Small plot mowing trials carried out on central North Island pumice soils have shown that Huia white clover and SI70 tall fescue support high grass grub populations, while the resistant legumes Wairau lucerne and Maku Lotus pedunculayus suppress grass grub numbers to low levels. Measurement of the effects of grass grub on herbage production has highlighted both the susceptibility of white clover, Nui and Ruanui ryegrasses, and browntop to grass grub attack, and the potential of highly productive resistant or tolerant specres (lucerne, tall fescue and to a lesser extent Apanui cocksfoot and Matua prairie grass) for lessening the impact of grass grub on pasture production in this region.