Studies were conducted in 1981 and 1982 to determine the general temporal occurrence of thrips in wheat, alfalfa, oat, and red clover fields adjacent to cabbage fields in upstate New York. Shifts in species composition of thrips on these crops were observed through time, and fluctuations in abundance were attributed to changes in habitat structure (e.g., maturation and senescence in wheat and oats, and cropping practices in alfalfa and red clover). All of these crops serve as a reservoir forThrips tabaciLindeman, which may move to and infest nearby cabbage plantings. By sampling the thrips populations within the foliage and utilizing sticky traps to monitor aerial populations, we may be able to predict the population buildup within these crops and the subsequent movement of thrips to adjacent crops.