Forage producers should be on the watch for and ready to act against two pests known for decimating hay fields – fall armyworms and Bermudagrass stem maggots, said a Texas A&M AgriLife Extension Service expert.
Dr. Vanessa Corriher-Olson, AgriLife Extension forage specialist, Overton, said she has been receiving calls and reports regarding fall armyworm and Bermudagrass stem maggot activity in East Texas and Central Texas pastures.
Armyworm numbers typically rise in the fall, but weather conditions, such as a dry spell followed by a rain event and cooler temperatures, can lead to flushes of the pest, Corriher-Olson said.
“They like cooler, moist conditions, and the last few rain events created the right environment for them,” she said.
The armyworm got its name because they appear to march across hay fields, consuming the grass in their path.
Producers should scout each morning for armyworms, she said. Armyworms are green, brown or black in color and can be identified by the white inverted Y on their head. They can grow up to 1 inch in length when mature.
The threshold for insecticide spray treating a pasture is three or more armyworms per square foot, Corriher-Olson said. Armyworms in those numbers should be treated immediately. Armyworms in the last two or three days of their larvae stage consume 85 percent of their diet.
Corriher-Olson recommends insecticides labeled for armyworm control in pastures and hayfields. She said applicators should always follow all label instructions on pesticide use and restrictions.
“Armyworms are principally night feeders and can do a lot of damage very quickly,” she said. “So we recommend that producers act immediately once they’ve seen armyworms reach the threshold.”
More information about armyworms can be found in AgriLife Extension entomologist Dr. Allen Knutson’s report The Fall Armyworm – Pest of Pastures and Hay.
Corriher-Olson said she had received several reports of Bermudagrass stem maggot, which hatch inside the grass stem and feed on the plant tissue, typically killing the top two leaves of the plant.
Herbicide Resistance Info
The stem maggot is difficult to scout, Corriher-Olson said. Maggots are typically not seen but become a small yellow fly, which is difficult to detect.
“Unfortunately, the way we typically detect stem maggots is by finding damage,” she said. “They typically kill the top two to three leaves, so If you look at your field and it looks like there’s been a frost event or you can pull the top two leaves from the stem very easily, you’ll want to take action.”
Corriher-Olson said producers should cut their hay meadow to reduce leaf, and therefore yield, losses once stem maggots are detected. Producers should follow by applying a pyrethroid insecticide seven days after the cutting to address the adult flies.
AgriLife Extension district reporters compiled the following summaries:
CENTRAL: No report
ROLLING PLAINS: Conditions were hot and humid across parts of the district. Isolated pockets of rain benefitted areas where it fell. Cotton conditions were mainly fair. Older dryland cotton looked good. Some younger cotton looked rough because of hail and wind and the fact some was replanted two or three times.
Weed control was becoming a problem. Grasshoppers were beginning to show up in numbers, and sugarcane aphids were on sorghum. Pastures were starting to turn yellow due to heat and lack of moisture. Hay was continually harvested.
COASTAL BEND: The weather was hot and humid with very little rain reported. Harvests continued in sorghum and corn. Some cotton was defoliated and will soon be harvested. Soybeans were above average. Insecticide treatments were made where warranted. Hay producers continued to see damage from fall armyworms. Cattle remained in good condition, but livestock markets were down.
EAST: Spotty afternoon showers and thunderstorms brought needed rain to the district. Pasture and rangeland conditions were mostly good, with Rusk, Marion and Gregg counties reporting excellent conditions. San Augustine County reported 1-3 inches of rain throughout the county. Subsoil and topsoil were mostly adequate. Ponds and creeks were full in Cherokee County. Reports of vegetation in ponds were coming in.
The rains slowed down cotton fields in Anderson County. Sorghum fields were three weeks from harvest. Corn fields were in good shape. Wild pigs continued to be active in corn fields, pastures and hay meadows. Warm-season vegetable production slowed with hot temperatures.
Summer plants were doing very well in Jasper County. Timber production picked up. Tons of bottomland hardwoods were being sold. Hay production yields were average to well above average for most producers. Producers were fighting armyworm infestations in many hay meadows in several counties. Some producers were spraying for both armyworms and grasshoppers.
Cattle were in good condition. Horn flies continued to be a problem in several counties. Weaning and selling of market-ready calves and cull cows continued. The cattle market was good in Shelby County.
SOUTH PLAINS: Conditions were dry and warm with temperatures below 100 degrees. Widely scattered showers were received in some areas, but more rainfall was needed for all aspects of agriculture. Overall, cotton fields looked good. A few cotton fields began blooming, and some were struggling to rebound from recent weather conditions. Corn stages ranged from vegetative to brown silk. Pastures and rangelands were green and in fair to good condition.
PANHANDLE: Rain helped where it fell, but more was needed across the district as daytime and nighttime temperatures were at or above average, including some triple-digit days. Both topsoil and subsoil moisture were much shorter due to hot, dry days and very little rain. Irrigated producers were running water as fast as possible as high temperatures and constant winds were drying out fields.
Corn was in good shape, but some dryland acres were starting to suffer. Cotton fields progressed with some irrigation applied. Insect pressure was light so far with no reports of the sugarcane aphids in the grain sorghum. Fields were being plowed behind harvested wheat.
Pasture and cattle needed rain and cooler temperatures to improve. Overall, cows were summering well with breeding season almost complete. An abundance of weeds and forbs were present in some areas.
NORTH: Topsoil and subsoil moisture levels ranged from mostly adequate to short, with a few counties reporting surplus. Most counties received rain. Temperatures were warm but pleasant for the middle of July. Drier conditions gave producers the opportunity to bale Coastal Bermuda, haygrazer and Sudan hay. Summer pastures looked green and healthy.
Soybeans continued to look good for this time of year and sorghum looked great. There were a few reports of sugarcane aphids and headworms in sorghum. Corn looked good and was being harvested. Cotton was doing well. Livestock were in good condition, and spring-born calves looked good.
FAR WEST: Temperature highs were in the 90s with lows in the 70s. Parts of the district received 3 inches or more of rain. Cloudy conditions persisted throughout the reporting period. Upland cotton looked very good. Cotton was transitioning into the blooming stage. All crops made good progress. Cooler temperatures eased the stress on plants, and recent rains allowed dryland fields to retain fruit or fill out seeds.
Pastures greened back up and alfalfa looked good. Rains delayed alfalfa harvests. Watermelon harvests continued with many producers on their second and third picking. Pecan orchards looked good as well. No supplemental feeding was needed, but some producers continued it to keep cattle body condition scores up. Forage quality was good, and the calf crop was doing well.
WEST CENTRAL: Weather conditions were seasonably hot and dry with a few isolated rain showers. Scattered storms were reported late in the reporting period in some areas. Fire dangers continued to increase in dry areas. Burn bans were reinstated in many areas that did not receive moisture.
Cotton conditions varied across the district, with some fields looking good due to timely moisture and others struggling to produce a good stand. Producers were busy spraying weeds in cotton after recent rains. Sugarcane aphids were noted in Sudan-type forages. Small-grain fields were in good condition.
Cutting and baling hay continued. Many producers started their second cutting of Coastal Bermuda. Hay reports were good. Rangeland and pasture conditions continued to look good in most areas that received rainfall. Stock tanks were in good shape. Livestock remained in fair to good condition. Pecan crops remained good.
SOUTHEAST: Most counties reported rainfall and wet conditions. Brazos County reported hot, dry conditions. Montgomery County received 4-7 inches of rain. Rice harvests were expected to start during the next reporting period.
In Fort Bend County, growers were harvesting sorghum while dodging rain showers. Cotton continued to fill bolls, but was nearing cutout. Corn was nearing harvest. Livestock and pasture conditions were good. Rains delayed hay harvests. Armyworms were still a concern for producers.
Soil moisture levels throughout the district ranged from adequate to surplus with mostly adequate conditions. Rangeland and pasture ratings varied from excellent to poor with good ratings being most common.
SOUTHWEST: Dry weather continued. The district was in desperate need of rainfall. Pastures and rangelands were showing stress from lack of moisture. Oats to be harvested were used as forage for livestock. Sorghum and corn were doing well, with some corn being harvested. Wildfire threats increased. Special attention was needed to ensure wildlife and livestock received water. Livestock and wildlife continued to do well.
SOUTH: Hot and dry summer conditions continued throughout the district with light to moderate showers occurring in some areas. Duval County received between 0.5-2 inches of rain. Other areas received up to half an inch. Some insect pressure was reported but were not meeting treatment thresholds. Corn and sorghum were being harvested.
Cotton in Frio County was setting bolls and peanuts were in the pegging stage, with both crops under irrigation. Bermudagrass hay was cut and baled. In most areas in the district, pasture and rangeland were showing signs of moisture stress, and conditions continued to decrease with no rainfall and hot temperatures.
In Live Oak County, unusually hot and dry conditions led to an earlier-than-normal harvest of sorghum and corn. Cotton fields were progressing rapidly. Topsoil and subsoil moisture levels were very dry. Cattle body conditions remained fair to good. Wildlife management looked good, with plenty of vegetation for deer.
Good numbers of deer, turkey, quail and dove were seen throughout Jim Hogg County. Watermelons and cantaloupes were still being harvested, and pecan orchards remained in decent shape. Pecans were halfway through development in orchards throughout the area. Native rangelands and pastures continued to provide adequate grazing for livestock in some areas, but supplemental feeding increased in other areas.