The effects of clover and nitrogen fertiliser on the presence of pasture pests in dairy pastures

A comprehensive dataset obtained from sampling four trials investigating interactions between perennial ryegrass and white clover under two levels of applied nitrogen (N) has highlighted different effects of pasture composition and N use on pasture pests.• For swards with white clover, presence of clover root weevil, whitefringed weevil and grass grub increased under low N by 36%, 11% and 5%, respectively, compared with high N treatments.• High N increased the presence of both Argentine stem weevil and root aphid by 7%.• Unexpectedly, clover reduced the presence of two grass feeders, Argentine stem weevil and black beetle, by 7% and 11% respectively.• Presence of grass grub was 17-30% lower under tetraploid ryegrasses than under diploids.• More clover and reduced N fertiliser inputs could reduce the frequency of black beetle and Argentine stem weevil with environmental benefits.