Project Details:

Utilizing Nuclear Polyhedrosis Virus as a Novel Insecticide

Parent Project: Utilizing Nuclear Polyhedrosis Virus as a Novel Insecticide
Checkoff Organization:Louisiana Soybean and Grain Research and Promotion Board
Categories:Insects and pests
Organization Project Code:
Project Year:2020
Lead Principal Investigator:Sebe Brown (Louisiana State University AgCenter)
Co-Principal Investigators:

Information and Results

Click a section heading to display its contents.

Project Summary

CEW(corn earworm) and SBL (soybean looper) are annual pests of soybean and corn in Louisiana. Unlike SBL, CEW infest every major row crop grown in Louisiana with corn being the preferred host. CEW produce three-four generations per year in Louisiana. Typically, the first generation migrates to corn (May/June) with the subsequent second generation (July/August) migrating into soybeans and cotton. Often late-planted soybeans, on wide rows that have open canopies, are most susceptible. Cultural practices can be used to lessen the likelihood of economically damaging populations of CEW. Early planting of early maturing varieties, narrow row spacing and irrigation all contribute to lessen economic injury sustained by CEW populations. However, insecticides are often the primary mode to control CEW populations in soybeans.

SBL migrate to Louisiana every year from Central and South America. Populations often appear in Louisiana’s southernmost soybean growing parishes and migrate north as the season progresses. Like CEW, late planted soybeans are often impacted most by SBL populations and require multiple insecticide applications to control damaging populations. Conventional insecticides used to control both pests are realistically effective for <14 days and new alternatives are needed.

Therefore, we propose to investigate the use of nuclear polyhedrosis virus (NPV) as an unconventional control tactic for SBL and CEW that brings minimal negative side effects typically experienced with traditional insecticides (reduced efficacy overtime and insecticide resistance). Once ingested, NPV kills larvae by replicating within the host cells. Small larvae (less than 0.5 inch) typically die within 3 to 5 days after infection. When the insect dies, they liquefy and release millions of viral particles back into the crop canopy. Thus, each infected insect causes the virus to cascade across the field effectively controlling the target insects while spreading. When utilized in corn, the CEW NPV may cause a substantial decrease in CEW populations primed for migration into soybeans. When utilized in soybeans, the SBL NPV has the potential to effectively control looper populations season long. The novel mode of action effectively prohibits resistance formation by CEW or SBL and it is the only insecticide that demonstrates increased control with moderate rainfall.

Project Objectives

Objective (i): To evaluate CEW and SBL nuclear polyhedrosis virus (NPV) efficacy in a variety of large plot planting arrangements across the soybean and corn growing regions of Louisiana.

Objective (ii): Evaluate the infection rate and spread of NPV across commercial soybean and corn fields under different weather conditions and planting arrangements.

Project Deliverables

Objective i: Insecticidal efficacy of CEW and SBL nuclear polyhedrosis virus (NPV) insecticides will be evaluated across different planting arrangements and cultural practices in soybeans and corn. Trials will be conducted on production fields across all soybean and corn growing regions of Louisiana under different planting arrangements, row spacings and seeding rates. A data collection protocol will be standardized across locations to facilitate analysis. Number of insects captured in sweep net and visual samplings will be recorded for each location. Length, speed of control and non-target impacts will be assessed at each location. Yield data will be collected where available.

Objective ii: Infection rate and spread of NPV virus after application will be evaluated. Applications of virus will be made in anticipation of differing precipitation events on differing planting arrangements. Trials will be conducted on production fields across Louisiana soybean and corn growing areas. Area of spread will be quantified at each location and weather conditions will be monitored accordingly. Yield data will be collected where available. This information will be disseminated to producers, consultants, and other individuals in the agricultural industry.

Progress of Work

Final Project Results

Benefit to Soybean Farmers

Farmers need additional, cost-effective options for worm control in soybeans. The use of nuclear polyhedrosis virus (NPV) insecticides could provide one such tool.

Performance Metrics

CEW nuclear polyhedrosis virus (NPV) provided satisfactory control of CEW in soybean with similar results occurring in growers’ fields across Louisiana.

SBL NPV formulation issues occurred in 2020 prohibiting trial work from occurring.

Project Years