Northwest Plains
Pest Management News
Volume 1 Issue 3
Bailey and Parmer Counties
June 28, 2002

Current Crop Conditions

Most area cotton has shifted into a higher gear, where adequate moisture is present that is. It is ranging from four to 14 true leaves and up to eight first position squares per plant. Square set has been good to this point. Most fields are in the 90% range. Squaring cotton is using .25 inches of water per day.

Corn continues to grow so fast you can hear it. There is a wide range of growth stages, 2 feet to tasseled. The earlier planted corn is reaching peak water use. Current water demand for 14 leaf to tasseled corn is .38 to .40 inches per day.

Most grain sorghum has been planted with the exception of some double crop or second crop behind failed cotton. Some of the early planted sorghum is 18 to 24 inches tall. Water usage for the early planted sorghum is .20 to .30 inches per day depending on growth stage.

Plant Bugs

Plant bugs (lygus, fleahoppers, and stink bugs) continue to be found in area cotton. Fleahoppers are historically more abundant but that does not appear to be the case this year.

adult lygusLygus bugs are most prevalent this year. Lygus, are small, very mobile insects that migrate locally into cotton as adults from weeds or other cultivated crops such as alfalfa.
Heat Units
Current
2001
Corn (April 1st planting)
1548
1488
Cotton (April 20th planting)
699
601
Cotton (May 1st planting)
660
572
Cotton (May 15th planting)
605
521

Several cotton fields have been heavily infested after a neighboring alfalfa field was cut. These pests injure cotton by inserting their "beaks" into tender terminals and small squares and injectingsalivary enzymes that affect terminal plant growth and cause small squares to abort. Cotton plants are typically most susceptible to this damage during the first four or five weeks of squaring. Plant bugs can also persist later into the season, damaging larger squares, blooms, and young bolls. During the first week of squaring, the economic threshold is one lygus bug adult or nymph per 3 feet of row combined with less than 90 percent square set. In the second week of squaring, the economic threshold is one lygus bug adult or nymph per 3 feet of row combined with less than 85 percent square set. In the third week of squaring, the economic threshold is one lygus bug adult or nymph per 3 feet of row combined with less than 75 percent square set.

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After the third week of squaring, the economic threshold is two lygus bug adults or nymphs per 3 feet of row with less than acceptable fruit retention.

Grain Crop Pests

There is really not much happening now in grain crops, which of course makes everyone a little nervous. In corn, southwestern and European corn borers have about finished the first flight which was relatively light. Highest numbers were in close proximity to unplowed sorghum stalks. Spider mites are still present and bear close monitoring. Comite treatments look good so far. Corn earworm moths are fairly abundant. The sorghum pest situation is quiet as well. Corn leaf aphids are present but damage so far is not severe.

Beneficial of the Week

Bigeyed bugs have been found in area cotton, corn and sorghum fields. Adults and nymphs have oval bodies and broad heads. Their most distinguishing characteristic is their large, bulging eyes.They have relatively short antennae that are slightly bigeyed bugenlarged at the tip. Adults are about 3/16 of an inch long. The immatures look like small adults, but lack fully developed wings."Hot dog" shaped eggs are laid singly on leaves and stems of many crops. They are white to tan with a distinctive red spot. Nymphs and adults are general predators, feeding on small caterpillars and caterpillar eggs, fleahoppers, lygus bugs, mites, and thrips.

Boll Weevil Eradication

No boll weevils were caught north of Hwy 145, 8759 traps inspected. One boll weevil was caught south of Hwy 145, 13490 traps inspected, with 81 acres sprayed. July 15th is the day failed cotton must be destroyed and kept non hostable the rest of the season to avoid the TBWEF assessment.

Trapping
Beet Armyworm
North of Hwy 145 337 in 25traps
South of Hwy 145 20 in 25 traps
Corn Earworm 1974 in 6 traps

 

Monti Vandiver
Extension Agent-Integrated Pest Management
Texas Cooperative Extension
401 3 rd Street
Farwell, Texas
806-481-3300
Educational programs conducted by Texas Cooperative Extension serve people of all ages regardless of socioeconomic level, race, color, sex, religion, handicap or national origin. The information given herein is for educational purposes only. References to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Texas Cooperative Extension is implied.
The Texas A&M University System, U.S. Department of Agriculture, and the Commissioners Courts of Texas Cooperating
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