Invasive harlequin ladybird: how to spot this predator
global agriculture
2025.08.04
Harlequin ladybirds (Harmonia axyridis) have been used as biocontrol agent against aphids for over 100 years, with their first release in North America in 1916. It was not until 1988 that the first individuals were found in the wild, but it has since spread rapidly and invaded most of North America and Europe, and is now spreading to other regions such as South America and South Africa.
In most regions where harlequin ladybirds have invaded, numbers have greatly increased, and it has quickly become the most widespread ladybird in a wide range of habitats. Its invasion is a concern for the populations of native ladybirds and other insects that also feed on aphids.
A recent example of this predation was shown by a CABI-led 11-year study, where the invasive harlequin ladybird was seen to cause severe decline of the two-spotted ladybird (Adalia bipunctata) on broadleaved trees and shrubs in northern Switzerland. First confirmed in the country in 2004, it quickly dominated and represented 60-80% of all specimens collected in broadleaved hedges.
Harlequin ladybirds (Harmonia axyridis) have been used as biocontrol agent against aphids for over 100 years, with their first release in North America in 1916. It was not until 1988 that the first individuals were found in the wild, but it has since spread rapidly and invaded most of North America and Europe, and is now spreading to other regions such as South America and South Africa.
In most regions where harlequin ladybirds have invaded, numbers have greatly increased, and it has quickly become the most widespread ladybird in a wide range of habitats. Its invasion is a concern for the populations of native ladybirds and other insects that also feed on aphids.
A recent example of this predation was shown by a CABI-led 11-year study, where the invasive harlequin ladybird was seen to cause severe decline of the two-spotted ladybird (Adalia bipunctata) on broadleaved trees and shrubs in northern Switzerland. First confirmed in the country in 2004, it quickly dominated and represented 60-80% of all specimens collected in broadleaved hedges.
Read more here.