Good question and I don't really know all that much about the moths. I struggle with this all the time as far as a lot of species of insects. Humans often get to make decisions about whether to kill insects that are eating their plants...or those eating other insects or larval forms of insects. Live or die? Just because we have the power to kill them. Personally I try to stay organic and to kill as few insects as possible, but feel I have to kill some from time to time. When certain beetles and their larva were killing and severely threatening my milkweed plants last year, I had no problem with picking off every single one I could find and killing them. I lost too many milkweed plants last year and the milkweed are food for the Queen and Monarch caterpillars, so I made that decision...because I love those butterflies. I also kill aphids if there are too many of them. Mosquitos, fleas, ticks...I have no problem with killing them on occasion. But I left the Genista moths alone, even though there were LOTS of them and the damage was more than I'd ever seen before. I knew they'd be gone after a while and the Texas Mountain Laurels would be okay, so I made that decision. Also, I didn't kill the 8-Spotted Forrester Moth, even though they stripped foliage of both wild grapevines and Virginia Creepers. Good point, Sandy...at least some things are able to eat those excessive amounts of Genista caterpillars!