Most people hate bugs and will usually do anything to avoid coming into contact with them. Unless, that is, the creepy crawlies concerned happen to be ladybirds. These colourful little creatures have always been welcome visitors to gardens and their appeal isn’t confined to their appearance.
Ladybirds (Coccineliidae) are helpful insects as both the larvae and the adults feed on garden and agricultural pests. This reduces the need for chemical pesticides. There are 46 species native to Britain and they exhibit a range of colours from subdued yellow to bright scarlet. Their striking appearance is a warning to predators that they taste unpleasant. The ladybirds also exude a bitter aroma to protect themselves. They are the skunks of the insect world! Fortunately we can’t really smell them!
During the winter months the adults hibernate under bark, in crevices and in leaf litter. They emerge in April to find a mate. Females lay eggs which will hatch after about four days. The larvae spend a couple of weeks eating aphids and shedding their skin. They then enter the pupa stage and a week later the adult beetle emerges. This will survive for up to a year.
Native British ladybirds are now threatened by the arrival of the harlequin ladybird (Harmonia axyridis). This species was introduced to North America in 1988 and is now the most widespread ladybird on the continent. It has already invaded large areas of northwestern Europe and arrived in Britain in 2004 where it was first discovered in Norfolk. The harlequin ladybird has since spread across the country.
This invasive species poses a threat because it is a voracious eater and consumes the natural diet of our native species. It boasts a longer reproductive period than other species, can disperse rapidly and will consume the eggs and larvae of native ladybirds when aphids are in short supply. Its dominance could eventually endanger our native bugs and see them die out. Their numbers are already declining.
It is important that the impact of the harlequin ladybird is closely monitored. You can help by taking part in the harlequin ladybird survey. Go to www.harlequin-survey.org for more information and to play your part in helping our ladybirds.
The Stamp Issue
14 September 2014 Royal Mail will issue a set of six appealing stamps which celebrate British Ladybirds. The stamps illustrate the fabulous variety of colours and forms that you will see and provide a useful reminder of the beauty and importance of these diminutive creatures.