Rice leafminer, Hydrellia prosternalis Deem. is one of important rice insects, as it causes economic yield losses, particularly in late-sown rice plantations. The current study was undertaken in 2010 rice season to monitor the population fluctuations of this insect pest. The losses resulting from the pest, in different rice plantations, were evaluated. Also, the correlations among some chemical components of rice plants and severity of the insect infestation were computed. The insect adult activity, monitored by water aluminum pan traps, exhibited five peaks from May up to September. The highest two peaks were detected during the second half of July. Yield losses due to this insect pest were negligible in rice plantations sown during the recommended duration; the first half of May. High yield losses were evaluated in rice plantations sown by late May or early June; with values of losses ranging between 21.99 and 25.24 %. Chemical analysis of rice leaves revealed a negative correlation between rice infestation by H. prosternalis and each of silica (r = - 0.605**), nitrogen (r = - 0.340) and potassium (- 0.198). However, the correlation between insect infestation and phosphorus content in rice leaves was insignificantly positive. This study show the importance of avoidance of sowing rice late in the season, otherwise chemical insecticides may be required to control the insect. The collaboration between rice breeders and entomologists is required to develop rice varieties with high silica content to reduce the infestation by H. prosternalis in rice plants.