Harlequin Ladybirds

The Harlequin ladybird spotted in my sister in laws garden last week

My brother has been busy tracking down our family tree.  It’s something that I have been interested in doing for a long time but I have always got distracted after a couple of minutes and generations.  What he has unveiled, mainly down to new websites that have centuries of information stored,  makes for a fascinating read and the further back he goes, the more interesting it gets.  I did know that somewhere along the line we had a French Countess and a few Yorkshire mill owners and also knew that any wealth accumulated by them had been watered down and dispersed amongst ancestors.  One notable relation retired at 21 because he went bald (then won the crufts with his own breed of whippets before retiring to Switzerland to take in the air) and  also a great-great grandmother who decided to live in a penthouse apartment in a seaside hotel for over 30 years, again to take in the fresh air.  

So far the search has revealed connections to Norman invaders to the Franks, Charlemagne, the King of the Germans, Saxons, Romans and finally to pre Romans in Asia Minor (Turkey). So I have French, Italian, Nordic, German ancestors and one line goes back to 60BC.  The research highlights how we humans move around the planet constantly. I’m keeping the tradition going by moving house more than 30 times over the years.

It’s not only humans

It’s not only people that are always on the move.  If you look at the plant world there are a lot of different species that grow happily here from other climates.  It’s not always a perfect match though as the Australians can prove with their rabbit and bitou weed problem, both were introduced to combat other problems and become ones themselves. I can’t actually think of one example of a plant or insect introduced into an ecosystem to eradicate another problem working over the longterm. The latest failure in this regard brought to my attention last week appears to be the Harlequin Ladybird that was introduced as a predator to get rid of greenfly.  So far the problem has avoided most of Ireland but now Belfast, Dublin and Cork have had sightings of this predator that not only kills greenfly, but other ladybirds too.  A single female can lay over a thousand eggs so their spreading fast.

Origins

The harlequin ladybird is a native of eastern Asia and has been introduced into many countries as a biological control agent against aphid and scale infestations in greenhouses, crops and gardens. Populations have now established in North America, France, Germany, Luxemburg, Belgium, Holland, Greece and Egypt, UK and now Ireland. 

Arrival in the UK and Ireland

The harlequin ladybird arrived in Britain in 2004 probably by a variety of routes. Some have probably flown across the channel, others have been found on flowers imported from Europe, and in packing cases from Canada.

Habitat range

The ladybirds have strong dispersal capabilities and can be found in many places. Most commonly found on deciduous trees, such as lime, sycamore and maple, and on low growing plants such as nettles. Will also inhabit reedbeds, coniferous woodland and crop systems.

Feeding

Harlequin ladybirds feed most commonly on aphids, but have a wide food range, also feeding on scale insects, adelgids, the eggs and larvae of butterflies and moths, many other small insects, including other ladybirds, pollen, nectar, and sugary fluids, including honeydew and the juice from ripe fruits.

Problems

Threat to wildlife -

• 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.
• 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.

Identifying Harlequin ladybirds

The problem of the Harlequin ladybird hasn’t been highlighted much in Ireland so that might be why there are not many sightings, that and the fact that the ladybirds look very similar to the ones we normally see.  There is a chart on the harlequin-survey.org website showing the differences between the two species.  You can see on my image of one frolicking in my sister in laws garden that some types are very easy to identify.

If you do spot one in the garden please report it to the harlequin-survey.org website where they have a form to fill in that updates the sightings map on the website. Alternatively let me know and I will pass the information on.