Content by Adam Varenhorst
Did Malathion Effectively Manage Your Red Sunflower Seed Weevils?
Now that the August 31 deadline for the application of products containing malathion for red sunflower seed weevil management has passed, it is time to determine if the product was effective. South Dakota State University entomologists have received varying reports on this topic.
Mosquitos to Watch for in South Dakota
After many areas in South Dakota experienced heavy rainfalls, mosquitos are now a major issue. Learn which species are most common throughout the state and which carry the highest risk for West Nile Virus.
Army Cutworm Migration Swarms Detected in Western South Dakota
Mass populations of army cutworm moths are being reported to entomologists at South Dakota State University. Thus far, these migratory swarms have only been observed in far western South Dakota, particularly within the Black Hills.
Western Bean Cutworms Detected in South Dakota Corn
Western bean cutworm caterpillars have been reported in South Dakota corn. This pest can cause yield loss by feeding on the tassels, silks, and ears. In addition, ear feeding activities increase the likelihood of secondary diseases and mold growth on the ear.
Aphids Infesting Corn in South Dakota
Aphid populations are taking off in some southeastern South Dakota corn fields. The two aphid species that are commonly observed in corn include the corn leaf aphid and the bird cherry oat aphid.
Is it Time to Spray Red Sunflower Seed Weevils?
Red sunflower seed weevil adult activity is well underway on sunflowers in South Dakota. Even though the red sunflower seed weevil numbers are down, we are still observing populations in South Dakota that are above threshold.
Wheat Streak Mosaic Virus Complex: Breaking the Green Bridge
As wheat harvest proceeds, it won’t be long until winter wheat planting is underway in South Dakota. To effectively reduce wheat streak mosaic virus, it is important to manage the green bridge effect to slow spread of disease in newly emerging wheat fields.
Volunteer Wheat and Kochia Management With Herbicides Will Likely Require Two Passes
Wheat curl mites, which carry wheat streak mosaic virus, use volunteer wheat and grass weeds as secondary hosts to infest recently planted winter wheat crops. Therefore, effective management of these plants before winter wheat planting is critical.
Soybean Aphids Exceeding Thresholds in Some Parts of South Dakota
There have been a few fields this week that were infested with soybean aphids that are getting closer to threshold. We have also received reports of insecticides being applied to manage soybean aphids in South Dakota.
Reports of Pyrethroid Failures for True Armyworm Caterpillar Management
True armyworm caterpillars reached thresholds in oats and wheat in many areas of South Dakota recently. Management efforts to reduce populations had varying levels of success, with SDSU Extension receiving numerous reports of pyrethroid insecticide failures.