Onglide, I'm not sure what it is that you're asking, here. Are you asking if rib stitching is necessary or required? Are you asking how to rib stitch?
If the Jodel uses stitching on only one rib, are you asking if another source will tell you to do more rib stitching? Not sure what it is that you're asking.
AC 43-13B (change 1) will give you ample information on how to rib stitch, and what materials to use, in considerable detail, including step by step directions on a proper seine knot.
The actual sequence of what to do on the rib stitch varies a little with each type of fabric application (stits, ceconite, etc), and you'll need to refer the specific manual for each application. Generally adhesive such as Superseam for the ceconite process will be painted on the surfaces to be stitched, a strip of ceconite layed over, and then brushed through with MEK to draw the superseam into the weave. Then the fabric over the top, shrunk down, then another reinforcement tape. Then the rib stitching, then another tape over the top of that, and in some cases, another rib stitching pinked cover over that...depending on the aircraft and the process.
Far more aircraft use mechanical means other than stitching these days, over ribs and supporting structures.
Whatever you do, don't mix processes, such as stits and ceconite.
Stitch spacing and methodology should match the original installation (or plans, if building from plans)...which is what AC 43.13b also directs. Changes from the original installation are considered a major repair or alteration.
I'm not entirely certain what it is that you're asking. If you want to know about the rib stitching spacing, then visit table 2-12 in AC 43.13b.
Again, the table won't tell you what to do in a specific application where the manufacturer or designer has specified a different spacing or type of stitching; the table and the circular are there to provide guidance when no other guidance is given.
I realize you're talking about the Jodel 117, but the LAA Acceptance Sheet for the Jodel 1050 specifically states regarding wing rib stitching:
http://www.lightaircraftassociation....%201050-M1.pdf
11. Standard Options
Fabric can be attached by bonding to the wing ribs with Super-seam cement (or equivalent) rather than rib stitching, but only if rib cap strips are fitted and fabric anchored at wing dihedral break in accordance with Jodel drawing G1 and translated covering notes available from LAA.
Note that this refers back to the Jodel drawings, as well, just as AC 43.13b will.
You noted that no rib stitching is in use on the ribs beyond the dihedral break...but are capstrips in place or ribs past that point?