Ladybugs are familiar insects, often recognized by their domed, spotted bodies. While many picture them as exclusively red with black spots, these beetles exhibit a surprising variety of colors and patterns across their numerous species, making them more visually complex than commonly assumed.
The Diverse Palette of Ladybugs
Ladybugs come in vibrant shades of orange, yellow, and black, and less common hues like pink, brown, and blue, such as the steelblue lady beetle. Some species, like the fifteen-spotted lady beetle, can even have a white body. Some ladybugs feature iridescent shells that shift color depending on the light.
Their patterns are equally varied. While many have distinct black spots, the number can range from none to over 20. Spots can differ in size, and some species exhibit stripes or checkered patterns. For instance, the Broad-Striped Ladybug has pink to violet bodies with three black vertical stripes.
The Meaning Behind Ladybug Colors
The coloration of ladybugs serves a biological purpose, primarily as a defense mechanism known as aposematism. This warning signals to predators, like birds, that the ladybug is unpalatable or toxic. Ladybugs can secrete a foul-tasting, yellowish fluid containing toxic alkaloids from their leg joints when threatened, reinforcing this warning.
The intensity of a ladybug’s color can signal its level of toxicity; brighter individuals often possess stronger chemical defenses. For example, orange ladybugs may contain higher levels of toxins, while some brown ladybugs, which rely more on camouflage, are less toxic. While aposematism is the primary function, some colors might also aid in camouflage or species recognition.
Identifying Ladybug Species by Color
Color and pattern are key for identifying the over 5,000 species of ladybugs worldwide. The Seven-Spotted Ladybug (Coccinella septempunctata) typically has an orangish-red body with seven black spots: one central spot at the thorax and three on each wing case. This species is one of the larger ladybugs, measuring about 1/3 of an inch in length.
The Harlequin Ladybug (Harmonia axyridis), also known as the multicolored Asian ladybird, presents a considerable challenge for identification due to its extreme variability. Its colors range from orange to red with many black spots (up to 21), or it can be black with orange or red blotches. A distinguishing feature of many Harlequin ladybugs is an M-shaped mark on the white or cream background of their pronotum, the section behind their head.
The Two-Spotted Ladybug (Adalia bipunctata) is generally red with two black spots, one on each wing case. This species also has a melanic form that is black with two red spots. Brown legs can help distinguish some Harlequin ladybugs from native species like the Two-Spotted Ladybug, which have black legs.