Yellow caterpillars are most commonly found in North America, Europe, and Asia. In the wild, they can be found in woods, fields, gardens, and parks. Some yellow caterpillars are pests of crops, such as tobacco and tomato hornworms. Others are considered beneficial because they help pollinate flowers or control pests.
For example, the common yellow woolly bear caterpillar becomes the Isabella tiger moth, a significant predator of crop-damaging insects. Many yellow caterpillars are brightly colored to warn potential predators that they are poisonous or distasteful. The yellow coloration is often a warning sign that the caterpillar contains toxins that could make a predator sick.
Some yellow caterpillars also have black, brown, or white markings on their bodies. These markings help the caterpillar camouflage itself from predators. When fully grown, yellow caterpillars transform into moths or butterflies. The adult stage of some yellow-colored insects, such as the goldenrod soldier beetle, is yellowish-orange. Thus, not all yellow insects are caterpillars at every life cycle stage.