This method can provide good control when applied just before winter wheat emergence, when crop plants are only a few inches tall, or in areas with short, dry vegetation. The keys to success are uniform distribution of bait and reapplication if the bait is no longer attractive to grasshoppers. Nosema locustae , a disease organism that attacks many grasshopper species, is also available in bait form. This disease can reduce grasshopper populations over a period of several years, but Nosema baits will not protect a crop during the same growing season in which it is applied. Nosema baits may be effective when applied early in the season against small nymphs, but there are no data showing their effectiveness in protecting field Crops.
Foliar insecticides are the treatment of choice in most situations.
The High Plains Integrated Pest Management Guide lists the insecticides currently approved for control of grasshoppers on Colorado field Crops and noncrop areas that serve as infestation sources. Be sure to follow all label instructions and precautions. Winter Wheat Grasshoppers pose a significant threat to emerging winter wheat because the plants are small and the grasshoppers are adults. Light to moderate infestations, as defined in Table 1, can cause stand reductions in field margins. Treatments can be limited to field borders.