Harlequin Ladybugs

Harlequin ladybugs are an invasive species that has established itself across New Zealand in recent years. Unlike our native ladybugs, harlequins can become a significant nuisance in large numbers, congregating on the exterior of buildings in autumn and finding their way inside to overwinter in wall cavities, window frames, and roof spaces. They can leave behind a yellow staining liquid when disturbed and their sheer numbers can be overwhelming.

JAE can treat entry points and affected areas to reduce harlequin ladybug numbers and help prevent them from getting inside.

Harlequin ladybugs are an invasive species that gather in large numbers inside ceilings, window frames, and wall cavities as the weather cools, looking for somewhere to overwinter. Unlike native ladybugs they can stain surfaces, release an unpleasant odour when disturbed, and occasionally bite. Once they establish in a roof void they tend to return to the same site year after year as new arrivals are drawn in by pheromone traces left by the previous group.

JAE treats the entry points and harbourage areas around the building with residual insecticide before the overwintering period, reducing the population that establishes and stopping the cycle of return visits. For active infestations, we treat inside the cavity and the surrounding entry points to clear the existing population.

Our technician will identify the gaps and entry points being used — typically around window frames, weatherboards, soffits, and roof penetrations — and recommend any sealing work that will further reduce the seasonal pressure on the building.