[Breeding of a biotype of the aphia Myzus persicae on a synthetic medium. IV. Influence of vitamins, especially vitamin C and pyridoxine, on the nutritional value of nutritive fluids].

The nutritive value of synthetic diets for Myzus persicae was evaluated by measuring reproduction of the third generation on each medium: 1. In the presence of a double dose of pyridoxin, the nutritional value of the basic diet was improved. This improvement disappeared when all the vitamins of the B group were also at double dose; 2. In the presence of a double dose of ascorbic acid, the nutritional value of all the diets was improved. This improvement was observed for a single or a double dose of pyridoxin and a single or a double dose of all the vitamins of the B group. The beneficial effect of a double dose of pyridoxin was not adding with the beneficial effect of a double dose of ascorbic acid; 3. A double dose of EDTA was detrimental to the aphid but a double dose of ascorbic acid was sparing this detrimental effect. The results are discussed in relation with the nutritional needs in vitamins and the action of the vitamins in the mineral nutrition of the aphid.