Summary: A test of the coevolution theory of autumn colours: colour preference
of Rhopalosiphum padi on Prunus padus
Marco Archetti and Simon R. Leather
Archetti, M. and Leather, S. R. 2005. A test of the coevolution theory of autumn
colours: colour preference of Rhopalosiphum padi on Prunus padus. ┴/ Oikos 110: 339┴/
According to the coevolution theory of autumn colours, the bright colours of trees
evolved as a warning signal towards parasites colonizing the plant in autumn. We
monitored colonization of the aphid Rhopalosiphum padi on individual tress of Prunus
padus in autumn and observed a strong preference of aphids for trees with green leaves.
This is the first direct observation of a key assumption of the theory, that parasites
avoid bright colours. Moreover our observations, compared with previous data
gathered on the same species, suggest that aphids colonizing trees with green leaves
develop better in spring than aphids colonizing trees with bright autumn colours, which
is consistent with the second main assumption of the coevolution theory.
M. Archetti, De┤partement de Biologie, Section Ecologie et Evolution, Universite┤ de
Fribourg, Chemin du Muse┤e 10, CH-1700 Fribourg, Switzerland (marco.archetti@
unifr.ch). Present address: Dept of Zoology, Oxford Univ., South Parks Road, Oxford,
UK, OX1 3PS. ┴/ S. R. Leather, Dept of Biological Sciences, Imperial College London,
Silwood Park Campus, Ascot, UK, SL5 7PY.