Long post warning. tl;dr Mealybugs have been in some Texas pastures since at least 2022. Prepare your anus.
If you are an at risk producer and want to hear from someone who has battled this multiple years, please read:
I mentioned having these in a thread or two over the past couple years. My first experience with mealybugs in pasture was in 2022. For background, I am in the Rio Grande Valley my pasture is improved Bermuda. The pasture is dryalnd but because I don't want to have to sell cows every dry spell, my stocking rate is low and in times of good rain I actually carry excessive biomass. (this is a contributing factor)
In the fall of 2022 we had a tropical system come in late summer and we got several inches of rain, but in response to that rain a big part of my pasture didn't bounce back like I thought it should it just looked brown and drought stressed. Looking closer, the leaves looked reddish and resembled the same symptoms as Rust (*mealybug damage can easily be dismissed as rust*) Coincidentally, I was telling my entomologist who looks at our cotton about it and he said, "It's mealybugs. Look close under the leaf once you see them you can't unsee them." He was exactly right. So I started calling around and asking for a recommendation of how to treat them - that's when I learned nothing is labeled for them in pasture. There are labels for mealybugs in ornamentals and turf grass - but nothing that offered a grazing restriction for pasture. Other products that WILL work are labeled for other pests... but not mealybugs. At least that is what my research turned up and that was backed up by Extension. I talked sternly to the mealybugs that fall and made them go away. This is a public Internet forum.
I should add that I did consult with our Extension Ento/Agronomist and she was very helpful, she came out and looked at it and participated in advice to the extend that she could. The key point here is - she sounded the alarm in 2022 - but for some reason, it was treated as an 'RGV problem.'
In 2023 I got by without any visits from this scourge, but in 2024 I had some small spots in late summer. Forward fast to spring of 2025 and boom, we were eaten up again; this was the first time I'd seen them in the spring. This was super wet year and I had a lot of grass - it wasn't hard to miss the spots the infestations started. Here is a picture I posted on this board a couple months ago:
This is the enemy and they are real. In the heat of summer I am completely consumed with harvest and don't have time to spare pampering my pasture - so it has to survive on autopilot June-Sept. I did all I could but this is what I am left with right now in a portion of my pasture (this is today):
That's the worst if it and now I can see what the Australians mean by 'Pasture Dieback' - those *******s will kill your stand. My strategy has been to fertilize in spring and try to encourage grass growth to reclaim these areas but that's a closed loop because high nitrogen and lush biomass are (what I'm told) are attractants and contributing factors.
In my experience here are some things to do to help yourself:
- Be on the lookout. When you are scouting you will generally see patches of grass that look like they are drought stressed. If the rest of the pasture is doing well they're easier to spot. Scout on the edges of the patch; they radiate out from the center. Get down in the grass and lay it over and look on the undersides of the leaf.
- High biomass and high nitrogen are thought to be attractants. I fertilize the **** outta my place because it's an extension of my yard. I might have to rethink this strategy.
- They will not go away or run their course. Army worms run in cycles and after they strip your leaves they're gone and you can wait for the grass to grow back. This is NOT that. They will suck the grass until there is nothing left of it and they literally kill the stand (see above).
- I did not fall into this trap - but I'm going to offer it as a warning because I saw it with a neighbor: be careful if you want to kill them with a pyrethroid. I am not an Ento and don't know beneficials are in our pastures - but there must be some because I know this can backfire and exacerbate the problem.
- If you have fire ants be on the lookout. There is a known symbiotic relationship between mealybugs and fire ants per Extension; it has to do with a secretion from the ants. If you have fire ants - controlling them is a step in controlling mealybugs.
- If your pasture is stressed - go LOOK NOW. Also, like I said above, the symptoms can easily be mistaken for Rust if you don't look UNDER the leaves and down in the grass.
For the first time or two, I felt like the Lone Ranger because I didn't see it in neighbor's pastures. Not so in 2025. As I've become more in tune with the symptoms I look around and have seen them in many pastures. This was confirmed by our Extension Ento. Until we have something labeled that we can treat them with - this has the potential to be a real problem.
