We have been interested for a while in the invasive alien harlequin ladybird (Harmonia axyridis) that arrived in the UK in 2004. The UK ladybird survey, co-lead by Helen Roy, has really clear information about where the harlequin ladybird is in the UK but we want to know about what affect it might be having on a parasite of one of our native ladybird species.
The favorite host of Dinocampus coccinellae is the 7-spot ladybird (Coccinella septempunctata) that is commonly found in gardens, parks and hedgerows in the UK. The parasitic Dinocamupus wasp attacks these ladybirds and lays an egg inside the adult, which hatches into a grub that pushes its way out of the back of the ladybird and spins a cocoon between the legs the ladybirds legs. Within the cocoon, the wasp develops into an adult wasp before chewing its way out of the cocoon and beginning the search for a new host ladybird. These wasps are asexual, meaning that they are all female and can reproduce without males.
Previous studies have shown that the Dinocampus coccinellae wasp often lays its eggs in harlequin ladybirds, but that this may be a ‘mistake’ as the eggs usually don’t develop into wasp offspring. We are looking for volunteer recorders to help us. The records you collect will allow us to get more of an insight of where the wasp is doing well and whether the harlequin ladybird is causing their numbers to reduce.