Effect of Nitrogen Fertilizer on the Intrinsic Rate of Increase of<i>Hysteroneura setariae</i>(Thomas) (Homoptera: Aphididae) on Rice (<i>Oryza sativa</i>L.)

Abstract

We studied the intergenerational effects of nitrogen (N) fertilizer applications to rice plants on the size, fecundity, and intrinsic rate of increase (r m ) of Hysteroneura setariae (Thomas). Treatments consisted of rearing aphids on rice plants receiving 0, 50, 100, and 150% of the standard N fertilizer rates. Adult females produced on the 0 and 150% treatments were transferred to new plants at 0 or 150% N levels to create a matrix of four treatments: 0 0, 0 150, 150 0, and 150 150%. Second-generation aphids produced on 150% N plants had signicantly higher survivorship, fecundity, and r m regardless of the N treatment of plants that parents fed on. N levels had no observed effect on head width. Aphids reared on 0% N plants whose parents were also reared on 0% N plants had signicantly shorter body lengths than aphids on all other treatments, including the 150 0% treatment, indicating that the effect of a high N diet was expressed in a second generation of aphids. Results are discussed in the context of aphid population outbreaks in rice elds and in greenhouses.