Abstract
Experiments were conducted in the laboratory and field during July 2014 to December 2017 to investigate the bio-ecology, spatial distribution and management of mango hopper. The biology of predominants species of mango hopper, Idioscopus clypealis Leth revealed that it completed life cycle in 24 to 35 days showing fecundity and incubation range 84 to 198 and 5 to 7 days respectively. The time required for 1st, 2nd, 3rd, 4th and 5th nymphal instars ranged from 2-3, 2-3, 2, 3-4 and 2-3 days, respectively. Adults lived for 4-8 days. Morphometrics of all the nymphal instars varied significantly. The abundance of the mango hopper on trunk, foliage and branch studied in its peak in February then started to decrease up to December showing some oscilation. Mango hopper caused yield loss of 17.70 to 19.48% in newly established orchard. Spatial distribution (intra tree) of mango hopper in four different directions of tree trunk (both on lower and upper side) indicated uniform distribution on the basis of various statistical parameters viz; mean, variance-mean ratio, Chi square (X2), mean crowding, Lloyd's index of patchiness and Clumping index. The practice of off-shoot cutting resulted in lower infestation than untreated control. Both in laboratory and field, the insecticide Plenum 50WG was found as the most effective to cause mortality of all stages of mango hopper followed by Bismark 20SP. The lowest performance was recorded when treated with Tracer. Among botanicals such as Karanja oil, Orange peel skin extract (OPSE) and Neem Seed Kernel Extract, Orange peel skin extract (OPSE) was found as the most effective botanicals in reducing the mango hopper population which was followed by Neem Seed Kernel Extract. The lowest performance was recorded in the plants treated with Karanja oil. Application of insecticides in different times and frequencies showed that two times application i.e. after panicle emergence but before flowers open + after fruit set resulted in lowest number of mango hopper in case of all chemical insecticides which was followed by one time application after panicle emergence but before flowers open. The insecticide, Plenum 50WG showed the lowest mortality of all the tested five pollinators and natural enemies which was followed by Bismark 20SP. Among botanicals, Orange peel skin extract (OPSE) caused minimum mortality of the pollinators and natural enemies. The evaluation of IPM module-1 consisting of Plenum 50WG, Orange peel skin extract (OPSE) and offshoot cutting, IPM module-2 consisting of Plenum 50WG, Weaver ants and offshoot cutting and IPM module-3 consisting of Orange peel skin extract (OPSE), Weaver ants and offshoot cutting along with a control showed that module-1 was the most effective package in managing mango hopper for about a month.