Sequential sampling plan for mango leaf hopper, Idioscopus clypealis Lethierry.
Verghese A., Rao G. S. P.
Author Affiliation: Cent. Mango Res. Sta., Lucknow, 226?006, India.
Entomon 10 : 285-290
Abstract : A sequential sampling plan for classifying infestation of the cicadellid mango pest Idioscopus clypealis into light, moderate and severe, was worked out following field studies in Uttar Pradesh, India, in 1982-83. Based on sample counts, negative binomial distributions for nymphs and adults were fitted. Operating characteristic values, giving the probability for reaching a correct decision for a range of population means for both adults and nymphs, and average sample number values, used to predict the average number of trees to be sampled under different sequential plans, were calculated. It is suggested that the decision lines plotted would be useful as a ready reckoner to assess infestation classes in extensive surveys.