A METHOD FOR ESTIMATING POPULATION SIZES OF WHITEFLY NYMPHS (BEMISIA-TABACI GENN) ON CASSAVA

被引:8
作者
ABISGOLD, JD
FISHPOOL, LDC
机构
[1] ODNRI, Chatham, Central Avenue, Chatham Maritime
[2] Institut Français de Recherche Scientifique pour, Développement en Coopération (ORSTOM), Abidjan, Adiopodoumé
来源
TROPICAL PEST MANAGEMENT | 1990年 / 36卷 / 03期
关键词
Bemisia tabaci; Cassava; Counting; Population estimates; Rating;
D O I
10.1080/09670879009371490
中图分类号
S3 [农学(农艺学)];
学科分类号
0901 ;
摘要
The aim of the study was to establish a sampling method for Bemisia tabaci nymphs on cassava which would give accurate estimates of population size. The number and distribution of third- and fourth-instar nymphs and ‘pupae’ were recorded for each leaf sector of each leaf within a plant. In addition, the number of nymphs per leaf was rated. The smallest sampling area of the plant that gave an accurate estimate of the number of nymphs on the entire plant was determined. Each sampling area consisted of a combination of a number of sectors taken from a number of leaves. Results showed that by restricting the area of the plant examined to sectors 3–5 of leaves 7–20, an accurate population estimate was achieved but with a considerable reduction in the amount of work involved. If the number of nymphs was rated rather than counted, the area of the plant could be restricted to leaves 8–18. Rating produced less accurate population density estimates than counting. The relative applications of a counting and a rating system in population estimates of Bemisia tabaci are discussed. © 1990 Taylor and Francis Ltd.
引用
收藏
页码:287 / 292
页数:6
相关论文
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