沙管石蛾幼蟲

石蛾其實唔屬蛾/蝶個鱗翅目[Lepidoptera], 而係獨立出來的毛翅目[Trichoptera], 英文唔係moth, 係Caddisfly, 幼蟲就係caddisfly larvae.
[http://baike.baidu.com/view/228774.htm
石蛾属昆虫纲毛翅目Trichoptera，成虫称为石蛾，幼虫叫石蚕]
至於沙管石蛾呢個品種, 我就唔清楚. 會不會帶著個沙管走來走去如蝸牛, 定係個沙管係一個固定的巢? 因為個英文名都分到case-making caddisflies定係 retreat-making caddisflies.
如果要我估就係retreat-making caddisflies.
http://en.wikipedia.org/wiki/Trichoptera
Caddisflies are considered underwater architects because most species use silt for building throughout their larval life. Caddisflies can loosely be divided into three behavioral groups based on this use of silt: retreat-making caddisflies, case-making caddisflies, and free-living caddisflies.
Those that build retreats build a net or retreat from silt and other materials and use it to catch food items algae, aquatic invertebrates and zooplankton from the flowing stream. Case-making caddisflies make portable cases using silk along with substrate materials such as rocks, sand, wood, aquatic plants, or sometimes silk alone. Many use the retreats or cases throughout their larval life, adding to, or enlarging them as they grow. Free-living caddisflies do not build retreats or carry portable cases until they are ready to pupate.