There are many species in the lady beetle family. Most are brightly colored, often shiny, typically red, orange, or yellow, and usually spotted, often with black. Several are all or mostly black. Their bodies are hemispherical, circular or oval and dome-shaped, and flat underneath. The antennae are short. The head can tuck (entirely or in part) beneath the pronotum (the shoulderlike or necklike part between the head and the shell-like forewings, or the elytra). The pronotum is often patterned to look something like a head. Like other beetles, they have shell-like forewings that meet together in a straight line down the back (this helps distinguish them from the many members of the "true bug" order whose wings generally form an X pattern when folded on the back).
The larvae are long, segmented, soft-bodied, and rather lizard-like, with six legs; they are often camouflaged with patterns in gray, tan, black, and brown, and often have small bristles.
Habitat and Conservation
Economically important for their agricultural service in eating aphids and other insects injurious to crops.
The multicolored Asian lady beetle (Harmonia axyridis) was imported to America to help control aphids. It is now well established and has become a nuisance. They often enter homes in large numbers as they seek shelter in late autumn. They emit a foul-smelling chemical when threatened.
There has been much discussion in social and even news media attempting to distinguish between supposed genuine "ladybugs" and the introduced "lady beetles." The fact is, all of the insects in family Coccinellidae are beetles, and calling any of them “ladybugs” is inaccurate. That is why biologists prefer to call all the members of this family "lady beetles" or "ladybird beetles." They prefer to use the word "bug" only for members of the true bug order (the Hemiptera), such as cicadas, aphids, leafhoppers, stink bugs, and assassin bugs. (Common names, although beloved, are often misleading. Another example is the so-called lightning bugs or "fireflies," which also are actually beetles; they are neither true bugs nor true flies.)
Lady beetles are a tremendous help to farmers and gardeners, performing natural, nontoxic pest-control.
Some of the Asian lady beetle species that were introduced to help control crop pests have become pests themselves, entering houses in foul-smelling masses when the weather turns cold. Fortunately, they are not harmful, only annoying.
The “lady” in the name arose in Medieval times, apparently when the grateful English thanked “Our Lady” (the Virgin Mary) for the presence of these agricultural helpers. Germans call these insects Marienkäfer, “Mary beetle,” probably for the same reasons.
The fertility of aphids and scale insects is staggering, and without legions of tiny predators like lady beetles, lacewings, and others, they have the potential to cause great harm to plants. Unfortunately, indiscriminate forms of pest control also harm the many insects that are natural exterminators.
Many kinds of animals prey on lady beetles. For one example, researchers in Wyoming discovered some grizzly bear scat that contained only the undigestible shells of thousands of lady beetles.