This research was conducted in the Lower Rio Grande Valley of Texas to determine damage, survival, and yield of Bollgard II (PHY 485 WRF, ST 4357 BGIIRF), Bollgard (DPL 444 BRR), and non-Bt cottons (AMX 262R, PHY 425 RF) by beet armyworm.  Experiments were on natural infested cotton field plots (6 rows, 6.1 m, wide and 100 m long) and artificial infested cotton in field cages (2rows, 2 m, wide and 10 m long) with egg masses, pupae, or adult beet armyworms.  Visual observations showed that beet armyworm leaf damage on non-Bt cotton was 4.4-fold higher than Bollgard II and 2.1-fold higher than Bollgard; larvae survival on non-Bt cotton were in 12-fold, 2.4-fold higher, respectively.  After 110 d old cotton, the damage of PHY 485 WRF was 1.4-fold higher than ST 4357 BGIIRF.  Ground reflectance spectra and airborne color-infrared (CIR) digital imagery were obtained from the test plots shortly before harvest.  The spectra and image were able to differentiate beet armyworm damage levels between Bollgard non-Bt cotton.  The yield for Bollgard II cotton was 1.5-fold higher than for Bollgard and non-Bt cotton, and the yield from the later two was not significantly different.