Silages can spoil when exposed to air during storage and feedout. The objective of this study was to determine the effects of treating whole plant corn with Lactobacillus buchneri 40788 on the fermentation and aerobic stability of silage stored with or without air stress during storage. Whole-plant corn was harvested at 34% DM and was untreated or treated with L. buchneri 40788 (LB), final application rate of 400,000 cfu/g fresh forage and Pediococcus pentosaceus, 100,000 cfu/g; Lallemand Animal Nutrition, Milwaukee, WI). Five replicated silos (7.5 L, density of 224 kg of DM/m³) for each treatment were not air-stressed (NS), air-stressed early (ES, 3 h/wk for wk 1–9), or air-stressed late (LS, 3 h/wk for wk 10–19). Air-stressed silos had 3 1.60-cm holes plugged with stoppers, 2 located on the bottom of the bucket and one on the lid of the bucket that were opened during periods of air stress. After 126 d of ensiling at 22°C, silos were opened and analyzed for microbial populations, fermentation profile, and aerobic stability. Numbers of yeasts were lowest (P < 0.05) in all treatments with LB regardless of air stress. Untreated LS silage had the greatest number of yeasts among all treatments. LB silages had greater (P < 0.01) concentrations of acetic acid then control silages as expected (2.28 vs. 1.22%), and silages subjected to ES had greater (P < 0.05) acetic acid concentrations compared with LS silages (2.13 vs. 1.52%). There was a tendency (P < 0.09) for air stress during storage to reduce aerobic stability (227 h for NS, 165 h for ES, and 140 h for LS). Regardless of air stress, LB silages were more stable (P < 0.01, 276 h) vs. untreated silages (76 h). These findings suggest that treatment with LB can markedly improve the aerobic stability of corn silages even when they are air-stressed during storage, and that air stress occurring near the time of feed out is more detrimental on aerobic stability during feedout than air stress occurring during early storage.