Abstract: 【Aim】 The effect of changes in food nitrogen content on insects is an important part of predicting the trend of pest population change. The aim of this study is to investigate the effect of changes in food nitrogen content on the feeding, nutritional utilization and growth rate of Locusta migratoria. 【Methods】 The 3rd instar female and male nymphs of L. migratoria were fed with the food with the nitrogen contents of 10%, 25%, 40%, 55% and 70%, respectively. Feces and food residues were collected daily, dried and weighed, and the food intake, growth rate and nutritional utilization indexes were calculated. 【Results】The food intake of the 3rd instar nymphs of L. migratoria in the food group with 10% nitrogen content was the most, being 02559 and 02326 g for females and males, respectively. The food intake of the 3rd instar female and male nymphs of L. migratoria was the least (00944 and 0.0766 g, respectively), when they were fed with the food with 70% nitrogen content. With the increase of food nitrogen content, the food intake of female and male nymphs decreased significantly, but the approximate digestibility, efficiency of conversion of ingested food and efficiency of conversion of digested food increased significantly. The growth rate of female nymphs was the highest in the food group with 2.5% nitrogen content. 【Conclusion】 L. migratoria nymphs can compensate for the nitrogen by increasing their intake of lownitrogen food.
Key words: Locusta migratoria; nitrogen; food intake; nutritional utilization; growth rate