From November 2011 to March 2012, the grassland temperature in Inner Mongolia and other four provinces (regions) was low and there was no stable snow cover, which was conducive to reducing the overwintering base of grasshopper eggs in the grassland. The warm and humid conditions in most grasslands in April were suitable for the incubation and larval development of grassland locusts, but the precipitation in most grasslands in early and mid-May was excessive, which was not suitable for the occurrence and development of grassland locusts. It is expected that in the summer of 2012, the meteorological level of locust occurrence and development in most grasslands in Inner Mongolia and other four provinces (regions) is low; The meteorological level of grassland locust occurrence and development was higher in central and northeastern Inner Mongolia, parts of northwestern Xinjiang, Longzhong and Hexi of Gansu Province, among which it was higher in Yili Valley of Xinjiang. All localities should pay close attention to weather changes and do a good job in prevention and control.
1. most of the four provinces (regions) such as Inner Mongolia have no stable snow cover in winter, and the temperature is low, which is conducive to reducing the overwintering base of grassland locust eggs
Grassland locusts were wintering from November 2011 to March 2012. Most grasslands in Inner Mongolia, Xinjiang, Gansu and Ningxia have less precipitation, small snow cover and thin thickness, and low temperature, among which the northeast and north-central areas of Inner Mongolia are 2 ~ 4℃ lower, and the weather is abnormally dry and cold, which is conducive to reducing the overwintering base of grasshopper eggs in the grassland. However, parts of northwestern Xinjiang and northeastern Inner Mongolia have stable snow cover of more than 10 centimeters, which is conducive to the safe overwintering of grassland locust eggs.
2. The temperature and humidity conditions in April were suitable for the incubation and larval development of grassland locusts in Inner Mongolia and other four provinces (regions); In the early and middle of May, most grasslands had more precipitation, which was not suitable for the occurrence and development of grassland locusts
April is the critical period for egg embryo development and incubation of northern steppe locusts. In April, the average ground temperature was above 10℃ in most of the northern grasslands, and 15 ~ 22℃ in most of Xinjiang. The precipitation of 10 ~ 25 mm occurred in the northeast of Inner Mongolia and the south-central regions, the northern and western parts of Xinjiang, and the central part of Gansu. The warm and humid conditions were suitable for the development and incubation of the eggs and embryos of the grassland locusts. Since May, most of the northern steppe had more precipitation, which was not suitable for the occurrence and development of grassland locusts. However, in central and northern Xinjiang, Gansu Longzhong and central Inner Mongolia, the weather conditions of high temperature and low rainfall are suitable for the growth and development of grasshopper larvae.
