What is in this article?:
- 2012 produced extreme spider mite infestations in corn
- Management tips
- AgriLife Extension offers insight for future management decisions.
- Many producers had a hard time controlling any mites with a single miticideapplication.
- Mite populations developed earlier and faster on corn grown under drip irrigation.
DR. ED BYNUM, AgriLife Extension entomologist in Amarillo, explains at a recent field day the results of his spider mite damage study looking at different irrigation levels and corn hybrids. Helping with this study were student workers Al Perez, center, and Joshua Correa, right.
Bynum outlined some management steps for producers trying to manage future mite infestations:
- If a mite infestation is developing, a preventive miticide should be considered at least two weeks prior to any pesticide application that is “harsh” on natural predators, especially when an insecticide is planned at tassel and during the grain developmental growth stages for other corn pests.
- Consider using pesticidesthatare softer on predators when spraying for southwestern corn borers, western bean cutworms, western corn rootworm adults, fall armyworms and other corn pests.
- Scout fields at least once a week to determine the dynamics of the mite/predator populations and damage. Consider treating if mite colonies are beginning to establish on the ear leaf and mite densities – eggs, immatures, adults – and damage continues to increase.
- Spray coverage is critical. Miticide applications to corn less than 2 feet tall only protect leaf tissue the spray contacts. Leaves that grow after application are not protected. Encourage applicators to spray the field in the early morning before the hotter times of the day.
- Do not rely on a single mode of action. Continued use of one product year after year and for multiple applications during a year creates heavy selection pressure for resistance development.