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Showing posts from July, 2018

What's Up With All the Earworms in Bt Corn?

This is a jointly issued article from Extension Entomologists Drs. Pat Porter (Lubbock) and Ed Bynum (Amarillo). There are large numbers of corn earworm larvae in Bt corn ears in the Texas Panhandle, and some people are spraying in an attempt to control them.  The first question we are getting is what to spray, but the better question would be whether to spray.  Corn earworm is usually an ear tip feeder, and on its own is seldom an economic pest of corn. However, this year we are seeing earworms doing more than just tip damage, and feeding lower in the ear. The reason(s) for this change in behavior are unknown.  We have not forgotten last year though, when there was good evidence that just a little ear tip damage resulted in higher fumonisin levels. This could happen again this year, especially if the weather in August and September turns off wet and relatively cool. However, based on what we saw last year, the little bit of tip damage needed to promote fumonisin has alre...

Bollworm situation: West Texas cotton

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I am glad folks are paying attention to what is happening in other areas. I had a few calls regarding bollworms this week--mostly in response to the hubbub in Central and South Texas. So far, worm pressure in cotton have remained light for the most part with some areas (e.g. parts of Swisher, Floyd, and Hale counties) just starting to show increase in numbers. Our Bt sentinel research plots at Texas A&M AgriLife Research and Extension center in Lubbock are showing a few worms in non-Bt plots�no activity has been spotted in any of the Bt technology plots so far. As the season progresses, we may see increase in moth flights and the egg lay. I wouldn�t spray for bollworm egg lay in West Texas cotton as very few eggs make it to worms (thanks to beneficials!). Treatment decisions should be made based on the amount of fruit injury and the presence of live worms in both Bt or non-Bt fields. Since newly hatched larvae must feed on the plant for the Bt toxin to be effective, delay decision ...

Sugarcane Aphid Arrives on the Texas Southern High Plains

Kerry Siders, EA-IPM in Hockley, Cochran and Lamb counties, just reported that Danny Quisenberry, a crop consultant, found sugarcane aphids on older grain sorghum four miles north of Earth in northern Lamb County. Additionally, Greg Cronholm, a private crop consultant, just reported sugarcane aphids on sorghum in southern Castro County. Neither of these populations is at a treatable level, just small colonies on isolated plants at present. If this year's infestation pattern follows those of 2014-2017, then it is likely the aphids are already present in Hale, Floyd and Lubbock counties, although we have had no reports of this as yet.