the grainy effect on this shot is more at the expense of image quality than enhancement of mood. Either your ISO was too high, or the effect was in excess.
I know you're going for a stippling effect, but it just looks pixelated to me. I'm sorry. I'd be interested to see the original, maybe in color... I just feel like this is lacking something.
The noise is perhaps on purpose... for my tastes, there's just too much of it. I want to focus on either the intricate parts of the flower or on the bug, but can't seem to focus on either one.
The composition is very nice. Two things which I fear might lower the scores on this one are the noise -- which may have been intentional, and if so I apologize for not realizing that -- and the soft focus.
This is a nice imige, but there is a lot of noise going on, and there's almost no detectable texture on the insect (it completly black) maybe because of the b/w conversion.