棉田种植苘麻诱集B型烟粉虱机制研究

Mechanism of Abutilon theophrasti Medic as a Trap Plant for Control of Bemisia tabaci(Gennadius) Biotype B in Cotton Field

摘要利用苘麻（Abutilon theophrasti Medic）的诱集作用是防治棉田烟粉虱的有效手段，本文报道了关于苘麻和棉花叶片颜色、气味、叶毛密度、细胞液pH值及营养等影响诱集作用因子的差异研究结果，试验结果表明，苘麻叶片的叶毛密度（197．7根／cm^2）和棉花叶片（19．6根／cm^2）有显著的差别；苘麻叶片在波长560nm下的光反射率达到0．2，显著高于棉花叶片（0．09）此外，苘麻叶片细胞液的pH值在整个生长季节均较棉花维持在一个较高的水平（5．8—6．2）．研究还表明，烟粉虱成虫对苘麻叶片颜色和挥发性气味表现出正趋性，但与棉花相比较差异不显著；苘麻叶片中可溶性蛋白质、可溶性糖和总氨基酸的含量与棉花没有显著的差别，因此，苘麻植株叶片较高的叶毛密度、光反射率和细胞液pH值可能是引起烟粉虱强选择性的主要原因。

Attraction of Bemisia tabaci （Gennadius） biotype B adults to velvetleaf （Abutilon theophrasti Medic） could be used as a pest control strategy in cotton field. The factors together with attraction mechanisms, including leaf color, odor, light reflection, hair density, pH value of leaf tissue, carbohydrates and nitrogen contents of the plant leaf were investigated under the laboratory controlled condition. The results showed that there was a significant difference in the hair densities between the velvetleaf leaves （ 197.7 per cm^2 ） and cotton leaves （ 19.6 per cm^2 ）. The surface reflecting rate at the wavelength of 560 nm on cotton leaves reached 0.20, which was significantly higher than that on cotton leaves （0.09）. Compared to the cotton leaves, the pH value of velvetleaf leaf tissue remained at a higher level （ from 5.8 to 6.2） during the whole developing stages. B. tabaci adults showed a stronger response to the odor and leaf color of velvetleaf plants, which showed no significant difference with cotton. While, there were no differences in the contents of soluble protein, carbohydrates and aminophenol between the two host plants. Thus, it was concluded that the higher leaf hair density, surface reflecting rate of light and pH value of leaf tissue in velvetleaf plants played an important role in the strong attraction of B. tabaci to the velvetleaf. Fig 4, Tab 2, Ref 26