  We report on the discovery of correlations between dust and CO gas tracers of
the 0.1-10 au region in planet-forming disks around young intermediate-mass
stars. The abundance of refractory elements on stellar photospheres decreases
as the location of hot CO gas emission recedes to larger disk radii, and as the
near-infrared excess emission from hot dust in the inner disk decreases. The
linked behavior between these observables demonstrates that the recession of
infrared CO emission to larger disk radii traces an inner disk region where
dust is being depleted. We also find that Herbig disk cavities have either low
(~ 5-10 %) or high (~ 20-35 %) near-infrared excess, a dichotomy that has not
been captured by the classic definition of "pre-transitional" disks.
