Unfortunately, he is wearing an Vereinfachte Feldrock with barrel cuffs; it would be 'easier' if he was clearly wearing Swedish cuffs which would make him Jäger and Schützen etc, or Brandenberg cuffs which would ID him as Landsturm. However, he is wearing a Tschako, and early war Landsturm guys typicially do not cover their old M1860 Tschakos with Überzugs. Plus, Überzugs were designed to cover post-1892 Tschakos, and probably would not fit on an M1860 pattern.
Kraus in his two volume set lists the Reserve Jäger and Schützen units in Vol 1 pp. 477-486. I suspect there is missing info, for example he lists no reserve Schützen units, when for example, the 4th Cavalry dismounted Division had on strength, the 87 and 89 reserve Schützen Regts. Presumably, these guys wore Swedish cuffs and a Tschako.
But back to your photo Joe, I vote that he is might be with Reserve Radfahrer Komp 76 as these guys were dressed as Jäger.