IN THIS ISSUE

· TPMA Website
· Upper Coast IPM Program Sponsors
· Cotton Insect Situation
· Stink Bugs in Soybeans
· Texas A&M IMPACT Center Field Day
· Did You Know

TPMA Website

The Upper Coast Crop Improvement newsletter and other Extension IPM Program newsletters from across the state can be viewed at the Texas Pest Management Association website at www.tpma.org.

Upper Coast IPM Program Sponsors

Cotton Insect Situation

Growth stages of cotton in the Tri-County area of Wharton, Jackson and Matagorda Counties range from one-third grown square through the second week of bloom. Scattered fields or areas of the Upper Coast Region that did not receive adequate rainfall throughout the spring season have reached cutout (NAWF=5).

Aphid numbers were light after the last two weeks invasion of parasitic wasps and other beneficial insects. Fleahopper numbers in fields ranged from 4 to 28% or an average of 16% for all the pre-blooming cotton fields monitored during the past week. Boll Weevil punctured squares were found in 27% of the fields that were monitored.

Boll weevil punctured square counts ranged from 0 to 4%. High numbers of boll weevil damage in some fields around the Danevang area was reported by consultants during the past week. Boll weevil trap counts during the entire season have been higher in this area compared to the rest of the traps along the 32-mile trap line. Boll worm eggs were found in 33% of the fields during the past week. Egg counts ranged from 0 to 7%. Boll worm larvae were found in 43% of the fields. Larvae counts ranged from 0 to 12%. Boll worm damaged squares were found in 40% of the fields. Damaged square counts ranged from 0 to 5%. During the past week, boll worm pressure was definitely the heaviest in Jackson and Matagorda Counties. One consultant reported that bollworm numbers were increasing in the Danevang area by the end of last week. Brown Stink bugs were in low numbers in 23% of the fields that monitored during the past week. Other pests, that were found in low numbers and in low numbers of fields included grasshoppers and saltmarsh caterpillars. One consultant reported that he found high numbers of creontiades in fields located near the Bay City area.

Stink Bugs In Soybeans

Stink bug numbers will need to be monitored in soybeans as the month of June progresses along. The most common species that infest soybeans in the Upper Coast include the Southern Green stink bug and the Brown Stink bug. Two other species that can be found as well include the red shouldered stink bug and a small brown looking stink bug that does not have a common name but goes by its scientific name of Euschistus quadrator. Stink bugs damage soybeans after pods start forming. They insert their beaks in the pod and suck out the contents of the bean inside the pod. Feeding while the beans are in the milk stage results in a complete loss of the beans. Stink bug feeding on beans in the dough stage causes a sunken area or a chalky-white spot on the beans. They overwinter as adults and feed on several other crops during spring and early summer. They invade soybean fields when pods start to form, starting on the margins of fields. Early infestations will be highest on field margins. Spot spraying field margins for them will often eliminate the need to spray the entire field for stink bugs later.

Research has shown that stink bug damage during the R3 to R5 growth stages can result in delayed maturity, commonly referred to the grean bean effect. Accurate sampling methods such as the sweep net or beat sheet method are required to estimate average field populations. From pod formation to bean maturity, insecticide applications should be applied when there is at least one stink bug per row foot, or 36 in 100 sweeps. Stink bugs should be ¼ inch or larger.

Texas A&M IMPACT Center Field Day

The IMPACT Center Field Day will be held on June 11, featuring the latest in corn hybrid research, conservation tillage systems and other techniques that can be applied to current operations.

The event is free, with registration beginning at 9 a.m. at the Texas A&M University farm service headquarters, located outside of College Station just one mile west of the Brazos River on F.M. 60.

The field tour will showcase research and field work pertaining to corn hybrid research, conservation tillage systems, managing volunteers in transgenic crops and on the cotton fleahopper trapping program.

During the lunch hour, presentations will be given on Texas Corn Board activities, precision agriculture, phosphorous fertility, and an overview of the Texas A&M University corn breeding program.

For more information about the field day, contact the Brazos County Extension office at 979-823-0129.

Did You Know

From the beginning, scientists noted that both the boll weevil and its host plant thrived in moist, warm weather. From 1888-1894, just as the boll weevil was establishing itself in South Texas, the weather was unusually wet. This was followed by another rainy interval between 1899 and 1900. Then, beginning in 1901, the weather turned unusually dry, which helped thwart the weevil's spread to the east and north, but may have also given cotton growers in other states a false sense of security. In fact, L. O. Howard expressed the desire of many growers across the South when he wrote, "It is now hoped that the early fears as to the possible spread of the species thoughout the entire Cotton Belt of the United States will not be realized. It is also hoped that a tolerably efficient remedy for the prevention of the spread of the insect in South Texas has already been ascertained."

As it turned out, some unique local weather patterns in central Texas gave the weevils a decided advantage in 1898. Although the overall conditions for that year were dry, a thin wedge of country that enjoyed damp morning fogs and frequent summer showers lay directly in the boll weevil's path. The infestation, which had been stopped in Gonzales, Lavaca, and Dewitt Counties, now spread north into Brazos, Bastrop, Lee and Burleson Counties. By invading Brazos County, the weevil struck at the heart of Texas' well-established and politically powerful cotton-growing region. It also landed on the doorstep of the Texas Agricultural and Mechanical College. The threat that was already so real to growers "was down in South Texas" now became a reality further up north, in the heart of "cotton country."

Suddenly, Governor Culberson and the Texas legislature became interested in fighting the boll weevil. The 26th legislature passed a law authorizing the Texas Agricultural and Mechanical College to employ an "expert entomologist, whose duty it shall be to devise means, if possible, of destroying the Mexican boll weevil, and Fred W. Mally, a distinguished and popular entomologist who managed a commercial nursery near Dickinson was hired.

When F. W. Mally and the newly elected governor, Joe Sayers, both took office early in 1899, the weather in Texas had turned cold. In fact, the winter of 1899 is the coldest on record, with Tulia (in the Panhandle region) registering a bone-chilling 30.6 degrees below zero on February 12. An ice sheet covered the entire State, including South Texas. People hoped this severe cold snap would wipe out the weevils, but it did not. Instead, cotton planting was delayed several weeks, and the weevils that survived the frigid winter began multiplying quickly. Then, as if to give the boll weevils a boost, the spring and summer of 1899 turned out the be relatively wet. The rains allowed the late cotton to thrive, giving the boll weevils plenty of food and prompting a tremendous population explosion. Then, in early July, floods swept through the Brazos, Guadalupe, and Colorado River bottoms. Floodwaters raged through cotton fields, sweeping up infested squares and scattering them far down stream. Many of the plants were swept away, roots and all, but wherever any cotton plants survived, the remaining boll weevils and other pests also survived.

The year 1900 was even wetter, with rainfall nearly 8 inches above average, but Mother Nature was not finished yet. A hurricane hit Galveston Island on September 8-9 before moving inland. The Great Galveston Storm, which killed more than 8,000 people, also generated winds that blew weevils all the way from Texas' coastal prairies up to the Red River, on the border of Indian Territory (Oklahoma). In one single weekend, the "Storm of the Century" marked an enormous increase in the insect's range.

Although the unusual weather made his task more Herculean, Mally continued to persevere. His reputation as a thorough scientist was well-deserved, and his observations and recommendations are still the basis for Texas cotton-insect strategies today. Mally noted that cotton varieties grown at that time were extremely slow fruiting, which gave the boll weevil a definite advantage, so he recommended planting types that fruited more quickly, i.e. early-season cotton. He aslo found that the boll weevil's weakness was its "distinct overwintering brood," which only appeared in the fall and then overwintered (hibernated), providing another generation of pests the next spring. Mally was convinced (and time has proven him correct) that stalk destruction in the fall would significantly reduce the number of overwintering weevils that emerged the following spring. In addition to planting early-season cottons and destroying cotton stalks in the fall, Mally encouraged farmers who had previously planted cotton whenever the mood struck them, to avoid planting after a certain date in the spring and to widen the spaces between their rows. (Source: Boll Weevil Eradication In The United States Through 1999, Number Six of the Cotton Foundation Reference Book Series).