Effects of El Nino，La Nina and solar activities on the outbreaks of the summer locust in Hebei Province

By using the method of laws of catastrophe—the Key Time Method，the relations between sunspot，El Nino as well as La Nina episodes and the outbreaks of summer locust in different ecotype areas，seashore areas and lowland areas inHebei Province were analyzed. Results show that El Nino and La Nina episodes have no influence on the outbreaks of summer locust in two ecotype areas in Hebei Province. El Nino and La Nina affect the outbreaks of summer locust mainly through inducing the weather and climate changes. And the solar activities show no obvious effects on the outbreaks of summer locust in two ecotypes areas in Hebei Province also, but there are some differences of outbreaks of summer locust between two ecotpye areas in the years fo sunspot at a peak value.