網室洋香瓜上銀葉粉蝨（Bemisia argentifolii Bellow & Perring）成蟲之空間分布及其最適取樣數估算

Spatial Pattern and Optimal Sample Size Estimation of Adult Bemisia argentifolii (Hemiptera: Aleyrodidae) on Cantaloupe in a Nethouse

林鳳琪(Feng-Chyi Lin) ； 王清玲(Chin-Ling Wang) ； 陳秋男(Chiou-Nan Chen)

《台灣昆蟲》 26卷4期 (2006/12) Pp. ap4+343-356

https://doi.org/10.6661/TESFE.2006030

摘要

本試驗探討銀葉粉蝨（Bemisia argentifolii Bellow & Perring）成蟲在網室內洋香瓜上的空間分布型式並估算其最適取樣數。試驗結果顯示，銀葉粉蝨於洋香瓜植株上的垂直分布，80%以上成蟲出現在頂芽以下第3～9葉上，可作為其最適取樣部位。而其於網室內洋香瓜全園的空間分布型式，經8次密度調查所得之平均擁擠度（mean crowding，m*）與平均值（mean，m）之比值（m*／m）均大於1，顯示其分布型式為聚集分布。分析頂芽以下3～9葉成蟲數，經由Iwao's patchiness regression得知截距α=12.29，斜率β=1.327，顯示其成蟲於植株上空間分布亦呈聚集型。依Taylor's power law導出之方程式得a=3.917，b=1.538，亦同樣顯示其空間分布為聚集分布型式。根據上列數值，本文亦估算在不同密度與精密度下之網室內洋香瓜上銀葉粉蝨成蟲最適取樣數。本調查期間，銀葉粉蝨族平均密度在7～137隻之間，當群平均密度每葉蟲數達5隻，精密度設為0.2時，經由Iwao's patchiness regression或Taylor's power law 計算，最適取樣數分別為75或47葉片。當族群平均密度每葉蟲數達15隻以上時，最適取樣數均低於30片葉片。本研究建議，基於防治之考量，欲於網室內洋香瓜上估計銀葉粉蝨成蟲數，可以逢機取樣10株以翻葉檢視頂芽以下3～9葉片葉背上成蟲數，為省工省時之取樣方法。

關鍵字

銀葉粉蝨 ； 空間分布 ； 最適取樣數 ； 洋香瓜

並列摘要

We conducted random sampling eight times in a nethouse to examine the spatial patterns and to estimate the optimal sample size of Bemisia argentifolii adults on cantaloupe plants. The vertical distribution of the whiteflies on cantaloupe plants was studied by inspecting adults using the leaf-turn method. More than 80% of adults occured on the third to ninth leaves from the terminal bud of the cantaloupe plant, and these groups of leaves were considered to be a suitable sampling position. Iwao's mean crowding (m*) - mean (m) regression and Taylor's power law (s^2 = am^b ) were used to analyze the data. Parameters derived from Taylor's power law were a = 3.917 and b = 1.538, those from Iwao's m*-m regression wereα = 12.29 and β = 1.327. Both Taylor's b and Iwao's β were significantly greater than 1, indicating that the spatial pattern of the whiteflies was an aggregative type. Using these parameters, we also estimated the optimal sample size necessary to achieve a predetermined statistical precision. At the 0.2 precision level, estimates of the optimal sample size based on Iwao' patchiness regression and Taylor's power law were less than 75 and 47, respectively, when the density exceeded five adult whiteflies per leaf. The density of whiteflies ranged from 7 to 137 per leaf during this survey. Therefore, in order to simplify the sampling method, we suggest that ten random plants be taken to inspect the adult whiteflies on the third to ninth leaves from the top by the leaf-turn method for monitoring the whitefly populations in nethouses for pest control purposes.

並列關鍵字

Bemisia argentifolii ； spatial pattern ； optimal sample size ； cantaloupe