Abstract: The objective of this work is to study the seasonal variation of percentage infestation, and effect of important weather factors viz. rainfall, relative humidity and temperature on the population of Citrus leaf miner, Phyllocnistis citrella Stainton in J&K State of India. Seasonal abundance of Citrus leaf miner was investigated fortnightly in an orchard of Mosambi (Citrus sinensis) from March 2005 to Feb 2008, located in Jammu. There were three infestation peaks in a year that coincided with the availability of new vegetative flush viz. mid April, mid July and mid September. Correlation analysis indicated that morning, afternoon and average relative humidity were negatively correlated, whereas, average rainfall, and maximum, minimum and average temperature were positively correlated with the population of citrus leaf miner. Rainfall and temperature had significant positive correlation with the population infestation. In general, population of P. citrella can not be predicted simply by observing the relative humidity of a particular area. However, rainfall and temperature all play important roles in affecting the pest infestation.

Key words: Phyllocnistis citrella; Citrus sinensis, infestation dynamics, weather factors, seasonal variation