The Control of Dragline Spinning in the Garden Spider

1962 ◽  
Vol s3-103 (64) ◽  
pp. 557-571
Author(s):  
R. S. WILSON
Keyword(s):  
Control Valve ◽  
Experimental Results ◽  
Abdominal Pressure ◽  
Silk Thread ◽  
Smooth Control ◽  
Factors Affecting ◽  
Orb Web ◽  
Araneus Diadematus ◽  
Orb Web Spiders

A study of the tarsal claws, the spinning apparatus, and other factors affecting dragline spinning has been made using certain orb-web spiders, principally Araneus diadematus. The structure of the tarsal claws suggests that they are incapable of smoothly controlling the speed at which the silk thread is extracted, although they can grip and release the thread quickly. Evidence is presented that smooth control of spinning is achieved through the interaction of the intra-abdominal pressure and the control valve which lies in the silk duct. The intra-abdominal pressure is shown to be equivalent to from 3 to 4 cm of mercury, and to be responsible for moving the fluid silk out of the gland and up the duct. The experimental results also suggest that the control valve regulates the amount of fluid silk available for spinning as a thread and that it also acts as the functional spinning orifice, its aperture controlling the diameter of the thread spun.

Factors affecting spider prey selection by Sceliphron mud-dauber wasps (Hymenoptera: Sphecidae) in northern Italy

2007 ◽  
Vol 57 (1) ◽  
pp. 11-28 ◽  
Author(s):  
Matteo Federici ◽  
Carlo Polidori ◽  
Carlo Pesarini ◽  
Francesco Andrietti
Keyword(s):  
Prey Availability ◽  
Prey Selection ◽  
Northern Italy ◽  
Generalist Predators ◽  
Factors Affecting ◽  
The Family ◽  
Orb Web ◽  
Males And Females ◽  
Orb Web Spiders ◽  
Wasp Nests

AbstractPredatory habits of apoid wasps are well documented for many species, revealing a choice of prey ranging from generalist to specialised, but few studies tested the degree of specialisation when compared with the availability of prey in the environment. In a study carried out in northern Italy, nests of the mud-dauber wasps Sceliphron spirifex L. and S. caementarium Drury were collected to obtain the spider prey of the wasps, and a survey of the nesting area was performed to ascertain frequency of the available spider prey species in the environment. Wasps preyed preferably upon spiders of the family Araneidae. Adult preferred spider prey size ranged from 4 to 6 mm in length. The factor which most affected prey selection was the ecology of the spiders, with orb-web spiders being the preferred prey despite the fact that terricolous, non-web groups were the most abundant in the locality. Sex (female, male or juvenile) of prey was also important in prey selection: juvenile spiders were the most preferred even though males and females were equally and most abundant (respectively). Sceliphron spp. seem almost to be specialised rather than generalist predators. These results suggest that the terms 'generalist' or 'specialised' should not be applied to predators solely on the basis of prey collected from wasp nests, but should also be related to local prey availability.

scholarly journals Dynamic environments do not appear to constrain spider web building behaviour

2021 ◽  
Vol 108 (3) ◽  
Author(s):  
Tom Mulder ◽  
Lucas Wilkins ◽  
Beth Mortimer ◽  
Fritz Vollrath
Keyword(s):  
Wind Loading ◽  
Spider Webs ◽  
Spider Web ◽  
Thread Tension ◽  
In The Wild ◽  
Orb Web ◽  
Araneus Diadematus ◽  
Orb Web Spiders ◽  
Building Behaviour ◽  
Web Building

AbstractMany laboratory experiments demonstrate how orb-web spiders change the architecture of their webs in response to prey, surroundings and wind loading. The overall shape of the web and a range of other web parameters are determined by frame and anchor threads. In the wild, unlike the lab, the anchor threads are attached to branches and leaves that are not stationary but move, which affects the thread tension field. Here we experimentally test the effect of a moving support structure on the construction behaviour and web-parameters of the garden cross spider Araneus diadematus. We found no significant differences in building behaviour between rigid and moving anchors in total time spent and total distance covered nor in the percentage of the total time spent and distance covered to build the three major web components: radials, auxiliary and capture spirals. Moreover, measured key parameters of web-geometry were equally unaffected. These results call for re-evaluation of common understanding of spider webs as thread tensions are often considered to be a major factor guiding the spider during construction and web-operation.

scholarly journals Distinct spinning patterns gain differentiated loading tolerance of silk thread anchorages in spiders with different ecology

2017 ◽  
Vol 284 (1859) ◽  
pp. 20171124 ◽  
Author(s):  
Jonas O. Wolff ◽  
Arie van der Meijden ◽  
Marie E. Herberstein
Keyword(s):  
High Performance ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Silk Thread ◽  
Extrinsic Factors ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Building Behaviour ◽  
And Function

Building behaviour in animals extends biological functions beyond bodies. Many studies have emphasized the role of behavioural programmes, physiology and extrinsic factors for the structure and function of buildings. Structure attachments associated with animal constructions offer yet unrealized research opportunities. Spiders build a variety of one- to three-dimensional structures from silk fibres. The evolution of economic web shapes as a key for ecological success in spiders has been related to the emergence of high performance silks and thread coating glues. However, the role of thread anchorages has been widely neglected in those models. Here, we show that orb-web (Araneidae) and hunting spiders (Sparassidae) use different silk application patterns that determine the structure and robustness of the joint in silk thread anchorages. Silk anchorages of orb-web spiders show a greater robustness against different loading situations, whereas the silk anchorages of hunting spiders have their highest pull-off resistance when loaded parallel to the substrate along the direction of dragline spinning. This suggests that the behavioural ‘printing' of silk into attachment discs along with spinneret morphology was a prerequisite for the evolution of extended silk use in a three-dimensional space. This highlights the ecological role of attachments in the evolution of animal architectures.

scholarly journals Design features of the orb web of the spider, Araneus diadematus

1994 ◽  
Vol 5 (3) ◽  
pp. 280-287 ◽  
Author(s):  
Alun ap Rhisiart ◽  
Fritz Vollrath
Keyword(s):  
Design Features ◽  
Orb Web ◽  
Araneus Diadematus

Web characteristics determine niche partitioning for orb-web spiders (Araneae, Tetragnathidae) in Malaysia

2017 ◽  
Vol 51 (3) ◽  
pp. 262-275 ◽  
Author(s):  
Dzulhelmi Muhammad Nasir ◽  
Thary Gazi Goh ◽  
Asraf Bakri ◽  
Faszly Rahim ◽  
Zulqarnain Mohamed ◽  
...  
Keyword(s):  
Niche Partitioning ◽  
Orb Web ◽  
Orb Web Spiders

scholarly journals Pneumatic Actuator Controlled by Proportional Valve. Experimental results

2021 ◽  
Vol 286 ◽  
pp. 04010
Author(s):  
Valentin Nicolae Cococi ◽  
Constantin Călinoiu ◽  
Carmen-Anca Safta
Keyword(s):  
Control Valve ◽  
Industrial Applications ◽  
Experimental Results ◽  
Pneumatic Actuator ◽  
Proportional Valve ◽  
Controlled Systems ◽  
Automation Systems ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Fire Ignition

In nowadays the pneumatic controlled systems are widely used in industrial applications where valves must be operated, where there is a fire ignition risk, or in different automation systems where a positioning action is desired. The paper presents the experimental results of a pneumatic actuator controlled by a proportional control valve. The goal of the paper is to compare the experimental results with the numerical simulation results and to improve the mathematical model associated with the experiment.

scholarly journals Guiding lights: Foraging responses of juvenile nocturnal orb‐web spiders to the presence of artificial light at night

Ethology ◽  
2019 ◽  
Vol 125 (5) ◽  
pp. 289-297 ◽  
Author(s):  
Nikolas J. Willmott ◽  
Jessica Henneken ◽  
Mark A. Elgar ◽  
Therésa M. Jones
Keyword(s):  
Artificial Light ◽  
Light At Night ◽  
Orb Web ◽  
Orb Web Spiders

The silk tuft web decorations of the orb-weaver Gasteracantha cancriformis : testing the prey attraction and the web advertisement hypotheses

Behaviour ◽  
2008 ◽  
Vol 145 (3) ◽  
pp. 277-295 ◽  
Author(s):  
Felipe Gawryszewski ◽  
Paulo Motta
Keyword(s):  
Drosophila Melanogaster ◽  
Foraging Success ◽  
Uv Reflectance ◽  
Web Advertisement ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Large Animals ◽  
And Control ◽  
The Web ◽  
Prey Attraction

AbstractSeveral orb-web spiders build conspicuous decorations in their webs. The prey attraction hypothesis proposes that decorations increase spider foraging success by attracting prey, and that attraction is linked to UV reflectance. Alternatively, the web advertisement hypothesis proposes that decorations are a signal that advertises the presence of the web to large animals. We tested both hypotheses for the web silk tufts of Gasteracantha cancriformis. Even though tufts are UV reflective, we did not find support for the prey attraction hypothesis. In the field, when webs with tufts painted black and control webs were compared, there were no differences in the number of prey captured, number of damaged areas in webs and type of prey captured. In the laboratory, Drosophila melanogaster did not demonstrate preference for tufted silk lines versus non-tufted silk lines. Our data also did not give support for the web advertisement hypothesis. The proportion of web destruction was similar between web with tufts painted black and control webs during four days of experimentation. Therefore, two of the most favoured hypotheses that attempt to explain decorations do not apply for web silk tufts in our study system. Instead we propose that silk tufts might be an aposematic signal.

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