关键词: 乳酸乳球菌, 乳酸乳球菌, 乳链菌肽, 诱变育种

Abstract: Oxya chinensis and Atractomorpha lata are the main pests of paddy and dry fields in Northeast China. To determine overwintering eggs supercooling point and cold resistance of the two pests, the thermocouple method, coupled with supercooling point testing instrument and cryogenic refrigeration storage box are used to measure the supercooling point, water content, the length and width, and the morphological index of oocysts of the Oxya chinensis and Atractomorpha lata. The conclusion shows that the supercooling point of Oxya chinensis overwintering eggs averages (-15.8±1.42)℃, freezing point (-12.73±1.29)℃, water content 59%, while the supercooling point of Atractomorpha?lata overwintering eggs averages (-19.44±0.40)℃, freezing point (-19.44±0.40)℃，water content 71%. The change of water content in Oxya chinensis and Atractomorpha lata has a significant effect on the supercooling point. Therefore, the research of the cold tolerance of grasshopper should be linked with its life history environment, development stage, biological state, body water content, anti-freeze protection material, ice core material and other factors.