Grain sorghum and cotton are grown in close association in most regions of Texas, and share a number of predators which can provide natural control of cotton bollworm and tobacco budworm in mid-late season cotton. The focus of this study was to determine the role of grain sorghum as a source of predators in cotton in the Southern Rolling Plains of Texas by identifying and quantifying important predators in grain sorghum and cotton through direct counts and collection, and quantifying the movement of predators from grain sorghum to cotton by self-marking of predators with fluorescent dust in sorghum and recovery of marked predators in adjacent cotton. Results show many of the common predators increase in both grain sorghum and cotton from early bloom of sorghum to hard dough stage, and continue to increase in cotton after sorghum harvest. Recovery of marked predators in cotton provide further evidence that grain sorghum is an important source of predators in cotton at a time when cotton is at risk from bollworm and budworm infestations.