256 Influence of abiotic factors on incidence insect pests of rice September 2018 Journal of Agrometeorology 20 (3) : 256-258 (September 2018) Rice (Oryza sativa L.) is one of the world’s most important cereal crops providing a staple food for nearly half of the global population (FAO, 2004).Introduction and wide adoption of high yielding varieties has led to severe incidence of different insect pests. Nearly 300 species of insect pests attack the rice crop at different stages and only 23 species cause notable damage (Pasalu and Katti, 2006).Among them, yellow stem borer (YSB), Scirpophaga incertulas (Walk.), plant hoppers [both brown plant hopper; Nilaparvata lugens (Stål) and white-backed plant hopper; Sogatella furcifera (Horvath)], Asian rice gall midge (GM), Orseolia oryzae (Wood-Mason) and leaf folder; Cnaphalocrocis medinalis Guenee are very important and responsible for huge economic crop losses (Seni and Naik, 2017). Weather plays an important role for determining the geographical distribution and periodic abundance of major insect pests in rice (Singh et al ., 2012). Among the weather factors; temperature, rainfall, relative humidity plays the crucial role in insect life. For this, it is necessary to acquire a thorough knowledge on relation of weather parameters to insect pests which will be very helpful to formalize a suitable management practices in the areas where major insect pests are appearing year after year and causing serious damage to rice crops. Hence, considering the importance of insect- pests of rice an attempt has been made to study the influence of different abiotic factors on the incidence of major insect pests of rice. The experiment was conducted at the experimental farm of Regional Research and Technology Transfer Station (OUAT), Chiplima, (Lat. 20 o 21’N, Long. 80 o 55’E, altitude 178.8 m above) Sambalpur, Odisha, during kharif 2015 and 2016 in randomized block design (RBD) with rice variety Jaya. The climate of the area is warm and sub humid. All the agronomic practices were followed except plant protection measures during crop growth period. Observations on the incidence of YSB producing dead heart/white ear head (DH/ WEH),GM producing silver shoot (SS), leaf folder damage leaves, plant hoppers number per hill were taken on 10 randomly selected hills per plot from each replication and were recorded at weekly interval, 10 days after transplanting to harvesting stage. Then percentage of dead hearts/ white ears/ silver shoot/ leaf folder damage leaves were worked out. The data on weather parameters during the crop growing periods were taken from the meteorological observatory located in the RRTTS, Chiplima.The influence of abiotic factors on the incidence of major insect pests of rice was analyzed by correlation analysis using SPSS 16 statistical software. The data on influence of major abiotic factors on the incidence of YSB producing dead heart or white ear-head (DH/WEH), gall midge producing silver shoot (SS), leaf Short Communication Influence of different abiotic factors on the incidence of major insect pests of rice (Oryza sativa L.) ATANU SENI* and BHIMASEN NAIK Orissa University of Agriculture and Technology, AICRIP, RRTTS, Chiplima -768025, Sambalpur, Odisha *E-mail: atanupau@gmail.com Table 1: Correlation between insect pests incidence of rice and different abiotic factors Weather Parameters Correlation coefficient (r) DH/WEH SS LFDL Plant hoppers (BPH+WBPH)/hill Max. temp. 0.072 0.743** 0.749** -0.619** Min. temp. -0.209 0.624** 0.654** -0.755** Rainfall -0.488* 0.168 0.216 -0.583* Morning relative humidity -0.506* -0.384 -0.365 -0.015 Evening relative humidity -0.680** 0.130 0.150 -0.788** *-Significant (p<0.05), **-Significant (p< 0.01)