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Grasshoppers 2011: State gears up for hopper treatment

by Wyoming Livestock Roundup

The University of Wyoming Entomology Department’s research program has one consistent forecast for this summer – a 50 percent chance of grasshoppers.
Wyoming Department of Agriculture (WDA) Weed and Pest Specialist Slade Franklin also predicts another summer of pest-grasshopper infestation to follow last summer, when farmers and ranchers across the state witnessed an onslaught of pest-classified grasshoppers in both their crops and rangeland.
“Where we did our adult surveys this year there are some definite indicators that we will have some problems, as far as the amount of acreage compared to last year,” states Franklin.
“We expect the same amount of acres as last year, but in different areas. For instance, Campbell County was a county of interest last year, and not so much this year and vice versa for Laramie County,” notes Franklin.
While the state focused on rangeland treatment in 2010, this year the attention will shift to farmland, which was hard-hit last season.
“One of our main concerns is crops this year. The counties are all trying to handle them differently this year, and one thing that we do have, especially on alfalfa, is the ability to use Dimilin, which is what we use on rangelands. This week we should have the final approval from EPA to use Dimilin on alfalfa,” says Franklin.
Grasshoppers are a large threat to crop growers and ranchers alike, but prevention starts in the spring. Many pest-classified grasshoppers begin to hatch in mid-May, and experts say it’s easier to terminate them before they become adults.
Entomologists say early detection is the first step in successful prevention of grasshopper infestation. By looking for grasshoppers still in the first stages of life, landowners can get a better idea of when and where to spray. Grasshopper eggs and young grasshoppers can both be detected by closely examining the ground and, in farmland regions, those areas close to and surrounding planting acres.
“The problem is that grasshoppers don’t actually hatch on the croplands themselves. They hatch on the areas surrounding them, whether that’s barrow ditches or trees. When the ground is disturbed eggs don’t typically survive, so with annual tillage the eggs can be terminated, except for in the instance of alfalfa, and that’s where Dimilin and other adulticides come into affect,” says Franklin.
Dimilin is an effective, inexpensive insecticide that the Wyoming Weed and Pest promotes in most counties for farmers and ranchers to use in affected areas. The chemical can be applied multiple times if necessary, and is considered one of the leading grasshopper terminators. Local Weed and Pest agents can help producers determine if it would be successful on their individual crops and range lands.
The summer of 2011 could be unique in terms of grasshoppers for many reasons, but the one that sets it apart is populations. With last year’s combination of a wet spring and a dry, prolonged fall, the laying season for grasshoppers was greatly extended. Specialists with Wyoming Weed and Pest and the University of Wyoming admit that, while they don’t have a good estimate of how many eggs were laid, they do know it could be substantial, and they’re concerned.
“We are stressing the importance of producers getting into their Weed and Pest Districts now to either register their rangeland for any spray-block programs that may be going on, or just finding out how their individual Weed and Pest districts will deal with the grasshopper issue this year,” Franklin notes.
In 2010 Wyoming’s treatment focus was on grasshopper control in rangelands, and the state was caught somewhat by surprise at the effect of grasshoppers on cropland. Thus, it’s no surprise that this year the WDA is focusing its efforts on farmland.
Some county Weed and Pest programs are now offering reimbursement plans for pesticide users. For example, Platte and Goshen counties are implementing programs of their own, where landowners will be able to turn in receipts from their pesticides and for partial reimbursement for their efforts to prevent grasshoppers. State Weed and Pest programs want all farmers and ranchers to be prepared for this year as best as possible.
Wyoming Weed and Pest funding for the grasshopper treatment and reimbursement programs has come from former Governor Dave Freudenthal, Governor Matt Mead and the Wyoming Legislature. This year the state has $2.7 million designated for suppression efforts.
“We are in for some significant numbers, just in various places this year compared to last year,” adds Franklin.
Tressa Lawrence is editorial intern for the Wyoming Livestock Roundup and can be reached at

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