Grasshopper Outlook on Rangelands: 2011

Grasshoppers are often found to be a significant problem for both farmers and ranchers. Even though grasshoppers are a normal component of a forage ecosystem and generally exert minimal disturbance, problems occur when conditions lead to grasshop¬per populations that increase to the point where they cause millions of dollars of damage. Grasshopper outbreaks are the result of a complex combination of factors. Several factors are beyond the control of managers. However, the “pasture microcli¬mate” (the immediate environment where grasshop¬pers hatch, grow, and reproduce) may be subject to subtle manipulation. Because grasshopper outbreaks are progressive and cumulative, small interruptions or reductions in the rates of metabolic processes may serve to reduce population expansion and consequent damage to vegetation. Spring weather plays a key role in the severity of outbreaks. Warm temperatures with little rainfall are favorable for the hatching and development of grasshoppers, while cool and wet conditions follow¬ing hatch are unfavorable to grasshopper growth and development. Surveyed grasshopper populations for 2010 are shown in fig. 1