web

zoology

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characteristics of spiders

  • lynx spider
    In spider

    …instead weave silk snares, or webs, to capture prey. Webs are instinctively constructed and effectively trap flying insects. Many spiders inject venom into their prey to kill it quickly, whereas others first use silk wrappings to immobilize their victims.

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  • lynx spider
    In spider: Spider webs

    Many web spiders construct silk sheets in vegetation, sometimes one above the other, and often add anchor threads, which trip unsuspecting insects. The irregular three-dimensional web of cobweb spiders (family Theridiidae) has anchoring threads of sticky silk. An insect caught in the web or touching an…

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respiration of water spiders

  • respiration: animals
    In respiratory system: Trachea

    …aquatica—known for its underwater silk web, which resembles a kind of diving bell—is the only species of spider that spends its entire life underwater. Using fine hairs on its abdomen, where its respiratory openings lie, the water spider captures tiny bubbles of air at the water’s surface, transports them to…

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testing of spider’s hearing

  • auditory mechanisms in insects
    In sound reception: Behavioral evidence

    …buzzing insect caught in their web. The spider apparently locates the insect at once, runs to it, and attacks it. An inactive object, however, such as a small pebble enmeshed in the web, produces a different response: the spider manipulates the strands of the web, locates the object, and cuts…

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type formed by Australian funnel-web spiders

  • Australian funnel-web spider
    In Australian funnel-web spider

    …are named for their funnel-shaped webs, which open wide at the mouth of an underground tube. The burrows are typically built under rocks and in crevices or in and under rotting logs, and some arboreal species inhabit holes in trees. The spider sits in the narrow funnel waiting for prey…

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use by caddisfly

  • caddisfly
    In caddisfly: Life cycle

    …some species the larvae form webs of debris for protection, while others form a funnel-like web between stones in running water to catch food. Some protect their bodies with cases, whereas others spin protective lairs or are free-living. They produce silk from glands on the lower lip (labium), and many…

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use in mating

  • In reproductive behaviour: Arachnids

    …movement or vibration of the web, causing the spider to rush forward and bite its prey as quickly as possible. Thus, it is not surprising that male spiders have evolved fairly elaborate display movements and patterns to convey their identity. Many males are quite strikingly coloured, providing additional information about…

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Related Topics:
spider
silk
web

Spiders are a diverse group of arachnids, with over 46,700 identified species. While not all spiders spin webs, those that do construct them in a variety of forms, including tube- and funnel-shaped webs, sheet webs, and elaborate orb-shaped webs. Orb weavers create the iconic circular webs most commonly associated with arachnids.

The process begins with the spider producing silk in its silk glands, which is then extruded through the spinnerets via spigots that open to the outside. The spider releases a silk thread into the air, allowing it to be carried by the wind. If the thread attaches to a surface, the spider secures it and uses it as a bridge. This bridge is reinforced with additional threads to ensure stability. The spider then descends from the center of the bridge, securing a thread on the ground or another surface. The center, or hub, of the web is established when the spider returns to the bridge with a thread and carries it partway across the bridge before securing it; this thread is the first radial line, or spoke.

The spider constructs the web’s framework by creating additional spokes that extend from the center of the web to the outer edges. These spokes are crucial for the web’s structural integrity. The spider returns to the center of the web, known as the hub, and begins to construct temporary spirals of dry silk. These spirals help the spider maintain the web’s shape as it works. After the framework is complete, the spider removes the temporary spirals and replaces them with a sticky spiral. This sticky silk is what traps prey, as it is coated with a glue-like substance that ensnares insects that come into contact with it. The spider carefully constructs this final spiral from the outside of the web inward, ensuring that it is evenly spaced and covers a large area to maximize the chances of capturing prey.

Once the web is complete, the spider may make final adjustments to ensure its effectiveness. Some spiders attach a signal thread from the hub to a retreat in a leaf, allowing them to detect vibrations from trapped prey. Others remain in the center of the web, sensing tensions or vibrations in the spokes to locate prey. Webs are often rebuilt or repaired regularly, as the sticky silk can dry out or become damaged over time.

The Editors of Encyclopaedia Britannica