I haven't seen many either, but I haven't been looking for them. I have seen swallowtails this year, so I know they're around. My butterfly bushes have been relatively empty as well. I'll start paying attention.

Kmass,
Your right. I haven't seen many either. I usually see lots of them, but only a couple this year.
Strange.
I have tropical milkweed planted out front too, and they love that!

Could last year's relatively hard winter have knocked back the population locally?

I was told that it was the wet cool weather last summer that did it. That butterfly numbers are down all over this region.

It couldn't possibly due to the increase in chemicals used in agriculture, seeds, bedding plants, and residential areas, could it?

I thought it was me. Last summer, they went nuts over my Pentas. I have not seen any in my yard this year. :(