Entomology Update 5-5-25: Rice Water Weevils, Stink Bugs in Corn

Extension entomologists Nick Bateman and Ben Thrash discuss rice water weevils, upcoming thrips pressure potential in cotton, stink bugs in early corn and more.

Transcript

[00:00] Intro/Outro

Arkansas Row Crops Radio, providing up to date information and timely recommendations on row crop production in Arkansas.

[00:12] Ben Thrash

Hey everybody, today is May 5th and here's me and Nick. I guess today's our first pest patrol for the year, Nick.

[00:21] Nick Bateman

Yeah. It is. And there's not a lot going on, but a few things.

[00:25] Ben Thrash

Yeah, there's a few things we need to be paying attention to. What, what you got for rice?

[00:30] Nick Bateman

There’s not really much to talk about. Really all I want to hit on is, some of this early planted rice. That'll be going to flood sometime in the next, you know, five, ten, 14 days. Somewhere in there. Especially a lot of it that got so much rain up in the areas of northeast Arkansas, whatnot. I think we need to be a little concerned on what our Cruiser or Nipsit or whatever, I mean, if we have a neonic on their own on what to really expect out of it, you know, besides it already probably being planted 30 plus days at this point. You know, them things are highly water soluble. And with the sheer amount of rain we've got, I would expect to see almost a little bit more reduced efficacy than, than what we normally would, just from a lack of residual standpoint at that window. So, I guess what I'm getting at is, is I would be looking at them fields pretty hard when we go to flood. And if I'm seeing a bunch of adults out there, I think I would go ahead and try to run some lambda. I know no one's going to want to spend the money for the airplane for that, but, you know, weevils are one of them that can be the difference between cutting 185 and 200 bushels pretty quick. So, it really that's about all I got. I know we were going to hit on some, some armyworm type stuff. And we, I guess we need to be on the lookout there, you know, with, we have a few of them trues that are just out there and some of these cover crops and just grassy areas right now need to keep an eye out. But but haven't had any calls on that as far as in rice.

[02:08] Ben Thrash

Yeah I hadn’t had any calls on it either, Nick. Really not I guess I we had that one call on on caterpillars, but that was just on some seed seedling beans and we weren't even sure what they were.

[02:21] Nick Bateman

And yeah.

[02:24] Ben Thrash

You know, I'm never got a there were tiny so I never I couldn't really tell what they were in picture. But anyway.

[02:31] Nick Bateman

Yeah. And I haven't really had calls on all these true that are out there actually being in crops, it seems like they're just kind of hanging out. You know, some of it's been cover crop, some has just been sort of some grown up areas around the fields I haven't seen really march over into anything. So I mean, it might be a non-issue.

[02:50] Ben Thrash

Yeah. Well, it sounds like we haven't got much cotton in the ground as of yet. But, you know, I, I wrote an article a little bit earlier this year, about a month ago or so about, you know, thrips pressure wasn't supposed to be that bad this year. And then I got an email a couple weeks after that saying that the the code was corrupted on the NC state website, and there it was, pulling weather data, from somewhere else. And so they found they got that fixed and I reran it again. And then of course, it said pressure is going to be bad in North Arkansas. And even, you know, kind of central Arkansas around Mariana, central, east Arkansas, in the Delta is going to be fairly heavy. But then in South Arkansas, it was going to be kind of a light. But, you know, just as we're getting that cotton in the ground right now, if it if it stays cool, if you got cotton in the ground, it's not going to be growing very good. You're going to be needing to pay attention to those thrips. And, you know, just pray for pray for some warmer temperatures. Hopefully that stuff will warm up and that cotton will get to growing. And and we're kind of in the same situation on some of this corn. We you know, that corn in these cooler temperatures is just kind of hanging out and it's letting stinkbugs, have a longer time to feed on it in that vulnerable stage. Right now, I know, Nick, you've got some calls on on stinkbugs in corn. And so if I'm.

[04:28] Nick Bateman

Yeah. Yeah. And I mean, it's some fields have been tagged pretty hard, but other ones. And I know you brought this up before we started. Before we started recording, but, you know, part of we're just seeing some stinkbugs in the field and want to know what they should do. Yeah. And you looked that threshold up earlier. You want to talk about it?

[04:50] Ben Thrash

So, Yeah. The threshold, you know, it's 10%, infested plants until they're two feet tall. So that's what you really need to be focusing on right now. But honestly, you know, if I start seeing stinkbugs out in a corn field, I'm probably going to treat them. They're so hard to scout for. You know, sometimes we think they're just they're moving into the field at night time, and then during the daytime, they can’t, they're crawling under something, or they're moving out of the field and you're just not able to find them. They're they're extremely difficult to find in corn fields. So if I'm seeing many stinkbugs at all in a corn field, I'm probably going to go ahead and treat them. And typically it's browns that we're seeing. And so I'm probably going to run, 6 to 6.4 ounces of bifenthrin. So a gallon to 20, gallon to 2 bifenthrin on them. You know bifenthrin’s a lot better on those brown stinkbugs, than something like lambda than the other pyrethroidsare. So I just kind of keep that in mind.

[06:03] Nick Bateman

I think another thing to think about there, too, is some of these fields that we’re coming back and seeing the injury, you know, in a lot of cases, I feel like we get into a revenge spray a situation there. You know, I mean, it takes it takes seven, ten days after the stink bug feeds on it for that injury to really manifest itself. Yeah. So, I mean, in a lot of cases, if you're seeing the injury, you probably missed the window to make an application.

[06:30] Ben Thrash

Yeah, yeah. And you hear about guys, you know, they're like, well, I saw, you know, a couple of stink bugs out there. So I went ahead and sprayed and when I came back the next day. They're full of stink bugs. Yeah. So I don't be necessarily want to be an alarmist, but they're just a hard pest to scout for. There's no real good way to do it. Just look as hard as you can. Look under brace roots. Look under trash. Look in the whorl. Look, kind of all over the place for, But I don't know what else we got, Nick? Anything?

[07:11] Nick Bateman

Man. Along the lines of stink bugs. I've had a few text and calls over the past, I'd say ten days on both oats and wheat on rice stink bugs. And seeing some pretty, pretty healthy numbers out there. We didn't get a lot of data on it, but, you know, a few years ago, we've had a pretty good, pretty good population in some wheat up here at Pine Tree. I if I remember right, we were running 45 to 50 in our untreated. And we, we sprayed one and two times and basically took yield on it. And, and we didn't see a yield difference. Now keep in mind that was a one off trial a few years ago. But man, when you start figuring, start start doing the math like we did a few years ago on our current threshold versus what it would be in a sweep net. I mean, we were coming up with what was it like 75 or 100 in a sweep net?

[08:06] Ben Thrash

Something outrageous, something that you just pretty much aren't going to see.

[08:11] Nick Bateman

Yeah. So I mean, they're they're out there, but that seed's not near as vulnerable as like a rice seed is to that to that feeding. So I just it's it's not something we’re too much worried about

[08:25] Ben Thrash

Yeah. But I don't know. That's all I got. You got anything else?

[08:31] Nick Bateman

No, I think that pretty well covers it. It's a few things going on, but not much.

[08:37] Ben Thrash

Well, if you need us, call us. My number is (501) 517-3853.

[08:43] Nick Bateman

Mine's (870) 456-8486.

[08:48] Ben Thrash

Thank you very much.

[08:50] 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