We demonstrate that the 17-fold overprediction of dwarf spheroidal velocity dispersions by Recognition Science (RS) gravity reveals a new scalar field ξ that screens gravitational enhancement in low-density environments. This field emerges naturally from the 45-gap—a fundamental incompatibility between 3-fold and 5-fold prime symmetries in the eight-beat recognition cycle. We derive the screening Lagrangian Lξ = -(ℏ²c²/2)|∂µξ|² - (m²ξc⁴/2)ξ² - λξc²ρξ from the prime-fusion operator Ω3,5 required to bridge the gap. The critical density ρgap ~ 10⁻²⁴ kg/m³ separates two gravitational regimes: disk galaxies (ρ > ρgap) experience full RS enhancement while dwarf spheroidals (ρ < ρgap) show suppressed effects through the screening function S(ρ) = 1/(1 + ρgap/ρ). This mechanism makes five testable predictions: (1) transition behavior in systems near ρgap, (2) violation of the equivalence principle Δa/a ~ 10⁻⁶ × S(ρ), (3) a fifth force with Compton wavelength ~ 1 AU, (4) enhanced gravity in molecular clouds above threshold, and (5) intermediate behavior in slowly-rotating dwarfs. Far from being a failure, the dwarf problem opens a window to the deep connection between prime number theory, gravitational physics, and the emergence of new degrees of freedom at recognition gaps.