| Thrips is one of the most harmful pests on alfalfa. The study has been conducted in mid part of Shaanxi to evaluate the dominant species, population, damage characteristics and dynamic variation of trrips. The results showed that Odontothrips loti is the predominant species; it mainly endangers the second and third cutting of alfalfa, especially during July and August; in the four insecticides applied to control alfalfa thrips, 5% cypermethrin is the best one with an ideal and durative controling effects and low cost. |