  Near-infrared and radio searches for core-collapse supernovae (CC SNe) in the
local universe have shown that the vast majority of the events occurring in
massive starburst are missed by the current optical searches as they explode in
very dusty environments. Recent infrared observations have shown that the
fraction of star-formation activity that takes place in very luminous dusty
starbursts sharply increases with redshift and becomes the dominant star
formation component at z>0.5. As a consequence, an increasing fraction of SNe
are expected to be missed by high-redshift optical searches. We estimate that
5-10% of the local CC SNe are out of reach of the optical searches. The
fraction of missing events rises sharply toward z=1, when about 30% of the CC
SNe will be undetected. At z=2 the missing fraction will be about 60%.
Correspondingly, for type Ia SNe, our computations provide missing fractions of
15% at z=1 and 35% at z=2. Such large corrections are crucially important to
compare the observed SN rate with the expectations from the evolution of the
cosmic star formation history, and to design the future SN searches at high
redshifts.
