Cotton Insect Newsletter Vol. 22, No. 1, May 19, 2004

Cotton Situation: Growers have planted close to 75% of their cotton acreage.  Now it's probably too dry in some areas to even put seed in the ground.  We are way behind on moisture and the forecast does not look good.  Insect Situation: You may not be able to depend on getting rain when you need it, but you can depend on thrips finding your cotton plants.  However, I looked at a few cotton fields with David Gunter in Darlington County on Tuesday, and didn't see any thrips.  Cotton plants varied in growth stages from one- to four-leaf.   There didn't appear to be any thrips in the air, as my pale yellow shirt was also free of thrips.  By the time you read this newsletter, your cotton will be exposed to millions and millions of thrips.  They feed and reproduce in small grains and other hosts, and when the juice runs out they do too.  Thrips don't actually leave wheat fields with cotton on their minds, but by sheer force of numbers they can virtually blanket a field of emerging cotton plants.  I can safely say that most cotton that has been planted up to this time will have Temik in the furrow.  Usually, 3-5 lbs of granules will suffice, but under very dry conditions there may be reduced uptake of the insecticide and some plants will be damaged.  If you are planting late (after May 20), our research has shown that seed treatments will provide adequate control of thrips.  Beware that seed treatments with Gaucho or Cruiser will not control, or even suppress nematodes.  The economic threshold for thrips is one adult per plant through the four-leaf growth stage.  The adult threshold is best employed from the time plants emerge to a stand until they reach the two-leaf growth stage, the earlier the better.   Pull the seedlings from the soil and shake off the thrips within a container or on to a handkerchief to facilitate counting.  I prefer to just pull up the plants and examine the undersides of leaves or cotyledons and terminal buds.  Look closely at terminals--if adults are present, you will usually find them wedged within the folds of the first or second true leaves.  When you find one adult thrips per plant on cotton with 2 or more leaves, you will usually find a lot more nymphs.  The presence of immature thrips on most plants tells you that your insecticide has not provided sufficient control for several days. Cotton Insect Information: The 2004 cotton insecticide recommendations are available in the publication  “Cotton Insect Management,” IC-97.  If you didn't get one in the mail, go to your County Extension Office.  Discard older versions of this publication, as there have been some insecticides added and some deleted.  There have been changes in thresholds for some insect pests.  You can find it online at http://www.clemson.edu/scg/ipm/cotton.html.  Cotton Scouting Schools: A Scouting School will be held at the PDREC on June 8.  Credits for CCA’s and private-pesticide applicator certification will be presented to those in attendance.  PROGRAM 8:00 to 9:00 AM....Registration 9:00....Cotton Production: Mike Jones, Cotton Specialist, Pee Dee REC              * Growth and development of cotton plants               * Production techniques 9:30....Insects that Damage Cotton: Mitchell Roof, Entomologist, Pee Dee REC              * Growth and development of insects              * Identifying common insect pests              * Insect damage  11:00....Weeds and Herbicide Injury to Cotton: Ed Murdock, Weed Scientist, Pee Dee REC              * Identifying the most troublesome weeds              * Characteristics of seedling plants useful in identifying weeds              * Herbicide injury symptoms 11:30.... Lunch on your own  12:30....Diseases and Nematode: John Mueller, Plant Pathologist, Edisto REC              * Symptoms of common diseases and nematodes of cotton              * Seed rot              * Handling diseased plant specimens for diagnosis  1:00....Beneficial Insects and Spiders              * Identifying the common beneficials              * Protecting honey bees  1:30.....Scouting Methods: Mitchell Roof              * Techniques used to scout for insect pests              * Determining threshold levels for control of insect pests              * Equipment needs  2:15....Pesticides and Safety: Mitchell Roof 2:45-4:00....Summary and Field Training   Mitchell Roof  Extension Entomologist

This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. Brand names of pesticides are given as a convenience and are neither an endorsement nor guarantee of the product nor a suggestion that similar products are not effective. Use pesticides only according to the directions on the label. Follow all directions, precautions and restrictions that are listed. The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer.  Clemson University Cooperating with U.S. Department of Agriculture and South Carolina Counties.  Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914.  Public Service Activities