On a fairly regular basis we find these moths that, at first glance look like Tersa Sphinx, but are grey or olive green with dark shaded spots, and with one of the longitudinal lines made of black dots. It is clearly not a Tersa, perhaps it is a X. libya, although it is not listed anywhere as occurring in Florida. Maybe another Xylophanes species? Whatever it is, I suspect it is breeding since we have seen it in different months of the year over the course of at least the last 2 years (maybe longer). Expert help to i.d. would be appreciated.