Norwich scientists have asked the public to help them build a research colony of harlequin ladybirds – the invasive beetles which swarmed across the region last year.

Many people reported their homes being invaded by large numbers of ladybirds after the hot summer boosted their numbers.

But now Dr Ian Bedford, head of entomology at the John Innes Centre at the Norwich Research Park, hopes people will help him find over-wintering clusters of them which can help the centre's research.

'We want to establish a colony here to do some studies, and now is the time to collect them,' he said. 'Leading up to winter these harlequin ladybirds start to come into people's houses, and we get emails saying they are around the window frames and in the curtains. Those will probably die because they get too hot in people's houses to start their hibernation cycle.

'But they will often go into colder buildings like a shed or an out-house and collect together in a group to wait until spring comes along.'

Dr Bedford urged anyone who thinks they might have a cluster of harlequin ladybirds to get in touch, as they may be useful to 'expand the gene pool' of the centre's existing harlequin ladybird colony. He said this species was easy to keep in captivity, and could help research aimed at protecting the insects in the wild.

'There are scientific techniques being looked at for pest control but before they are used as pest control agents we need to make sure they are not going to damage the important bugs in the environment – and ladybirds are very important because they eat aphids,' he said.

The harlequin ladybird has a very variable appearance, which can make it difficult to tell apart from our native ladybirds – but it should be easy to identify a cluster of them, said Dr Bedford.

'At this time of year it will be a cluster of ladybirds which look different to each other,' he said. 'Some will be orange with black spots, some will be black with red spots. It won't be like our native species, which won't cluster in huge numbers, and will all look the same.'

• If you think you have found some harlequin ladybirds which could help the John Innes Centre's studies, contact ian.bedford@jic.ac.uk or contact the entomology department on 01603 450000.