"It is thought that phobias are caused by a fear of the unknown and can be overcome by self-help learning resulting in better understanding. Observation and scientific investigation have been used to create a body of artwork for the purpose of helping to desensitize people who suffer from arachnophobia. Field trip collections, photography, printmaking and installations have been used to capture, explore and create visual artworks that have been designed to highlight fact-based features of spiders and their webs." / Master of Arts (Visual Arts)

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Thesis (Honors)--College of William and Mary, 2010. / Includes bibliographical references (leaves 93-98). Also available online.

Idiops é um dos maiores gêneros dentre as aranhas migalomorfas, apresentando 80 espécies e uma subespécie, com distribuição nas Américas do Sul e Central, África e oeste asiático. São chamadas popularmente de aranhas-de-alçapão, escavando tocas no solo com auxílio do rastelo e protegem sua área interior com uma porta bem camuflada. As fêmeas vivem permanentemente nas tocas, enquanto os machos são errantes na fase adulta, procurando ativamente as fêmeas para cópula. O presente trabalho teve como objetivo revisar taxonomicamente as espécies de Idiops, redescrevê-las e realizar uma análise filogenética, testando o monofiletismo do gênero e analisar o relacionando das espécies. Os estudos taxonômicos resultaram nas seguintes sinonímias: Idiops crudeni é sinônimo-junior de I. flaveolus; I. gunningi e a subespécie I. gunningi elongatus são sinônimos-junior de I. pretoriae; I. munois e I. lusingius são sinôminos-junior de I. straeleni comb. nov.; I. pullus é sinônimo-junior de I. parvus comb. nov.; e I. rubrolimbatus é sinônimo-junior de I. fossor. A análise cladística contou com 54 espécies de Idiops, além de pelo menos um representante de cada gênero da subfamília Idiopinae. Em todas as análises realizadas, Idiops foi considerado parafilético. Através dos resultados filogenéticos, Idiops foi redefinido, cotando agora com dez espécies em seu elenco: I. clarus, I. germaini, I. argus, I. cambridgei, I. camelus, I. pirassununguensis, I. rastratus, I. opifex, I. fuscus e I. rohdei, todas sul americanas. Idiops possui uma sinapomorfia homoplástica: quelícera com fileira retrolateral de dentes paralela a fileira prolateral e ocupando o terço basal. Três gêneros novos são prospostos. Gen. n. 1, com as espécies Gen. n. 1 upembensis comb. nov., Gen. n. 1 wittei comb. nov., Gen. n. 1 schenkeli comb. nov., Gen. n. 1 kaperonis comb. nov., Gen. n. 1 kazibius comb. nov.; Gen. n. 2., com as espécies Gen. n. 2 kanonganus comb. nov., Gen. n. 2 fageli comb. nov., Gen. n. 2 angusticeps comb. nov.; e Gen. n. 3, com as espécies Gen. n. 3 castaneus comb. nov., Gen. n. 3 versicolor comb. nov., Gen. n. 3 yemenensis comb. nov., Gen. n. 3 parvus comb. nov., Gen. n. 3 pretoriae, Gen. n. 3 fry comb. nov. As seguintes transferências são realizadas: I. straeleni é transferida para Heligmomerus; I. crassus, I. constructor, I. fortis, I. bombayensis e I. robustos são transferidas para Titanidiops; e I. flaveolus e Gorgyrella schreineri minor são transferidas para Segregara. As espécies de Idiops não incluídas nos gêneros acima são consideradas incertae sedis ou species inquirenda / Idiops is one of the diverse genera among Mygalomorphae spiders, presenting 80 species and one subspecies, occurring in Central and South America, Africa and west Asia. They are known as trapdoor spiders, and use their rastellum to excavate burrows in the soil and protect the entrance with a well masked trapdoor. The females live permanently in burrow, while adult males usually wander around in search of mate. The present study aimed to taxonomically revise Idiops species, redescribe then and develop a phylogenetic analysis, testing Idiops monophyly, and analyze its species relationship. The taxonomic review resulted in the establishment of the following synonyms: Idiops crudeni is junior-synonym of I. flaveolus; I. gunningi and the subspecies I. gunningi elongates are junior-synonym of I. pretoriae; I. munois e I. lusingius are junior-synonym of I. straeleni; I. pullus is junior-synonym of I. parvus; .and I. rubrolimbatus is junior-synonym of I. fossor. The cladistic analysis included 54 Idiops species and at least one representative of each Idiopinae genus. Idiops was considered paraphyletic in analysis made here. Based on the phylogenetic results, Idiops is redefined with only ten species: I. clarus, I. germaini, I. argus, I. cambridgei, I. camelus, I. pirassununguensis, I. rastratus, I. opifex, I. fuscus and I. rohdei, all occurring in American continent. Three new genera are proposed based on the cladistic results: Gen. n. 1, with Gen. n. 1 upembensis comb. nov., Gen. n. 1 wittei comb. nov., Gen. n. 1 schenkeli comb. nov., Gen. n. 1 kaperonis comb. nov. and Gen. n. 1 kazibius comb. nov.; Gen. n. 2., with Gen. n. 2 kanonganus comb. nov., Gen. n. 2 fageli comb. nov. and Gen. n. 2 angusticeps comb. nov.; Gen. n. 3, with Gen. n. 3 castaneus comb. nov., Gen. n. 3 versicolor comb. nov., Gen. n. 3 yemenensis comb. nov., Gen. n. 3 parvus comb. nov., Gen. n. 3 pretoriae and Gen. n. 3 fryi comb. nov. The cladistic results also led to the following transferences: I. straeleni is transferred to Heligmomerus; I. crassus, I. constructor, I. fortis, I. bombayensis and I. robustos are transferred to Titanidiops; and I. flaveolus and Gorgyrella schreineri minor are transferred to Segregara. Idiops species that are not listed in the genera above are considered species inquirenda> or incertae sedis.

A mecanismos fisiológicos é frequentemente usada para explicar fenômenos importantes da evolução (p.e. endotermia) e ecologia (p.e. limitações fisiológicas para ocupação de determinado microhabitat) dos vertebrados. Apesar de ser uma área promissora para fornecer explicações e mecanismo que tornam hipóteses evolutivas e ecológicas mais robustas, como já é amplamente praticado no estudo dos vertebrados, ela é raramente usada nas hipóteses elencadas para explicar a megadiversidade das aranhas de teia. Por outro lado, as leis da fisiologia são baseadas fortemente em dados de vertebrados que consistem em menos de 1% da biodiversidade existente no planeta. As aranhas são o sétimo maior táxon em número de espécies e são um bom modelo para testar a validade das regras gerais propostas para os vertebrados. Com insto em mente, o presente trabalho investigou três tipos de taxa metabólica - Metabolismo Padrão, Metabolismo Espontâneo Máximo e Metabolismo Diário - em aranhas de teia. Todas estas taxas foram obtidas através de respirometria intermitente Em um primeiro experimento, usando como modelo Loxosceles, um gênero de aranhas especialmente homogêneo em sua morfologia, testou-se o efeito de sedentarismo e intensidade de construção da teia nas taxas metabólicas. Em um segundo experimento, testou-se como as taxas metabólicas se apresentariam frente a grande diversidade das aranhas do clado Orbiculariae. Os resultados mostram que: as diferenças comportamentais analisadas não afetam significativamente as taxas metabólicas; as taxas metabólicas não possuem sinal filogenético; e o melhor modelo é o que ajusta uma relação alometrica diferente para cada gênero em detrimento de um coeficiente exponencial da massa único para toda a amostra. As diferenças comportamentais de Loxosceles provavelmente apresentam-se na distribuição de gasto energético ao longo do dia partindo de um mesmo montante energético. Os dados de diversidade de Orbiculariae provavelmente precisam ser investigados futuramente sob o aspecto das diferenças morfológicas subjacente à diversidade do clado. / The physiological mechanisms are often applied to explain important evolutionary adaptations (e.g. endothermy) and ecology (e.g. physiological limitations to occupy a particular microhabitat) of vertebrates. Despite the fact that it improves vertebrates ecological and evolutionary hypotheses with possible processes and mechanisms, it is scarcely used to understand the megadiversity of web spiders. On the other hand, the physiological rules are based mainly on vertebrates data, an animal group that represents less than 1% of the world biodiversity. Spiders group is the seventh most diverse taxon in terms of species number on the world and are a good model to test the validity of the general rules proposed for vertebrates. Accordingly, this study investigated three types of metabolic rate - Standard Metabolism, Maximum Spontaneous Metabolism, Daily Metabolism - on web spiders. All these rates were obtained by intermittent respirometry. In the first experiment, the Loxosceles model was chosen, a genus of spider with a especially homogeneous morphology, with whom we tested the differences on metabolic rates of spiders with different sedentarity and web building expenditure. In a second experiment we tested how metabolic rates would vary under the high diversity of Orbiculariae spiders clade. The results show that: behavioral differences do not affect significantly the metabolic rates examined, metabolic rates do not have any significant phylogenetic signal and the best model is the one that adjusts a separate allometric relation for each genus at the expense of an unique allometric model for the whole sample. The behavioral differences of Loxosceles probably could be explained by the distribution of energy expenditure throughout the day under the same amount of energy. The diversity of data of Orbiculariae clade probably need to be investigated in the future under the aspect of morphological differences underlying the diversity of the clade

Biological indicators measure components of the biota and are used to give general information about complex ecosystems in which they occur, playing key roles in conservation planning and management. This study illustrates the impact of habitat change by factors that are extrinsic to the habitats in question and the importance of spider responses in aiding management decisions. The spider responses illustrated existence of environmental change and represent responses of other biota. The conclusions drawn from this study have important management implications for protected areas with grazing herbivores and occurrence of alien invasive plants. Grazed sites showed the highest abundance, diversity and species richness, while ungrazed had the lowest. The implications from this study are that no grazing has negative implications on lower trophic levels, whereas grazing seems to result in favourable conditions for optimal abundance, diversity and species richness. The higher abundance, diversity and species richness associated with grazed sites could result from increased ground cover, greater variation in habitat structure, increased plant diversity and enhanced soil/plant nutrient concentrations. But, ungrazed sites in turn become more monotonous and provide less habitat diversity. However, the characteristic species for each grazing intensity level demonstrates the difficulty in making generalizations for management even for closely related species. The results further opposed the assumption that grazing lawns are a result of overgrazing and thus highly undesirable. This grassland type in comparison to tall bunch grassland displayed the highest spider diversity and species richness. This evidence further supports the conclusion that grazing lawns are steady state communities of their own and not a sub-set of any other grassland type. Therefore, veld management decisions that eradicate grazing lawns are negative for the park as the fauna and flora associated with this grassland type will be lost, leading to cascading effects. Additionally, this study illustrated that habitat modification by invasion of invasive alien plant species has detrimental consequences for the endemic fauna. C. odorata invasion results in a monotonous habitat structure. Consequently, structural heterogeneity is a primary determinant for spider diversity as opposed to abundance of prey, because plant height and architecture drive spider colonization. Therefore, removal of alien invasive weeds results in returning a system to close approximation of its condition prior to disturbance with both structure and function recreated. Assemblage patterns can be selected as endpoints to measure the ecological rehabilitation; thus, the non-significant differences in assemblage patterns of the control versus cleared sites imply that the system is rehabilitating with clearing without further management intervention. This study adds to the limited information on the implications of grazing intensities, grassland types, short and long-term invasion and clearing of an alien invasive plant on spider communities. Copyright / Dissertation (MSc)--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted

This study examines locomotor activity in samples of Frontinella pyramitela collected over its active season (April-October) to investigate whether seasonality and/or age may help explain the exceptional variability typically found in spider clock systems. Despite its noteworthy variability (%CV= 7.7), we have found that Frontinella has a mean free-running period of 28.4±2.18 hours that does not significantly vary over time. There is no correlation between day length and free-running period, indicating that varying length of FRP is not a function of photoperiod length. In LD 12:12 h, the window of activity is significantly smaller in April, gradually widening as the season continues, which may be evident of a shift in foraging strategy. Frontinella’s clock appears to mature before its entrainment mechanisms are fully developed, and towards the end of its season, there is strong evidence of circadian misalignment which may be a product of physiological age.

In my master's thesis, I deal with reproduction of central European wolf spiders of the genus Alopecosa. Here I present patterns and duration of courtship behaviour and copulation of 15 members of the genus Alopecosa. Such information were never published before. I recognized 17 courtship elements, six of them are described here for the first time. Duration of copulation, number of palpal insertions and number of hematodochal expansions of 15 species were examined. The obtained data were analyzed, courtship and copulations among species and species groups are discussed. Courtship behaviour of two sibling species, A. striatipes and A. mariae, is compared, as well as differences in reproduction of Czech and Italian populations of A. accentuata. Based on courtship behaviour, I propose placing Alopecosa psammophila in a striatipes group. Stridulatory apparatus on male pedipalps was not detected, however, some pegs on vetral side of the abdomen in males of Alopecosa pinteroum were found. These pegs could serve as a source of vibratory signals. The thesis provides some new remarks on ecology of members of the genus Alopecosa and contains faunistical information, including those on the recent occurrence of some of the rarest Czech spiders.

Patterns of sperm usage in multiply-mated females have profound fitness consequences for males, and create strong selective pressure on male behavior. In the cooperative theridiid spider Anelosimus studiosus Hentz 1850 adult males are tolerated in females' webs, and females have been observed to mate multiply with different males. In this experiment, virgin females were mated with two different males on consecutive days under controlled conditions to determine paternity patterns and behavioral responses of males to non-virgin females. The paternity of broods was analyzed using randomly amplified polymorphic DNA (RAPDs). Fifteen broods were analyzed and complete first male sperm precedence was found. Mating behavior differed between first and second males with the first males attempting fewer intromissions, but having a longer total time of intromission. This suggests that the second males are either prevented from normal copulation, or are reacting to the different condition of the females. The sperm precedence pattern is discussed with respect to its ramifications for male behavior, juvenile inclusive fitness, and the evolution of cooperative behavior.

When touched with a contact stimulus, 50% of adult Uloborus glomosus jumped from the web; 33% remained motionless; 13% moved to the edge of the web; and 4% shook the web. In a population of juveniles, 45% moved to the edge of the web; 27% jumped from the web; 24% shook the web; and 4% remained motionless. Adults with either stabilimenta or eggsac chains in their webs showed a tendency to shake their webs in the morning and move to the edge in the evening. Those without web structures jumped from their webs throughout the day. Juveniles with stabilimenta shook their webs in the afternoon; those without stabilimenta shook their webs in the evening. Adults aligned with web structures remained motionless when disturbed. Marked adults observed over the course of 4 weeks moved to the edge of the web or remained motionless when contacted in the mornings and jumped in the afternoons and evenings. During this time, the frequency of the jumping behavior increased. An adult U. glomosus jumped from its web in response to contact by a spider-hunting wasp. Other spiders tested with a contact stimulus and the combined visual and vibratory stimuli produced by a tethered wasp responded only to contact. Females tending their eggsac chains exhibited two types of defensive behaviors when either the parasitoid Arachnopteromalus dasys or spiderlings were placed on their eggsacs. They jerked their webs and swept the eggsacs with their long front legs. / Master of Science