The fraction of sources expected to be missed in the 24   μm band at 0.2 < z < 0.6 (left) and 1.0 < z < 1.7 (right) as a function of the 24   μm vs. 100   μm (top) and the 24   μm vs. 160   μm (bottom) depths. Black circles indicate the depths of PACS and MIPS24   μm surveys for some of the most important cosmological fields, i.e. EGS, Lockman and COSMOS. We note that the region where the constant fraction isocontours run horizontally, cannot be constraint by the data. The adopted detection limits (5σ) at 24   μm are 80   μJy for COSMOS and 50   μJy for EGS and Lockman. Similarly the 3σ detection limits at 100   μm are 5.0-, 3.8- and 3.6 mJy (COSMOS, EGS and Lockman), while at 160   μm are 10.2-, 8.6- and 7.5 mJy.