Sunflower blooming is nearly complete in Northern Ag territory and some insects enjoy those flowers as much as we do.
The Sunflower Highlight newsletter form the National Sunflower Association mentions a couple of insects producers should be looking for. With sunflower fields blooming, adults of red sunflower seed weevil (RSSW) will be emerging and will fly to the nearest flowering sunflowers.
North Dakota State University Extension Cropping Systems Specialist Ryan Buetow, from the Dickinson Research Extension Center, told Northern Ag Network it’s all about timing with RSSW. He mentioned their damage is not very visible right now but going out around harvest producers would see holes in the seeds.
“If you wait too long, those eggs are already in those seeds and the damage is already done,” Buetow said. “When scouting, you can spray some DEET in the head and count how many (weevils) come out. You can also rub the head and they’ll come out from inside. Try and find at least five different sights of twenty-five plants so you get a good estimate. Don’t look on the field edge because you’re generally going to find more insects there.”
Trap catches for banded sunflower moth (BSM) and Arthuri sunflower moths (SM) have increased in the last week and are at economic thresholds for control in some locations. Severe infestations of RSSW and moths can be very damaging to the sunflower head and result in seed loss. Once the decision to treat has been made, it is critical to time the spray application correctly to get effective management of all sunflower head insects including RSSW, BSM, SM, and Lygus bug. The best sunflower plant stage to treat is when the majority of plants are in the R5.1 growth stage until they are passed R5.7 growth stage.
Buetow said, “Insects may not be an issue everywhere but we’ve seen a lot more insects this year it seems like.”
National Sunflower Association
Northern Ag Network – 2020