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Stink Bug Outbreak in Texas High Plains Cotton: What Can We Do Better Next Season?

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Suhas Vyavhare and Katelyn Kowles, Texas A&M AgriLife Extension Service Stink bug infestation in cotton during August-September Rotten bolls in stink bug infested field  T his season we experienced unusually high numbers of conchuela stink bugs in Texas High Plains cotton (parts of eastern Lubbock and Crosby counties in particular). Stink bug numbers peaked during August-September when plants were loaded with tender bolls that stink bugs feed on with their piercing-sucking mouthparts. Farmers who spotted stink bugs early and took timely action are now reaping the benefits. However, those who missed an insecticide application in infested fields are seeing severe stink bug damage now that bolls have opened. A few infested fields we visited last week have very little to harvest due to the extent of boll damage by stink bugs. During August-September, stink bug numbers were overwhelmingly high in spots�in some fields numbers were over 2-3 stink bugs per boll. When stink bugs feed on...

Cry1F No Longer Effective Against Western Bean Cutworm

Western bean cutworm is a serious corn pest in the northern Texas Panhandle and occurs in lower numbers as far south as Hale County. Several years ago the insect underwent a major range expansion and is now the primary corn caterpillar pest in several Midwestern states to as far east as New York and as far north as Canada. This year there have been major field failures of Cry1F in these areas, and the Land Grant entomologists have written an open letter to the transgenic seed industry to prompt them to stop claiming that Cry1F corn controls western bean cutworm. Laboratory data confirming resistance to Cry1F are in the scientific publication process. Given these new developments, we will be modifying our suggestions for Bt corn to control western bean cutworm to include primarily those that contain Vip3a in combination with other toxins. Our now outdated suggestions are in Table A20 (page 32) of Managing Insect and Mite Pests of Texas Corn , 2016. You will easily find the hybrids with ...

Is There Still Value in GM Crops?

The day after the Bayer/Monsanto agreement was announced this week, The Wall Street Journal had an article entitled " Behind the Monsanto Deal, Doubts About the GMO Revolution " (subscription required or article can be purchased). The paragraph that best summarizes the article was, "Today, farmers are finding it harder to justify the high and often rising prices for modified, or GMO, seed, given the measly returns of the current farm economy. Spending on crop seeds has nearly quadrupled since 1996, when Monsanto Co. became the first of the companies to launch biotech varieties. Yet major crop prices have skidded lower for three years, and this year, many farmers stand to lose money." The article contained a graphic that showed that since 1996, the year GM soybeans were introduced on a commercial scale, soybean seed prices have risen 305% to $60.75 per acre, but commodity prices have risen only 31% to $9.79.  It is a bit puzzling why the Wall Street Journal did not c...

Shuffling the Deck Chairs in Bt Crops

2016 has been a challenging year for our Bt crops. Cotton bollworms did an unusually high amount of damage in many fields of Bt cotton, and corn earworms (which are bollworms by another name) caused a significant amount of damage to corn crops from Texas through Kansas. Western bean cutworm caused severe damage in fields of Cry1F corn in the Midwest and Canada where once the toxin provided a reasonable level of control. Fall armyworm is known to be resistant to Cry1F corn in parts of the country. Corn rootworm is resistant to toxins that once did a good job of control. One question this fall is whether we have resistance to our Bt toxins targeted at caterpillars and, if so, how far it has spread. Field observations suggest that we do have resistance, but we will have to wait for the results of the laboratory tests on the progeny of the insects collected from the field. We don't have a magic genetic test to detect resistance, so we do things the old fashioned way by crossing field c...

Green cloverworms in alfalfa and soybeans

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If you are growing soybeans or alfalfa on the Texas High Plains it would be a good idea to scout for green cloverworms. I was in a soybean field near Ralls earlier in the week that had approximately 8 larvae per plant, and I just got a call about soybeans near Clarendon that were heavily infested. In both cases the people making the reports thought the worms were soybean loopers. It is easy to tell the two caterpillars apart because loopers have two pairs of prolegs on the abdomen while the green cloverworm has three pairs. Loopers are fairly lethargic, but green cloverworms hop around quickly when disturbed. Green cloverworm larvae near Ralls Typical defoliation in soybean caused by green cloverworm Fortunately the green cloverworm is only a leaf feeder in soybean and it does not damage pods. For alfalfa here is a quote the Oklahoma guide, "These defoliators are rarely a significant problem in established alfalfa, although seedling stands can be heavily damaged by their feeding....

Cotton on the Texas High Plains: Watch out for Bollworm Activity

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Suhas Vyavhare, Texas A&M AgriLife Extension Service Insect pressure remains light in most parts with cotton ranging from 5 nodes above white flower to hard cutout. We are seeing conchuela stink bug population reaching economic threshold in few fields in Crosby County. However, the infestation is much localized and it is unlikely that we will see economic stink bug infestations in cotton in other areas of the High Plains. I often encounter a few lygus adults and nymphs but the numbers remain well below economic threshold. At this point, one insect that is on our radar is the cotton bollworm. Although much of our cotton has cutout hard and is becoming non-attractive to worms, there are still enough suitable cotton fields out there to worry about. Earlier this week, Brad Easterling, IPM-agent in Glasscock, Reagan, and Upton counties reported above threshold levels of bollworms in Bt cotton fields near Garden City. Blayne Reed, IPM-agent in Hale, Swisher, and Floyd counties reports th...

Sugarcane aphid update and conditions for using Transform insecticide

As of this writing on Friday, August 5th, sugarcane aphids have been found over much of the Texas High Plains. Tommy Doederlein, Extension IPM Agent in Dawson and Lynn counties, raised the alarm on Monday. Today we know that fields in Floyd, Crosby, Lubbock, Hale and Hockley counties have required insecticide applications. In the northern Panhandle the aphid has been found as far north as Perryton and as far west as Bushland. We are seeing abundant winged adults, so it goes without saying that sugarcane aphids could be anywhere on the High Plains. Scouting procedures and treatment thresholds are presented in our 2016 sugarcane aphid publication . There are only two good insecticides for sugarcane aphid control; Sivanto and Transform. By "good" I mean high efficacy with little effect on beneficial insects. Sivanto has a full label and Transform can be used through its Section 18 label. This puts some additional restrictions on Transform use, although they are not onerous. Dr. ...