No. They do not store vitamin A in any quantity above that needed to form rhodopsin in the eyes (and need very tiny amounts to complete growth). In addition, they have such as high rate of turnover of thier gut contents that it makes it impractical. This is even before we get to the point that many sources of vitamin A in the form of retinoids, contain tocopherols (either naturally as in fish oils) or added as a preservative. The flies do uptake and store tocopherols potentially to levels that would disrupt the uptake of vitamin A and D3 when the flies are dusted. Gutloading flies has been discussed repeatedly over the years including several very in depth one in the last six months. The search function will bring them up.Dear Brothers:
Is it possible to increase the Vit.A in PDF's diet by gut-loading the fruit fly?
Like adding cod-liver oil to the F.F. culture......