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Web Architecture (web + architecture)
Selected AbstractsPrey protein influences growth and decoration building in the orb web spider Argiope keyserlingiECOLOGICAL ENTOMOLOGY, Issue 5 2009SEAN J. BLAMIRES Abstract. 1. Protein is important for a foraging animal to consume, as it promotes growth and enhances survival, particularly in web-building spiders, which need to invest considerable protein into web building and may trade-off growth for web investment. 2. The influence of dietary protein uptake on growth and web investment was tested in the orb web spider Argiope keyserlingi, by feeding them flies reared on three different media: (1) high protein, (2) low protein, and (3) standard (control) media. There was a negative correlation between protein and energy content of the flies across treatments; flies reared on the high protein media had the highest protein, but lowest energy, while flies reared on the low protein media had the lowest protein but highest energy. 3. It was found that silk investment and web architecture in A. keyserlingi was not affected by diet. Growth and decoration building were both enhanced when spiders were fed a high protein diet. 4. It was concluded that protein intake, rather than energy, influenced both growth and decoration building because: (1) protein intake enhances growth in other animals, (2) protein is essential for silk synthesis, especially aciniform silk, and (3) protein is a limiting factor actively sought by foraging animals in natural environments. [source] A landscape theory for food web architectureECOLOGY LETTERS, Issue 8 2008Neil Rooney Abstract Ecologists have long searched for structures and processes that impart stability in nature. In particular, food web ecology has held promise in tackling this issue. Empirical patterns in food webs have consistently shown that the distributions of species and interactions in nature are more likely to be stable than randomly constructed systems with the same number of species and interactions. Food web ecology still faces two fundamental challenges, however. First, the quantity and quality of food web data required to document both the species richness and the interaction strengths among all species within food webs is largely prohibitive. Second, where food webs have been well documented, spatial and temporal variation in food web structure has been ignored. Conversely, research that has addressed spatial and temporal variation in ecosystems has generally ignored the full complexity of food web architecture. Here, we incorporate empirical patterns, largely from macroecology and behavioural ecology, into a spatially implicit food web structure to construct a simple landscape theory of food web architecture. Such an approach both captures important architectural features of food webs and allows for an exploration of food web structure across a range of spatial scales. Finally, we demonstrated that food webs are hierarchically organized along the spatial and temporal niche axes of species and their utilization of food resources in ways that stabilize ecosystems. [source] How to visualize the spider mite silk?MICROSCOPY RESEARCH AND TECHNIQUE, Issue 9 2009G. Clotuche Abstract Tetranychus urticae (Acari: Tetranychidae) is a phytophagous mite that forms colonies of several thousand individuals. Like spiders, every individual produces abundant silk strands and is able to construct a common web for the entire colony. Despite the importance of this silk for the biology of this worldwide species, only one previous study suggested how to visualize it. To analyze the web structuration, we developed a simple technique to dye T. urticae'silk on both inert and living substrates. Fluorescent brightener 28 (FB) (Sigma F3543) diluted in different solvents at different concentrations regarding the substrate was used to observe single strands of silk. On glass lenses, a 0.5% dimethyl sulfoxide solution was used and on bean leaves, a 0.1% aqueous solution. A difference of silk deposit was observed depending the substrate: rectilinear threads on glass lenses and more sinuous ones on bean leaves. This visualizing technique will help to carry out future studies about the web architecture and silk used by T. urticae. It might also be useful for the study of other silk-spinning arthropods. Microsc. Res. Tech. 2009. © 2009 Wiley-Liss, Inc. [source] Does the Giant Wood Spider Nephila pilipes Respond to Prey Variation by Altering Web or Silk Properties?ETHOLOGY, Issue 4 2007I-Min Tso Recent studies demonstrated that orb-weaving spiders may alter web architectures, the amount of silk in webs, or the protein composition of silks in response to variation in amount or type of prey. In this study, we conducted food manipulations to examine three mechanisms by which orb-weaving spiders may adjust the performance of webs to variation in prey by altering the architectures of webs, making structural changes to the diameters of silk threads, and manipulating the material properties or amino acid composition of silk fibers. We fed Nephila pilipes two different types of prey, crickets or flies, and then compared orb structure and the chemical and physical properties of major ampullate (MA) silk between groups. Prey type did not affect orb structures in N. pilipes, except for mesh size. However, MA silk diameter and the stiffness of orbs constructed by spiders fed crickets were significantly greater than for the fly group. MA fibers forcibly silked from N. pilipes fed crickets was significantly thicker, but less stiff, than silk from spiders fed flies. Spiders in the cricket treatment also produced MA silk with slightly, but statistically significantly, more serine than silk from spiders in the fly treatment. Percentages of other major amino acids (proline, glycine, and glutamine) did not differ between treatments. This study demonstrated that orb-weaving spiders can simultaneously alter some structural and material properties of MA silk, as well as the physical characteristics of webs, in response to different types of prey. [source] | ||||||||||