Pasture Mealybug Creates New Challenge for Louisiana Sugarcane Growers

By Anna Holmes, Neil Melançon

As sugarcane planting nears completion across south Louisiana and growers prepare for the start of harvest season, farmers are facing an additional challenge in their fields in the pasture mealybug.

The relatively new pest has become a growing concern for Louisiana’s sugarcane industry this year, as researchers, consultants and farmers continue working to better understand the insect and limit its spread. In the meantime, it’s the busiest time of year for sugarcane as planting winds down and harvest begins.

Recent storms have caused some sugarcane to lodge, or fall over, creating another obstacle for growers and crop consultants. The downed cane can make it more difficult to move through fields and scout for pasture mealybugs.

Crop consultant Bret Barick said the lodged cane slows the scouting process and makes it harder to get a clear picture of what is happening beneath the leaves.

“As you can imagine, it's difficult to walk in and get a good visual picture in your mind and be able to pull leaves,” Barick said. “When we're tripping all over ourselves, it's part of the job, but it slows it down.”

While the insects themselves can be difficult to spot, Barick said yellowing or orange discoloration in the crop can be an important warning sign.

“We look for this coloration when we're scouting for the pasture mealybugs,” Barick said. “The two don't always go together, but most times, if you see the orange, there's a good chance you'll find them.”

The insects typically hide near the bottom of the plant, requiring scouts to pull back leaves and inspect the cane closely.

The bugs may be difficult to spot, but the potential for damage remains a concern for growers. The sugarcane industry recently received emergency approval for an insecticide not normally used on sugarcane to help combat the pest.

Mike Melancon, a sugarcane grower in St. Martin Parish, said he has already sprayed his fields three times this year as growers work with researchers and consultants to determine the best way to manage the insect.

“We're just throwing darts now,” Melancon said. “We're doing everything we think is the right thing to do. Research and consultants are guiding us, but there's still the unknowns.”

One of those unknowns is the long-term impact the pest could have on the crop.

“We still don't know what the effect on this crop is going to be,” Melancon said. “Is it going to affect our sugar content, even in fields that don't show any damage?”

The concern extends beyond this year's harvest. As growers finish planting cane that will produce future crops, the industry is watching closely to see how the pasture mealybug could affect Louisiana sugarcane in the seasons ahead.

For now, growers are balancing the final weeks of planting with preparations for a harvest that typically begins in mid-September and can continue into January.