Overview 2.Distribution Ground pests found all over the country. More species and more severe damage in north than in south or in dry-land than in irrigable land. Most severe damage found in middle and downstream area of Yellow River. 5 2. Distribution Ground pests found all over the country. More species and more severe damage in north than in south or in dry-land than in irrigable land. Most severe damage found in middle and downstream area of Yellow River. Overview