1. M. Florkin andC. H. Jeuniaux, inThe Physiology of Insecta (Ed.M. Rockstein; Academic Press, New York 1964), vol. 3, p. 109.
2. A. P. de Groot, Experientia8, 192 (1952).
3. N. Fujii, Miyazaki Univ. Fac. Agric. Bull.7, 1 (1962).
4. Z. Glinski andT. Kostarz, Med. Weterynar., Poland24, 183 (1968).
5. P. F. Lue andS. E. Dixon, Can. J. Zool.42, 205 (1967).