Are orb-weaver spiders dangerous? Orb-weaver spiders are considered beneficial to humans . They eat flies, mosquitoes, ants, and other pest insects. Although many can give a painful bite, no orb-weaver spiders are considered dangerous to humans (except to rare individuals who have severe allergic reactions to insect and spider bites).

OFTEN FOUND IN GARDENS

Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields and forest . “Orb” can in English mean “circular,” hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs. With 3122 species in 172 genera worldwide, Araneidae is the third-largest family of spiders .

ENGINEERING FEAT

Generally, orb-weaving spiders are three-clawed builders of flat webs with sticky spiral capture silk. The building of a web is an engineering feat, begun when the spider floats a line on the wind to another surface. The spider secures the line and then drops another line from the center, making a “Y.” The rest of the scaffolding follows with many radii of non-sticky silk being constructed before a final spiral of sticky capture silk.

ALL FOR LOVE

Araneid species either mate at the central hub of the web, where the male slowly traverses the web, trying not to get eaten, and when reaching the hub, mounts the female; or the male constructs a mating thread inside or outside the web to attract the female via vibratory courtship, and if successful, mating occurs on the thread. The much smaller males are attacked during copulation and are cannibalized in up to 80% of the cases.

CHECK THIS OUT

In 2009, workers at a Baltimore Wastewater Treatment Plant called for help to deal with over 100 million orb-weaver spiders living in a community that managed to spin a phenomenal web that covered some 4 acres of a building with spider densities in some areas reaching 35,176 spiders per cubic meter . Wow.