Effect of Feeding on Peanut Growth by Corn Earworm, Helicoverpa Zea

Abstract

Two growth chamber experiments were conducted to evaluate the effect of feeding by corn earworm, Helicoverpa zea (Lepidoptera: Noctuidae) on peanut growth and development. In Experiment 1, H. zea eggs and larvae were transferred to peanut plants during the vegetative growth stage and larvae were allowed to feed on components of the peanut canopy. Feeding resulted in 25%, 50%, and 65% defoliation. In Experiment 2, 25% or 35% of the leaves were defoliated by corn earworm introduced at the pod forming and pod-filling stage. Results and observations showed that corn earworm preferred feeding on young peanut shoots. Excessive damage was caused by the large larvae feeding on new shoot growth, flowers, pegs, portions of the stems, and leaves. Corn earworm feeding resulted lower leaf, stem, root, peg, and pod masses. The effect lasted throughout the sampling period (about 5 weeks). The infested plants recorded fewer pods and lower pod mass at harvest.