THE ROLE OF SYMBIOTES IN-FLIGHT ACTIVITY OF SITOPHILUS WEEVILS

The flight activity (take-off) of various strains of Sitophilus oryzae L. and S. zeamais Mots. (Coleoptera, Curculionidae) have been compare d on wheat. It was shown that males are more active than females and t hat S. zeamais, is more active than S. oryzae. Furthermore, in the two species, when reared on wheat kernels, only symbiotic weevils were ab le to fly, while aposymbiotic insects did not. By supplementation of t he diet with vitamins (pantothenic acid, riboflavin) and amino acids ( phenylalanine and proline), this activity could be restored in part. T he influence of symbiosis on the flight ability of Sitophilus weevil i s discussed in relation to the energy metabolism (coenzymes, proline), the role played by symbiosis in this behaviour and its possible effec t on the dissemination of the species.