Grasshoppers seemed to have started feeding in my landscape a few weeks ago. Their main target has been my Mexican sunflower blooms. I’m not sure what makes them so tasty to the grasshoppers.
Believe it or not, Kansas has approximately 115 grasshopper species. Fortunately though, only 5 species are considered as threats to crops and vegetables. The differential and two-stripped grasshoppers are the most common type found in the home garden.
These two types of grasshoppers are characterized by their large size, with adults averaging 1½ to 2 inches in length. The differential grasshopper is mostly yellow and black and has a V-shaped pattern on their hind legs. The two-striped grasshopper is brownish or grayish in color. As you look at them from above, there are two yellow stripes running down the top of the head.
Grasshoppers remain in the area where they were hatched, and feed primarily on grasses and broadleaf plants. Sometimes when there are large populations of grasshoppers and all of the available plants have been consumed, they will seek out new food sources. Trees may become targets once other plant materials have been eaten. In drought situations, grasshoppers will feed on anything containing moisture including moist soil, wood and even linens that are left outside.
Sometimes you will hear people say that grasshoppers like hot dry conditions. That is sort of true. Basically, grasshoppers are more noticeable during drought conditions because they are in search of new food sources. In years of low populations or when there is adequate moisture, grasshoppers will stay in their hatching area and they do not cause a great deal of damage.
So what is a homeowner supposed to do to protect their plants? I am sure some of you have used a spray treatment and are convinced that the spray did not kill the grasshoppers. Some of the grasshoppers were more than likely killed, but you probably didn’t notice the dead ones because new ones had already hatched and had begun their destruction.
Before spraying any insecticide, please check the product label. Permethrin and carbaryl (Sevin) will work on vegetables and ornamentals. For insecticides applied to vegetables, it is important to observe the post-harvest intervals listed on product labels. For a complete list of available insecticides, please contact me at the Extension office.
Krista Harding is a K-State Research and Extension Horticulture agent assigned to Southwind District.
