Abstract
Non-myrmecophilous lepidopteran larvae using plants bearing ant attractants such as extrafloral nectaries are good models for studying morphological and behavioural mechanisms against ant predation. Udranomia spitzi (Hesperiidae) is a butterfly whose larvae feed on leaves of Ouratea spectabilis (Ochnaceae), a plant with extrafloral nectaries. We described the early stages of U. spitzi, and used field observations and experiments to investigate the defensive strategies of caterpillars against predatory ants. Larvae pass through five instars and pupation occurs inside larval leaf shelters. Ant-exclusion experiments revealed that the presence of ants did not affect significantly caterpillar survival. Predation experiments showed that vulnerability to ant predation decreased with increase in larval size. The present study showed that predatory ants are not as relevant as demonstrated for other systems, and also illustrates how observational data and field experiments can contribute to a better understanding of the biology and ecology of a species of interest.
Acknowledgements
We thank CCPIU for permission to work in its cerrado areas, Sebastián F. Sendoya for pictures, Denise Lange and Tatiane G. Alves for ant identification and Estevão Alves-Silva for review. A.B. was sponsored by graduate fellowships from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). K.D.C. acknowledges research grants from the Conselho Nacional de Pesquisa (CNPq 3012248/2009-5 and 500868/2010-7) and Fundacão de Amparo à Pesquisa do Estado de São Paulo (FAPESP 10/5223-18). L.A.K. was supported by FAPESP (10/51340-8) and A.V.L.F. was supported by the FAPESP (00/01484-1, 04/05269-9, and the Biota-FAPESP programme 98/05101-8 and 11/50225-3), and CNPq (300282/2008-7, 300315/2005-8). P.S.O. acknowledges research grants from the CNPq (301853/2009-6), FAPESP and the Fundo de Apoio ao Ensino, à Pesquisa e à Extensão (FAEPEX).