Comparative Magnetic Measurements On Social Insects

Biogenic magnetite has been detected in several species of social insects and may well form the basis of a magnetic sensory system in these animals, although other physiological functions are possible, too. We report here on hysteresis measurements on honeybees (Apis mellifera) and the termite Neocapritermes opacus. The ratio of saturation remanence to saturation magnetization, J rs/J s, was determined as 0.11 (0.15) in bees (termite), the coercive force H c as 90 (50 Oe). The magnetic remanence is generally low (of the order of 10 -6 emu per individual). The values obtained are similar to the ones reported previously on a migratory ant species, which suggests that biomineralization of magnetic material in social insects may underlie a generic process. © 2004 Elsevier B.V. All rights reserved.289442444Wiltschko, R., Wiltschko, W., (1995) Magnetic Orientation in Animals, , Springer BerlinVacha, M., (1997) Biologia Bratislava, 52, p. 629Gould, J.L., Kirschvink, J.L., Deffeys, K.S., (1978) Science, 201, p. 1026Kirschvink, J.L., Gould, J.L., (1981) Biosystems, 13, p. 181Maher, B.A., (1998) Proc. R. Soc. London, Ser. B, 265, p. 733Esquivel, D.M.S., Wajnberg, E., Cernicchiaro, G.R., Alves, O.C., (2004) J. Magn. Magn. Mater., 278, p. 117Acosta-Avalos, D., Wajnberg, E., Oliveira, P.S., Leal, I., Farina, M., Esquivel, D.M.S., (1999) J. Exp. Biol., 202, p. 2687Wajnberg, E., Cernicchiaro, G., Esquivel, D.M.S., (2004) BioMetals, 17, p. 467Lucano, M., Wajnberg, E., Esquivel, D.M.S., (2004) Proceedings of Ninth Joint MMM/Intermag Conference, p. 464Esquivel, D.M.S., Acosta-Avalos, D., El-Jaick, L.J., Cunha, A.D.M., Palheiros, M.G., Wajnberg, E., Linhares, M.P., (1999) Naturwissenschaften, 86, p. 30Wajnberg, E., Acosta-Avalos, D., El-Jaick, L.J., Abraçado, L., Coelho, J.L.A., Bakuzis, A.F., Morais, P.C., Esquivel, D.M.S., (2000) Biophys. J., 78, p. 1018Alves, O.C., Wajnberg, E., De Oliveira, J.F., Esquivel, D.M.S., (2004) J. Magn. Res., 168, p. 246Araujo, R.L., (1969) Biology of Termites, 2. , K. Krishna F.M. Weesner Academic Press New Yor