Corn earworm (CEW), Helicoverpa zea (Lepidoptera: Noctuidae) is one of the most damaging pests in soybeans and grain sorghum. On average, 50% of southern USA soybeans are infested with CEW, costing farmers over $100 million, annually. Most of this cost results from half of the infested acres not being sprayed with chemical insecticides, causing yield loss from “sub-threshold” damage. Among the most used chemical control options are the diamides, which, because of their high cost (>$15 per acre), are only applied at high thresholds (e.g. 9 per 25 sweeps for $9 per bushel soybeans). A new approach, based on applying Helicoverpa nucleopolyhedrovirus (NPV) at a much lower threshold, has been evaluated in southern soybeans over the last 6 seasons. This technology is unique because the baculovirus replicates in the field, providing long lasting control at a similar cost to pyrethroids. Importantly, HearNPV will often eliminate the need for a subsequent insecticide application, further improving farmer’s profitability. Key advantages of an NPV-based program are resistance management for diamides, which are valuable tools during high pressure situations; and preservation of beneficial species, which provide important “behind-the-scenes” suppression of several soybean pests. The Midsouth Entomologist Group’s HearNPV recommendations are based on a multi-year evaluation of Heligen, a commercially available HearNPV product with over 15 years of proven field performance in other markets. Further adoption of this technology will require intensifying educational and training efforts as well as field demonstrations to growers and consultants.
