Cotton Insect Newsletter Vol. 20, No. 6, June 26, 2002 Call 1-877-629-1474 for Cotton Insect Hotline

Cotton Situation: South Carolina cotton fields are finally getting some rain.  We were bone dry here at the Pee Dee Research and Education Center until Monday after lunch, when we received our first substantial rainfall of the current weather system.  After a couple more showers, cotton fields are now too wet to run a tractor through.  In fact, I almost got stuck this morning just trying to drive down an in-field road to look at some plots (I should have bought the 4-wheel drive).  Setting squares will be important in a crop that is already delayed from drought.  There is still plenty of time for the crop to catch up, however.  You may remember in some research conducted in the early 1990's, Mann and Turnipseed removed up to 100% of the squares for 4 straight weeks to simulate severe insect damage?  They looked at different varieties, planting dates, and dryland vs. irrigated cotton.  In most instances the injured plants recovered and produced as good a crop as the plants that were protected and had no squares removed.  In the few instances where plants did not recover, they were planted very late.  This study really served to highlight the compensatory ability of the cotton plant.   Insect Control Recommendations: Everyone should have received the 2002 revision of the “Cotton Insect Management” (IC-97), which is printed on yellow paper (the color is changed each year; last year it was green).  This publication was sent out through County Extension offices directly to the growers.  The latest insecticide recommendations and economic thresholds are presented in this publication.  There is currently a problem with the web version of the “2002 Pest Management Handbook.”  When it was last updated, an older version of the recommendations was somehow inserted, so you won't get the latest recommendations by accessing the internet Handbook until this problem has been corrected.  Please make sure that you have the 2002 insect control recommendations, because there have been a substantial number of changes. Insect Situation: We are still catching quite a few budworm and bollworm moths this week.  Numbers were somewhat higher than the previous week at some locations.  Scouts were finding fewer eggs this week in this area, but they were seeing more small worms in terminals and squares.  In fact, conventional cotton was infested in numbers that would require spraying if we could get the Hi-Boy in the field.   We are seeing quite a few beet armyworms in some fields at the experiment station, while in many other fields you don't see any damage.  BAW moths counts are still relatively high at some locations.  A few fall armyworm moths are being captured in traps, but the numbers have been in single digits, as you would expect for this time of year.  Sucking insect pests have been few in numbers.  Aphids are just beginning to show up on a few plants.  Most of the aphids that I have seen were in fields where conservation tillage practices were used.  If you will notice, fire ants may be involved in some of these early infestations as they “tend the flock.”  They will move the aphids around to different cotton plants and provide protection from predators in return for the honeydew that the aphids will provide to them.  Fire ants are excellent predators and they will often do a good job of protecting cotton from pests such as bollworms and beet armyworms.  They attack both the eggs and small larvae.  You could say that fire ants are pest management specialists and livestock producers.  I haven't found anything beneficial about being stung by fire ants, but perhaps researchers will one day find that the toxin they inject has some therapeutic effect.   For example, the venom from honeybee stings has been found to relieve the symptoms of arthritis.   Perhaps the stings from honeybees could grow hair on a bald head or cure the common cold, or prevent allergies, .....naah. Tarnished plant bugs have been noticeably absent up to now.  I think my scouts have reported seeing one lygus bug so far on the station.  Occasionally I see a field where plants do have a problem holding on to their squares because of plant bugs, but this has been a relatively rare event.  As I said previously, research in South Carolina has shown that cotton plants are able to compensate well for the loss of squares, unless it happens in fields that were planted very late in the season.  I have seen a few stink bugs in squaring cotton, so I know there should be some movement on to plants that are setting bolls.  Boll Weevil Program: Randy Lynch said that pheromone traps are going up now and they should all be up by July 10.   Supervisors will be using bar-code scanners to facilitate trap-checking on about 80,000 acres this year.  On these traps, they will not record dates on the yellow cups.   If you look inside the cup there will be a bar-code decal.  If you want to know when it was last checked, the date will be recorded on the pheromone lure.   This system has been used elsewhere with great success and will even cut costs.  If you decide to look at a lure, make sure that you don't let a boll weevil escape.  There is always a chance (though slim) of catching a boll weevil and you wouldn't want to let it go. Trappers are having trouble servicing some traps this year.  Many fields were planted wall-to-wall and they have no access roads to get to the traps.   They must have access to the traps, and they don't want to run over cotton plants.  Farmers, please work with them to provide access.  This is your program and efficient, cost-effective trapping requires vehicular access.     Mitchell Roof  Extension Entomologist

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