Hi, its actually related to the Marigold, so has similar effects. It also has herbal and culinary uses, but be warned, it can grow to over a meter high. so be careful where you plant it.

I planted tagetes (not sure whether they would have been minuta) in my vegetable garden last year as a natural pest deterrent, and it seemed to have some slight effect on aphids. I intend to do it on a wider scale this year, but our main garden pests, which are "pidocchi" (I think this is translated as plant lice) anyway, some kind of sucking hemipterans, not aphids, seem to be unaffected, and munch away regardless. I should be interested to hear what the rest of you have found.