is given, together with distribution maps and an identification key to genera. Seven species are newly described: Anansus kamwai sp. nov., Leptopholcus gabonicus sp. nov., Ninetis faro sp. nov., Pholcus punu sp. nov., P. rawiriae sp. nov., Spermophora abibae sp. nov., and S. awalai sp. nov. Additional new records are given for 16 previously described species, including 17 new country records. Distribution and diversity patterns are compared with data on West and East Africa. While West Africa contains a similar set of genera it is significantly less diverse than Central Africa. East Africa is taxonomically more distinct. It has similar levels of diversity as Central Africa, but appears to be less undersampled.

  17. 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.

  18. Verified spider bites in Oregon (USA) with the intent to assess hobo spider venom toxicity.

    Science.gov (United States)

    McKeown, Nathanael; Vetter, Richard S; Hendrickson, Robert G

    2014-06-01

    This study compiled 33 verified spider bites from the state of Oregon (USA). The initial goal was to amass a series of bites by the hobo spider to assess whether it possesses toxic venom, a supposition which is currently in a contested state. None of the 33 bites from several spider species developed significant medical symptoms nor did dermonecrosis occur. The most common biters were the yellow sac spider, Cheiracanthium mildei (N = 10) and orb-weavers of the genus Araneus (N = 6). There were 10 bites from three genera of funnel web spiders of the family Agelenidae including one hobo spider bite and one from the congeneric giant house spider which is readily confused as a hobo spider. The hobo spider bite resulted in pain, redness, twitching in the calf muscle and resolved in 12 h. Also generated from this study were possibly the first records of bites from spiders of the genera Callobius (Amaurobiidae) and Antrodiaetus (Antrodiaetidae), both with minor manifestations.

  19. Microsecond folding and domain motions of a spider silk protein structural switch.

    Science.gov (United States)

    Ries, Julia; Schwarze, Simone; Johnson, Christopher M; Neuweiler, Hannes

    2014-12-10

    Web spiders rapidly assemble protein monomers, so-called spidroins, into extraordinarily tough silk fibers. The process involves the pH-triggered self-association of the spidroin N-terminal domain (NTD), which contains a structural switch connecting spidroins to supermolecules. Single-molecule spectroscopy can detect conformational heterogeneity that is hidden to conventional methods, but motions of the NTD are beyond the resolution limit. Here, we engineered probes for 1 nm conformational changes based on the phenomenon of fluorescence quenching by photoinduced electron transfer into the isolated NTD of a spidroin from the nursery web spider Euprosthenops australis. Correlation analysis of single-molecule fluorescence fluctuations uncovered site-dependent nanosecond-to-microsecond movement of secondary and tertiary structure. Kinetic amplitudes were most pronounced for helices that are part of the association interface and where structural studies show large displacements between monomeric and dimeric conformations. A single tryptophan at the center of the five-helix bundle toggled conformations in ∼100 μs and in a pH-dependent manner. Equilibrium denaturation and temperature-jump relaxation experiments revealed cooperative and ultrafast folding in only 60 μs. We deduced a free-energy surface that exhibits native-state ruggedness with apparently similar barrier heights to folding and native motions. Observed equilibrium dynamics within the domain suggest a conformational selection mechanism in the rapid association of spidroins through their NTDs during silk synthesis by web spiders.

  20. Good reasons to leave home: proximate dispersal cues in a social spider.

    Science.gov (United States)

    Berger-Tal, Reut; Berner-Aharon, Na'ama; Aharon, Shlomi; Tuni, Cristina; Lubin, Yael

    2016-07-01

    Natal dispersal is a successful tactic under a range of conditions in spite of significant costs. Habitat quality is a frequent proximate cause of dispersal, and studies have shown that dispersal increases both when natal habitat quality is good or poor. In social species kin competition, favouring dispersal may be balanced by the benefits of group living, favouring philopatry. We investigated the effect of changes in the local environment on natal dispersal of adult females in a social spider species, Stegodyphus dumicola (Araneae, Eresidae), with a flexible breeding system, where females can breed either within the colony or individually following dispersal. We manipulated foraging opportunities in colonies by either removing the capture webs or by adding prey and recorded the number of dispersing females around each focal colony, and their survival and reproductive success. We predicted that increasing kin competition should increase dispersal of less-competitive individuals, while reducing competition could cause either less dispersal (less competition) or more dispersal (a cue indicating better chances to establish a new colony). Dispersal occurred earlier and at a higher rate in both food-augmented and web-removal colonies than in control colonies. Fewer dispersing females survived and reproduced in the web-removal group than in the control or food-augmented groups. The results support our prediction that worsening conditions in web-removal colonies favour dispersal, whereby increased kin competition and increased energy expenditure on web renewal cause females to leave the natal colony. By contrast, prey augmentation may serve as a habitat-quality cue; when the surrounding habitat is expected to be of high quality, females assess the potential benefit of establishing a new colony to be greater than the costs of dispersal.

  1. Δ-matroid and jump system

    Directory of Open Access Journals (Sweden)

    Santosh N. Kabadi

    2005-01-01

    Full Text Available The concept of Δ-matroid is a nontrivial, proper generalization of the concept of matroid and has been further generalized to the concept of jump system. In this paper, we show that jump systems are, in some sense, equivalent to Δ-matroids. Using this equivalence and the Δ-matroid theory, we give simple proofs and extensions of many of the results on jump systems.

  2. Time change, jumping measure and Feller measure

    OpenAIRE

    He, Ping

    2007-01-01

    In this paper, we shall investigate some potential theory for time change of Markov processes. Under weak duality, it is proved that the jumping measure and Feller measure are actually independent of time change, and the jumping measure of a time changed process induced by a PCAF supported on $V$ coincides with the sum of the Feller measure on $V$ and the trace of the original jumping measure on $V$.

  3. The aerodynamics of jumping rope

    Science.gov (United States)

    Aristoff, Jeffrey; Stone, Howard

    2011-03-01

    We present the results of a combined theoretical and experimental investigation of the motion of a rotating string that is held at both ends (i.e. a jump rope). In particular, we determine how the surrounding fluid affects the shape of the string at high Reynolds numbers: the string bends toward the axis of rotation, thereby reducing its total drag. We derive a pair of coupled non-linear differential equations that describe the shape, the numerical solution of which compares well with asymptotic approximations and experiments. Implications for successful skipping will be discussed.

  4. Spider silk gut: Development and characterization of a novel strong spider silk fiber

    Science.gov (United States)

    Jiang, Ping; Marí-Buyé, Núria; Madurga, Rodrigo; Arroyo-Hernández, María; Solanas, Concepción; Gañán, Alfonso; Daza, Rafael; Plaza, Gustavo R.; Guinea, Gustavo V.; Elices, Manuel; Cenis, José Luis; Pérez-Rigueiro, José

    2014-12-01

    Spider silk fibers were produced through an alternative processing route that differs widely from natural spinning. The process follows a procedure traditionally used to obtain fibers directly from the glands of silkworms and requires exposure to an acid environment and subsequent stretching. The microstructure and mechanical behavior of the so-called spider silk gut fibers can be tailored to concur with those observed in naturally spun spider silk, except for effects related with the much larger cross-sectional area of the former. In particular spider silk gut has a proper ground state to which the material can revert independently from its previous loading history by supercontraction. A larger cross-sectional area implies that spider silk gut outperforms the natural material in terms of the loads that the fiber can sustain. This property suggests that it could substitute conventional spider silk fibers in some intended uses, such as sutures and scaffolds in tissue engineering.

  5. Spider silk gut: development and characterization of a novel strong spider silk fiber.

    Science.gov (United States)

    Jiang, Ping; Marí-Buyé, Núria; Madurga, Rodrigo; Arroyo-Hernández, María; Solanas, Concepción; Gañán, Alfonso; Daza, Rafael; Plaza, Gustavo R; Guinea, Gustavo V; Elices, Manuel; Cenis, José Luis; Pérez-Rigueiro, José

    2014-12-05

    Spider silk fibers were produced through an alternative processing route that differs widely from natural spinning. The process follows a procedure traditionally used to obtain fibers directly from the glands of silkworms and requires exposure to an acid environment and subsequent stretching. The microstructure and mechanical behavior of the so-called spider silk gut fibers can be tailored to concur with those observed in naturally spun spider silk, except for effects related with the much larger cross-sectional area of the former. In particular spider silk gut has a proper ground state to which the material can revert independently from its previous loading history by supercontraction. A larger cross-sectional area implies that spider silk gut outperforms the natural material in terms of the loads that the fiber can sustain. This property suggests that it could substitute conventional spider silk fibers in some intended uses, such as sutures and scaffolds in tissue engineering.

  6. Dynamic jump intensities and risk premiums

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Ornthanalai, Chayawat; Jacobs, Kris

    2012-01-01

    We build a new class of discrete-time models that are relatively easy to estimate using returns and/or options. The distribution of returns is driven by two factors: dynamic volatility and dynamic jump intensity. Each factor has its own risk premium. The models significantly outperform standard...... models without jumps when estimated on S&P500 returns. We find very strong support for time-varying jump intensities. Compared to the risk premium on dynamic volatility, the risk premium on the dynamic jump intensity has a much larger impact on option prices. We confirm these findings using joint...... estimation on returns and large option samples....

  7. Laminar circular hydraulic jumps without separation

    Science.gov (United States)

    Dasgupta, Ratul; Tomar, Gaurav; Govindarajan, Rama

    2009-11-01

    The traditional inviscid criterion for the occurrence of a planar, standing hydraulic jump is to have the Froude number decrease downstream and go through a value of 1 at some location. Here, upstream propagating, small-amplitude, long, non-dispersive gravity waves are trapped, and non-linear steepening is said to result in a near-discontinuous height profile, but it is not clear how. Such a condition on the Froude number is shown in the present axisymmetric Navier-Stokes computations to hold for a circular jump as well. The relevance of non-linear steepening to a circular jump is therefore a question we wish to answer. In circular jumps, moreover, a region of recirculation is usually observed underneath the jump, underlining the importance of viscosity in this process. This led Tani (J. Phys. Soc. Japan, 1949) to hypothesise that boundary-layer separation was the cause of the circular jump. This hypothesis has been debated extensively and the possibility of circular jumps without separation hinted at. In our simulations, we are able to obtain circular hydraulic jumps without any flow separation. This, and the necessity or otherwise of viscosity in jump formation will be discussed.

  8. A Molecular Jump Mechanism of Water Reorientation

    National Research Council Canada - National Science Library

    Damien Laage; James T. Hynes

    2006-01-01

    .... This water reorientation mechanism involves large-amplitude angular jumps, rather than the commonly accepted sequence of small diffusive steps, and therefore calls for reinterpretation of many...

  9. Spiders spinning electrically charged nano-fibres.

    Science.gov (United States)

    Kronenberger, Katrin; Vollrath, Fritz

    2015-01-01

    Most spider threads are on the micrometre and sub-micrometre scale. Yet, there are some spiders that spin true nano-scale fibres such as the cribellate orb spider, Uloborus plumipes. Here, we analyse the highly specialized capture silk-spinning system of this spider and compare it with the silk extrusion systems of the more standard spider dragline threads. The cribellar silk extrusion system consists of tiny, morphologically basic glands each terminating through exceptionally long and narrow ducts in uniquely shaped silk outlets. Depending on spider size, hundreds to thousands of these outlet spigots cover the cribellum, a phylogenetically ancient spinning plate. We present details on the unique functional design of the cribellate gland-duct-spigot system and discuss design requirements for its specialist fibrils. The spinning of fibres on the nano-scale seems to have been facilitated by the evolution of a highly specialist way of direct spinning, which differs from the aqua-melt silk extrusion set-up more typical for other spiders.

  10. Maternal care and subsocial behaviour in spiders.

    Science.gov (United States)

    Yip, Eric C; Rayor, Linda S

    2014-05-01

    While most spiders are solitary and opportunistically cannibalistic, a variety of social organisations has evolved in a minority of spider species. One form of social organisation is subsociality, in which siblings remain together with their parent for some period of time but disperse prior to independent reproduction. We review the literature on subsocial and maternal behaviour in spiders to highlight areas in which subsocial spiders have informed our understanding of social evolution and to identify promising areas of future research. We show that subsocial behaviour has evolved independently at least 18 times in spiders, across a wide phylogenetic distribution. Subsocial behaviour is diverse in terms of the form of care provided by the mother, the duration of care and sibling association, the degree of interaction and cooperation among siblings, and the use of vibratory and chemical communication. Subsocial spiders are useful model organisms to study various topics in ecology, such as kin recognition and the evolution of cheating and its impact on societies. Further, why social behaviour evolved in some lineages and not others is currently a topic of debate in behavioural ecology, and we argue that spiders offer an opportunity to untangle the ecological causes of parental care, which forms the basis of many other animal societies. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

  11. Spider silk gut: Development and characterization of a novel strong spider silk fiber

    OpenAIRE

    Ping Jiang; Núria Marí-Buyé; Rodrigo Madurga; María Arroyo-Hernández; Concepción Solanas; Alfonso Gañán; Rafael Daza; Plaza, Gustavo R.; Guinea, Gustavo V.; Manuel Elices; José Luis Cenis; José Pérez-Rigueiro

    2014-01-01

    Spider silk fibers were produced through an alternative processing route that differs widely from natural spinning. The process follows a procedure traditionally used to obtain fibers directly from the glands of silkworms and requires exposure to an acid environment and subsequent stretching. The microstructure and mechanical behavior of the so-called spider silk gut fibers can be tailored to concur with those observed in naturally spun spider silk, except for effects related with the much la...

  12. Spider silk gut: Development and characterization of a novel strong spider silk fiber

    OpenAIRE

    Ping Jiang; Núria Marí-Buyé; Rodrigo Madurga; María Arroyo-Hernández; Concepción Solanas; Alfonso Gañán; Rafael Daza; Plaza, Gustavo R.; Guinea, Gustavo V.; Manuel Elices; José Luis Cenis; José Pérez-Rigueiro

    2014-01-01

    Spider silk fibers were produced through an alternative processing route that differs widely from natural spinning. The process follows a procedure traditionally used to obtain fibers directly from the glands of silkworms and requires exposure to an acid environment and subsequent stretching. The microstructure and mechanical behavior of the so-called spider silk gut fibers can be tailored to concur with those observed in naturally spun spider silk, except for effects related with the much la...

  13. Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers.

    Science.gov (United States)

    Pauli, Carole A; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R; Lorenzetti, Silvio

    2016-03-01

    Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance.

  14. Spider Silk Spun and Integrated into Composites

    Science.gov (United States)

    2009-02-20

    Vollrath, F. The role of kinetics of water and amide bonding in protein stability Soft Matter , 4 328-336 2008 Holland, C.A. Vollrath F.V. Biomimetic... Soft Matter 2, 448^151 2006 Emile, O. Floch, A.L. Vollrath, F. The self shape-memory effect in spider draglines. Nature 440, 621 2006 Vollrath F...Porter Spider silk as archetypal protein elastomer. Soft Matter 2;377- 385 2006 Vollrath F, Porter, D. Spider silk as a model biomaterial. Applied

  15. Spiders for rank 2 Lie algebras

    CERN Document Server

    Kuperberg, G

    1996-01-01

    A spider is an axiomatization of the representation theory of a group, quantum group, Lie algebra, or other group or group-like object. We define certain combinatorial spiders by generators and relations that are isomorphic to the representation theories of the three rank two simple Lie algebras, namely A2, B2, and G2. They generalize the widely-used Temperley-Lieb spider for A1. Among other things, they yield bases for invariant spaces which are probably related to Lusztig's canonical bases, and they are useful for computing quantities such as generalized 6j-symbols and quantum link invariants.

  16. Electroencephalographic recordings during parachute jump sessions.

    Science.gov (United States)

    Gauthier, P; Jouffray, L; Rodi, M; Gottesmann, C

    1980-04-01

    Electroencephalographic (EEG) recordings of experienced parachutists were done by means of telemetry before, during, and after jumps of up to 3500m. During free-fall and after stabilization, alpha rhythm was recorded from several alpha reactive subjects when they closed their eyes. No pathological EEG recordings were obtained during the different phases of the jump.

  17. Jump Detection in the Danish Stock Market

    DEFF Research Database (Denmark)

    Høg, Esben

    2002-01-01

    It is well known in financial economics that stock market return data are often modelled by a diffusion process with some regular drift function. Occasionally, however, sudden changes or jumps occur in the return data. Wavelet scaling methods are used to detect jumps and cusps in stock market...

  18. Rope Jumping: A Preliminary Developmental Study.

    Science.gov (United States)

    Wickstrom, Ralph L.

    The basic movement pattern used in skilled individual rope jumping performance was determined and used as a model against which to evaluate the rope jumping form used by children at various levels of skills development. The techniques of adults and nursery school children were filmed and analyzed. The specific causes of unsuccessful attempts were…

  19. Separation and pattern formation in hydraulic jumps

    DEFF Research Database (Denmark)

    Bohr, Tomas; Ellegaard, C.; Hansen, A. Espe;

    1998-01-01

    We present theory and experiments on the circular hydraulic jump in the stationary regime. The theory can handle the situation in which the fluid flows over an edge far away from the jump. In the experiments the external height is controlled, and a series of transitions in the flow structure appe...

  20. Internal hydraulic jumps with large upstream shear

    Science.gov (United States)

    Ogden, Kelly; Helfrich, Karl

    2015-11-01

    Internal hydraulic jumps in approximately two-layered flows with large upstream shear are investigated using numerical simulations. The simulations allow continuous density and velocity profiles, and a jump is forced to develop by downstream topography, similar to the experiments conducted by Wilkinson and Wood (1971). High shear jumps are found to exhibit significantly more entrainment than low shear jumps. Furthermore, the downstream structure of the flow has an important effect on the jump properties. Jumps with a slow upper (inactive) layer exhibit a velocity minimum downstream of the jump, resulting in a sub-critical downstream state, while flows with the same upstream vertical shear and a larger barotropic velocity remain super-critical downstream of the jump. A two-layer theory is modified to account for the vertical structure of the downstream density and velocity profiles and entrainment is allowed through a modification of the approach of Holland et al. (2002). The resulting theory can be matched reasonably well with the numerical simulations. However, the results are very sensitive to how the downstream vertical profiles of velocity and density are incorporated into the layered model, highlighting the difficulty of the two layer approximation when the shear is large.