The following image showing various stages of Camnulla pellucida is provided below - note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.
Generally, the economic threshold for grasshoppers in cereals is 8-12 per square metre but will vary by crop and growing conditions.
|Figure 1. Life stages of Camnulla pellucida which including eggs, first-fifth instar nymphs and adult (L-R).|
Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta, British Columbia and the Prairie Pest Monitoring Network. Also refer to the grasshopper pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" - both English-enhanced or French-enhanced versions are available.