{"id":14460,"date":"2023-11-17T12:08:34","date_gmt":"2023-11-17T18:08:34","guid":{"rendered":"https:\/\/uwm.edu\/field-station\/?p=14460"},"modified":"2023-11-17T12:09:55","modified_gmt":"2023-11-17T18:09:55","slug":"lined-orbweaver-spider","status":"publish","type":"post","link":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/lined-orbweaver-spider\/","title":{"rendered":"Lined Orbweaver Spider"},"content":{"rendered":"\n

Note: All links below go to external sites.<\/p>\n\n\n\n

Howdy, BugFans,<\/p>\n\n\n\n

When the BugLady spotted this small spider on its horizontal web (while she was officially censusing butterflies and dragonflies), she thought it might be one of the sheet-web spiders. Fortunately, she has a Spider Guy, and he set her straight (thanks as always, BugFan Mike). <\/p>\n\n\n\n

Turns out that it\u2019s a small orbweaver called the Lined orbweaver (much has been written in BOTW about some of the larger species in the orbweaver family Araneidae<\/em>). <\/p>\n\n\n\n

Orbweavers, famously, spin circular\/orb-shaped trap webs (the silk that makes up the radii isn\u2019t sticky but the silk in the spiral is). The spiders often hang from the web\u2019s center during the day, or they hide in a nearby retreat. They monitor the vibrations of the web, and when an insect sticks and struggles, they\u2019re all over it. Harmless prey is bitten, stunned, and wrapped for later consumption<\/a>, but prey that bites back or stings is wrapped and immobilized before the coup de grace<\/em> is delivered. One source said that the orbweavers are the only spiders that chew their food. <\/p>\n\n\n\n

Many orbweavers (but not this one) spin their webs at night and eat the day-old web, thereby recycling the proteins.  They have eight eyes and poor vision, and they communicate via vibration and chemicals (pheromones). According to an article entitled \u201cOrb-weaver spider uses web to capture sounds\u201d on a Cornell University College of Arts and Sciences Animal Behavior website, \u201cOrb weaver spiders are known to make large webs, creating a kind of acoustic antennae with a sound-sensitive surface area that is up to 10,000 times greater than the spider itself<\/em>\u201d (another article said that they \u201coutsource\u201d their hearing). They both can and will bite (not dangerously) if mishandled, so — don\u2019t.   <\/p>\n\n\n\n

There are more than 3,100 species of orbweavers throughout the world.   <\/p>\n\n\n\n

THE STABILIMENTUM RABBIT HOLE<\/strong><\/p>\n\n\n\n

Some orbweavers, especially those that are active in the daytime, that spin webs in the open, and that leave the webs up for a few days (like spiders in the genus Argiop<\/em>e), take the time and energy to produce a heavy silk and to weave it into a non-sticky, thickened area in the web called a \u201cstabilimentum<\/a><\/em>.\u201d Why? Short answer \u2013 no one knows for sure, but stabilimenta might serve different purposes for the various species that deploy them. Nocturnal spiders and those with unobtrusive webs don\u2019t make them.<\/p>\n\n\n\n

Originally, scientists believed that these structures strengthened the web (hence the name), but the silk is only loosely attached, and the web fares just fine if the stabilimentum is removed. <\/p>\n\n\n\n

In other hypotheses, the stabilimentum:<\/p>\n\n\n\n