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Grasshopper -- credit Dan Johnson - Alberta agriculture

2021 grasshopper forecast for Alberta

Jan 29, 2021 | 4:30 PM

EDMONTON, AB. — The 2021 grasshopper forecast map from Alberta Agriculture is based on adult grasshopper counts in August 2020 which were conducted by Agriculture Fieldmen across the province. Adult grasshopper counts give an indication of the number of individuals capable of egg reproduction and laying.

Specific environmental factors can result in higher or lower actual populations in specific areas. For this reason, producers need to be aware of potential risks in their area, monitor fields accordingly and make appropriate decisions if control measures are required.

For the Peace River and Central Alberta, fieldmen were hard pressed to find grasshoppers in the Peace and northern portions of central Alberta. Bruner’s spur-throat grasshopper wasn’t recognized as a pest until recently. This species has been documented as having a biennial lifecycle, which has an impact on grasshopper forecasts. To view previous year forecasts see: Historical grasshopper population maps.

The grasshopper forecast for a particular year is based on the grasshopper count from the previous August. If the grasshopper population in the Peace River Region and northern central Alberta is following a biennial cycle then the grasshopper counts from 2019 indicate that 2020 will be a low grasshopper year followed by a higher population in 2021 and then lower again in 2022.

In Southern Alberta, dry summers are resulting in increasing grasshopper numbers, particularly in the M.D. of Acadia, Vulcan, Willow Creek, Lethbridge, Cardston, and Forty Mile counties. The grasshopper species found in southern Alberta are a blend of Melanoplus bivitattus, M. packardi, M. sanguinipes and Camnula pellucida.

Grasshopper projections from Alberta Agriculture

Portions of southern Alberta indicating moderate to severe risk could experience problems with grasshoppers if environmental conditions favour grasshopper hatching and development in late May through June. Localized factors such as light soils or south-facing slopes result in an elevated risk of grasshopper infestations. Conditions in late spring 2021 will determine the extent of the grasshopper problem.

The rest of the province shows light to no grasshopper populations.

Grasshoppers tend to lay their eggs near areas of green growth in the fall that will provide potential food sources for emerging young the following spring. Areas with early green plant growth such as field margins, fence-lines and roadsides are also areas that will give early indications of potential grasshopper problems. For this reason, individual farms, particular attention should be paid to areas that traditionally have higher grasshopper populations