A small boy asked “what’s your favorite insect?” I answered without hesitation: caddisflies. Not the short-lived adults, which while charming in their own hairy moth-like way, do not capture my attention. My caddisfly predilection is reserved for the larval stages that last for most of the insect’s one or, less often, two or three year life span. These larvae, like their caterpillar cousins, make and use silk in ways that fascinate me. Silk permits their use of a wide variety of freshwater habitats and food sources.
Consider the caddisflies of the family Rhyacophilidae. Their name translates to “rock loving,” and this preference serves them well in fast-flowing streams. They spin silk ropes that anchor firmly to rocky surfaces, helping them to defy the pull of currents, and stay off some trout’s dinner menu. Like ice climbers using crampons, they also have impressive claws that grow right out of their rear ends. Their anal claws and silk lines keep their bulging, segmented, Michelin-Man bodies secured while they scramble about, eating insects including other caddisflies. » Continue Reading.