New Bt Cotton Coming

USDA Seeks Comments on Bt Cotton Trait Targeting Plant Bugs and Thrips

Emily Unglesbee
By  Emily Unglesbee , DTN Staff Reporter
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Tarnished plant bugs are a major pest of cotton, but a new Bt trait targeting them is nearing commercialization in the U.S. (Photo courtesy Lisa Ames, University of Georgia,

ROCKVILLE, Md. (DTN) -- A new Bt cotton variety took another step toward commercialization this fall, after USDA released its preliminary risk assessments for the trait and recommended its deregulation.

The cotton trait, MON 88702, was developed by Monsanto and is now owned by Bayer. It expresses a new Bt protein, mCry51a2, which targets two types of plant bugs, tarnished plant bug and western tarnished plant bug, and also provides some control of thrips.

USDA's Animal and Plant Health Inspection Service (APHIS) released two assessments of the trait's safety this month: a draft environmental risk assessment and a draft plant pest risk assessment. Both concluded the trait was unlikely to have negative effects on the environment and recommended deregulation.

Now those assessments are up for public comment through Nov. 16. Readers can view them here:… and comment here:….

The new cotton trait, which Bayer has branded ThryvOn, isn't through the regulatory woods yet. The trait still needs to gain approval from EPA, which regulates any crops that produce pesticides, such as Bt proteins. EPA has approved the trait for planting in the U.S. for agronomic evaluations, breeding and seed production, but has not yet issued full commercial registration for it.

See the EPA's review of this trait to date here:….

Both thrips and plant bugs are major pests of cotton; one Mississippi State University study estimated that they cost cotton growers a combined $242 million in 2018 in control costs and yield losses.

Both insects can be controlled by insecticides, but resistance has developed among both plant bugs and thrips to pyrethroids and organophosphate insecticides, as well as neonicotinoid resistance in thrips, Monsanto noted in its original petition for deregulation of MON 88702.

Interestingly, the mCry51a2 trait in MON 88702 also has activity against two other agricultural insect pests: the Colorado potato beetle and southern corn rootworm, though neither are likely to be exposed to the protein as they aren't pests of cotton, Monsanto's petition noted.

See more on new cotton traits in the pipeline here:….

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Emily Unglesbee