作物景观结构对旋幽夜蛾种群动态的影响

农业景观复杂性对昆虫种群的影响是目前昆虫生态学研究的热点。新疆兵团和地方在土地利用模式及作物景观上存在着明显的差异,这可能影响昆虫种群动态及其管理策略。在兵团和地方的不同试验点,应用智能测报灯、杀虫灯诱集监测在地区尺度和区域尺度旋幽夜蛾Scotogramma trifolii种群动态,结合各样点作物种类及面积调查,分析旋幽夜蛾种群动态与景观复杂性之间的关系,研究结果表明:(1)在地区尺度上,简单景观条件下旋幽夜蛾诱集量小于复杂景观,不同调查半径下旋幽夜蛾诱集量与景观多样性指数(Shannon-Wiener)呈显著正相关(P0.05);(2)在区域尺度上,兵团作物体系内,南疆的旋幽夜蛾诱集量小于北疆,并且存在显著性差异;地方作物体系内南疆的旋幽夜蛾诱集量大于北疆,同样存在显著性差异;在南疆地区,兵团和对应地方的诱蛾量均呈现显著性差异(P0.05),在北疆地区,兵团与对应的地方之间无显著性差异(P0.05),这可能与北疆地区兵团和地方在土地利用模式及其作物布局趋于一致有关。

Effects of crop landscape structure on the population dynamics of the clover cutworm Scotogramma trifolii

The effect of the complexity of the agricultural landscape on insect population is the focus of insect ecology at present. There are contrasting difference in the agricultural landscape and crop planting structure between Xinjiang Production and Construction Corps (broad-acre farming) and Local agriculture (small-holder farming), which may influence the population dynamics of insect pests. The population of the clover cutworm Scotogramma trifolii in different collection scales (region scale and district scale) in both farming systems were monitored by the intelligent monitoring lamps. Moreover, crop type and area investigations in each sampling sites were surveyed, and our results showed that: (1) At the region scale, moths trapped in simple landscape were less than in complex landscape; the amount of clover cutworm had a significant positive correlation with the landscape diversity index (Shannon-Wiener) (P<0.05) at different radii surrounding the survey sites; (2) At the district scale in broad-acre farming, the abundance of moths in southern Xinjiang was less than that in northern Xinjiang, and there was a significant difference between southern and northern Xinjiang. At the same time, there had a significant difference within small-holder farms (southern Xinjiang and northern Xinjiang), but the abundance of moths in southern Xinjiang was larger than that in northern Xinjiang. The amount of moths showed a significant difference (P<0.05) between corresponding broad-acre farming and small-holder farming at the same area in southern Xinjiang, while northern Xinjiang had no significant difference (P>0.05) between the corresponding broad-acre farming and small-holder farming at the same area, which may be related to the fact that there was a a relatively consistent land use pattern and crop distribution between broad-acre farming and small-holder farming in northern Xinjiang.