Harmonia axyridis (Pallas, 1773) More commonly known as the “Harlequin Ladybird”.
Family: Coccinellidae,
Adults on wing from April to October.
Sizes vary from 5.5 to 8.5mm in length.
Also, the patterns and colorations on this species of ladybird are variable. Apparently worldwide, over a 100 different colour patterns have been recorded. This can make it difficult to separate the Harlequin from some other species of ladybirds; cross breeding with other species of ladybirds is also a possibility, that could lead to identification mistakes.
In 2004, the Harlequin ladybird was first officially recorded in the UK. It has not taken as long as ten years for this ladybird to be recorded throughout the UK, unfortunately the downside of this, is the disappearance of our native ladybirds, especially the “Two-spot ladybird” which are now becoming very scarce, because they cannot compete for food, The Harlequin ladybird is more aggressive and will feed not just on aphids, but will also devour the eggs of and larvae of other ladybirds.
The Harlequin ladybird is native to Asia, was introduced to North America and Europe as a natural control of aphids. Although in the UK, it has mainly migrated in huge numbers from European countries, either through wind currents, via transportation of fruit, vegetables and flowers; also packing cases from Canada, are credited for its success in numbers.
Habitat: Found in a variety of habitats where aphids are abundant, grasslands, Farm-lands orchards, woodlands, hedgerows, urban town gardens and parks.
Adults can lay between 20 to 50 eggs a time, usually two or three broods a year. The eggs will hatch in about four to five days in temperate conditions. The larval stage will be approximately three weeks and pupal stage, lasts around a week. Adults live for around a year, usually hibernating throughout the winter months in large numbers.
Harlequin ladybirds don’t just feed on aphids, but will also hunt out other ladybird eggs and larvae, also on the menu will be eggs of moths and butterflies. Having very large appetites, causes a problem for other species of ladybirds to compete. In many places in the UK other species of ladybirds have declined rapidly, as drastically as, 90%.
This species (as with other ladybirds), has a defensive chemical of “isopropyl methoxy pyrazine”, when threatened, it can produce this chemical by a “reflex bleed”, which gives off a pungent odour. It also carries this chemical in its haemolymph, (A fluid in most invertebrates, equivalent to blood).
This ladybird can also give a small “bite”, although considered not serious, unless one is allergic to its bite.