The Harlequin Ladybird Survey
Harlequin ladybird elytra
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Judith K. Pell


Research Group Leader: Insect Pathology


Plant and Invertebrate Ecology Department, Rothamsted Research

Ladybird research keywords

Coccinella septempunctata, Harmonia axyridis, multitrophic interactions, habitat diversity, behaviour, biological and integrated pest management.

Description of work

My main interests are in the ecology of insect pathogens and the role they play in structuring insect communities and in regulating pest populations (e.g. aphids, lepidoptera, varroa mites on bees). This includes studies on competition between pathogens sharing the same host and pathogen-mediated host behavioural changes. However, pathogens do not function alone, but within diverse guilds of natural enemies that also include predators and parasitoids. A long term interest has been in quantifying the competitive and complementary interactions between guild members and understanding their implications for long term pest control. I am increasingly interested in the relationship between guild diversity and habitat diversity and how the latter can be manipulated to enhance guild function and thereby pest control. The impact of the alien harlequin ladybird, Harmonia axyridis, on native aphid enemy guilds has implications for guild diversity and function and is of key interest. Understanding multitrophic interactions underpins the development of conservation biological control strategies.

Key publications

Pell, J. K., Baverstock, J., Roy, H. E., Ware, R. L. & Majerus, M. E. N.(2008). Intraguild predation involving Harmonia axyridis: a review of current knowledge and future perspectives. BioControl 53: 147-168.

Roy, H. E., Baverstock, J., Ware, R. L., Clark, S. J., Majerus, M. E. N., Baverstock, K. E. & Pell, J. K. (2008). Intraguild predation of the aphid pathogenic fungus Pandora neoaphidis by the invasive coccinellid Harmonia axyridis. Ecological Entomology 33: 175-182.

van Veen, F.J.F., Muller, C.B., Pell, J.K. & Godfray, H.C.J. (2008) Food web structure of three guilds of natural enemies: predators, parasitoids and pathogens of aphids. Journal of Animal Ecology 77: 191-200

Meyling, N.V. & Pell, J.K. (2006) Detection and avoidance of an entomopathogenic fungus by a generalist insect predator. Ecological Entomology 31: 162-171

Ekesi, S., Shah, P.A., Clark, S.J. & Pell, J.K (2005) Conservation biological control with the fungal pathogen Pandora neoaphidis; implications of aphid species, host plant and predator foraging. Agricultural and Forest Entomology 7: 21-30

Harlequin eating a lacewing larva

Judith's "multitrophic interaction" means being eaten for this lacewing larva.