  Asymptotic giant branch stars are essential contributors to the near and
mid-IR emission of intermediate age (0.1-1Gyr old) stellar populations.
Detecting this light sets constraints on the star formation history in galaxies
and, conversely, the search for AGB signatures in well studied populations will
help us reduce some of the still large uncertainties in AGB models. This paper
reviews how AGB stars are currently included in population synthesis models and
which spectral features can be used to identify their emission in galaxy light;
targets for observational tests are suggested, and some observational and
theoretical difficulties are discussed.
