ORIGINAL PAPER Recovery of indigenous butterfly community following control of invasive alien plants in a tropical island’s wet forests F. B. Vincent Florens • John R. Mauremootoo • Simon V. Fowler • Linton Winder • Cla ´udia Baider Received: 30 May 2009 / Accepted: 18 October 2010 / Published online: 4 November 2010 Ó Springer Science+Business Media B.V. 2010 Abstract Invasive alien species pose one of the highest threats to biodiversity, especially in isolated oceanic islands where high rates of both endemism and extinction risk also usually prevail. Few studies have investigated the impact of invasive alien plants on butterflies in insular ecosystems, despite butterflies representing a key indicator group for terrestrial arthropod diversity. Using the Pollard Technique, we quantified butterfly species richness and abundance in eight wet lowland forest areas invaded by alien plants, prin- cipally the strawberry guava (Psidium cattleianum Sabine) on the tropical volcanic island of Mauritius, and compared the results with paired adjacent forest plots that had been weeded of alien plants between 2 and 12 years previously. Butterfly assemblages in weed- infested and weeded forests were distinctly different with higher species richness and much higher butterfly abundance in the latter. At least some of these differences seemed attributable to weed removal effects on forest structure, but understanding the precise F. B. V. Florens UMR PVBMT (Peuplements Ve ´ge ´taux et Bioagresseurs en Milieu Tropical), Universite ´ de la Re ´union, 15, Avenue Rene ´ Cassin, BP 7151, 97715 St Denis, La Re ´union, France F. B. V. Florens (&) Department of Biosciences, University of Mauritius, Re ´duit, Mauritius e-mail: V.Florens@gmail.com J. R. Mauremootoo Mauritian Wildlife Foundation, La Preneuse, Mauritius J. R. Mauremootoo BioNET-INTERNATIONAL Secretariat, Bakeham Lane, Egham, Surrey TW20 9TY, UK S. V. Fowler Manaaki Whenua Landcare Research, PO Box 40, Lincoln 7640, New Zealand L. Winder Research and Knowledge Transfer, Innovation Centre, Rennes Drive, University of Exeter, Exeter, Devon, UK C. Baider Mauritius Herbarium, MSIRI, Re ´duit, Mauritius 123 Biodivers Conserv (2010) 19:3835–3848 DOI 10.1007/s10531-010-9930-x