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Abstract
Air-pollution has frequently been suggested as a cause of the decline of some butterfly species: a suggestion based mainly on lowered species richness close to industrial areas in Europe. There have been frequent calls, in vain, for research on the direct effect of air-pollution on Lepidoptera, recent research being confined to the indirect role via climate change.
Based on studies of the species loss and natural recolonisation of Epping Forest (a large woodland area close to London, UK) I suggest that those species feeding as adults on sugar-rich fluids direct from the surface of trees or leaves (i.e. aphid honeydew on leaves or sap-runs on tree-trunks) were affected by particulate air-pollution.
Species loss was high during the period of maximum smoke emissions. Since 1950 five species have recolonised naturally, of which four are honeydew feeders. It is possible that high levels of particulate air-pollution caused the extinction of butterflies feeding on honeydew from polluted leaves. Predictions are made which will allow this hypothesis to be tested.[PUBLICATION ABSTRACT]