Population density and spatial distribution pattern of South American tomato leaf miner, Tuta absoluta (Meyrick) on open field tomato in Andhra Pradesh

Abstract

One of the most important factors in a sampling and integrated pest management program is to know the population density and spatial pattern of the insects, especially the invasive ones such as Tuta absoluta (Meyrick) that cause a serious problem in tomato cultivation. Field experiment was conducted to determine the spatial distribution and population density of T. absoluta in tomato during rabi 2016-17 in a farmer’s field at Yellampalli, Kalikiri in Chittoor district, Andhra Pradesh. T. absoluta was a severe pest and caused damage up to 100 per cent in field level. The various indices of distribution viz., mean, variance, variance mean ratio, David and Moore’s index, Lloyd’s index of mean crowding, Lloyd’s index of patchiness, Lexis index and Charlier coefficient revealed that aggregated or clumped distribution of T.
absoluta throughout the crop growing season..