Walt,
I'm not an expert, but I've got a pretty good reference book at hand (the one by Hodges that I ref'd in your other post). That book recognizes four species:
thysbe, gracilis, diffinis, and
senta. From the book's description, trying to get this picture down to exact species may not be real easy. Quoting perhaps the most relevant snippet...
Our members of this genus are highly variable, in part. But at the same time given populations tend to be quite constant in maculation and size. This has led to naming of numerous forms, varieties and species in the past. It appears as though the species vary in the following ways: 1, number of broods -- in a given area, particularly in the south where the species are multivoltine, spring and summer broods tend to be quite different in appearance; 2, geographically -- specimens of a given species tend to be darker and larger in southern regions as contrasted with smaller, often hairy or fuzzy specimens of the same species in the north or at higher elevations in the mountain systems of the West. Our four species may be separated by the following key: ...
Unfortunately, almost every character listed in the key has to do with markings on the underside of the thorax and abdomen, which we can't see in this photo.
Having said that, let me proceed anyway.
I think we can rule out
diffinis because the border of the wing looks way too broad. Likewise for
senta, which in any case "is questionably distinct from
diffinis". That leaves
thysbe and
gracilis. The book's key distinguishes between them based on the color of the ventral surface (underside) of the thorax --
gracilis is yellow but "banded from anterior to posterior margin with a pair of red or black lines", while
thysbe is yellow, not banded. Unfortunately we can't see the underside of the thorax in this picture. However,
this web page notes that the bands on the thorax are mirrored in the color of the front legs, which are red in
gracilis and white in
thysbe. Yours are white. In addition,
thysbe is common, and
gracilis is not. All told, I'd say you've got a
Hemaris thysbe, the "Common Clearwing".
Thysbe also has a much wider range, particularly in the west. Where did you shoot this picture?
By the way, my refs have the preferred name as
Hemaris, with
Haemorrhagia as an obsolete synonym. Same thing for
Manduca versus
Protoparce. What ref are you getting the names from?
--Rik
Considering your location (Illinois?) possibly Hemaris thysbe. If you location is Turkey I could think about Hemaris dentata. 
