重寄生蜂对烟株不同部位僵蚜的寄生特点研究

Study on characteristics of hyperparasitic parasitism on aphid parasites in different tobacco plant positions

烟蚜茧蜂是蚜虫的主要天敌,但其控制作用又受到重寄生蜂的影响。我们在烟株封顶后将其分为上、中、下3个部位,对不同部位重寄生率进行分析,为弄清重寄生蜂的活动及寄生规律做了初步研究。结果表明:在前期,烟株下部的重寄生率明显高于中部和上部;在中后期,大田重寄生率高达40%,且此时烟株上部和中部的重寄生率均显著高于下部。研究发现在云南大理烟区有2种重寄生蜂,蚜虫宽缘金小蜂[Pachyneuron aphidis(Bouche)]和长背瘿蜂(Phaenoglyphis sp.),以蚜虫宽缘金小蜂为优势种,长背瘿蜂在云南的发现尚属首次;大田重寄生率在8月初达到高峰。

Aphidius gifuensis is the main parasite enemy of tobacco aphid. However, the manipulative effect of A. gifuensis to aphid is greatly influenced by hyperparasitoid. Tobacco plants were divided into upper position, middle position, and lower position after topping. The hyperparasite rate of A. gifuensis to tobacco aphid at different positions, parasitism activities, and regularity of hyperparasitoids were preliminary studied. Results showed that the hyperparasitic rates in lower tobacco plant position were higher than that in the middle and the upper position at the beginning of tobacco growth. In the middle and late period, the hyperparasitic rate in the tobacco field was up to 40 percent, and the hyperparasitic rate in the middle and upper positions were remarkbaly higher. There were two kinds of hyperparasitoids in Xiangyun tobacco district of Dali, which were Paehyneuron aphidis （Bouche） and Phaenoglyphis sp. P. aphidis was the dominant species, and Phaenoglyphis sp in Yunnan have not yet been reported. The hyperparasitic rate in tobacco field reached its peak in early August.