A Risk Index for Determining Insecticide Treatment for Southern Corn Rootworm in Peanut
DA Herbert; WJ Petka; RL Brandenburg
Type of Document:
Date of Publication:
Place of Publication:
Abstract: The southern corn rootworm, Diabrotica undecimpunctata howardi Barber, is a primary pest of peanut, Arachis hypogaea L., in Virginia and North Carolina and an occasional pest in South Carolina, Georgia, Alabama, and Texas. Currently, no alternatives involving integrated pest management exist for this pest, and control is based solely on preventive application of soil insecticides. Recent reductions in federal price support for peanut grown in the U.S. have provided incentives for growers to look for ways to reduce production costs. A risk index was developed that integrates factors that influence rootworm abundance and peanut pod damage to estimate levels of risk in individual peanut fields, and thus allows for more prescriptive and economical rootworm management. This index was evaluated using 44 field case studies in Virginia and North Carolina commercial peanut fields over the period 1989 to 1996. In each field case, predicted risk was compared to actual percent pod damage. Results showed that in 29 of 44 cases, the index accurately predicted General levels of risk to pod damage, and insecticide treatment decisions based on the index would have been correct in 32 of 44 cases. This report contains the individual index components, the justification for each, the indexing process, example index scenarios, and results of the process used in field case study evaluation.