In-Season Alert: NDSU has reported an increase in the number of Banded Sunflower Moth (BSM) in their traps over the week prior to July 14, 2017. The moth itself doesn’t do damage to the plant, but rather its larvae. When the larvae hatch they eat the seed and then exit, leaving behind a small hole. Typically, the moth will move into the sunflower field around the R3 stage and will lay their eggs on the back of the bracts.
Scouting: This can be done one of two ways. The first is by looking for eggs on the back of the bracts when the sunflowers are R3 to R4. The threshold for the number of eggs per bract varies based on the cost of treatment and market price. Currently, a $17 sunflower crop with an $8 treatment and 20,000 plants per acre would need 3.9 eggs per six bracts to reach the threshold. The second is to monitor for the adults by walking into the field away from the margins and looking for the moths. They tend to rest on the leaves during the day and can often be seen when you walk through a field. A $17 sunflower crop at 20,000 plants per acre has a threshold of one moth per 100 plants.If you would like to monitor the adults in your field Legend Seeds has pheromone traps available for Nuseed customers, contact Jed Wall at (701) 640-1653.
Scouting Video: NDSU has some great resources out there with videos for egg scouting and tables showing Economic Injury Levels so a grower knows when they should spray: https://www.youtube.com/watch?v=exH6DFTLjsA
Optimal time to spray with an insecticide is at R5.1 (early bloom) and most labeled insecticides are very effective. If you have a confection field, continue to scout your fields even after spraying in case a second application is needed.
Image courtesy of NDSU Entomology