Dr Helen Roy
Helen is an ecological entomologist at the Biological Records Centre – part of the Centre for Ecology & Hydrology. She is interested in the influences of environmental change on the interactions between different species, and is particularly fascinated to know how these influences actually operate. Helen is a ladybird expert and co-ordinates the UK Ladybird Survey. The many people who contribute to this survey, with observations on ladybirds, are an inspiration to Helen, and she feels that it is a great privilege to collate their information. At the moment, the UK Ladybird Survey is expanding to investigate the distribution of ladybird parasites – this exciting new development will allow Helen and her colleagues to look at whether the alien harlequin ladybird is escaping the parasites that attack native ladybird species. Helen has a keen interest in alien species such as the harlequin ladybird and spends much of her time looking at how they affect our wildlife (see her PlanetEarth online blog). Linking with this theme, she leads a European study group, within the International Organization for Biological Control, on the Risks and Benefits of Exotic Biological Control Agents.
Hi Helen
Look like sycamore aphids to me. I too am getting a lot of Harlequin pupae but mainly on the upper side of the leaves. Is that common in your experience?
Simon
Thanks Simon. I have also been noticing that there are harlequin ladybird on the upper leaf surfaces as well as the lower leaf surfaces (I have also seen a scattering of other species pupate on the upper leaf surfaces too though). It is thought that by pupating on the lower side of a leaf the ladybird gains some protection from environmental conditions and, some suggest, parasites (although our recent surveys are showing that this isn’t terribly successful!). The harlequin ladybirds do seem to be less choosy than other species in many ways – I wonder whether harlequin ladybird denisty is a key factor in determining pupation position? I have observed fourth instar larva (the final instar) cannibalising pupae very frequently. Perhaps cannibalism is reduced on the upper leaf surface because the larvae mainly forage on the lower leaf surface (sensibly where the aphids are positioned!). Lots of questions to answer – so anyone out there thinking of becoming an entomologist will never be short of work (although funding is another matter!).
Thanks, Helen