This scanning electron micrograph shows the minute structural detail of barbed setae on the larva of the ragweed plume moth, Adaina ambrosiae (Lepidoptera: Pterophoridae). These tiny caterpillars, reaching only 10 mm in length, feed on the leaves of ragweed, Ambrosia artemisiifolia. When not feeding, the larvae rest in a groove eaten out along the leaf midvein. The caterpillar snuggles into this grove with the long barbed setae fanned out along the surface of the leaf.