Not quite sure where to start with this image so this is going to be rather random.
--There isn't really anything in focus. While the fly is closest to sharp, there is enough camera and/or leaf movement to slightly blur the fly.
--I'm not sure where you're going with the composition. In truth, there really isn't a composition to this image. Your main subject is in the center of the image. It's better if you employ the rule of thirds.
--Your depth of field is much too narrow. At this distance it should at least encompass the fly.
--You need to decide what role the leaf is going to play in the image. It either should fill the frame entirely and serve as the background or there should be some reason for not filling the frame. As composed, my eye moves right past the out-of-focus fly and wants to know what I'm supposed to see behind the leaf. When I discover that there is nothing there, my interest in the image is lost.
--Other than the blown out areas on the fly, the brightest areas, and the areas that attract the viewer, are at the bottom of the leaf, in both left corners, and behind the leaf. All of those areas pull the eye away from the fly.
--In the upper left there is a circle that is a reflection or OOF water droplet. It's distracting and should be cloned out.
--The lighting is generally too harsh, making it difficult to view the image. Some type of diffuser would help.
Basically, you have a snapshot of a fly on a leaf, but you do not have a photograph that is going to captivate the viewer.
Gary