Science Behind the Photo #32

Seven-Spot Ladybird

Seven-Spot Ladybird (Coccinella septempunctata)

The seven-spot ladybird is one of Britain’s most common beetles, easily recognisable by its distinctive markings. As its name would suggest, this ladybird has seven black spots – three on each side of the red elytra (the hardened forewing that protects the hindwings used for flying) and one split across the junction at the top of the elytra. The seven-spot preys on aphids and is therefore highly regarded by gardeners and farmers across Europe.

However, the seven-spot is being threatened by an invasive species introduced to Britain in 2004 – the Harlequin ladybird (Harmonia axyridis). The Harlequin has already conquered North America and is rapidly increasing in numbers in Britain. Its variable appearance makes it much harder to identify. Although Harlequin ladybirds also prey on aphids, they can easily out-compete other aphid predators such as the seven-spot and, when aphids are scarce, will even prey on ladybird eggs, larvae and pupae, butterfly and moth eggs and caterpillars. For more information on the rising number of Harlequin ladybirds and useful tools for identifying them, visit: www.harlequin-survey.org/

Image: Peter Larkin

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