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Spider Mite Research Goes


Spider mites have traditionally been considered an occasional cutout pest for cotton during hot and dry years. In recent years however, the percentage of cotton acres in the Mid-South requiring treatment for spider mite control has increased two-fold.

“In 2007, spider mites were the third most damaging pest on cotton behind plant bugs and bollworms,” says Pat O’Leary, senior director, agricultural research, Cotton Incorporated.

Because mites are becoming more of a problem for cotton, O’Leary is spearheading a multi-state research effort to lend insight and develop specific recommendations to better control mites.

“Mites are a yield-limiting pest and because of that, it’s important to conduct research to show exactly how yield is affected when mite infestations occur at various times of the growing season – and when miticide applications should be terminated,” she says.

Multi-State Cooperators

O’Leary is drawing on the same cooperative researchers who participated in the Cotton Incorporated-funded multi-state Tarnished Plant Bug (TPB) research project in 2005.

Key findings from that study were as follows: 1) During bloom, the drop cloth was found to be the most efficient and accurate sampling method for TPB; 2) During squaring, the sweep net was shown as the most efficient and accurate sampling method for TPB; 3) TPB during bloom was established as 2.5-3 TPB per 5-row foot on a drop cloth and 4) TPB threshold during squaring was established as 8 TPB per 100 sweeps.

O’Leary explains: “The objectives of this project are two-fold and include: Determine the impact of spider mites on cotton yields at different times of the year and when applications can be terminated; and perform a standardized, regional efficacy trial using labeled miticides.”

This portion of the trial will be performed by applying the most commonly used miticides and initiated when spider mite infestations exceed a treatment threshold of 30 to 50 percent infested plants with increasing populations. Although there have been previous studies similar in nature, all were conducted in production systems and environments much different than what are found in the Mid-South.

The Cotton Board, which administers the Cotton Research and Promotion Program conducted by Cotton Incor-porated, contributed to this article.

LSU Entomologist To Join Special ‘Fellows’ Program

It is critical to have young, trained scientists in each area of cotton research. Entomology is no different.

Cotton Incorporated’s “Fellowship” program has done an excellent job attracting young, talented scientists into disciplines related to cotton breeding. Because of that success, it has expanded the Fellows program to include the science of entomology.

The newest Cotton Incorporated “Fellow” is Jarrod T. Hardke. Currently a candidate for the Doctor of Philosophy degree in the Department of Entomology at Louisiana State University, he is studying cotton pest insect management under the direction of Dr. B. Rogers Leonard, Professor of Entomology and J. Hamilton, Regents Chair in Cotton Production with the LSU AgCenter.

Jarrod’s dissertation research topic will be evaluating the efficacy of Bt cotton as well as conventional insecticides against the fall armyworm, while describing the symptoms of fall armyworm injury on both Bt and conventional varieties.

His work will become increasingly important as U.S. cotton nears elimination of single-gene Bt cotton technology and converts all Bt cotton acreage to multiple-gene technologies.


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