麦长管蚜为害损失估计及防治阈值研究

Study on the Damage and Control Threshold of Sitobion Avenae

研究结果表明,麦长管蚜种群数量和为害历期是造成小麦产量损失的主要因素,抽穗、扬花、灌浆3个发育阶段产量损失差异显著,灌浆期间蚜量对产量损失最严重,百株蚜量达1000头,占扬花期开始受害的85.13%,蚜量与产量损失率的关系式为y=0.0088x-0.7582。扬花末期至灌浆期是防治较适宜的时期。在5250～6750kg/hm2产量水平的麦田,其防治指标应为百穗蚜量500头。

The major factors reducing wheat yields are the population quantity of sitobion avenae and damage duration. During three developing periods-the ear sprouting, flowering and grain filling period, the yield losses have a significant difference. Among them, the aphid density at grain filling period makes the largest losses on the yield. During this period aphid density per 100 plants can amount to 1 000. The relation of aphid density and yield losses rate can be expressed by y = 0. 0088 x - 0. 7582 . The appropriate control periods are from late flowering to grain filling period. As to the fields of yield 5 250 -6 750kg/hm^2, the economic control threshold is 400 aphids per 100 wheat ears.