The beneficial insect known for eating aphids and helping gardeners is the ladybug.
Ladybugs, also called ladybirds or lady beetles, belong to the beetle family Coccinellidae. Most species are predators, and both adults and larvae may eat aphids, scale insects, whiteflies, and other small pests that damage garden plants. Their appetite makes them familiar allies in natural and biological pest control.
The name “ladybug” is especially common in North America; British English generally uses “ladybird.” Their often red-and-black patterns are warning coloration, signaling to predators that they may taste unpleasant or contain defensive chemicals. Not every coccinellid is beneficial, however. Some species eat plants or fungi, and the invasive harlequin ladybird can become a nuisance.
Another common mistake is identifying the larva as a harmful insect. Ladybug larvae are usually elongated and spiny-looking, rather than round and spotted, but they also consume large numbers of aphids. Gardeners should also remember that ants may protect aphids for their honeydew, making aphid control more complicated.