Seasonal incidence of gall midge, Orseolia oryzae (Wood-Mason), a major insect pest of rice and its reaction on various rice germplasm

Maximum infestation of gall midge was observed from 35^th to 43^rd (August - October) standard meteorological week (SMW) and highest infestation of gall midge producing silver shoots was observed in 38^th SMW whereas peak catches by light trap were obtained in 40^th SMW. Infestation of gall midge in field was positively correlated with maximum and minimum temperatures whereas it was negatively correlated with morning and evening relative humidity. Regression analysis showed that the maximum temperature significantly contributed nearly 30% variation to their population build-up. Highest incidence of silver shoot was recorded in TN-1 (17.02% SS) whereas 9 entries viz., W 1263, RP 6290-20-6, RP 5925–24, RP 5923, INRC 17470, Mahamaya, Akshayadhan, PTB 33 and Suraksha were found highly resistant to gall midge biotype 1.