Allison what is Merit?
I would think any systemic type treatment would show up in nectar. Glad you mentioned that as I had never thought about the possibility of poisoning the hummers, bees, etc that we all want to have around.
I got rid of fungus gnats with the use of systemics and peroxide drenching. This winter I did not have any in the plants I brought indoors. Mealy bug did however attach a few of my tender succulents, others of the same family they never went near.
