An experiment was performed to test whether the larvae of the sciomyzid fly Dichetophora biroi are able to ‘recognize’ and reject Lymnaea tomentosa snails infected with Fasciola hepatica.
The analysis of the results indicates that the larvae do not show any obvious preference when given the simultaneous choice of non-infected and infected snails, and also that, under laboratory conditions, the latter are not more vulnerable than the former to the larval predation.
I wish to express my sincere gratitude to Dr R. P. Herd for his help and encouragement during this work. I am also grateful to Professor C. O. Berg, Cornell University (U.S.A.); Dr J. J. Lynch, C.S.I.R.O. Pastoral Research Laboratory, Armidale (N.S.W.) and Dr M. D. Rickard, University of Melbourne, for valuable advice and fruitful discussions. Dr J. A. Thomson, University of Melbourne, critically read the manuscript.