Native ladybirds are quite harmless and are actually beneficial in the removal of aphids. Simply hoovering the ladybirds up is one way of dealing with an infestation, or there are various insecticidal sprays you could use against them.
Insecto Super bug Destroyer, Insectaclear Strong or Protector C would all be effective. Dethlac could be applied to window frames and as a residual treatment, would remain effective for a period of about 3 months after application.
For serious infestations we supply three sizes of insect smoke bomb, which will kill all the ladybirds in one hit. The pheromones that the ladybirds leave behind will attract other ladybirds, so it is advisable to thoroughly clean the places you have seen the ladybirds.
October- February: Adult ladybirds spend winter in a dormant state, known as 'overwintering'.
March- April: Adult ladybirds become active and leave their overwintering sites to find food, aphids (greenfly).
May: Male and female ladybirds mate.
June- July: Mated females lay eggs which hatch into immature stages called 'larvae'. Larvae feed on aphids and then form 'pupae'.
August: The new generation of adult ladybirds emerge from the pupae.
September: These new adults feed but do not mate until next spring after they have overwintered.
Harlequin ladybirds have very strong dispersal capabilities and can be found just about anywhere. They are most commonly found on deciduous trees, such as lime, sycamore and maple and on low growing plants such as nettles. They will also inhabit reed beds, coniferous woodland and crop systems