Such is the case with scuds. Most articles are like every one was originally issued a press release from the Fishing Guru 25 years ago and every writer feels obligated to issue the same chopped release/phrases for their region. It smacks of an obligatory inclusion on the last page of a book.
As with any outing, it is better to do some research first re a stream, lake, etc. before going blind. Research on line for info about hatches and when they most often appear (May to June; late afternoons; overcast days best). Also, how to fish them is critical. The presentation of the fly. How would the real ‘insect’ or critter act in the water?
You might be able to gather some meaningful info from your fly shop and a pattern or two to use.
Such is the case with scuds, the ‘must have’ pattern. You will find this must have pattern: drifted and jerked in rapids and riffles with a split shot 6″ above; also you will find it fished deep in stillwaters and the slower, backwaters of rivers beneath a strike indicator with no weight save the fly’s/hook’s weight.
The ‘must have’ scud seems capable of being in all waters and anywhere in those waters according to the varied articles and posts. As with many things for the beginning fly fisher/tier the signs of certainty and clarity are confusing re scuds once you read past ‘must have’.
I won’t propose to be an expert re scuds. I have fished them on tailwater fisheries and done well in quieter, weedy side waters drifting slowly near the bottom. In stillwaters in B.C. and near home, I have fished longer leaders on a floating line and let the fly sink down amongst the weeds and worked the pattern near the bottom, moving it in a slow jigging motion (and yes getting tangled, so a slip strike indicator may be in order…query upper right in search box re slip strike indicator).
I tied the patterns from size 18’s to size 10’s. I like Orange ( a common color for a dead or supposedly egg laden female), tan, and my favorite olive.. Some patterns can be tied with the traditional scud/Czech-Caddsi Pupa configuration as below here:
Both of the above patterns have the back strap of plastic material that is tied in at the bend with ribbing material (wire usually). The body material is either dubbed up the shank or wrapped up the shank (micro chenille and a sparse hackle wrap or two). Then the back strap is pulled over and secured at the eye with the ribbing following to hold the back strap in place. This tying sequence is used in one form or another for Czech, Polish, Caddis, Scud patterns. Large or small.
Another pattern, less sophisticated and still worthy is one I use for Scuds for sizes 10 to 14. I use an Estaz material that is a synthetic (plastic) chenille material. I tie on and wrap up and simply trim the top bristly material away and that is it. It is a great pattern. It can be slightly weighted. I don’t put on a bead, but you could for a Caddis Pupa pattern.
So, to recap on ‘must have’ Scud’ pattern: research your waters you fish. Do they have scuds? Where are they likely to live in your waters? How would you present the pattern to best put it where they live and maybe move it to suggest life? How would I tie a pattern that looks close in size, color and movement to imitate the real life scud. Research Estaz as a fly tying material and look at the sizes. It is not the same as Sparkle Chenille.
Not to confuse matters more, for the heck of it do a little research on sow bugs as well as they are often linked to scuds (freshwater shrimp) in stream habitat. See if they reside in the same parts of the stream’s holding waters. Good luck and as usual have fun!