I have a Plumbago (of course
) and only things I noticed on it were Monarchs and Hummingbirds. Not sure if any of the Swallowtails we have here enjoy it.
Great plant BTW - I love it and it over winters indoors just fine. Its striking blue color always get oohs and ahs from garden visitors. It never stops blooming.
It is still outside on my deck - will come in tomorrow.
I also have a lovely ground cover called Leadwort (Ceratostigma plumbaginoides) which is just as blue. It draws lots of bees of several different types.
The weather has still be warm the past few days (70 ish) and I have noticed a lot of smaller butterflies and many moths. None seen close enough to ID.