Harlequin Ladybirds & Cluster Flies:
At PEST UK we have experienced more calls concerning Harlequin ladybirds in the past 8-9 years. This is because mainly due to their hibernation habits. This species tends to be more numerous than the native ladybird and hibernated in greater numbers similar to Cluster Flies. We used to get calls from customers concerning the native ladybird as these hibernate in groups as well but they usually hibernate in smaller numbers in window frames where they would be a nuisance to people. There hibernation sites are rarely buildings while the Harlequin Ladybirds nearly always chose buildings to hibernate in. As with Cluster Flies the hibernation process takes time and Harlequin Ladybirds and Cluster Flies will often hibernate together. The Ladybirds may go into the hibernation sites then come out when the weather warms at midday or sunny periods. It is not thought that Harlequin Ladybirds do any damage except for displacing the native Ladybirds. In fact they may do some good with all the aphids they eat.
Harlequin Ladybirds were introduced into North America in 1988 and are now the most widespread lLadybird on the continent. There are currently 46 species of Ladybirds in the UK. Control for Harlequin Ladybirds from a domestic pest control point of view can only be done in buildings and on external walls and window frames. Treating on plants should be done with a garden insecticide labelled for the purpose although as this would kill native ladybirds as well it would be pointless as it would make no difference to the numbers coming into hibernation sites as they will come from a large catchment area. Treatment may involve a fogging insecticide treatment and the application of a residual insecticide to walls, ceilings, windows, window frames as well as external walls and window frames. Types of treatments may vary depending on individual circumstances.
To book a pest control treatment or free advice then please call us at PEST UK: 0330 100 2811 (local rate) or 0800 026 0308 (free from land lines & some mobiles).