June 2010 - Harlequin ladybirds

Bawburgh church looked a picture on Sunday the 25th April. The spring flowers in the churchyard looked beautiful in the morning sunshine. I was attending the communion service at 10am and had plenty of time to appreciate the well kept churchyard. The sunlight streamed through the windows of the church as the service proceeded. We got to the prayers – Philip was sitting in front of me and my eyes were drawn irreverently to a harlequin ladybird which settled in his hair. After a minute or two it flew off towards the sunlight. We were called to the altar rail to take the communion. We knelt down. Looking at the floor I suddenly noticed many more harlequin ladybirds – was Colin, our priest of the day, going to tread on them? I cringed at the thought, not only from the ladybirds’ point of view, but also the clean up job which would be needed if lots of their bodies got crushed. Then I looked at the altar rail. There were dozens of harlequins crawling over it. My mind was certainly not on the communion service now! When the service was over I got to work with a dust pan and brush. The more I looked, the more I saw. They were large ladybirds, black with red spots and red with black spots, typical of the harlequin. David raised the altar cloth. There were hundreds of harlequins crawling up the legs of the table. And the reason for this mini plague of ladybirds in our church? They had sought refuge for their winter hibernation and as the church warmed up in the spring sunshine they all decided the time was right to wake up.

Harlequin ladybirds were introduced on the continent and in the US for controlling agricultural pests such as aphids. They were first seen in the UK in 2004, and are now widespread. The British 7 spot ladybird is sometimes confused with the harlequin as it is similar in size, but it differs in its arrangement of spots. As a defence mechanism harlequins exude a yellow fluid which smells unpleasant. They can bite producing a small bump on the skin. Harlequins do not only feed on aphids but on many other insects, including eggs and larvae of butterflies and moths. They also feed on pollen, nectar, and the juice of ripe fruits. They can be a problem in wineries as they like grapes, and during the harvest it is difficult to separate harlequins from grapes before pressing. The resulting wine may be tainted. They do have enemies – swifts and swallows are immune to the defence chemicals as they only eat the wings. Spiders will eat the ladybirds and their larvae. Parasitic wasps may lay their eggs inside the adult’s body, their emerging larvae feeding on the beetle. Certain soil dwelling fungi can kill the harlequin.

 If you want to join a survey monitoring the harlequins spread and their effect on native ladybirds go to http://www.harlequin-survey.org.

 

lingibson@bawburghvillage.co.uk

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