Louisiana Rice Notice--Pasture Mealybug

By Tyler Musgrove

LSU Rice Extension Specialist

In Louisiana, 2026 has definitely been the year of the insect. Now this doesn’t mean we’ve had widespread yield losses and control failures, but instead we’ve seen insects do things we don’t normally expect. South American Rice Miner showed up pretty consistently in most fields and didn’t go away. Chinch bugs took a bite out of stands all across southwest Louisiana and many replanted. Stink bugs and stem borers are building in the ratoon crop a little more than we’re comfortable with. However, this segment will focus on two newcomers that may be causing more concern than they’re actually worth. Both insects have also been identified this year in isolated rice fields in Texas, according to Dr. Sam Rustom, Texas A&M AgriLife

Bank’s Grass Mite

A couple weeks ago, we began receiving calls about what appeared to be water weevil-type damage occurring on rice leaves in astounding number (Image 1). It was clear water weevils wouldn’t cause this sort of injury and so I went under the microscope—mites (Image 1). I scouted several fields around Acadia, Vermilion, Jeff Davis, and Calcasieu Parishes and the mites and their damage (stippling) was present throughout, although mostly found on the edges of fields. After consulting with other LSU entomologists, we landed on the Bank’s Grass Mite, which had shown up in sugarcane earlier in the year and in the same areas. These things are incredibly difficult to see with the naked eye but having a hand lens handy would help. These are different from the rice panicle mite which is an actual problem. These grass mites are only feeding on the leaves and appear to be causing superficial damage. We’ve been monitoring their progression, and they haven’t posed any threats that we can tell.

Mealybugs in rice

A ton of rice acres in Louisiana share a field road with sugarcane, and there’s no secret as to what the cane industry is currently dealing with. As a result, we’ve been receiving questions about mealybugs in rice and whether we should have any concerns. The short answer is— maybe, but not really. The mealybug (Heliococcus novovillei) affecting pasture fields and sugarcane requires access to the soil to complete its lifecycle. A flooded rice field doesn’t exactly allow for this. So, from this angle, mealybugs will not pose a significant threat to the US rice industry. However, there are three scenarios where I can see mealybugs getting into rice:1) preflood early season 2) ratoon stubble that hasn’t been flooded yet and 3) furrow-irrigated rice (my big worry). For scenario 1, mealybugs need to emerge much earlier in the spring than they do based on observations from the last two years. However, we expect insecticidal seed treatments, especially neonics like Cruiser or NipsIt Inside, to bring a lot to the table. That being said, I’m hoping to verify this in greenhouse this off-season.

Before getting to scenario 2, furrowirrigated rice or row rice is where I think mealybugs pose the greatest threat. In Louisiana, row rice does meet the most northern cane region across Rapides, Avoyelles, and Point Coupee Parishes, and I’ve even seen row rice share a turn row with cane. We don’t have many row rice acres in the state, but we certainly need to watch those. As for scenario 2, we observed mealybugs in preflood ratoon stubble in Vermilion Parish, right next to an infested cane field ). We collected samples for genetic confirmation and sent them to USDA. I couldn’t determine if the damage I was seeing was from mealybugs or chinch bugs, but the mealybug pressure was only 5 or so insects per sq ft. This particular field was intended for crawfish, and the farmer was not planning to cut the second crop. Going forward, I do not anticipate mealybugs causing widespread issues in the rice producing regions of the Gulf South, but their presence warrants just a little attention.