Weed & Pest
Grasshoppers, Learning from 2010, preparing for 2011
“We did very well with planning and implementation, and couldn’t have done any better making landowners aware of the program. Setting up the program and actually going and doing surveys to determine when to spray is another thing that went really well,” says Weed and Pest Coordinator for the Wyoming Department of Agriculture (WDA) Slade Franklin of the grasshopper infestation in 2010.
“That being said, there were some areas we would have liked to see much better control. We had some issues with crop counties; Goshen and Platte counties had some big problems. Next is determining if it is more financially viable to spray or endure loss to grasshoppers,” he continues.
“It was harder to put together an effective spray program and utilize some tools such as aerial spraying with the checkerboard effect in cropland areas. There were also issues with pesticides, as only specific pesticides can be used on specific crops, and they don’t always overlap,” notes Franklin.
He adds that when calculations were complete, landowners across the state paid between 25 cents and $1.15 per acre. “That’s still pretty dirt cheap for the cost of the application, which is between $3 and $3.50 per acre,” notes Franklin.
Bruce Shambaugh, State Plant Health Director of the USDA APHIS Plant Protection Quarantine (PPQ) program, adds that in areas with a high percentage of federal land, APHIS was involved in planning and treatments and paid for 100 percent of the cost on federal lands. He notes the BLM also obtained funds to pay for BLM lands treated under county weed and pest programs.
“We work very closely with county Weed and Pest districts and rely on them to act as a representative for the private landowners who request our assistance. I think both the federal- and county-run treatments were a huge overall success. There are very few examples of density counts after treatments with more than three grasshoppers per yard, which is well below economic numbers,” explains Shambaugh. He adds that federal treatments were strictly on rangeland, which saw higher treatment success levels than croplands.
“Last year county weed and pest districts conducted many public meetings in which we were involved, and they met with numerous landowners. Then, as the sign-up sheets developed, and decisions were made as to which areas made the most sense for a PPQ program versus a county program. The Wyoming program was a cooperative effort between federal, state and county agencies and the landowners, and it went very well, especially considering the daunting number of acres signed up,” comments Shambaugh.
Franklin explains that, for 2011 grant applications, weed and pest districts are encouraged to include more cost-share dollars directly for landowners. This would allow producers to purchase chemicals and do the work themselves, or coordinate with their local weed and pest district. This is especially encouraged in crop-oriented counties.
“If you use a chemical with a seven-day window of efficacy, grasshoppers from your neighbors can move in after that time period and there’s no residual killing effect. But, if producers could use Dimlin early, its 45-day residual would be much more effective,” says Franklin.
“Those growing crops need to start scouting source habitat areas in late spring or early summer. Grasshoppers come from the borrow ditches and the fencerows, and if you can treat those areas early you’ll prevent a lot of crop damage later in the growing season,” adds UW Research Scientist Scott Schell.
“APHIS conducts a pretty comprehensive adult grasshopper survey used as a guide to locate potential problem areas for the next year. There are still many areas with high densities, according to the 2010 survey – probably very similar to the number of high-density acres we saw a year ago,” explains Shambaugh.
“Based on those same surveys, the high count areas were outside where we sprayed at least 95 percent of the time,” notes Franklin. “That’s a positive indication that spraying was effective.”
“We put together a lot of data from each survey point after sorting through the grasshopper species by hand. Of the 120 species, only about a dozen are considered bad. So far we’ve seen that the treatment blocks on rangelands were successful in reducing numbers to non-economic levels, and that bodes well for next year,” notes Schell.
He adds that UW is trying to quantify grasshopper damage through tools like remote sensing from satellites, which look at areas of forage loss.
“We would eventually like to find a way to establish damage with satellite imagery. This year I sampled a couple places with similar vegetation that were partially infested and partially controlled, either because the rancher didn’t have the funds to spray the entire area, or because of a cut-off in spraying. I did an arbitrary sample in the treated and untreated rangelands, and want to use the samples to figure out the difference in forage quantity based on grasshopper presence. I also had the samples analyzed to see if there was a difference in forage quality where grasshoppers were numerous versus where there weren’t very many,” explains Schell.
“I did this in September, after the grass had cured, and the results surprised me in one respect. There was a big, and obvious, difference in the amount of forage in the two sampled areas, but the forage quality wasn’t that much different, even though there wasn’t much left beyond the stems where grasshoppers were present. That was interesting,” explains Schell.
He adds the sampling he did was small and very preliminary, but that the ultimate goal is using satellites to locate grasshoppers. “If we could rapidly assess regions of the state with grasshopper problems with the satellite and get those areas mapped out for treatment, it would save a lot of time and money.”
“We’ve also talked to the people at the National Agricultural Statistics Service (NASS) about how to figure out loss due to grasshoppers, or what loss is prevented due to the grasshopper control program, and how to quantify that. We took them to some damaged areas and discussed how we can measure loss from grasshoppers versus that due to weather or other natural causes in a given year,” says Franklin.
“So far the information we are receiving just confirms our management efforts, which was not about killing grasshoppers, but about preserving forage for livestock and wildlife. That looks like it’s working effectively,” says Schell. “We are trying to show that we aren’t just killing them, but what we’re really doing is saving forage.”
“Grasshoppers are too big of a problem for most landowners to manage on their own, as they are a fairly mobile pest that can impact entire regions. We need to utilize economies of scale against them. I would encourage producers to attend meetings early and be aware of what’s going on in their area in 2011,” notes Schell.
The grasshopper control program is dependant on the WDA, receiving $2.7 million in their supplemental budget this year. “We have a supplemental request out for 2011. If that isn’t approved we probably won’t have a grasshopper program for next year,” says Franklin.
“PPQ obtained emergency funding for the grasshopper issue in 2010. We have to request those dollars every year, and all of our treatment decisions are based on the available funding,” adds Shambaugh. “The first thing we’re doing for the 2011 season is a session devoted to the grasshopper at the upcoming Wyoming Weed and Pest fall conference. I expect there will be a number of landowner meetings throughout the winter, in addition to federal and state agency meeting to prepare for the upcoming 2011 season.”
“We will also utilize all the data obtained from the adult grasshopper survey to focus efforts on potential problem areas next year. If conditions are favorable for hatch and survivability of young grasshoppers next spring, there will be areas with high densities of grasshoppers,” says Shambaugh.