We present Spitzer /IRAC observations at 3.6 and 4.5 \mu m along with optical data from the Local Group Galaxies Survey to investigate the evolved stellar population of the Local Group dwarf irregular galaxy WLM .
These observations provide a nearly complete census of the asymptotic giant branch ( AGB ) stars .
We find 39 % of the infrared-detected AGB stars are not detected in the optical data , even though our 50 % completeness limit is three magnitudes fainter than the red giant branch tip .
An additional 4 % of the infrared-detected AGBs are misidentified in the optical , presumably due to reddening by circumstellar dust .
We also compare our results with those of a narrow-band optical carbon star survey of WLM , and find the latter study sensitive to only 18 % of the total AGB population .
We detect objects with infrared fluxes consistent with them being mass-losing AGB stars , and derive a present day total mass-loss rate from the AGB stars of \dot { M } = 0.7-2.4 \times 10 ^ { -3 } M _ { \sun } yr ^ { -1 } .
The distribution of mass-loss rates and bolometric luminosities of AGBs and red supergiants are very similar to those in the LMC and SMC and the empirical maximum mass-loss rate observed in the LMC and SMC is in excellent agreement with our WLM data .