The HearNPV virus contained in Heligen is a living organism that can be degraded before it arrives in the field if handlers don’t follow precautions.
“It’s important that we don’t expose it to very hot temperatures,” said Scott Graham, Extension entomologist at Auburn University. “We also need to keep it out of direct sunlight. The virus is protected in occlusion bodies, casings that protect the viral bodies.
“They are rapidly broken down by UV light, heat and pH. Keep it out of direct sunlight; try to keep it as cool as we can; and if we need to add a buffer to the spray tank if our pH is going to get above 8.0.”
Coverage by the spray is another important factor, said Graham, a speaker at the University of Tennessee’ Milan No-Till Field Day. The university has been holding the field day every other year in recent years, but decided to make it a virtual presentation this summer because of the Covid-19 pandemic.
“On the label, AgBiTech lists a minimum of 3 gallons of spray solution by air,” he said. “I think they would like to see closer to 5 gallons per acre, if possible. By ground rig they’re wanting at least 10 gallons per acre. It’s very important we get a good uniform coverage in the initial infection, and a good gpa is critical for that.”
Graham displayed a montage of photos of some of the caterpillars that can be found in a soybean field in Tennessee. “Green cloverworms, velvetbean caterpillars, soybean loopers — sometimes if we’re not looking close enough, we could say, ‘Oh yeah, we have podworms and spray,’” he said.
“But I want to drive home the fact this product only works on the podworm. It’s not going to control silver spotted skippers; it’s not going to control painted lady larvae. It will only control podworms. Make sure we’re scouting and identifying the proper insect at the time of application.”
For more information on this presentation, click on https://milannotill.tennessee.edu/research-tours/.