Entomology Update 5-23-25: Rice Water Weevils, Thrips in Cotton, Salt Marsh Caterpillars and Armyworms

Extension entomologists Nick Bateman and Ben Thrash discuss current concerns about rice water weevils, thrips, salt marsh caterpillars and more.

Transcript

[00:00] Intro/Outro

Arkansas Rock Crops Radio, providing up to date information and timely recommendations on rock. Rock production in Arkansas.

[00:14] Ben Thrash

Hey everybody, today is May 23rd, and, And people are still trying to get planted between all these rains. I know, I know, some people have been trying to get their cotton still in the ground, and I've heard a couple people still trying to plant some rice. It's just been so dadgum wet. All these showers and storms coming through. But, Anyways, Nick, what's going on with rice?

[00:44] Nick Bateman

Kind of like you said. It's too wet to fertilize. Half of it ain't got levees up in part of it, but have gotten a couple calls in. Y'all know it's not uncommon to get big rain to see weevils. You know what I mean? Move in there. And what concerns me, though, and I actually talked with Gus a few days ago about this as well, is how dadgum wet it stayed and whether or not we have any larval activity going on out there right now. And I've had a few people call wanting to know should they let that ground try to firm up and, and, you know, go to cracking before they actually go to flood in case there are some larvae out there. I mean, you know, the more I think about it like, yeah, in the in the perfect scenario, that's definitely what we would do. But I think at this point, as light is we're starting to get as big as some of this rice is and needing to go to flood, getting into the end of the, you know, optimal window for nitrogen to me, I think as soon as the ground gets dry enough to fertilize it, I think we got to send it to flood. I don't know, with the current rain patterns and stuff we have, if we can wait till it gets to cracking, in general, you know, we've been keeping up with these few fields around here, talking to some folks around the state. I mean, overall, it seems like right now weevil pressure’s pretty light. But, you know, they Jarrod and Gus actually did a bunch of planting studies right before me and Ben got hired. And if you just look at the weevil population really it seems like I mean planting data effect, yes. But really it seems like once you go to flood first of June, mid-June that kind of seems to be the peak of, of sort of that migration into rice, which is also when we're flooding a lot of that rice as well around the state. So I mean, I, I think we're kind of on the front end of it, I think over the next ten, 14 days, really need to be paying attention to that rice when it goes to flood. I've had a few questions about this sweet net thing we're doing. Don't have a good number for you yet to really base that off of, but what I can tell you is normally it seems like once we start getting around maybe 15 adults in ten sweeps somewhere in that ballpark, we we start, you know, getting around threshold from a larval core, deal where we've got some more work to do there to give you a hard number, but that that's kind of where it looks like it's falling right now. 15 to 20 somewhere in there. The other thing is, got a few calls on on cut worms earlier this week and over the weekend of, you know, and rice and they weren't really clipping it off of the ground is more clipping leaves off. And I gotta be honest with you, I'm not going to worry about that too much because, I mean, we've done all this defoliation work, and not that there might not be a heading delay to an extent. It's usually pretty minor whenever that rice is that size. But there's really no yield loss potential there. But outside of that, that's pretty much all that's going on at rice other than it's flooded when it don't need to be flooded right now, in a lot of cases.

[03:51] Ben Thrash

Yeah. So just kind of wet everywhere. It's been that way for cotton, too. I mean, we're, you know, people are still trying to get cotton in the ground right now, and there's some of it up. It just seems to be a late crop. And of course, that makes it bad for thrips. I mean, it sounds like thrips have been pretty bad this year. I've just got cotyledon cotton up on on a lot of my stuff, and I was out looking at it yesterday. And the thrips pressure, I'm running, I don't know, 1 or 2 per plant, on some of my stuff. And that's on, that's on just cotyledon stuff. And honestly, I would not spray cotyledon cotton. I'm going to want to wait until that, you at least get a true leaf trying to come out, before, I'm going to want to spray that up. Hopefully that, that, imidacloprid seed treatment is still going to be giving you some control. Really on my stuff I couldn't find any immature. There were plenty of adults out there. But that even a imidacloprid seed treatment will really help you out. At least you know, they're early in the season. You know, I hear sometimes this my seed treatment ain't doing anything for me. Well, I'll tell you, it's doing a lot more than what you think it is. If you ever look at just untreated cotton seed, compared to some imidacloprid treated seed, it makes a massive difference. And so it's doing a lot. It might not be doing what you want it to do, but it's providing you quite a bit of, of protection against those thrips. But I said probably the, I'm going to run, I'm going to probably stick with Intrepid Edge in, most areas of the state. I know down and down in, southwest Arkansas, those guys still say acephate work for them, and I believe that they're pretty far away from kind of at the center of this op resistant, but for the vast majority of the rest of the state, I'm going to, I'm going to stick with Intrepid Edge at three ounces and make sure you have a surfactant in there. If you're not running your roundup or, Liberty or something, herbicide with a high surfactant load in there. You know, outside of that, there's really not a lot going on. I mean corn, most of this corn is kind of past the stinkbug stage. Just keep an eye out for Stinkbugs. There there is some later planted stuff that probably is still vulnerable to those stinkbugs. So just keep an eye out. You know, we have a 10%, infestation. So if 10% of your plants are infested with stink bugs, you're supposed to spray. But honestly, if I start picking up a few stink bugs, if I'm less than that threshold, I'm probably going to go ahead and hit them just because they are so dadgum hard to find out there in that corn. What else we got? Nick, I know we were talking about some caterpillars in in weeds, and you had a you had a call the other day. Kind of an interesting situation.

[07:11] Nick Bateman

Yeah, it was, it was, you know, it reminds you of what you see with armyworm. Let it get grown up in grass and those, those army worms move off that grass into beans or whatever is planted there. This actually was salt marsh caterpillar, the neighbor had stayed wet and couldn't couldn't get in there and get it burned down in a timely manner. When he did burn it down, there was a ton of salt marsh, big salt marsh, the that actually marched across the turn row just like army worms and they mowed down 2 or 3 acres of some V4 v5 beans. They eat them plumb to the ground. As far as all that leaves 100% defoliation, it was pretty impressive, but still getting some calls about, you know, seeing a bunch of trues out on turn rows or is folks are burning down some of these grassier fields and so, you know, move out of there. I think right now, if we have some grown up areas that we still plan on planting, it probably wouldn't hurt to put a sweet mat in there and treat it almost like a cover crop and see what you got out there. And maybe try to run something at burndown there to to take care of that issue before we before we plant into, it just seems like there's a lot of random caterpillars out there in a bunch of this stuff right now. And, you know, as late as of some of this is fixing to get planted. We really don't need to deal with any kind of delays there. Potential yield loss.

[08:39] Ben Thrash

Yeah, but, that that's about everything I got, Nick. 

[08:44] Nick Bateman

You were mentioning earlier about Marianna or whatever. Them blooming beans having stinkbugs in it.

[08:49] Ben Thrash

Oh, yeah. That's right. I swept some beans that got planted on, I think it was March 15th. And they're blooming right now. And I was running. I was running a couple, green stinkbug adults per 25 sweeps in those beans. Course, they're pod feeders. That's not anything to worry about out there. So if you are, if you do have any early planted beans and you're picking stinkbugs up in them, those blooming beans, they're not going to harm. They're not going to harm those beans. Typically they're just flying through, and they're probably going to go find something with some pods on them somewhere or something to actually feed on. So just kind of keep that in mind. Don't worry about stinkbugs and blooming beans. Well, that's all I got.

[09:39] Nick Bateman

That's pretty much it.

[09:41] Ben Thrash

All right, well, if you need us, call us my number (501) 517-3853.

[09:46] Nick Bateman

Mine’s 870-456-8486.

[09:51] Ben Thrash

Thank you very much.

[09:54] Intro/Outro

Arkansas Row Crops Radio is a production of the University of Arkansas System Division of Agriculture. For more information, please contact your local county extension agent or visit uaex.uada.edu.