莲缢管蚜对水葫芦生长的抑制作用

Inhibitory Effect of Rhopalosiphum nymphaeae on Growth of Water Hyacinth,Eichhornia crassipes

采用室外试验方法研究了不同密度和不同生育期的莲缢管蚜(Rhopalosiphum nymphaeae)对水葫芦(Eich-hornia crassipes)生长的影响。结果表明,莲缢管蚜成虫对水葫芦生长具有明显的抑制作用,表现在水葫芦植株鲜重减轻,总叶片数和新芽数减少,叶片枯萎数增加。低密度莲缢管蚜对水葫芦根和叶片生长的抑制作用不明显,但当莲缢管蚜密度大于20头·株-1时抑制效果显著,且随着作用时间的推移抑制作用更为明显。莲缢管蚜虽然对水葫芦生长具有一定的抑制作用,但由于其食性广泛,很可能会危及其他相邻水生植物,因此作为水葫芦天敌控制水葫芦生长的可行性还有待深入研究。

An outdoor experiment was condUcted for the inhibitory effect of Rhopalosiphum nymphaeae various in population density and growth stage on growth of water hyacinth, Eichhornia crassipes （ Mart. ） Solms. Results show that growth of water hyacinth was significantly inhibited by adult aphids, which was demonstrated in reduction of fresh plant weight, number of leaves and sprouts, and increase in the number of wizened leaves. R. nymphaeae feed on water hyacinth, thus affecting their growth. However the effect is positively related to their density, i.e. if the density is higher than 20 aphids per plant, the effect is significant and will become more and more significant as time goes by. But it should also be noted that R. nymphaeae have a relatively broad range of hosts and may endanger other aquatic plants in the neighborhood. Thus, the applicability of R. nymphaeae as natural enemy to control water hyacinth needs to be further studied.