The damaged area may appear thinner or more translucent than the surrounding tissue. In fossils, the scraped region can differ in color or texture from the rest of the leaf impression. When the outer surface is removed, the fine network of internal veins (vascular bundles) may become more visible. Insects that feed exclusively by surface scraping are less common than those that practice margin feeding or hole feeding. In many species, early instar larvae scrape away only the epidermis and part of the mesophyll, producing translucent “window feeding” patches; as they grow, they often shift to margin feeding or hole feeding. This type of damage is known in some leaf beetles, particularly tortoise beetles (subfamily Cassidinae), and occasionally in certain longhorn beetles (family Cerambycidae). Some sawfly larvae also feed in a scraping manner. In aquatic environments, caddisfly larvae (Trichoptera) may graze on submerged fallen leaves, producing similar surface-scraping marks; in such cases, the feeding usually occurs after the leaf has fallen into the water and is already dead.