hi guys, my question is whats the difference between the march brown and the gray fox ? is the gray fox smaller ? what is the difference in the body color ? i`ve found some pics of a march brown but can`t seem to find any of the gray fox, also i noticed that entomologist now consider them to be of the same species...maccaffertium vicarium.....formely stenonema vicarium and fuscom

No more Stenonema fuscum (Gray Fox). Stenonema fuscum (Gray Fox) is now considered to be the same as Stenonema vicaruim (March Brown). This makes perfect sense to me, for years I've been puzzled by these insects a March Brown looked identical to a Gray Fox except for size and a slight color difference. Hey now with new DNA testing I don't have to worry about it anymore, they have been found to be exactly the same insect except for a difference in color.

http://www.jerryhadden.com/newnames/explain.html

I've been fishing both hatches for quite some time - I'm still convinced there are some notable differences in them.
A march brown is larger and darker.
I tie my March Brown's on #10 hooks - using brown mallard flank for wings, cream colored body, black tail, and brown and grizzly hackle.
I tie Gray Fox on #12 hooks- using undyed mallard flank for wings - gray, gray tails, yellowish body, and ginger and grizzly hackle

thanks dryflyguy, your right there is a notable difference, i found a good pic of both in the book, hatches II i`m gonna ty some using your pattern