Grasshopper populations increasing

Lonnie Jenschke
Lonnie Jenschke

We are starting to see a heavier infestation of grasshoppers in the area, and while tiny now, without treatment they could double in size, numbers and amount of damage.

There’s a wide assortment of grasshopper species present. The egg hatch typically ends by late June, but the nymphs will be molting four to five more times and will become adults over the next 40 to 60 days.

With warm, humid weather, grasshoppers can become infected and die from a naturally occurring entomopathogenic fungus. Infected grasshoppers move to the top of a plant and die in a characteristic pose, with the front and middle legs grasping the object and the hind legs extended out.

AgriLife Extension publications recommend control measures begin while grasshoppers are still young nymphs and to treat along the hatching sites – roadsides, fencerows, etc.

Treating now can mean fewer acres need to be treated, requiring less insecticide, and excessive crop damage might be prevented. Also, the nymphal stage grasshoppers are not able to fly and are more susceptible to insecticides than are the larger nymphs and adults.

To control the grasshoppers, insecticide sprays and baits are the primary options. Baits are effective, but limited to those grasshoppers it attracts. Insecticide sprays can be used for larger acreage and are more economical.

There are numerous organophosphate, pyrethroid and other classes of insecticides labeled for grasshopper control in field crops. Primarily the pyrethroids will be labeled for urban/homeowner use. Sevin products with carbaryl also are labeled for use by homeowners and in urban landscapes.

Each product is labeled for specific crops or non-cropland usage and should be consulted before use.

Another insecticide labeled for select crops and non-cropland areas is Dimilin 2L, a bio-insecticide. This product is an insect growth regulator that interferes with grasshopper nymphs ability to molt to the next life stage.

Two other products with a new chemistry insecticide are Besiege and Prevathon. These products contain the insecticide chlorantraniliprole, which provides good control of grasshoppers.

Prevathon only has this insecticide as its active ingredient, but Besiege is a chemical mixture of chlorantraniliprole with a pyrethroid insecticide. Both products are labeled for use in several crops and for range, pasture, and forage and silage production of grass.

Neither of these products are labeled for use in non-cropland areas, so that means that homeowners do not have them as an option.

All chemicals have restrictions, so it is important to read the labels before use.

Lonnie Jenschke is an Erath County extension agent.