INFESTATION LEVELS OF SUGARCANE SHOOT BORER CHILO INFUSCATELLUS IN CAUVERY DELTA ZONE OF TAMIL NADU, INDIA

Status of sugarcane shoot borer Chilo infuscatellus Snellen (Lepidoptera: Pyralidae) in the sugarcane command area of  Pudukottai and Thanjavur districts lying in the Cauvery delta zone of Tamil Nadu, India, was assessed in May and October  during 2013-2015. Infestation levels of the borer varied among eight divisions of the command area, two seasons and three  years. In May, mean infestation rate was the highest in Vallathirakottai division (44.32%) and lowest in Andakulam division  (37.86%). In October, the highest mean infestation rate was observed in Avanam (37.99%) and the lowest in Andakulam  (25.49%). Repeated measures ANOVA analysis indicated that mean shoot borer infestation rate was significantly higher  (40.84%) in May than in October (31.24%). Also, mean infestation rate was significantly lower in 2013 than in 2015. The  possible factors responsible for the observed variation are discussed.