March of the Harlequins
This is the larvae of the Harlequin Ladybird which can be seen feasting on aphids on my balcony’s hop plant.
Although Harlequins closely resemble our own native Ladybirds they are actually introductions from Asia and are rapidly spreading northwards across the UK.
According to the National Harlequin Survey ;
” Harlequin ladybirds can seriously affect native ladybird species
- Harlequin ladybirds are very effective aphid predators and have a wider food range and habitat than most other aphid predators (such as the 7-spot ladybird) and so easily out-compete them.
- Harlequin ladybirds do not have a requirement for a dormant period before they can reproduce, as some ladybirds have (e.g. 7-spot and eyed ladybirds), and so have a longer reproductive period than most other species. In 2004 in London, harlequin ladybird larvae were found still feeding in late October, long after all the native species had sought overwintering sites.
- When aphids are scarce, harlequin ladybirds consume other prey including ladybird eggs, larvae and pupae, butterfly and moth eggs and caterpillars.
- Harlequin ladybirds can disperse rapidly over long distances and so have the potential for rapid geographic expansion. “
Although they clearly pose a threat to many of our popular native species insects, including butterflies and ladybirds, I’m keeping a careful eye on their “expansion” on my balcony and hoping that natural predators eventually emerge to help keep down their numbers and so reduce their threat to native species.