First - just because you have grasshoppers in a field, does not mean that they are causing you economic harm. You need to find at least 25 grasshoppers per square yard (which equals about 120,000 per acre) before they are eating enough to cause you economic damage. You can make this estimate by walking in a pasture and trying to estimate the number of grasshoppers in a 1 square foot area. Take this count 18 times. Total the number of grasshoppers from all 18 observations and divide by 2. This number is the number per square yard.
Second - decide whether or not you need the forage the grasshoppers are eating. If you have reduced stocking rates of livestock due to higher input costs, you may be ok in not treating. If you have kept the same number of livestock, but cut back on fertilizing because of high input costs, you may need to treat. If you have cut back on you hay field acreage this year and are dependent upon the smaller area for your winter feed source, you may need to treat.
Third - consider the timing of the application. The primary grasshopper control products used on pastures in East Texas include Malathion, Carbaryl, and Diflubenzuron. Malathion has no waiting period from spraying to grazing or cutting for hay. Carbaryl has a 14 day waiting period from spraying to grazing or cutting for hay. Diflubenzuron is not effective on grasshoppers once they have matured (developed wings and can fly) and it is probably too late to use this product this year. Spraying will cost up to around $10 per acre, depending upon product used and rate applied. If you are close to cutting hay in a field and are seeing grasshoppers in great numbers, you might consider cutting a little early. Cutting early will sacrifice a little yield, but will provide you with a little better quality hay.
