Ladybugs, scientifically known as beetles in the family Coccinellidae, are instantly recognizable insects often associated with the color red. However, the common image of a bright red beetle with black spots represents just a small fraction of this diverse family. Thousands of species across the globe demonstrate that these dome-shaped insects are not only red, challenging the popular perception of what a ladybug looks like.
The Spectrum of Ladybug Colors
The Coccinellidae family is defined by a remarkable range of colors and patterns that extend far beyond the standard red and black. Many species display shades of yellow, orange, or even a pale pink across their hardened wing covers, called the elytra. Other variations include beetles that are solid black, gray, or, in rare cases, a metallic blue-green. These colors are produced by pigments like carotenoids, which create the reds and yellows, and melanins, which are responsible for the darker black coloration.
Pattern variations are just as diverse as the colors themselves, helping distinguish the approximately 6,000 known species. While many have distinct spots, the number can range from none to over twenty, and the spots can vary in size and shape. Some ladybugs feature stripes or checkerboard patterns, while others have fused spots that form complex designs. The variety in color and pattern acts as a visual cue for both defense and species recognition.
The Purpose of Bright Coloration
The bright, high-contrast colors seen in ladybugs serve a crucial function by advertising their unpalatability to predators. This defensive strategy is known as aposematism, where conspicuous coloration warns potential threats, such as birds, that the insect is toxic or tastes extremely bad. The visual signal saves the ladybug from being eaten, as predators learn to associate the bright color with an unpleasant experience.
When a ladybug is threatened, it can perform a defensive action called “reflex bleeding,” excreting a foul-smelling, yellowish fluid from its leg joints. This fluid is hemolymph, the insect’s blood, which contains toxic compounds known as alkaloids. Alkaloids such as precoccinelline and coccinelline are synthesized by the beetle and are distasteful in minute amounts, effectively deterring an attacker. The intensity of the warning coloration is often directly related to the concentration of these defensive chemicals.
Identifying Common Non-Red Species
Many of the ladybugs commonly encountered are not red at all, displaying a spectrum of colors that often leads to confusion about their identity. One of the most common non-red species is the multicolored Asian lady beetle (Harmonia axyridis), which frequently appears yellow or orange. This species has highly variable patterns, sometimes having many spots, few spots, or a completely spotless back. Its defining feature is a distinct black “M” or “W” shape located on the white section behind its head.
Another readily identifiable non-red example is the 22-spot ladybug (Psyllobora vigintiduopunctata), which is bright yellow with 22 small black spots. This species is unique because it feeds primarily on mildew and fungi rather than preying on aphids. Conversely, some ladybugs feature a dark background color, such as the Thrice-Struck Ladybug, which is black with three conspicuous red spots. These examples illustrate how color alone cannot identify a ladybug, as the family embraces a broad palette.