MATERNAL CARE IN THE NEOTROPICAL HARVESTMAN BOURGUYIA ALBIORNATA (ARACHNIDA: OPILIONES): OVIPOSITION SITE SELECTION AND EGG PROTECTION by GLAUCO MACHADO and PAULO S. OLIVEIRA 1,2) (Departamento de Zoologia, Universidade Estadual de Campinas, CP 6109, 13083-970 Campinas SP, Brazil) (Acc. 29-X-2002) Summary Females of the harvestman Bourguyia albiornata oviposit almost exclusively inside the tube formed by the curled leaves of the bromeliad Aechmea nudicaulis . Oviposition is not correlated with rainfall or with temperature, but is negatively correlated with the number of individuals of A. nudicaulis emitting owers. Because the inorescence stalk occupies the tube of leaves of owering bromeliads, oviposition site is not available for ovigerous females. During one year, 83.6% of the females produced only one egg-batch and the remaining produced two or three batches. The mean number of eggs per batch along successive reproductive events decreased signicantly. A eld experiment in which females were removed from the nest bromeliad showed that less than 7% of the unprotected eggs survived beyond two weeks. In a control in which females were maintained over the eggs, predators attacked only one egg-batch. Ants were the most important egg predators, and at the study site at least 20 species nest and/or forage in A. nudicaulis . Intense predation on eggs by generalist predators may be an important pressure promoting parental care in Neotropical harvestmen. 1) E-mail address: glaucom@unicamp.br and pso@unicamp.br 2) We are very grateful to the staff of the Parque Estadual da Ilha do Cardoso for logistical support. Taxonomic identications were provided by R. Pinto-da-Rocha (harvestman), A.D. Brescovit and A.J. Santos (spiders), and C.R.F. Brandão and R. Cogni (ants). We also thank M. Sazima for the photo of the bromeliad, and several friends for help in the eld. A.A. Giaretta, P. Gnaspini, R. Macías-Ordóñez, and an anonymous reviewer provided helpful comments that greatly improved the manuscript. The study was supported by fellowships from the Conselho Nacional de Desenvolvimento Cientíco e Tecnológico (CNPq), and the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). © Koninklijke Brill NV, Leiden, 2002 Behaviour 139, 1509-1524 Also available online -