北疆棉区不同杂草上草蛉发生密度及季节消长

Lacewing Density and Dynamics on Different Weeds in Cotton-growing Region of Northern Xinjiang

本研究于2015—2017年通过扫网法系统调查了北疆棉田周边17种常见杂草上草蛉种群密度与季节动态。结果表明:北疆棉区杂草带上共有6种草蛉分布,其中普通草蛉Chrysopa carnea(占64.8%)、叶色草蛉C.phyllochroma(占25.8%)为优势种。草蛉种群密度在不同杂草上存在显著差异,紫花苜蓿、大麻上的草蛉密度分别在2015年、2016年显著高于其他杂草,2017年甘草、罗布麻、苦豆子上的草蛉密度较高。另外,草蛉密度呈现出明显的季节性波动,棉花花铃期(7月—8月)、吐絮期(9月)杂草上草蛉密度显著高于棉花苗期与蕾期(5月—6月)。本研究明确了北疆棉区草蛉种类组成结构,筛选出紫花苜蓿、大麻、甘草、罗布麻、苦豆子5种对草蛉存在潜在保育作用的功能杂草,为利用田埂杂草促进棉田草蛉类天敌的保育控害提供了科学依据。

In 2015—2017,the densities and dynamics of lacewings on 17 common weeds around cotton fields were systematically investigated using a sweeping method in the northern Xinjiang cotton-growing region.The results indicated there were six lacewing species in weed strips of northern Xinjiang,with the dominant species of Chrysopa carnea(64.8%)and Chrysopa phyllochroma(25.8%).The density of lacewings varied significantly on different weeds.Medicago sativa and Cannabis sativa harbored significantly higher lacewing densities among all weed species in 2015 and 2016,respectively.Higher densities of lacewings were found on Glycyrrhiza uralensis,Apocynum venetum,Sophora alopecuroides in 2017.Besides,obvious seasonal fluctuation of lacewing density was also observed.The density of lacewings during flowering and boll-opening stages of cotton(July-September)was significantly higher than that in cotton seedling and bud stages(May-June).This study clarified population composition,densities,and dynamics of lacewings on various weeds adjacent to cotton fields in northern Xinjiang.M.sativa,C.sativa,G.uralensis,A.venetum,and S.alopecuroides were proved to have the potential as functional plants for lacewing conservation.These results provide a scientific basis to promote the conservation and biological control service of predatory lacewings.