番茄潜叶蛾卵和幼虫在温室大棚及露地的空间分布型及抽样技术

Spatial distribution patterns of Tuta absoluta eggs and larvae in greenhouses and open fields and sampling techniques for monitoring their abundance

【目的】明确外来入侵害虫番茄潜叶蛾Tuta absoluta的卵及幼虫的空间分布型(温室和露地),建立最适理论和序贯抽样模型,为其田间取样调查提供科学依据,更精准地进行测报与防控。【方法】于2023年在宁夏银川市及石嘴山市的温室大棚及露地番茄种植区进行,采用隔行取样法和5点取样法调查了种植区内番茄潜叶蛾的虫口密度,根据聚集度指标和Iwao回归模型等对数据进行分析,建立了理论抽样模型和序贯抽样模型。【结果】番茄潜叶蛾卵和幼虫在温室及露地的扩散系数、负二项分布K指标、扩散指数、丛生指标、平均拥挤度综合呈现为聚集分布。温室内的番茄潜叶蛾种群聚集均数λ>2,露地的种群聚集均数λ<2。拟合得到番茄潜叶蛾卵和幼虫的线性回归方程m^(*)=4.01+0.46m、m^(*)=2.11+0.93m;露地卵和幼虫分别为m^(*)=2.00+2.75m、m^(*)=7.38+0.48m。【结论】在温室及露地番茄种植区内,番茄潜叶蛾的卵和幼虫均为聚集分布,种群个体间相互吸引。当番茄潜叶蛾在露地及温室内的卵量为2粒/叶时,建议分别取样310和190片;当幼虫量为2头/叶时,建议分别取样350和140片。

[Aim]To determine the spatial distribution patterns of eggs and larvae of Tuta absoluta in greenhouses and open fields,develop optimal theoretical,sequential,sampling models to improve the precision of monitoring,occurrence prediction,prevention,and control measures for this pest.[Methods]Surveys were conducted in 2023 in tomato growing areas in Yinchuan and Shizuishan,Ningxia.The interlaced and five-point sampling methods were used to assess the density of T.absoluta.Data analysis was performed using an aggregation index and the Iwao regression model,leading to the establishment of theoretical sampling models and sequential sampling models.[Results]Based on the diffusion coefficient,the negative binomial distribution K index,diffusion index,clumping index,and mean crowding of the eggs and larvae in both greenhouse and open field conditions,our findings demonstrate an aggregation distribution pattern.Specifically,we observed a mean aggregation number(λ)greater than 2 in the greenhouse environment whileλwas less than 2 in the open field.Linear regression equations were derived as m^(*)=4.01+0.46m and m^(*)=2.11+0.93m for eggs and larvae in the greenhouse respectively;whereas for open field samples,the equations were m^(*)=2.00+2.75m and m^(*)=7.38+0.48m for eggs and larvae respectively.[Conclusion]The results revealed that the eggs and larvae of T.absoluta had an aggregated distribution in both greenhouses and open fields.For an egg density of 2 eggs per leaf in open fields or greenhouses,we recommend sampling 310 or 190 specimens,respectively,whereas for a larval density of two per leaf,we recommend sampling 350 or 140 specimens,respectively.