甘蔗间作玉米对亚洲玉米螟发生为害的控制作用

为明确甘蔗间作玉米对亚洲玉米螟Ostrinia furnacalis(Guenée)发生和为害的控制作用,于2012—2013年在云南省元江县甘蔗种植区设置甘蔗间作玉米小区,采用目测法和马氏网法系统调查了该生境下亚洲玉米螟卵块密度与卵粒密度、蛀孔密度与百秆虫量、寄生性天敌昆虫种类及其种群动态。结果表明:与甘蔗间作种植的玉米上亚洲玉米螟落卵量、蛀孔密度、百秆虫量均明显低于单作玉米田,2012和2013年,间作玉米上百株卵块数比单作玉米分别减少了29.32%和35.73%,每卵块所含的卵粒数分别减少了34.22%和51.02%,百秆玉米蛀孔数分别减少了42.53%和31.25%,百秆虫量分别降低了58.18%和52.73%。间作田中亚洲玉米螟的3种主要寄生蜂螟蛉绒茧蜂Apanteles ruficrus、黄眶离缘姬蜂Trathala flavoorbitalis和大螟钝唇姬蜂Eriborus terebrans的种群密度显著高于单作玉米田,而数量较少的广大腿小蜂Brachymeria lasus及广黑点瘤姬蜂Xanthopimpla punctata种群密度在间作与单作田间无显著差异。表明甘蔗间作玉米对亚洲玉米螟的发生为害具有明显的控制作用,可用于亚洲玉米螟的生态控制。

Control efficacy of maize-sugarcane intercropping against the occurrence and the damage of Ostrinia furnacalis

Intercropping of maize with sugarcane had been a popular planting pattern in most sugarcane planting areas throughout the world. In order to confirm the effect of intercropping of maize with sugarcane, a study on the population dynamics of Ostrinia furnacalis and its main natural enemies in the habitat of maize monoculture or intercropping with sugarcane was conducted in Yuanjiang County during 2012 and 2013 using the Malaise traps and eyeballing method. The results showed that the density of egg mass and wormhole of O. furnacalis in intercropping maize fields was less than that in monoculture fields, and the number of O. furnacalis in the maize stalk after harvest was significantly different as the number in the monocultured maize plants was higher than that in the intercropped maize plants. The number of egg mass per 100 maize plants in intercropping system decreased by 29.32% and 35.73%, and the number of eggs per egg mass decreased by 34.22% and 51.02% in 2012 and 2013, respectively. The number of wormholes per 100 maize plants in intercropping system decreased by 42.53% and 31.25% in 2012 and 2013, respectively. The number of larvae of O. furnacalis in 100 maize stalks decreased by 58.18% and 52.73% in the monocultured maize in 2012 and 2013, respectively. The populations of the predominant parasitic wasps of O. furnacalis, including Apanteles ruficrus, Trathala flavoorbitalis and Eriborus terebrans, were significantly higher in the intercropped maize field than those in the monocultured fields, and no significant difference was found in the populations of the non-predominant parasitic wasps, including Brachymeria lasus and Xanthopimpla punctata, between the intercropped maize field and monocultured field. This study suggested that the corn intercropping with sugarcane could be beneficial to the conservation of natural enemies and control of insect pests to some extent.