What is the term for spider dispersal by air using silk?

The term for spider dispersal by air using silk is ballooning. A spider, usually a spiderling, climbs to an exposed position and releases fine silk threads that catch air currents and help carry it away.

The silk acts less like a rigid parachute than a flexible network of drag-producing threads. Wind, rising air, and in some circumstances Earth’s electric field can lift the spider. Ballooning allows young spiders to escape crowded egg sacs, spread to new habitats, and reach isolated patches of vegetation. Most journeys are short, but some spiders have traveled hundreds of kilometres, and airborne spiders have been detected several kilometres above the ground.

The behavior has been known since antiquity, with more precise observations published by arachnologist John Blackwall in 1827. It is sometimes called kiting, which is a defensible informal synonym, but ballooning is the standard quiz and scientific term. “Parachuting” is a tempting answer because the silk resembles a parachute, yet it is not the usual name for the behavior.

Ballooning is risky. Air currents are unpredictable, and a spider may land in unsuitable terrain or become prey during the journey. Although spiderlings are the most frequent ballooners, adults of some species can also disperse this way.