Grasshopper - Frequently Asked Questions

 
 
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 Identification
  • Clear winged- The younger instars are black or black and white, The adults wings are clear and mottled with dark patches.
  • Two- striped- Brown to greenish brown. As they mature they will develop pale stripes on their back from the eyes to the tips of the forewings. They also have a solid black stripe on the back legs that runs parallel with the leg.
  • Packard- Bright green in color.
  • At high numbers any type of grasshopper is considered a pest. Assess the damage present. If the damage needs control to prevent economic loss and the loss is greater than the cost of the control, then control should be taken.
Control/Chemical Considerations
  • It is important to control the grasshoppers before they become winged. A good size is 7-16 mm in length, or1/2 to of an inch. Once they become winged they are much harder to kill.
  • Talk to your neighbors. Try to get large groups of farmers in one area to agree to control the grasshopper populations. This way the grasshoppers won’t migrate from their unsprayed land onto yours.
  • Temperature: Avoid spraying when it is really hot. At higher temperatures they can metabolize the chemical faster and some chemicals won’t be nearly as effective. At higher temperatures there is also increased spray evaporation. Avoid spraying when it is cold, as the grasshoppers may be near the ground surface, under the canopy trying to stay warm, making it harder to reach them with the chemical. The ideal temperature range for spraying grasshoppers is around 20 to 25 degrees Celsius, as most chemicals fit into this range and the grasshoppers should be active. Check the label for the temperature range of whatever chemical you are using to maximize its effectiveness.
  • If you are having your crops sprayed by an aerial applicator it may be beneficial to pay for a little extra water volume to ensure that you have good coverage of the area that you are spraying.
  • It is important to be realistic. If you have high population numbers, even with a 90% kill with an insecticide there may be numbers left that are still higher than the thresholds. Be aware of this. It might not be that the chemical is not working; it could just be that your numbers were so high to start with.
  • Different chemicals have different residual times. If this is important check with the label.
  • Make sure the insecticide that you are using is registered for that crop. Registered crops can be found in the 2005 Crop Protection Book (the blue book).
  • Insecticides may harm beneficial insects needed to pollinate some crops. For this reason avoid spraying when the crop is in bloom.
Pasture/Grazing Considerations
  • Each insecticide has a different interval for the length of time that cattle have to be left out of the treated field before grazing. It can range from immediately after application (Sevin) to up to 14 days after application (Matador).
  • When applying insecticide to pasture or hay land check to make sure that the insecticide is registered for all species of forage in the mix. An example of this is Decis. It is only registered on alfalfa for seed production, not for forage.
Ecobait Applicators
  • Check with your local chemical dealers. They may be able to direct you to a spreader.
Grasshopper Management
Alberta Aerial Applicators Association
Grasshoppers: Their biology, Identification, and Management

Prepared by Ag-Info Centre, Alberta Agriculture and Rural Development (310-3276)

 
 
 
 
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For more information about the content of this document, contact the Ag-Info Centre.
This information published to the web on July 8, 2003.
Last Reviewed/Revised on April 27, 2015.