影响禾谷缢管蚜自然种群变动的关键因素研究

试验表明 ,影响禾谷缢管蚜自然种群变动的主要因素是气候和天敌。低龄若蚜主要受风雨的影响 ,高龄若蚜和成蚜主要受天敌和风雨共同作用。天敌主要为七星瓢虫和食蚜蝇。禾谷缢管蚜是典型的γ对策昆虫 ,具有较高的内禀增殖率 ,又具有较高的死亡率。种群的变动受自身密度的影响 ,γ值的大小可以说明自然种群变化的趋势

Studies on key influencing factors on the dynamics of natural population of Rhopalosiphum padi (Linnaeus)

Studies on the life table showed that key influencing factors on the dynamics of natural population of Rhopalosiphum padi Linnaeus were weather and natural enemies. The density of young nymph could be reduced more than 22.6%-50.0% in strong wind and heavy raining days. The main factors for influencing the old nymph and adults were natural enemies, mainly Coccinella septempunctata and hover flies. R. padi is a typical r strategist insect which has high mortality as well as high intransic increase rate. Therefore, the study indicated that the dynamics of the population was also influenced by its own density.