Grasshopper levels have been increasing over the past couple of years. Whether populations continue to increase will depend on factors such as weather and natural enemies. Grasshopper levels should be monitored carefully, beginning in late-May or early-June in 2020.
Grasshopper populations have more successful development in dry years and generally increase more over a series of dry years. The rainy weather in September and early-October may have somewhat reduced the number of eggs laid, although conditions for egg laying in August were good. The early snowfall in October will not likely significantly decrease overwintering success. Our pest species of grasshoppers all overwinter in the egg stage, which is quite resilient to excess moisture. Populations of bee flies, field crickets, and Epicauta species of blister beetles, all of which feed on grasshopper eggs, were quite noticeable in some locations of Manitoba in 2019.
The risk of economical populations of grasshoppers developing in 2020 varies, depending on location. Overall the risk is generally low to moderate in most areas, but there has been a progressive increase in higher counts in the past two surveys. If weather is favourable for grasshopper survival and development there may be areas where grasshoppers are a concern to crops in 2020.
Click here to see more...