Why Do Spiders Not Stick to Their Webs?
All of us know what a spider web is. It is a
sticky net used to trap prey. When insects fly into the web, they become stuck
in the viscid thread, and spiders eat them. Spider webs are thin but very
strong.
Spiders produce silk from their spinneret glands at the tip of their abdomen. Each gland produces a thread for a different purpose.
Example: a trailed safety line, sticky silk for trapping prey, or fine silk for wrapping it. Spiders use different gland types to produce different silks, and some spiders can produce up to eight different silks during their lifetime. [16]
Most spiders have three pairs of spinnerets, each having its function. There are also spiders with just one pair and others with as many as four pairs.
Webs allow a spider to catch prey without having to expend energy by running it down, making it an efficient method of gathering food. Constructing the web is costly due to the amount of protein required in silk. In addition, later, the silk will lose its stickiness and thus become inefficient at capturing prey. It is common for spiders to eat their web daily to recoup some of the energy used in spinning. Through ingestion and digestion, the silk proteins are getting recycled.
Types
We can see a few categories of spider webs in the wild and can classify them by the webs they weave.
Different types of spider webs include:
- Spiral orb webs, associated primarily with the family Araneidae, as well as Tetragnathidae and Uloboridae[18]
- Tangle webs or cobwebs with the family of Theridiidae
- Funnel webs, with associations divided into primitive and modern
- Tubular webs, which run up the bases of trees or along the ground
- Sheet webs
Several types of silk may be used in web construction, including sticky capture silk and fluffy capture silk, depending on the category of a spider. Webs may be in a vertical plane (most orb webs), a horizontal plane (sheet webs), or at any angle. As insects are spiders' main prey, they would likely impose strong selectional forces on the foraging behavior of spiders. [17][19] Most commonly found in the sheet-web spider families, some webs will have loose, irregular tangles of silk above them. These tangled obstacle courses disorient and knock down flying insects, making them more vulnerable to being trapped on the web below. They may also help to protect the spider from predators such as birds and wasps. [20] A report revealed that several Nephila pilipes individuals can collectively construct an aggregated web system to counter bird predation from all directions. [21]
Many webs span gaps between objects, which the spider could not cross by crawling. It is possible by producing a fine adhesive thread to drift on a faint breeze across a gap. When it sticks to a surface at the far end, the spider feels the change in the vibration. The spider reels in to tighten the first strand and carefully walks along to strengthen it with a second thread. This process continues until the thread is strong enough to support the rest of the web. [28]
After strengthening the first thread, the spider makes a Y-shaped netting. The completion of the first three radials of the web happens like this. The next step is adding more radials, making the distance between each radial and the next small enough to cross. That means the number of radials in a web directly depends on the size of the spider plus the size of the web. It is common for a web to be about 20 times the size of the spider building it. [29]
After the radials are complete, the spider fortifies the center of the web with about five circular threads. It makes a spiral of non-sticky, widely spaced threads to enable it to move around its web during construction, working from the inside outward. Then, beginning from the outside and moving inward, the spider methodically replaces this spiral with a more closely spaced one made of adhesive threads. It uses the initial radiating lines and the non-sticky spirals as guide lines. The spaces between each spiral and the next are directly proportional to the distance from the tip of its back legs to its spinners. It is one method the spider uses its own body as a measuring/spacing device. While completing the sticky spirals, they remove the non-adhesive spirals because of no need.
What a good planner!
After the spider has completed its web, it chews off the initial three center spiral threads and then sits and waits, usually with the head facing downwards. [30] If any breaking happens on the web without structural damage during the construction, the spider does not make any initial attempts to rectify the problem.
After spinning its web, the spider waits on or near the web for a prey animal to become trapped. The spider senses the impact and struggle of a prey animal by vibrations transmitted through the web. A spider positioned in the middle of the web makes for visible prey for birds and other predators, even without web decorations; many day-hunting orb-web spinners reduce this risk by hiding at the edge of the web with one foot on a signal line from the hub or by appearing to be inedible or unappetizing. [25]
Spiders do not usually adhere to their webs because they can spin sticky and non-sticky silks and are careful to travel across only non-sticky portions of the web. However, they are not immune to their glue. Some of the strands of the web are sticky, and others are not. For example, if a spider has chosen to wait along the outer edges of its web, it may spin a non-sticky prey or signal line to the web hub to monitor web movement. However, in the course of spinning sticky strands, spiders have to touch these sticky strands. They do this without sticking by using careful movements, dense hairs, and nonstick coatings on their feet to prevent adhesion. [31]
- Spiders use different gland types to produce silk.
- Some spiders can produce up to eight different types of silk throughout their lifespan. [1] Spiders use this silk to build webs to catch prey.
- The interesting fact is the irreversible transformation of the water-soluble protein inside the spider into a non-water-soluble thread outside of the body.
- Scientists believe that it is the act of pulling on the thread that realigns the molecules, forming a solid structure.[2]
Spiders can spin different kinds of silk, and
not all are sticky. In a spider web, the silk with glue is used for the
intricate catching spirals, so spiders know which threads to avoid. All spiders
have two claws on their feet, but the web-spinning ones possess three. Using
claws to grasp threads and provide traction, the spider moves along.[3]
- Spiders can spin both sticky and non-sticky silk
- They avoid walking on the sticky silk
- Spiders touch the web with the tips of their feet, which have a nonstick coating.
- Spiders have movable claws on their feet that grip and release the threads as they walk.
- Spiders routinely clean their legs to remove silk and other debris that might cause them to get stuck in their webs.[4]
- A special claw on the end of each foot grips and pulls it against springy hairs.
- When the claw is released, the hairs push the web strand away, preventing it from sticking.
- First, during web construction, their legs have to touch the spirals hundreds of times, and the area of contact with the glue becomes minimal due to dense arrays of branched bristles. [5]
- Second, careful engagement and withdrawal of the legs prevent any contact with the sticky line. Spiders only put glue droplets on some of their strands of silk, and they tend to avoid those strands as they move around their web.
- Other areas where the spider rests are built without glue to make it easier for the spider to move around the web.[6]
- Third, the legs appear to have a non-stick coating of chemicals, which may be applied from glands in the mouthparts during grooming.
Let me discuss orb-weavers because their webs
are the most recognizable. Their webs are complex nets of strong dragline,
elastic, and sticky spiraling threads into the center. An orb-weaver begins its
web with radial and framework threads using dragline silk. It provides a
foundation upon which they widen the sticky threads. The spiders then create an
auxiliary spiral to help the radial threads support the weight as the spider
builds. Next, the spider uses and subsequently destroys the supplementary spiral
as a guide to create the catching spiral with glue. In this hour-long process,
orb-weaving spiders weave using only their sense of touch because they often
have poor eyesight. [7-9]
Uses
Some spiders use their webs for hearing, where the giant webs function as extended and reconfigurable auditory sensors. [22]
Not all use their webs for capturing prey directly. Trapdoor spiders pouncing from concealment. Wolf spiders run them down in open chase. The net-casting spider balances the two methods of running and web spinning in its feeding habits. This spider weaves a small net which it attaches to its front legs. It then lurks in wait for potential prey and, when such prey arrives, lunges forward to wrap its victim in the net, bite, and paralyze it. Hence, this spider expends less energy catching prey than a primitive hunter, a wolf spider. It also avoids the energy loss of weaving a large orb web.
Many species also spin silk to catch the wind and then sail on the wind to a new location.
Others manage to use the signaling-snare technique of a web without spinning a web at all. Several types of water-dwelling spiders rest their feet on the water's surface in much the same manner as an orb-web user. When an insect falls onto the water, the spider can detect the vibrations and run out to capture the prey.
The diving bell spider and Desis marina, an intertidal species, use their web to trap air underwater, where they can stay submerged for long periods. [23][24]
Human use
Do you know about cobweb paintings?
A few paintings in private collections survive today. [32]
In the 16th century, in a remote valley of the Austrian Tyrolean Alps, they created paintings on fabrics consisting of layered and wound cobwebs, stretched over cardboard to make a mat, and strengthened by brushing with milk diluted in water.
Apply watercolor to the cobwebs or custom tools to create engravings using a small brush.
Cobwebs were used in traditional European medicines on wounds and cuts to reduce bleeding and aid healing. [33] Recorded this use in ancient Greece and Rome. It has reference in Shakespeare's A Midsummer Night's Dream. [23] Spider webs reduce wound healing times. They are rich in vitamin K and are essential in blood clotting, and their large surface area also helps coagulation. [34]
The effects of some drugs can be measured by examining their outcome on a spider's web-building. [35]
In northeastern Nigeria, cow horn resonators in traditional xylophones often have holes covered with spider webs to create a buzzing sound. [36]
The technologies to mass-produce spider silk have led to the prototype of military protection, wound dressings, and other medical devices and consumer goods. [37][38][39] Spiderweb has another use as a single-step catalyst to make nanoparticles. [40] [41]
Physical and chemical properties
The stickiness of spiders' webs is due to droplets of glue suspended on the silk threads. Orb-weaver spiders, Larinioides cornutus, coat their threads with a hygroscopic aggregate. [43] The glue's moisture-absorbing properties use environmental humidity to keep the captured silk soft and tacky. The glue balls are multifunctional, which means their behavior depends on how quickly something touching a glueball attempts to withdraw. At high velocities, they function as an elastic solid, resembling rubber; at lower velocities, they act as a sticky glue. It allows them to retain a grip on attached food particles. [44]
The web is electrically conductive, which causes the silk threads to spring out to trap their quarry, as flying insects tend to gain a static charge that attracts the silk. [45]
They detected neurotoxins in the glue balls of some spider webs. These toxins help immobilize prey, but their function could also be antimicrobial or protection from ants or other animals that steal from the webs or might attack the spider. [46]
Spider silk has greater tensile strength than the same weight of steel and much greater elasticity. Its microstructure is under investigation for potential applications in industry, including bullet-proof vests and artificial tendons. Researchers have used genetically modified mammals and bacteria to produce the proteins needed to make this material. [47][48][49]
Spider sociality
Whereas most spiders are solitary and even aggressive toward other members of their species, some hundreds of species in several families show a tendency to live in groups, often referred to as colonies [9].
Most social spiders live in tropical regions, but several species reached the eastern United States and other temperate areas.
By building a communal web, the spiders maximize total biomass capture per spider [50]. Large webs and multiple spiders working together to subdue prey allow them to prey on larger organisms than the solitary effort.
The colonies can grow large enough to take down birds, bats, and insects.
Living in a colony also has another benefit of cooperative nest maintenance for spiders. Nest maintenance does not rely solely on an individual in a colony setting and thus saves on a per-capita investment in maintaining silk structures. Predator defense is also increased in a colony with a web and multiple individuals analogous to schools of fish or herds of mammals. [51]
After severe, extensive flooding in Sindh, Pakistan, spiders built their webs together on many trees.
A group of spiders may build webs together in the same area as the communal spider web.
Massive flooding in Pakistan during the 2010 monsoon drove spiders above the water level into trees. The result was trees covered with spider webs. [52]
One such web, reported in 2007 at Lake Tawakoni State Park in Texas, measured 200 yards (180 m) across. Entomologists believe that it may be the result of social cobweb spiders. There is no consensus on how common this occurrence is. [53][54]
Brazil has two instances of this phenomenon known as raining spiders. Communal webs made by social spiders that cover such wide gaps and whose strings are difficult to see that hundreds of spiders seem to be floating in the air.
Low gravity
Spider webs were spun in low Earth orbit in 1973 aboard Skylab, involving two female European garden spiders (cross spiders) called Arabella and Anita, as part of an experiment on the Skylab 3 mission. [55] the experiment aimed to test whether the two spiders would spin webs in space and, if so, whether these webs would be the same as those that spiders produced on Earth. The experiment was a student project of Judy Miles of Lexington, Massachusetts. [55]
After the launch on July 28, 1973, entering Skylab, the spiders were released by astronaut Owen Garriott into a box that resembled a window frame. [55] The spiders constructed their web while a camera took photographs and examined the spiders' behavior in a zero-gravity environment. Both spiders took a long time to adapt to their weightless existence. However, after one day, Arabella spun the first web in the experimental cage, although it was initially incomplete.
They completed the web the following day. The crew members fed and watered the spiders, giving them a house fly. [56] The first web was removed on August 13 to allow the spider to construct a second web. At first, the spider failed to build a new web. When given more water, it built a second web. This time, it was more elaborate than the first. Both spiders died during the mission, possibly from dehydration. [55]
When scientists were allowed to study the webs, they discovered that the space webs were finer than Earth webs, and the patterns of the webs were not dissimilar. Variations were there in the web, and it has a definite difference in the characteristics of the web. Additionally, while the webs were finer overall, the space web had variations in thickness. The thickness of the web was uneven in some points, slightly thinner, and in others, slightly thicker.
It was unusual because Earth webs have uniform thicknesses. [57]
In the 1952 children's novel Charlotte's Web, the spider web plays a crucial role. Many other cultural depictions also feature spiderwebs. In films, illustrations, and other visual arts, spider webs create a spooky atmosphere, especially in horror films. Artificial spider webs are popular in Halloween decorations. Spider webs are often depicted in tattoo art, symbolizing long periods spent in prison, etc.
The
name "World Wide Web" is derived from its tangled and interlaced
structure, which resembles a spiderweb.
Superhero
Spider-Man uses artificial spider webs. The Sam Raimi film trilogy and
Spider-Man 2099 use organic webs.
Science
fiction often utilizes the tensile strength of spider webs as a plot device to
justify the presence of artificially giant spiders. [10-11]
Posters
used by the women at Green Ham Common Women's Peace Camp featured the symbol of
a spider web, meant to symbolize the fragility as well as the perseverance of
the protesters. [12]
References:
1. Craig, C. L. (1997). "Evolution of arthropod silks". Annual Review of Entomology. 42: 231–67. doi:10.1146/annurev.ento.42.1.231. PMID 15012314.
2. ^ ^ Penalver, E.; Grimaldi, D. A.; Delclos, X. (2006). "Early Cretaceous spider web with its prey". Science. 312 (5781): 1761–61. doi:10.1126/science.1126628. PMID 16794072. S2CID 34828913.
3. ^ Anotaux, M.; Marchal, J.; Châline, N.; Desquilbet, L.; Leborgne, R.; Gilbert, C.; Pasquet, A. (2012-11-01). "Ageing alters spider orb-web construction". Animal Behaviour. 84 (5): 1113–1121. doi:10.1016/j.anbehav.2012.08.017. ISSN 0003-3472. S2CID 53184814.
4. ^ "Spider - Spider webs | Britannica".
5. ^ "Ask Smithsonian: How do Spiders Make Their Webs?".
6. ^ Zschokke, S., Nakata, K. (2010). "Spider orientation and hub position in orb webs" (PDF). Naturwissenschaften. 97 (1): 43–52. Bibcode:2010NW.....97...43Z. doi:10.1007/s00114-009-0609-7. PMID 19789847. S2CID 24603824.
7. ^ Briceno, R.; Eberhard, W. (2012). "Spiders avoid sticking to their webs: clever leg movements branched drip-tip setae, and anti-adhesive surfaces". Naturwissenschaften. 99 (4): 337–41. Bibcode:2012NW.....99..337B. doi:10.1007/s00114-012-0901-9. PMID 22382404. S2CID 5794652.
8. ^ Zhou, J., Lai, J., Menda, G., Stafstrom, J.A., Miles, C.I., Hoy, R.R. and Miles, R.N., 2022. Outsourced hearing in an orb-weaving spider that uses its web as an auditory sensor. Proceedings of the National Academy of Sciences, 119(14), p.e2122789119. https://doi.org/10.1073/pnas.212278911
9. Wikipedia
10 "Spider-Man Technology from Science Fiction to Reality". 2 July 2021.
12 Fairhall 2006, pp. 40–41.
13 Vollrath, F.; Selden, P. (December 2007). "The role of behavior in the evolution of spiders, silks, and webs". Annu. Rev. Ecol. Evol. Syst. 38: 819–46. doi:10.1146/annurev.ecolsys.37.091305.110221. S2CID 54518303.
14^ Kaston, B.J. (May 1964). "The evolution of spider webs". American Zoologist. 4 (2): 191–207. doi:10.1093/icb/4.2.191. JSTOR 3881292
15 ^ Blackedge, T. A.; Scharff, N.; Coddington, J. A.; Szuts, T.; Wenzel, J. W.; Hayashi, C. Y.; Agnarsson, I. (2009). "Reconstructing web evolution and spider diversification in the molecular era". Proceedings of the National Academy of Sciences of the United States of America. 106 (13): 5229–34. Bibcode:2009PNAS..106.5229B. doi:10.1073/pnas.0901377106. PMC 2656561. PMID 19289848.
16 ^ Craig, C. L. (1997). "Evolution of arthropod silks". Annual Review of Entomology. 42: 231–67. doi:10.1146/annurev.ento.42.1.231. PMID 15012314
20 ^ Blackledge, T.A.; Coddington, J.A.; Gillespie, R.G. (January 2003). "Are three-dimensional spider webs defensive adaptations?". Ecology Letters. 6 (1): 13–18. doi:10.1046/j.1461-0248.2003.00384.x. S2CID 43521213.
21^ Harvey, Mark S.; Austin, Andrew D.; Adams, Mark (2007). "The systematics and biology of the spider genus Nephila (Araneae: Nephilidae) in the Australasian region". Invertebrate Systematics. 21 (5): 407. doi:10.1071/is05016. ISSN 1445-5226
24^ How diving bell spiders can breathe underwater
27 ^ Anotaux, M.; Marchal, J.; Châline, N.; Desquilbet, L.; Leborgne, R.; Gilbert, C.; Pasquet, A. (2012-11-01). "Ageing alters spider orb-web construction". Animal Behaviour. 84 (5): 1113–1121. doi:10.1016/j.anbehav.2012.08.017. ISSN 0003-3472. S2CID 53184814
30^ Zschokke, S., Nakata, K. (2010). "Spider orientation and hub position in orb webs" (PDF). Naturwissenschaften. 97 (1): 43–52. Bibcode:2010NW.....97...43Z. doi:10.1007/s00114-009-0609-7. PMID 19789847. S2CID 24603824
31 ^ Briceno, R.; Eberhard, W. (2012). "Spiders avoid sticking to their webs: clever leg movements branched drip-tip setae, and anti-adhesive surfaces". Naturwissenschaften. 99 (4): 337–41. Bibcode:2012NW.....99..337B. doi:10.1007/s00114-012-0901-9. PMID 22382404. S2CID 5794652
33^ "German pharmacist used cobwebs". Channel 4. 10 September 2008. Archived from the original on 2008-06-16. Retrieved 2008-09-10.
34^ "Chance meeting leads to the creation of antibiotic spider silk". phys.org. Retrieved 2019-09-13.
35^ Tahir, H. M.; Rakha, A.; Mukhtar, M. K.; Yaqoob, R.; Samiullah, K.; Samiullah, K.; Ahsan, M. M. (31 December 2017). "Evaluation of the wound-healing potential of spider silk using mice model". Journal of Animal and Plant Sciences – via The Free Library.
36^ Jackson, Robert R (1974). "Effects of D-Amphetamine Sulphate and Diasepam on Thread Connection Fine Structure in a Spider's Web" (PDF). North Carolina Department of Mental Health. Archived from the original (PDF) on 2010-09-17. Retrieved 2006-12-21.
37^ Blench, Roger. 2009. A guide to the musical instruments of Cameroun: classification, distribution, history and vernacular names. Cambridge: Kay Williamson Educational Foundation.
38^ Service, Robert F. (18 October 2017). "Spinning spider silk into startup gold". Science Magazine, American Association for the Advancement of Science. Retrieved 2017-11-26.
39^ Zhao, Liang; Chen, Denglong; Yao, Qinghua; Li, Min (2 November 2017). "Studies on the use of recombinant spider silk protein/polyvinyl alcohol electrospinning membrane as wound dressing". International Journal of Nanomedicine. 12: 8103–8114. doi:10.2147/IJN.S47256. PMC 5679674. PMID 29138566.
40^ Veerabahu, Subbukutti; Ethirajulu, Sailatha; Sethu, Gunasekaran; Janarthanan, Uma Devi Kumba; Singaravelu, Ganesan (10 June 2021). "Synthesis and Characterization of Wound Dressing Material from Bio-Wastes Impregnated with the Spider Web and the Ethanolic Weaves Extract of Mangifera indica (L.)" (PDF). Biointerface Research in Applied Chemistry. 12 (2): 1998–2012. doi:10.33263/BRIAC122.19982012. S2CID 241004125.
41^ Lateef, A.; Ojo, S. A.; Azeez, M. A.; Asafa, T. B.; Yekeen, T. A.; Akinboro, A.; Oladipo, I. C.; Gueguim-Kana, E. B.; Beukes, L. S. (2016). "Cobweb as a novel biomaterial for the green and eco-friendly synthesis of silver nanoparticles". Applied Nanoscience. 6 (6): 863–874. Bibcode:2016ApNan...6..863L. doi:10.1007/s13204-015-0492-9. S2CID 138160768
43^ Singla, Saranshu; Amarpuri, Gaurav; Dhopatkar, Nishad; Blackledge, Todd A.; Dhinojwala, Ali (May 22, 2018). "Hygroscopic compounds in spider aggregate glue remove interfacial water to maintain adhesion in humid conditions". Nature Communications. 9 (1890 (2018)): 1890. Bibcode:2018NatCo...9.1890S. doi:10.1038/s41467-018-04263-z. PMC 5964112. PMID 29789602.
44^ Sahni, Vasav; Blackledge, Todd A.; Dhinojwala, Ali (2010). "Viscoelastic solids explain spider web stickiness". Nature Communications. 1 (2): 1. Bibcode:2010NatCo...1E..19S. doi:10.1038/ncomms1019. PMID 20975677.
45^ Whipple, Tom (17 January 2014). "The shocking secret of a spider's web". The Times: Nature. Times Newspapers Limited. Retrieved 2014-01-20.
46^ Wilcox, Christie (29 August 2020). "Orb Weavers may spin poisonous webs". Science News. 198 (4): 18.
47^ "GM goat spins web-based future". BBC News. 21 August 2000. Retrieved 2008-01-06.
48^ Becker, Nathan; Oroudjev, Emin; Mutz, Stephanie; Cleveland, Jason P.; Hansma, Paul K.; Hayashi, Cheryl Y.; Makarov, Dmitrii E.; Hansma, Helen G. (2003). "Molecular nano springs in spider capture-silk threads". Nature Materials. 2 (4): 278–83. Bibcode:2003NatMa...2..278B. doi:10.1038/nmat858. PMID 12690403. S2CID 7419692.
49^ Connor, Steve (18 January 2002). "A spider's web that could catch an F-16". The Independent. Independent News and Media Limited. Archived from the original on 2008-01-22. Retrieved 2008-01-06.
50Yip EC, Powers KS, Avilés L (2008). "Cooperative capture of large prey solves scaling challenge faced by spider societies". Proceedings of the National Academy of Sciences. 105 (33): 11818–11822. Bibcode:2008PNAS..10511818Y. doi:10.1073/pnas.0710603105. PMC 2575263. PMID 18689677.
51 ^ "Social organization of the colonial spider Leucauge sp in the Neotropics vertical stratification within colonies" (PDF). Archived from the original (PDF) on 2016-02-04. Retrieved 2015-10-09.
52 Than, Ker (31 March 2011). "Trees Cocooned in Webs After Flood". National Geographic. Archived from the original on April 3, 2011.
53 ^ "Spider web engulfs Texas park trail". Associated Press. 30 August 2007. Retrieved 2007-08-30. [dead link]
54^ "Giant Spider Webs". www.badspiderbites.com. 8 August 2007.
55 Burgess, Colin; Dubbs, Chris (2007). Animals in Space: From Research Rockets to the Space Shuttle. Chichester UK: Praxis. pp. 323–26. ISBN 978-0-387-36053-9.
56 ^ "Spiders in Space on Skylab 3". About.com. Archived from the original on 2011-10-21. Retrieved 2010-08-13.
57 ^ "Guinness World Records". www.guinnessworldrecords.com. Retrieved 2017-12-23.
58^ Zschokke, S., Countryman, S., Cushing, P. E., Spiders in space—orb-web-related behavior in zero gravity, The Science of Nature, 108, 1 (2021), pdf available via https://doi.org/10.1007/s00114-020-01708-8
59^ Dvorsky, George, Space Station Spiders Found a Hack to Build Webs Without Gravity, Gizmodo, December 10, 2020
..
Comments
Post a Comment