Nilaparvata lugens(Stål) populations on very early and early maturing rice cultivars with growth durations of 94–103 days from sowing to harvest were much lower than those on ‘IR20’, a medium-duration (120 days) cultivar, on which populations reached a peak in the third generation. The very early and early maturing cultivars, which were nearing harvest and were apparently unsuitable to the insects at the time of their final buildup, escaped damage.N. lugens/predator ratios were lower in the very early and early cultivars than in ‘IR20’.