Abstract: 【Aim】 To clarify the adaptation of different geographic populations of Leguminivora glycinivorella to the temperature changes by determining the activities of the key enzymes involved in respiratory metabolism in mature larvae of different geographic populations of this insect in response to temperature.【Methods】The activities of the key enzymes involved in respiratory metabolism, including 3-phosphoglyceraldehyde dehydrogenase (GAPDH), 3-phosphoglycerol dehydrogenase (GDH), 3-hydroxyacyl coenzyme A dehydrogenase (HOAD), citrate synthase (CS) and lactate dehydrogenase (LDH), in mature larvae of four geographic populations of L. glycinivorella from Du′an, Guangxi, Zunyi, Guizhou, Suzhou, Anhui and Changchun, Jilin at the temperatures of 18, 21, 24, 27 and 30 ℃, respectively, by using biochemical methods. The correlations between the ratio of GAPDH activity to HOAD activity and the geographic latitude and altitude were analyzed. 【Results】The activities of five key enzymes involved in respiratory metabolism in mature larvae of L. glycinivorella of different geographic populations were significantly different at different temperatures. Among them, the ratio of GAPDH activity to HOAD activity was significantly correlated with the geographic latitude and altitude where the populations were located, and the ratio of GAPDH activity to HOAD activity in L. glycinivorella mature larvae was positively correlated with the geographic latitude and the geographic latitude superimposed with altitude-converted latitude at 18 ℃, with their regression curves fitted with the quadratic polynomial regression models y=-0.1312+0.0313x-0.0003x² and y=1.0905-0.0391x+0.0007x², respectively. The ratio of GAPDH activity to HOAD activity in L. glycinivorella mature larvae was negatively correlated with geographic latitude and altitude-converted latitude superimposed with geographic latitude at 21 ℃, with their regression curves fitted the quadratic polynomial regression models y=-0.1350-0.0568x-0.0010x² and y=0.8334-0.0002x-0.0002x², respectively. The ratio of GAPDH activity to HOAD activity in L. glycinivorella mature larvae was also negatively correlated with geographic latitude and geographic latitude superimposed with altitude-converted latitude at 24 ℃, with their regression curves fitted the quadratic polynomial regression models y=0.9268+0.0973x-0.0015x² and y=1.3423-0.0215x+0.0006x², respectively.【Conclusion】 Among different geographic populations, there are differences in carbohydrate metabolism, lipid metabolism, tricarboxylic acid cycle metabolism and the level of glycolysis. L. glycinivorella mature larvae can adapt to the changes in ambient temperature by regulating the intensity of respiratory metabolism, and the utilization of energy substances in their respiratory metabolism and their ability to adapt to ambient temperature are closely related to the geographic latitude and altitude of the environment in which they live.

Key words: Leguminivora glycinivorella, temperature, geographic population, respiratory metabolism, enzyme activity