Recent crop reports from Texas AgriLife Extension Service have indicated several troublesome areas across the state, especially Central Texas, but Allen Knutson, Extension entomologist in Dallas, said some areas have seen few hoppers at all this year, the differences being attributable to the timing and amount of rainfall in the different locales. Hot, dry summers and warm, dry autumns increase their chances of survival, while cool, wet weather slows nymphal development, reduces the number of eggs and makes them more prone to disease.
Yet some areas that had wetter and cooler weather last fall and this spring are still seeing outbreaks this summer. Chris Sansone, a long-time entomologist in Texas now working for Bayer Crop Sciences in North Carolina, said this year was probably already set up favorably for grasshoppers because of the persistent heat and drought of the last few years.
“It seems like any time rainfall is below normal then grasshoppers are a threat,” he said. “It also appears that there are ebbs and flows, so it takes a year or two for populations to build up and then a year or two for populations to decline. So it seems that the cycle can be from three to even more years. The people around Comanche would tell you that they have had consistent grasshopper problems for six or seven years.”
Grasshoppers lay their eggs in "pods" in the fall an inch or two inches below the soil surface. Each pod can contain from 40 to 4,000 eggs and averages about 200 during a season. The eggs are deposited in ditches and along fence rows, hayfields and weedy fields where the soil is less likely to be disturbed.
Knutson said the grasshoppers have been there all along, but people see for them for the first time in early summer when the nymphs mature into adults with wings and can move from one place to another in search of food. Thirty of them can eat a ton of vegetation in 10 days, or about the same as one cow.
The legendary grasshopper plagues of the 1930s during the Dust Bowl were mostly a result of extremely favorable weather conditions for a long time. Knutson said the drought favored grasshopper survival and egg deposition for several years in a row, leading to extremely large numbers.
In “The Worst Hard Time,” author Timothy Egan describes a 1937 swarm of grasshoppers on Bam White’s place near Dalhart, where the Dust Bowl’s effects were at their worse. The grasshoppers appeared as a cloud so thick that Melt White, a young boy at the time, thought at first it was another duster.
But this one made a noise. It was grasshoppers.
“They consumed everything the family had grown,” Egan wrote. “The grass was gone in minutes. The hay disappeared in a hurry ... They swallowed every cell of fiber in the ground until nothing was standing, and the field looked dead and brown again, and then they lifted off, fortified by the White’s season of labor.”
Estimates put the number of grasshoppers in some areas of the Plains during the 1930s at 23,000 per acre, or 14 million per square mile. People combated the plagues by mixing a blend of arsenic, molasses and bran and, with the help of the National Guard, spread it across the land.
Neither the numbers nor the methods are as severe now as they were back then. Still, the sheer number of grasshoppers in an outbreak year can be a surprise.
A blog post on the Bosque County Extension office website offers an example: “This past week, I was driving between Walnut Springs and Iredell. To my surprise the road was covered in grasshoppers. I have been on many farm and project visits all around the county the last couple of weeks. I knew we were going to have a higher than normal grasshopper population, but the sheer number I saw on that road was concerning.”
At least it’s not as concerning as it was during the onset of the Great Depression. Knutson said it would take a weather pattern like that of the 1930s to create a similar plague, and Sansone said the environment for grasshopper outbreaks has changed drastically since the Dust Bowl days.
“In the 1930s Texas was a predominantly rural state with large areas of pasture and crop land that allowed grasshopper populations to develop,” he said. “Now the state is more urban and the landscape is much more patchy. Just not as much food for the insects.”