晋南小麦红吸浆虫发生规律及防治对策

小麦红吸浆虫在土内有4种虫态,其分布以中层(7～13厘米)最多,下层(13～20厘米)次之,上层(0～7厘米)最少,20～38厘米仍有虫口分布.幼虫以上层为最多,中层次之、下层最少;圆茧以中,下层最多,上层很少;长茧及蛹以上层为最多,中、下层较少.成虫发生迟早及持续时间长短的关键因素是3～5月的降雨量,其中以4月下旬降雨最为重要.4月下旬降雨多,则成虫发生早,持续时间长,成虫发生盛期与小麦抽穗期相吻合的机会多,小麦受害重.在小麦抽穗前施一次长效农药封闭地面,可杀死不断上升地面的幼虫和蛹,阻止成虫羽化.

Pattern of Occurrence of Sitodiplosis mosellana Gehin in South Area of Shanxi Province and Strategy for Its Control

Sitodiplosis mesollana (Gehin) have 4 forms in the soil. They are the distributed most in the middle layer (7-13cm), less in the lower layer (13-20cm), the and least in the upper layer (0-7cm).They are also found in the layer ranging from 20-38cm. Their larvas are most in the upper layer, less in the middle layer, and least in the lower layer. Round cocoons are found the most in the middle and lower layers, the least in the upper layer. As for long cocoons and pupas, they are found the most in the upper layer, and less in the middle and lower layers. The critical factor for the time and duration of adults occurrence is the rainfall in March, April and May, and the rainfall in April is the most important. The rainfall in late April is heavy, so adults occur early and last a long time, and the peak ofadult occurrence coincides with the peroid of wheat ear sprouting,wheat will be heavily damaged. Before the ear sprouting application of slow-release insecticide to cover the ground surface can kill the larvas and pupas which increasingly rise to the surface, and prevent adults from emergence.