Cotton Insect Newsletter Vol. 21, No. 2, May 28, 2003 Call 1-877-629-1474 for Cotton Insect Hotline

Cotton Situation: Cotton has been growing rather slowly as temperatures have been a bit on the cool side.  Moisture is not a problem so far this year, except where there has been too much rain.  Most cotton seedlings are now in the cotyledon to 3-leaf growth stages. Hotline: I mentioned last week that the Cotton Insect Hotline is being updated on Tuesday and Friday mornings by 9:30 AM.  Information may also be obtained via email on your personal computer from “Cotton Insect Blurbs,” which is published on Clemson University’s Cotton Listserver.   Blurbs are sent when I need to get information out in a hurry about an insect problem, or maybe I just have a bit of information that I was unable to include in the “Cotton Insect Newsletter.”  If you want to get on the Cotton Listserver, just send your name and email address to me at my email address mroof@clemson.edu.  Also, notice that the header at the top of the page includes my telephone number, my email address, my physical address, and the number to call for the Hotline.    Insect Situation: Thrips are active now in most cotton fields.  I sprayed cotton for the second time today in a thrips test that is located here at the PDREC.   Plants are in the 2-leaf stage and thrips seem to be predominately tobacco thrips.  I did see some that were probably western flower thrips, but these were much less numerous.  Western flower thrips are more difficult to control with most insecticides.  On a scale of 1-6, where 1 is no damage and 6 is a dead plant, my untreated plants rated from 4-5 and the Temik treated plants were mostly 1-2.   Gaucho and Cruiser seed treatments produced plants that were rated mostly between 2 and 4.  Thrips are still out and about.  One  cotton scout reported a heavily infested tee-shirt on May 27.  This tells me that thrips are still leaving wheat and wild host plants that have matured and are no longer suitable food sources.   Cotton that is just coming up still needs to be checked for thrips for the next couple of weeks.  If you haven't had time to go back and check seedling that have emerged to a stand, now would be a good time to do it.  For the best results with foliar sprays against thrips, applications should be made prior to seedling making it to the 2-leaf stage.  False chinch bugs may be present in some cotton fields in fairly large numbers.  They should not be doing any damage to the plants, but they just seem to be hanging out there.  The same can be said for the brown cigar-shaped click beetles that congregate in cotton.  You can find them on almost every plant in some fields.  Sometimes there are two or three per plant, but they don't feed or reproduce there.  They might grab an occasional drink from a nectary, although I have never seen one of them do so.  As you might expect false chinch bugs are primarily a problem where there is an abundance of wild host plants in fields that haven't seen a disc or a plow all spring.  They don't seem to do much damage, but there have been rare instances where there have been some small seedlings killed.  Cutworms have been causing some problems on seedling cotton.  These worms will clip off leaves or may eat through the stems thereby killing the plants.  They hide during the day in the soil around the plants.  When you see a cut plant, take a knife blade and slowly scrape the soil away and you can usually find the wily worm.  Sometimes a cutworm will cut off a leaf and then the leaf will be pulled into a hole in the ground.  The risk of infestation will be greatest in heavier soils and under reduced tillage conditions.  Lorsban, Orthene, and several pyrethroids are recommended as rescue treatments when cutworms threaten to destroy stands.  Some of these materials may be used at planting where wild host plants can not be destroyed 3 to 4 weeks ahead of planting and cutworms are known to be there.   But you had better be sure there are cutworms, because this could be a pretty darned expensive insurance program.   Publications: The “South Carolina Cotton Growers’ Guide” is now available at your County Extension Office.  The Guide contains all of the chemical recommendations under one cover, as well as information from cotton variety trials conducted in South Carolina. The cotton insect control recommendations may be obtained on the internet at http://cufan.clemson.edu/pestmgmtguide/.   My Information Card 97 “Cotton Insect Management 2003” should also be available.   Discard old recommendations, because there have been many changes in the last few years. Cotton Scouting School:  A registration fee of $10 will be charged to attend scouting school.   Please pay with a check made out to Clemson University.  If you are planning to attend, plan to arrive well before 9:00.   It does take a while for you to register, make out a check, pick up materials, take a coffee break, etc.  If more of you come between 8:00 and 8:30, then it relieves the pressure, and we can start the program promptly.  Also, you will have more time to drink coffee and chat with others who are interested in scouting cotton.    Mitchell Roof  Extension Entomologist

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