Sex-ratio-distortion
Guides
Adalia bipunctata
Two-spotted Lady Beetle, Two-spot Ladybird, Two-spotted Ladybug
Adalia bipunctata is a small predatory ladybird beetle native to the Holarctic region, with populations in Europe, North America, and Central Asia. It is one of the most extensively studied ladybird species due to its complex color polymorphism and ecological interactions. The species exhibits remarkable variation in elytral coloration, ranging from the classic red-with-two-black-spots form to multiple melanistic variants. Populations show geographic variation in life history: European populations are typically multivoltine, while some introduced populations (e.g., Japan) exhibit univoltine cycles with extended adult inactivity. The species has declined significantly in parts of its native North American range but remains common in western and central Europe. It is frequently employed as a biological control agent against aphid pests in greenhouses and agricultural systems.