Talked about this a bit. I think there can be reasonable arguments for a few different ways of handling these, but we feel that if the galls were reared at home, then an observation of the adults should use the date and location of when they were observed in your house (or wherever they were reared) and marked captive. You can then then add links on each observation to the other observation. If you make a new observation of the reared adults and use the date and location of collection, that information is not necessarily accurate regarding the phenology and conditions of the galls in the wild.
You should probably make a new, captive observation for the reared adults and link to it, but I think you could make an argument that photos of the reared adults represent further evidence of the galls you encountered in the wild, similar to spore prints, etc and can be added to the original observation. Either way, make sure you clearly describe what you’ve done so that anyone wanting to use the data can evaluate it for themselves.