Ladybugs, also known as ladybird beetles, are familiar insects often recognized by their distinctive dome-shaped bodies and vibrant coloration. These small beetles frequently feature prominent spots on their backs, a characteristic that often sparks curiosity regarding their purpose. Understanding what these spots truly signify reveals fascinating aspects of ladybug biology and survival.
Dispelling Common Myths About Spots
A widespread misconception suggests that the number of spots on a ladybug indicates its age. This is inaccurate; a ladybug’s spots do not change throughout its adult life, remaining fixed from the moment they emerge.
Other myths, such as spots signifying a ladybug’s gender or health, are also untrue. The spots are a permanent feature determined by genetics. While diet and environmental factors can influence color intensity, the number and arrangement of spots remain consistent for an individual.
The True Significance of Ladybug Spots
Ladybug spots primarily function as aposematism, or warning coloration. Their bright colors, typically red, orange, or yellow, contrasted with black spots, signal to predators that these beetles are unpalatable or toxic. This visual deterrent helps protect ladybugs from being eaten.
Ladybugs produce defensive chemicals called alkaloids, which make them taste foul and can be toxic if ingested. When threatened, they may exude a yellowish fluid from their leg joints, known as “reflex bleeding.” The intensity of a ladybug’s color can signal its toxicity, with brighter individuals often possessing higher concentrations of these chemicals. The specific patterns and number of spots are largely determined by the ladybug’s species and are genetically inherited.
Identifying Ladybugs by Their Spot Patterns
The species-specific nature of ladybug spot patterns makes them useful for identification. For instance, the Seven-spotted ladybug (Coccinella septempunctata) is recognizable by its seven black spots on a red or orange background. One spot is typically at the junction of the wing covers near the head, with three additional spots on each wing cover.
In contrast, the Multicolored Asian lady beetle (Harmonia axyridis) exhibits significant variation in its spot count, ranging from zero to 19 spots. A reliable identifying feature for this species is a distinct black “M” or “W” shaped marking on the white plate behind its head. While the overall pattern is consistent within a species, minor variations in the size or precise shape of spots can occur among individual ladybugs.