POPULATION ECOLOGY, DAMAGE EXTENT OF MAJOR INSECT PESTS AND MANAGEMENT APPROACHES FOR JHUM AND RICE-COTTON INTERCROPPING IN CHOTTOGRAM HILL TRACTS OF BANGLADESH

Abstract

The study comprised four experiments conducted at four separate trials at jhum and intercrop fields in different hills of Bandarban, Rangamati and Kagrachari during March 2014 to February 2016 to find out insect pests of existing cropping system, identify common insect pests their population dynamics and extent of damage in addition evaluate effective pest management approaches for jhum and rice-cotton intercropping system at hill region of Bangladesh. The field experiments were conducted in RCBD from farmer’s field of jhum and rice-cotton intercropping on hill during April 2015 to January 2016. Among the 150 farmers, average, 19.33% received pest management and other training whereas 80.67% did not received any types of training. Jhumian people were used to their traditional practice to suppressed pest and diseases. Forty eight insect mite pests on rice, country bean (22), hill sesame (30), cowpea (17), yard long bean (16), marpha served as (18), okra (13), eggplant (24), chili (11), maize (12), roselle (6), whereas cotton plant serve as a host for an extensive range of insect mite (45) similar to rice. Among them leaf webber on sesame, BSFB on eggplant, fruit flies on marpha and cucumber, mite and thrips on chili and red cotton bug on cotton were reflected as major insect mite pests. Nonetheless phloem-feeders bugs, aphid, jassid, whitefly, leaf feeding epilachna beetle and grasshoppers were abundance extent of damage were maximum on different jhum crops and intercrops thus considered as major. The infestation by the major and promising insect and mite pests and their abundance, seasonal incidence their extent of damage of jhum and hill rice-cotton intercrop significantly varied with mean temperature, rainfall and humidity. Farmer’s practices of Jhumian people treatment were less effective to suppress the insect pests predominant on hill districts. The rate of infestation, decreasing invasion over untreated control, yields, monsoon season, accessibility at hills, their traditional practices on different crops in jhum and hill rice-cotton intercrop, chemical treatment T (spraying Voliam Flexi 300 SC @ 0.5 ml Liter -1 3 water at 25 days interval) was most effective and other chemical treatments also performed significant and recovering of yield than traditional practices and untreated control plots.