云南不同生态区玉米害虫优势种及其天敌优势种的种群动态

Population dynamics of dominant insect pests and natural enemies on maize in different ecological systems of Yunnan Province

通过对滇东北温凉地区和滇南暖热地区夏玉米田害虫及其天敌种群的系统调查,明确了云南南北两地玉米上的害虫优势种及其天敌优势种的发生动态规律,以期为玉米害虫的预测预报及防治提供理论依据。结果表明,滇东北昭通地区害虫优势种是玉米蚜,发生高峰期为抽雄散粉期和蜡熟期;天敌优势种是异色瓢虫,发生高峰期滞后于玉米蚜。滇南普洱地区玉米抽雄散粉期之前害虫优势种为黄脸油葫芦,发生高峰期为小喇叭口期;抽雄散粉期之后害虫优势种是玉米蚜,发生高峰期为完熟期;天敌优势种是异色瓢虫和黑带食蚜蝇,两种天敌的发生高峰期和玉米蚜吻合。因此,昭通地区防治重点为玉米蚜,防治适期为玉米抽雄散粉期之前。普洱地区防治重点为黄脸油葫芦,可从从苗期开始采取防治措施;玉米蚜的发生时间较晚、为害较轻,可在玉米吐丝期之后对其进行防治。田间施药的时间应注意避开天敌的发生高峰期。

In order to discover occurring dynamics of dominant insect pests and natural enemies on maize, investigation was conducted on insect pests and their natural enemies in summer maize fields in areas of two different ecological condition in Yunnan, which would provide some theoretical references for forecasting and controlling of maize insect pests. The results indicated that Rhopalosiphum maidis Fitch was the dominant insect pest in Zhaotong（northeastern Yunnan）, which had a peak period at tasseling and waxy ripe stages of maize; Harmonia axyridis（Pallas） was dominate natural enemy,which reached the maximum at spinning and full ripe stages（later than H. axyridis）. In Pu′ er（southern Yunnan）,Teleogryllus emma was the dominant insect pest before stage of tasseling, with occurring peak at trumpet stage; then R.maidis was the dominant insect pest and H. axyridis and Episyrphus balteatus De Geer were dominate natural enemies.Population of R. maidis Fitch and its enemies H. axyridis and E. balteatus reached the maximum at full ripe stage. Therefore, controlling measures should be taken before tasseling stage with the aim at R. maidis in Zhaotong; and controlling measures should be taken at seedling stage with the aim at T. emma while after spinning stage with the aim at R. maidis in Pu′er, because of its late occurrence and light damage. It should be noted that spraying date is necessary to avoid peak period of natural enemies.