不同种植年限苜蓿草地昆虫种群及群落的发生规律

苜蓿是我国西北重要的牧草,明确苜蓿多年种植情况下害虫-天敌生态演变规律,对宁夏南部山区畜牧产业结构调整、持续发展牧草种植和提高防治水平有着重要意义。在研究区域,针对不同种植年限的苜蓿草地昆虫种群数量进行调查,通过对其发生规律和群落结构分析,结果表明:种植5年以内的苜蓿草地中,昆虫总个体数以及害虫的危害较轻,昆虫总个体数比较稳定,没有明显的变化,但种植年限5年以上的苜蓿草地中害虫逐步开始发生严重,尤其是地下害虫。因此苜蓿草业发展应当注意合理安排种植规模和时间,充分利用害虫-天敌发展的生态规律进行控害增产,进入持续发展的良性轨道。

Dynamics of Insect Population and Community on Grassland of Alfalfa in Different Evolution Stages

Alfalfa is an important forage in northwest China. Making certain of the ecological evolution of the pests - natural enemies of alfalfa in various evolution stages is of great significance to the adjustment of the structure of the animal husbandry industry, the sustainable development of grass growing and raising the prevention and control level. In the study, an investigation was made on the insect populations on the grassland of alfalfa in various evolution stages and an analysis was made on their occurrence regularity and community structure. The results showed that during the first 5 years of the alfalfa, the total number of the insects was less, the pest damage was weak and the abundance of the pests was stable and did not have significant fluctuation. But after 5 years, the occurrence of the pests on the grassland of alfalfa was gradually serious, especially the soil-inhabiting destructive insect. Therefore, the planting area and time should be arranged rationally in the development of alfalfa grasslands industry. Furthermore, the ecological evolution of the pests - natural enemies should be applied to control the pests and increase the yield which would lead to the sustainable development of alfalfa.