Cotton Insect Newsletter Vol. 21, No. 4, June 11, 2003 Call 1-877-629-1474 for Cotton Insect Hotline

Cotton Situation: Temperatures are warming and cotton is beginning to grow.  Most areas of the state seem to be in good shape for moisture.  Only time will tell if this is going to be a bountiful harvest, but stands are the best I have seen in 21 years (at least in the Pee Dee area).  Let's not let pests stand in the way of making a crop this year.  We still have to manage our insect, weed and disease problems.  In fact, it's safe to say that you will get more bang for your pest management buck in a good crop year.   It looks like better than 90% of the cotton has been planted.  The earliest cotton that I saw on Monday was in Marlboro County.  Plants had up to nine leaves and pinhead squares were present on the 8th nodes.  In Sumter and Lee Counties, there were a fairly large number of fields on June 10 with plants from cotyledon to 2-leaf growth stages.       Insect Situation:  It's time to close the door and turn out the lights on thrips.  In my travels this week, I have seen no evidence that thrips are still causing problems in cotton.  There were a few fields with old damaged leaves, but all the new growth was clean and free of thrips.  The smallest seedlings were not attracting any attention either.  I know some growers are still tank mixing an insecticide for thrips with their herbicide.  That was fine two or three weeks ago, but now it could actually cause you some problems with other insects when beneficials are knocked down.  I know it's a cheap application, but why spend the money if you don't have to.  Thrips could reappear later in the season.  Western flower thrips often accumulate in large numbers in white blooms.  These flower feeders may ultimately cause some damage to small bolls, but researchers have been unable to determine what constitutes an economic threshold.  To my knowledge, insecticide treatments to control thrips in flowers have never proven to be of economic value. Cutworms problems are still possible.  I saw several fields yesterday with small seedlings where there was still an abundance of weeds that were alive and well.  These are the kind of fields where cutworms may have already been present at planting time.  Scouts should be looking for cut plants and leaves that have been clipped.  Consider an insecticide treatment only when it appears that stands are in danger of being reduced to undesirable levels.  In most cases, cutworms will not be distributed equally over a field, and spot treatments may do the job.   I did not see an armyworm yesterday, but I would imagine that a scout will be able to find a few yellow striped armyworms in most fields.  These worms are easily recognized by their black velvet coats with prominent yellow stripes on the sides.   Though seldom economic pests, they may be sprayed occasionally by someone who doesn't take the time to properly identify them.  They tend to be loners, unlike the beet armyworms that tend to congregate.  We often see early infestations of beets at this time of year or even earlier.  Last year, a field near Mayesville was sprayed in late May or early June for this pest.  It's likely that cooler temperatures last winter prevented beets from overwintering in or around South Carolina.  If that assumption is true, it will be late July before we start seeing very many.  Grasshoppers are going to be a problem in some areas of the state.  These insects hatch from eggs that were laid in the soil the previous year.  We know that it's possible for them to just keep hatching out through June and early July.  If you see large numbers of hoppers in fence rows and along field borders, it might be wise to spray them before they get a chance to hop on the cotton plants.  Lorsban and the pyrethroids are recommended for control.  Apply the rates as instructed by the labels.  It's always a good idea to read the labels even when someone else tells you what rate to use.  Some of us are getting older and we might even get confused about rates.   Beneficials are rapidly moving into fields inhabited by older cotton plants (6 or more true leaves).  Big eyed bugs are probably the best of the early colonizers.  These insects have a wide head with bulging eyes and piercing sucking mouth parts.  They are true bugs with the same type of mouthparts that you will see on a plant bug or a stink bug.  In fact, they have even been mistaken for pests in situations where you can find one on about every plant. Please don't make that mistake.  These guys are great predators.  Big eyed buys are just a little over an 1/8 of an inch long, but they are probably one of the principal control agents for early infestations of yellow striped armyworms, beet armyworms and bollworms (also budworms in conventional cotton).  You can find these good predators throughout the year in cotton.  If you don't know how to identify them, call on your County Agent or look in the “Cotton Scouting Manual.” Lady beetles, damsel bugs, fire ants, and spiders are some of the other predators that should be showing up in cotton fields.  Boll Weevil Containment:  Trap installation is underway.  Permanent employees started the process on June 5 and they will finish by July 9.  Don't expect to see as many traps this year as they are going from one trap/10 acres to one trap/20 acres.  There will still be a minimum of two traps per field.      Mitchell Roof  Extension Entomologist

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