SEASONAL INCIDENCE AND DAMAGE SEVERITY OF MAJOR INSECT PESTS ON BORO RICE IN KHULNA AND SATKHIRA DISTRICTS OF BANGLADESH

ABSTRACT: Study was conducted at farmers boro rice field in Khulna and Satkhira districts of Bangladesh to find out the incidence and damage of stem borer, leaf folder and BPH at different growth stages of rice during December 2023 to June 2024. Results revealed that the highest number of white stem borer larvae was recorded from Asashuni upazila and the lowest was from Koyra. The highest number of dead heart symptoms was found in Satkhira sadar and the lowest in Paikgasa. The highest number of white head was recorded from Dumuria upazila and the lowest was from Kaliganj. At 40 DAT, the highest number of stem borer larva was found in Koyra (1.4/10 hills) and the lowest number of larva was recorded from Paikgasa (0.4/10 hills). The highest number of dead heart symptoms was recorded from Sathkhira sadar (1.4/10 hills). At 60 DAT, the highest number of stem borer larva was found in Assashuni (0.8/10 hills), the highest number of moth was recorded from Kaligonj (2/10 hills) and the lowest was from Sathkhira sadar (0.8/10 hills). The highest number of dead heart symptoms was recorded from Kaligonj (2.4/10 hills) and the lowest was in Sathkhira sadar (0.8/10 hills). At 90 DAT, the highest incidence of rice stem borer larva (2.8/10 hills) and moth (3/10 hills) was observed in Paikgasa. The highest number of white head damage was recorded in Paikgasa (3.2/10 hills) and the lowest was in Koyra (1.4/10 hills). At 110 DAT, the highest incidence of rice stem borer larva was observed in Paikgasa (2.8/10 hills) but the highest number of stem borer moth was recorded in Assashuni (1.8/10 hills) and the lowest was in Sathkhira (1.4/10hills). The highest number of white head damage was recorded in Kaligonj (4.4/10 hills) and the lowest was in Sathkhira sadar (1.8/10 hills). In case of rice leaf folder, at 40 DAT, the highest number of leaf folder larva (2/10 hills) and folded leaves (0.8/10 hills) was observed in Satkhira sadar followed by Assashuni (0.4/10 hills) but incidence of leaf folder larva and its damage were not found in Kaligonj, Koyra and Paikgasa. At 60 DAT, the highest number of leaf folder larva was observed in Satkhira sadar (1/10 hills) and the lowest number of leaf folder larva was in Koyra (0.4/10 hills) but the highest number of folded leaves was observed in Kaligonj (1.2/10 hills). No folded leaf was recorded from Dumuria. In case of BPH, the highest number (114/10 hills) of Brown Plant Hopper (BPH) was recorded from BR 26 rice field and the number infested tiller was 10. But from rod miniket rice, the number of BPH was 112 and the number of infested tiller was 5. No BPH was found in remaining 5 studied locations. 

Keywords: White head, dead heart, WSB, BPH, rice leaf folder, YSB, seasonal incidence