Description
Harlequin ladybirds are a globally invasive species native to Central and Eastern Asia. They were first detected in Auckland in 2016 and quickly spread throughout the North Island and established themselves on the East Coast of the South Island. They vary in appearance from red, orange with zero to 21 black spots, or can be black or black with two or four orange or red spots. They grow between 5 and 8 millimetres in size. A distinguishing feature of the harlequin ladybird is black spots on the pronotum (the first segment behind the head) which form an M shape.
Harlequin ladybirds can be found in large clusters in homes and tend to overwinter indoors. As a defence mechanism they produce an unpleasant odour when frightened or squashed. They are known to bite humans.
They feed on aphids and other small insects including native ladybirds and can harm native and beneficial insects. They have been documented in Aotearoa New Zealand feeding on giant willow aphids. They are also regarded as a pest on fruit trees and grape vines.