Grasshopper Nymph Populations Surge in Western Kansas Amid Unusual Weather Patterns

Western Kansas is experiencing a notable surge in grasshopper populations this summer, driven by a combination of wet spring weather and subsequent hot conditions. Kansas State University Research and Extension entomologist Anthony Zukoff explains that the spike in grasshopper nymphs is a direct result of recent climatic shifts and emphasizes the potential impact on agriculture in the region.

According to Zukoff, the spring’s increased moisture levels have created an ideal environment for grasshopper eggs to hatch and nymphs to thrive. Grasshoppers, particularly their nymph stages, benefit from the wet conditions of early spring, which promote the growth of broad-leaf weeds and other vegetation that serve as food sources. This in turn supports a larger population of young grasshoppers. As the summer heats up, the hot and dry conditions are favorable for the nymphs’ survival, allowing many to reach adulthood.

The cycle continues as adult grasshoppers lay eggs, which are more likely to survive in warm, wet springs. Thus, multiple years of hot, dry summers followed by warm, wet springs can culminate in significant grasshopper infestations in certain areas. This year’s weather patterns fit this model, contributing to the increased numbers of these pests.

The weather outlook for the coming days suggests a decrease in rainfall, with the National Weather Service in Dodge City forecasting a tapering off of thunderstorms and temperatures hovering around 90 degrees. The hottest period of the summer seems to have passed, with July 15 marking the highest average temperatures of the year across Kansas, reaching up to 102 degrees in some areas. Webster Dam in Rooks County recorded a peak of 111 degrees on July 13.

In light of these conditions, Kansas State’s assistant state climatologist Matt Sittel notes that while temperatures are expected to remain above normal through August, precipitation levels are anticipated to be near normal. This continued warmth and sporadic rainfall will likely sustain grasshopper populations, posing challenges for agricultural producers.

Zukoff advises farmers to monitor their fields closely for grasshopper activity. The extra moisture from early spring has led to an abundance of leafy plants, which grasshoppers prefer. For crops such as corn or sorghum, a presence of five to eight grasshoppers per square yard may necessitate insecticide treatment to prevent excessive damage. Fall-planted crops are particularly vulnerable as alternative food sources diminish or go dormant.

For alfalfa fields, if grasshopper numbers reach 15 or more per square yard before planting, Zukoff recommends preemptive treatment to safeguard the crops. Similarly, for wheat, scouting the vegetated borders of planting areas is crucial. If grasshopper counts are between seven and twelve per square yard, treatment is advised. Within established wheat fields, the presence of three or more grasshoppers per square yard can jeopardize seedling stands, making seed treatments a viable option to protect emerging plants, provided the grasshopper population remains manageable.

Overall, the rise in grasshopper nymphs in western Kansas is a direct consequence of recent weather conditions and underscores the need for vigilant pest management. Agricultural producers are encouraged to stay informed and prepared to mitigate the impact of these pests on their crops as the season progresses.