The daylily leafminer was first noticed in North American around 2006 in Maine. If you look at the daylily dictionary entry I posted above, you can see how many states had it by 2014. See:
https://bugguide.net/node/view...
Larry, Google with the keywords neem oil systemic soil drench. I don't think I would try it without testing on a plant or two first that way. It may be the the neem derivative, azadirachtin, works better. I haven't looked into it that much recently.
Edited to add - here's one study on neem for a different leafminer, although note they used the neem extract azadirachtin (which you can also buy in various products) as a soil drench compared to leaf dipping:
"The systemic effects from a soil drench had a greater adverse effect on pupation and adult eclosion than leaf dipping."
https://www.researchgate.net/p...
