A very tricky shot to get I am sure. My gut feeling tells me this might have been a little more illustrative had it been taken just a little more distant. There is a lot to look at and whilst someis in sharp focus other areas are not quite so sharp. I amy be wrong here - please correct me if you think so but I get the impression that if the flash was hot shoe mounted then it has not lit the subject evenly.
I used an old 550 flash gun this had the benefit of pointing slightly downwards, (i dropped it and so it now works intermittently) I have just ordered a 430 mk 11 but I don't think it has this facility.
Hi Allen. This is an interesting looking spider with all the points on its abdomen! I like the comp and background. I would wish for a little more DOF - the abdomen is sharp, but the head around the eyes is a little softer. As you were already at f/16, I think your best option would have been to back off a couple inches from the spider - and crop more in post. I think the image would also be stronger if you had a diffuser on your flash which would have reduced, or eliminated, the specular highlights.