Vertical Activity Characteristics of Pleonomus Canaliculatus in Winter Wheat and Summer Maize Rotation Fields

Abstract

Based on the stratified survey data of Pleonomus canaliculatus in the soil of winter wheat and summer maize rotation field in North China Plain, the vertical activity of Pleonomus canaliculatus in the soil of winter wheat and summer maize rotation fields, the correlation between meteorological conditions and farmland planting management are observed and analyzed, and effects of Pleonomus canaliculatus damage on the yield of winter wheat are analyzed. By combining the insect population weight index with population density index, characteristics of the harm-dormancy activity of Pleonomus canaliculatus are investigated comprehensively in different soil layers. Results show that in the winter wheat and summer maize rotation growing season, there are 3 harm and 3 dormant periods, 3 harm periods appear in the winter wheat regreening-jointing period, the summer maize seedling period and the autumn seedling period of winter wheat, and 3 dormant periods appear in winter wheat overwintering period, winter wheat ripening-harvesting period and summer maize filling-ripening period. Among 3 harm periods, winter wheat regreening-jointing period is the most serious, which could lead to serious yield reduction of winter wheat. Winter is warmer, and spring temperature is warmer early, so Pleonomus canaliculatus exhibits characteristics of going down late and coming up early, which shortens the dormant period in winter and prolong the harmful activity period. Soil temperature, moisture, and the relationship between food and source affect the damage, dormancy, and feeding activities of Pleonomus canaliculatus. The suitable soil moisture content for it is about 15% to 18%, and the suitable soil temperature is 14 to 18 ℃. In summer, Pleonomus canaliculatus may enter dormancy or reduce activity due to lack of food sources or high temperatures and humidity of soil, Pleonomus canaliculatus can enter the dormancy or reduced activity. The analysis of winter wheat yield reduction caused by Pleonomus canaliculatus damage shows that the yield reduction rate is increased by 5.1% with an increase of 10 m-2 in insect population density or with an increase of 1.0 g·m-2 in insect weight. Results provide reference for agricultural production in North China to address climate change and scientifically manage farm to avoid diseases and pests.

Keywords

• vertical activity
• winter wheat
• summer maize
• rotation field