Estimates of Losses Caused in Paddy Due to Rice Hispa, Dicladispa armigera (Oliver) (Coleoptera:Chrysomelidae)

Studies were undertaken for two consecutive years (kharif 2015 and 2016) at the CSK Himachal Pradesh Krishi Vishvidyalaya, Rice and Wheat Research Centre, Malan (Himachal Pradesh, India) under field conditions using paddy variety ‘Kasturi Basmati’. Losses in paddy due to rice hispa, Dicladispa armigera (Oliver) were quantified in terms of release density (number of adults per tiller) and phenological stages of crop. Results revealed that both these aspects significantly influenced leaf damage as well as yield of paddy. Early stage release (20 DAT, days after transplanting) contributed to maximum leaf damage (69.9 PLDI (per cent leaf damage index)) and at the same time exerted a significant negative influence on various yield components, viz. number of tillers, panicles, grains and grain weight (g) for which the respective regression coefficients were 5.82, 5.73, 441.4 and 8.06, respectively (per 4 rice hills).