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We present a JHKL survey of the massive star forming region RCW 57 (NGC 3576)based on L-band data at 3.5 micron taken with SPIREX (South Pole InfraredExplorer), and 2MASS JHK data at 1.25-2.2 micron. This is the second of twopapers, the first one concerning a similar JHKL survey of 30 Doradus.Colour-colour and colour-magnitude diagrams are used to detect sources withinfrared excess. This excess emission is interpreted as coming fromcircumstellar disks, and hence gives the cluster disk fraction (CDF). Based onthe CDF and the age of RCW 57, it is possible to draw conclusions on theformation and early evolution of massive stars. The infrared excess is detectedby comparing the locations of sources in JHKL colour-colour and L vs. (K-L)colour-magnitude diagrams to the reddening band due to interstellar extinction.A total of 251 sources were detected. More than 50% of the 209 sources includedin the diagrams have an infrared excess. Comparison with other JHKL surveys,including the results on 30 Doradus from the first paper, support a very highinitial disk fraction (>80%) even for massive stars, although there is anindication of a possible faster evolution of circumstellar disks around highmass stars. 33 sources only found in the L-band indicate the presence ofheavily embedded, massive Class I protostars. We also report the detection ofdiffuse PAHs emission throughout the RCW 57 region.Comment: 15 pages, 13 figure

L-band (3.5 $\mathsf{\mu}$m) IR-excess in massive star formation