Insect pressure has been “extraordinarily heavy” for Texas crops, according to Texas A&M AgriLife Extension Service pest management expert David Kerns, Ph.D., professor and associate department head for the Department of Entomology.
He said part of the increased pressure comes from unusual pests such as corn leafhoppers that Texas doesn’t typically have in great numbers.
Kerns, who oversees the Texas Integrated Pest Management Program, IPM, has heard from IPM agents, AgriLife Extension specialists and agriculture and natural resources agents with similar pest pressure concerns. Collectively, they say this has been a bad year for pest pressure in grains across the state.
Kerns said with the warmer weather patterns we’ve been having, the increase in pests doesn’t come as a surprise.
Corn leafhopper concerns
Corn leafhoppers, a pest originating in South America, aren’t normally a concern in Texas. Warmer temperatures, however, have helped expand the corn leafhoppers habitat range and this season they have moved much deeper into the state than before.
“It was 2016 that we last saw these pests in large numbers in the lower Rio Grande Valley, but now they are back again and spreading,” Kerns said. He said disease symptoms have been documented all the way up to San Angelo and into the Comanche area, where some good-sized populations have been seen.
Most of the state’s corn was already at a point where the corn leafhoppers, which suck the nutrients from the plants and excrete honeydew, weren’t as much of a concern as the vectors they carry – diseases that can stunt growth, reduce yield and even kill the plant.
“As far as disease goes, most of the corn that was affected was far enough along that you wouldn’t think it would have a huge impact,” he said. “But there’s a lot of anecdotal evidence out there that it very well could be having an impact. Not a devastating impact, but a definite impact.”
Plant pathologists are currently working to get a positive identification on samples taken from the state’s affected areas.
“It could be a number of different diseases that this thing vectors and even the actual impact on the corn itself is debatable,” Kerns said. “If you look at some of these pathogens we know the insect can transmit, you know that the earlier the plant gets infected, the worse it is. In the long run, if it becomes a pest that sticks around or that we see earlier in the season, then the greater impact possibility.”
While the U.S. hasn’t seen large losses to the pest, that can’t be said for other places. In Argentina, once corn leafhoppers spread to what were previously cooler regions of the country, corn losses totaled over $1 billion. Brazil has also been in a fight against the pest as numbers grow across that country as well.
Kerns doesn’t think Texans need to worry since conditions are very different between North America and South America, but the pest is one that needs to be closely watched and will continue to be monitored.
Grazing grasshoppers
Grasshoppers in greater numbers across a larger swath of the state than typical are causing issues for producers as well.
“This year the western parts of the state seem to be getting it much worse than usual,” Kerns said. “Even up in the Texas Panhandle they’ve been having issues with them.”
He said weather plays the biggest role in grasshopper outbreaks since temperatures and moisture influence how many eggs are laid, when they hatch and how many survive.
A free, downloadable guide available on AgriLife Learn identifies the main grasshoppers responsible for crop damage as well as suggested treatments.
False chinch bugs and corn leaf aphids
There have been a lot of issues with false chinch bugs this year, Kerns said. And while this has mainly been seen in grains, it has also impacted some cotton.
False chinch bugs are typically more of an issue for the eastern half of the state, and it isn’t unusual to have problems with the pest even in the South Plains, but this year is different.
“It started down in South Texas, but then followed all the way up,” he said. “I have heard of people having issues as far north as Oklahoma. So, it just seems to be a pretty widespread problem.”
And, he said, producers are still having a lot of issues with corn leaf aphids, which in and of itself isn’t uncommon, but the numbers earlier in the season were really high, which is kind of unusual.
Fall armyworms, fleahoppers and cotton bollworms
Some reports of fall armyworms have already come in and there’s been incidences of pasture-to-pasture spread, Kerns said.
“With the weather we’ve been having, you would expect that to continue and probably to amplify,” he said. “I wouldn’t be surprised at all if we see a pretty good fall armyworm outbreak across the eastern half of Texas.”
Cotton is also seeing more than its fair share of pest pressure.
“We see cotton fleahoppers every year just about, but populations have been extraordinarily high this year,” Kerns said.
“Cotton had to be treated multiple times for pests already, and last week we saw a really big egg lay from the cotton bollworm.”
Panhandle
The district experienced hot and dry conditions, which dried out needed soil moisture for dryland crops and native rangeland. The farming of fallow ground and future wheat ground continued while corn crops were being irrigated. Most wheat fields were harvested with many replanted to row crops. In most cases, no tillage was done in these fields. Sporadic showers helped conserve the soil profile moisture, with overall soil moisture very short to adequate. Pasture and range conditions were reported to be fair to very poor. Overall crop quality ranged from fair to good.
