Pest Management Newsletter Heading
Dale A. Mott, EA-IPM
3151 S.E. Inner Loop, Suite A
Georgetown, TX 78626
Phone: 512/930-4400
E-Mail: d-mott@tamu.edu
IPM Logo VOL XXI NO. 12
July 20, 2001
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GENERAL SITUATION

Hot and dry conditions continue to persist across the area and there does not appear to be any change in site. Grain harvest is just getting underway with a few producers cutting some corn or grain sorghum. Grain harvest will pickup quickly as many growers are preparing to start harvest sometime next week. In cotton, a few open bolls are being found in fields south and east of Taylor. However, it will still be another week to 10 days before the majority of the cotton begins to reach cracked boll.

SORGHUM INSECT PESTS

Because of the lateness in the grain, there is very little potential for further damage from insects. Grasshoppers are about the only pest that growers need to monitor. Grasshopper pressure has dropped off considerably over the past couple of weeks and I do not see much potential for any more significant damage. Most of them are mature. The females have fully developed eggs and therefore only need to eat enough to stay alive. They are no longer in a growing mode where they eat everything in site.

COTTON

Cotton ranges from one week into bloom and nodes above white bloom at 5 to open bolls. Most fields are at the stage where they are dropping all young bolls and squares. There are still some fields that were either planted late or have adequate moisture that are still holding on to small bolls.

The major insects that are being found in fields are boll weevils and worms. Boll weevils punctured squares/small bolls are ranging from 0 to 10 per 100 checked. Boll weevil activity has picked up for the second week in a row. Many fields are running 2% to 4% punctured squares. Some isolated spraying is taking place where weevil infestations are isolated into one area of the field. Most cotton has between 1-2 more weeks to go before it will be past potential danger from weevils and worms.

Bollworm/budworm levels are ranging from 2-26 per 100 plants checked. Most fields are ranging from 4-10 worms per 100 plants checked. Several fields have been treated for worms within the past 10 days. As the crop progresses and as more of the fruit is anticipated to shed, we are raising our thresholds for number of worms to justify a treatment. Treatment thresholds are affected by crop potential, size of worms present, and crop stage.

Worm egg numbers are ranging from 2 to 22 per 100 plants checked. The hot weather and beneficial insects are helping to reduce the number of eggs that hatch out. However, there is still the potential to run into treatable levels of worms. Because of the difficulty with setting a good bottom crop, most of the cotton is trying to mature out a top crop. These bolls are still young and tender and will be susceptible to worm damage for another one to two weeks.

BOLL WEEVIL ERADICATION

The following data is from information provided by the Southern Blacklands Boll Weevil Eradication Foundation. They have had all of their traps up for over two weeks now.

Date

Unit

Location

# of traps monitored

# of weevils/trap/week

July 2 - 8

3

N of 79 Williamson

60

0.55

July 9 -15

3

N of 79 Williamson

135

0.9

July 2 - 8

8

S. of 79 Williamson

/Travis Co.

173

.14

July 9 -15

8

S. of 79 Williamson

/Travis Co.

223

24

July 2 - 8

4

BuckholtsCameron/

Calvert

100

.39

July 9 -15

4

BuckholtsCameron/

Calvert

209

2.20

July 2- 8

9

Lockhart

138

.20

July 9-15

9

Lockhart

165

.06

Overall

July 2 - 8

471

.26

July 9 -15

732

.87

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The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension service implied.

We will seek to provide reasonable accommodations for all persons with disabilities who wish to attend meetings, seminars, or training. We request that you contact the Williamson County Extension Office at (512) 930-4400 as soon as possible to advise us of the auxiliary aid or service that you will require.