2012 Produced Extreme Spider Mite Infestations In Corn

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. (Texas A&M AgriLife Extension Service photo by Kay Ledbetter)

Spider mite infestations across the entire Texas High Plains were among the worst producers have had to deal with in a number of years, according to a Texas A&M AgriLife Extension Service entomologist.

AgriLife Extension entomologist in Amarillo, said corn producers primarily saw populations of the Banks grass mite, which "are supposedly easier to control than the two-spotted spider mite.

" But, Bynum said, this year many producers had a hard time controlling any mites with a single miticide application. In many instances, mites were never controlled with multiple applications.

"As we look back on the season, there are some factors that contributed to the rapid mite infestation development and poor control," he said.

One factor was the timing of the hot, dry conditions this summer, which Bynum said provided an ideal environment for mite populations to get out of hand. Daytime temperatures began to reach the high 90s and into the 100s during the last half of June and again during mid-July into August.

Coupled with the dry conditions, mite populations were able to become established across the field in June, he said. Then in July, corn fields were tasseling and starting grain development growth stages, which further enhanced the reproductive capacity of mites.

"Once mite infestations moved up the plant and began causing damage below the ear leaf, the populations reached levels that even a miticide application controlling 60 percent to 80 percent of the mites left sufficient numbers to rebound rapidly," Bynum said. The entomologist said one observation this year was that mite populations developed earlier and faster on corn grown under drip irrigation.