Generally feeding of onion thrips cause yellowing or dropping of leaves, buds, or flowers. High infestation results in stunted growth, brown blisters, white blotches, silvery whitish areas or feeding scars. Young terminal leaves frequently show malformation when heavily attacked, with crinkly surfaces, sunken and raised thin areas, marginal erosion, margin curling inwardly, and a chlorotic yellowish appearance with grayish color along all large veins. Young buds may be killed as soon as they come out. In addition, they freely feed within flowers, attacking the tender portions.
Onion thrips have six to ten generations depending on temperature.
Adults and larvae overwinter in the soil or plant litter on the ground. Pupae and prepupae overwinter in the soil. The lower developmental threshold is about 11.5 C and using this threshold as a base, development required 191 degree days. Adults reproduce parthenogenetically through out the season, rarely reproduce sexually, and resulting m that most adults in the field are female. The application of chemical insecticides is the common control measure.