IN THIS ISSUE

· Upper Coast IPM Program Sponsors
· TPMA Website
· Cotton Insect Situation
· Boll Weevil Trap Counts
· Evaluation of At-Planting Systemic Insecticides on Grain Sorghum
· Did You Know

Upper Coast IPM Program Sponsors

The Upper Coast IPM Program would like to recognize and express our sincere appreciation to the following gins that have provided financial support for our cotton-monitoring program for the past five seasons. Without their support, we would not have been able to monitor the cotton fields in the Tri-County area. The monitoring program is how we have been able to provide you with information that has been included in this newsletter pertaining to crop conditions and the insect situation as well. The monitoring program has been a valuable tool in helping identify key or important areas of applied research as well.

TPMA Website

This newsletter as well as other Extension IPM newsletters from across the state can be viewed at the Texas Pest Management Association website at www.tpma.org.

These newsletters are a cooperative effort of the Texas Pest Management Association, Texas Cooperative Extension, and the Texas A&M University Department of Entomology.

Cotton Insect Situation

Growth stages of cotton in the Tri-County area of Wharton, Matagorda, and Jackson Counties range from the cotyledon to the first square stage.

Thrips numbers have been low in cotton fields that were monitored during the past two weeks. However, foliar insecticide applications were made during the past week in fields that did have a soil or seed applied systemic insecticide with the seed at planting. Thrips are slender, and range in color from dark brown to a light straw color. Insects are about 1/15 inch long, with piercing-sucking mouthparts. Adults are winged. Thrips attack leaves, leaf buds and very small squares, and may cause silvering of the lower leaf surface, deformed or blackened leaves, terminal loss and square loss. Thrips often infest the folded small leaves of the plant terminal and are difficult to count unless the terminal area is dissected or pulled apart. Control may be justified when the average number of thrips counted per plant is equal to the number of true leaves present at time of inspection. Generally, insecticidal control is rarely justified once plants reach the five to six true-leaf stages or when the plants begin to square.

Aphid numbers have been low during the past two weeks throughout the Tri-County Area. Aphid numbers appeared to be significantly increasing in one field that was planted around the 15th of March and was at the first square stage.

Fleahopper counts have been extremely low so far. Fleahopper counts have ranged from 0 to 2 % in cotton that has begun to square.

Spider mites, loopers and yellow striped armyworms were found in low numbers in a small percentage of cotton fields that were monitored.

Boll Weevil Trap Counts

Below are the 2002 boll weevil trap counts for the months of March and April compared to the three previous years. Traps are located on farm to market highway 1162, county roads 442, 422, 409, 426 and farm to market highway 441 between El Campo and Hillje. Boll weevil numbers for March and April of this year appear to be slightly lower than 2001 and not even close to the high numbers we experienced in 2000.

Table 1. Number of boll weevils captured per pheromone trap per month, thirty-two mile trap line, 1999-2002, Wharton County, Texas. Texas Cooperative Extension operated traps.

Evaluation of At-Planting Systemic Insecticides
on Grain Sorghum

An at-planting systemic insecticide test was planted on March 9th in the Friendly Corner area of Wharton County with Duane Lutringer. Counter 20CR, Cruiser 5FS and Gaucho 480FS were compared to the untreated check. Each treatment was replicated three times in a randomized complete block design. Plots were 8 rows (40-inch centers) by 870 feet or .53 acres in size. Dekalb 54 was planted at a seeding rate of approximately 93,750 an acre.

Plant population counts, visual ratings, chinch bug, yellow sugarcane aphid, corn leaf aphid, and greenbug counts have been determined and have been compared among the treatments (for results see enclosure included with newsletter). Yield results will be determined at harvest.

Did You Know

Through carbon dating, archeologist found the boll weevil was present in the Zapotec Nation south of Mexico City in 900 AD.

Table 1. Evaluation of At-Planting Systemic Insecticides on Grain Sorghum, Duane Lutringer, Wharton County, Texas. 2002

Means in a column followed by the same letter are not significantly different by ANOVA.

1. Plant damage ratings range from 1 = no damage to 5 = severe stunting, yellowing and thin plant stand.
2. Ratings were determined 26 days after planting.
3. Ratings were determined 44 days after planting.