1. Werren, J. H., Windsor, D. & Guo, L. R. Proc. R. Soc. Lond. B 262, 197–204 (1995).
2. O'Neill, S. L., Hoffmann, A. A.& Werren, J. H. Influential Passengers: Inherited Microorganisms and Arthropod Reproduction (Oxford Univ. Press, Oxford, 1997).
3. Callaini, G., Dallai, R. & Riparbelli, M. G. J. Cell Sci. 110, 271–280 (1997).
4. Callaini, G., Riparbelli, M. G., Giordano, R. & Dallai, R. J. Invert. Pathol. 67, 55–64 (1996).
5. O'Neill, S. L. & Karr, T. L. Nature 348, 178–180 (1990).