Jeff Whitworth Sorghum Bugs


(Conrad) Good morning and welcome to Farm Factor on AGam in Kansas. I’m your host Conrad Kabus. Pests are always a tricky problem for producers because of the cost, education and supply it takes to eradicate them from an operation. That’s why a series of sorghum production schools were offered in early February of 2015 to provide in-depth training targeted for sorghum producers, including ones that are having problems with pests in their crops. The schools were held at a variety of locations and the one AGam in Kansas attended was in Hutchinson and this one was sponsored by several entities with an interest in the sorghum industry. Take a look. (Jeff) I’m Jeff Whitworth. I’m an Extension Specialist in Entomology. We were in Hutchinson, Kansas, today at the sorghum school, our annual sorghum school. Today I was talking about insects that affect sorghum. Probably our most consistent number one pest all across the state as far as sorghum goes and maybe a little bit in corn also, is the chinch bug. The true chinch bug is sometimes mistaken for a false chinch bug. But there’s considerable differences especially in the amount of damage they can do. False chinch bug doesn’t really do damage. A true chinch bug really can. The true chinch bug actually is right now overwintering in bunch grasses or in residue out in some of the fields that have heavy residue. The winter’s don’t get too bad, we’ve found that the chinch bugs have been able to survive winters just in residue. Otherwise they’re around the root systems in bunch grasses, the little blue stems, etc. And probably whenever the wheat starts to break down dormancy, the chinch bugs, the adults will move out of the bunch grass and the residue or where ever they are overwintering and they will move into the wheat. They will start feeding in the wheat. Like I said once the wheat breaks dormancy, they’ll start feeding in the wheat, probably for two to three weeks. Then they’ll start mating and they’ll start laying eggs. Then the eggs will hatch and have little nymphs are red, they’ll start feeding in the wheat also. Then they start moving out of the wheat as the wheat starts to turn yellow. It starts losing its juice in other words. So, it’s not on a suitable host for the chinch bug. And as that starts to happen they start moving out of the wheat, moving into the sorghum or corn whichever the adjacent crop is. And they can do a real number on seedling sorghum and/or corn plants, especially in dry conditions. If the moisture is lacking the plants are struggling anyway because of moisture stress, they have thousands, literally hundreds and thousands of little plant sucking chinch bugs on them, they can do a number on these plants very quickly. (Conrad) The chinch bug, a native of the United States is common to Midwest states and has a great effect on producers. The chinch bug naturally feeds on wild prairie grass, but when the Midwestern states were settled in the 19th century, crops of wheat, corn, sorghum and other grains were planted and they adapted well to these new species as habitat and food. Throughout the 20th century the chinch bug was a major pest to farmers as they quickly decimated corn and wheat fields. (Jeff) What we normally recommend as that wheat starts to turn yellow, get out and sample the wheat. If you find one chinch bug in one square foot in your wheat field, then delay planting your sorghum or your corn if you are going to plant adjacent to that wheat field. So, just delay two to three weeks and you shouldn’t have a problem because the chinch bugs when they’re nymphs they have to feed within seven to ten days or else they just die. So, if there’s no plants there for them to eat, they’ll just naturally go away and then you can plant your sorghum or your corn and you won’t have a problem with chinch bugs.

(Conrad) Good morning and welcome to Farm Factor on AGam in Kansas. I’m your host, Conrad Kabus. There are a variety of insects that producers tackle on a daily basis and pests are always a tricky problem for producers because of the cost, education and supply it takes to eradicate them from the operation. That’s why a series of sorghum production schools were offered in early February of 2015 to provide in-depth training targeted for sorghum producers, including ones that are having problems with pest in their crops. The schools were held at a variety of locations and the one AGam in Kansas attended was in Hutchinson. And this one was sponsored by several entities with an interest in the sorghum industry. Take a look. (Jeff) Also there’s some other aphids that can affect sorghum. One is the green bug. Green bugs used to be our primary sorghum best in the 70’s and 80’s, early 90s. Everybody was worried about green bugs. There was all kinds of plant breeding going on to develop resistance to the green bug and we do have five different bio types of green bugs. And we do have resistance to those green bugs. But primarily we don’t have green bugs to worry about anymore. So, most of the growers don’t worry about resistant varieties as far as green bugs. Last year in 2014, we had our first official case of the white sugar cane aphid, or the sorghum aphid, whichever you prefer. It’s the same insect. It’s normally been in Louisiana and the Gulf Coast states. It’s moved from Louisiana, Mississippi, Georgia. It’s moved up to Oklahoma, Texas, Kansas. And last year in August we found it in Sumner County in one field I believe in Sumner County. So, that was our first official detection of the sorghum aphid in Kansas. This aphid can be devastating. And it depends on when it comes in. We don’t really think it’s gonna overwinter in Kansas. We’re not sure where it’s going to overwinter in Oklahoma or not, but you know, it just depends on how fast it migrates south… or I mean how fast it migrates north once the growing season starts as to whether it’s actually going to cause a problem in sorghum producing… in sorghum producing fields in Kansas. It can reproduce quite rapidly as all aphids can because they do not mate; they do not have to wait for eggs to hatch. They’re just all females. They produce females. Three to five days later those females are feeding and they’re reproducing more females so those populations can explode very, very quickly. Whether it’s a green bug or the sorghum aphid, either one, those populations can just go bananas on you very quickly. Especially anymore we’re spraying a lot of alfalfa fields. We’re spraying a lot of wheat fields, so we’re killing a lot of the beneficial insects that help hold some of these aphids in check. So, if we do get the sorghum aphid early on, it could be a problem. There’s no way to tell, but one of the nice things is there is some resistance available in some commercial varieties if we do start having consistent problems with the sorghum aphid, there’s like I said, some varieties that have some resistance so it shouldn’t be a problem early on. There are some insecticides that are just being registered. Special local need insecticides to spray later in the year as a foliar spray which do a pretty good job of controlling the aphids. So, I think if we do have it and if it does become a problem we have some of the management tactics that we can use to help overcome the problem. (Conrad) Be sure to discuss any problems that you have on your operation with local extension agents if you’re unsure what to do. Thanks for watching. We’ll have more after the break.

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