Nebraska: Cool, wet May might reduce grasshopper numbers in parts of the state | TSLN.com

Nebraska: Cool, wet May might reduce grasshopper numbers in parts of the state

Jeff Bradshaw, Extension Entomologist Panhandle REC, Scottsbluff; David Boxler, Extension Educator, West Central REC, North Platte; and Bob Wright,

Areas of Nebraska pasture and rangeland are at high risk of damaging grasshoppers this year, based on the number of grasshopper eggs at the start of last winter, according to the U.S. Department of Agriculture.

However, a cool, wet May, along with beneficial organisms, could reduce grasshopper numbers. So far, many areas of western Nebraska have remained cool and wet, while some areas have remained relatively dry. As is often the case, some areas of Nebraska will be much more affected by grasshoppers than others.

The Nebraska Panhandle and much of southern Nebraska should begin seeing the first grasshopper hatch of the season soon, if they haven’t already. These are not the bandwing grasshoppers that overwinter as late nymphs or adults and would have appeared in March or April. These grasshoppers spent the winter as eggs in the ground and have now begun to hatch.

To estimate the potential for damaging populations of grasshoppers on rangeland, use the following method based on the USDA Agricultural Research Service resource “Grasshopper: Their Bioloty, Identification and Management.” This 18-square-foot sample method used by many USDA Animal and Plant Health Inspection Service (APHIS) offices in the western U.S. is a simple and quick way of determining grasshopper density.

At each survey site, choose a sample area typical of the rangeland to be surveyed. Next, look ahead and determine the approximate route you will walk. Pick a spot on the ground about 10 paces in front of you. Choose the spot before you determine if any grasshoppers are present.

Visualize a sample area surrounding the spot equal to 1 square foot on the ground. You can use landmarks such as a stick, pebble, tuft of grass, or flower to help keep your eye focused on the sample area chosen. Or you can use a piece of wire bent into a square foot placed at your feet to help train your eye. Once the area is set, walk slowly toward it and determine the number of grasshoppers by counting the grasshoppers as they flush out of the visualized sample area.

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Do not count individuals that hop into the sample area while conducting the sample count. When you reach the spot, probe the area with the handle of your insect net or other suitable object to make sure all individuals have flushed and been counted.

Record the number counted and repeat the process at 17 more sample areas. The total number of grasshoppers counted in the 18 one-square-foot sample areas, divided by 2, gives you the number of grasshoppers per square yard.

Grasshoppers develop through four immature stages, or instars, prior to becoming winged adults. For optimal results, delay treatment until you begin to spot third and fourth instars. For help with staging grasshoppers, see the Department of Entomology Grasshopper Web site at entomology.unl.edu/grasshoppers. This site also has more information on grasshoppers, grasshopper management, and a list of compounds that can be used to control grasshoppers in Nebraska.

Treatment is warranted when grasshopper nymphs at the third and fourth instar are spotted and the total number averages 25 to 30 per square yard.

Note that some areas of Nebraska may have restrictions on pesticide applications due to deleterious impacts to state or federally protected species.

However, producers and landowners can request a site specific survey to be conducted by APHIS. Contact your local Extension Office or call USDA-APHIS directly at 402-434-2345.

Areas of Nebraska pasture and rangeland are at high risk of damaging grasshoppers this year, based on the number of grasshopper eggs at the start of last winter, according to the U.S. Department of Agriculture.

However, a cool, wet May, along with beneficial organisms, could reduce grasshopper numbers. So far, many areas of western Nebraska have remained cool and wet, while some areas have remained relatively dry. As is often the case, some areas of Nebraska will be much more affected by grasshoppers than others.

The Nebraska Panhandle and much of southern Nebraska should begin seeing the first grasshopper hatch of the season soon, if they haven’t already. These are not the bandwing grasshoppers that overwinter as late nymphs or adults and would have appeared in March or April. These grasshoppers spent the winter as eggs in the ground and have now begun to hatch.

To estimate the potential for damaging populations of grasshoppers on rangeland, use the following method based on the USDA Agricultural Research Service resource “Grasshopper: Their Bioloty, Identification and Management.” This 18-square-foot sample method used by many USDA Animal and Plant Health Inspection Service (APHIS) offices in the western U.S. is a simple and quick way of determining grasshopper density.

At each survey site, choose a sample area typical of the rangeland to be surveyed. Next, look ahead and determine the approximate route you will walk. Pick a spot on the ground about 10 paces in front of you. Choose the spot before you determine if any grasshoppers are present.

Visualize a sample area surrounding the spot equal to 1 square foot on the ground. You can use landmarks such as a stick, pebble, tuft of grass, or flower to help keep your eye focused on the sample area chosen. Or you can use a piece of wire bent into a square foot placed at your feet to help train your eye. Once the area is set, walk slowly toward it and determine the number of grasshoppers by counting the grasshoppers as they flush out of the visualized sample area.

Do not count individuals that hop into the sample area while conducting the sample count. When you reach the spot, probe the area with the handle of your insect net or other suitable object to make sure all individuals have flushed and been counted.

Record the number counted and repeat the process at 17 more sample areas. The total number of grasshoppers counted in the 18 one-square-foot sample areas, divided by 2, gives you the number of grasshoppers per square yard.

Grasshoppers develop through four immature stages, or instars, prior to becoming winged adults. For optimal results, delay treatment until you begin to spot third and fourth instars. For help with staging grasshoppers, see the Department of Entomology Grasshopper Web site at entomology.unl.edu/grasshoppers. This site also has more information on grasshoppers, grasshopper management, and a list of compounds that can be used to control grasshoppers in Nebraska.

Treatment is warranted when grasshopper nymphs at the third and fourth instar are spotted and the total number averages 25 to 30 per square yard.

Note that some areas of Nebraska may have restrictions on pesticide applications due to deleterious impacts to state or federally protected species.

However, producers and landowners can request a site specific survey to be conducted by APHIS. Contact your local Extension Office or call USDA-APHIS directly at 402-434-2345.

Areas of Nebraska pasture and rangeland are at high risk of damaging grasshoppers this year, based on the number of grasshopper eggs at the start of last winter, according to the U.S. Department of Agriculture.

However, a cool, wet May, along with beneficial organisms, could reduce grasshopper numbers. So far, many areas of western Nebraska have remained cool and wet, while some areas have remained relatively dry. As is often the case, some areas of Nebraska will be much more affected by grasshoppers than others.

The Nebraska Panhandle and much of southern Nebraska should begin seeing the first grasshopper hatch of the season soon, if they haven’t already. These are not the bandwing grasshoppers that overwinter as late nymphs or adults and would have appeared in March or April. These grasshoppers spent the winter as eggs in the ground and have now begun to hatch.

To estimate the potential for damaging populations of grasshoppers on rangeland, use the following method based on the USDA Agricultural Research Service resource “Grasshopper: Their Bioloty, Identification and Management.” This 18-square-foot sample method used by many USDA Animal and Plant Health Inspection Service (APHIS) offices in the western U.S. is a simple and quick way of determining grasshopper density.

At each survey site, choose a sample area typical of the rangeland to be surveyed. Next, look ahead and determine the approximate route you will walk. Pick a spot on the ground about 10 paces in front of you. Choose the spot before you determine if any grasshoppers are present.

Visualize a sample area surrounding the spot equal to 1 square foot on the ground. You can use landmarks such as a stick, pebble, tuft of grass, or flower to help keep your eye focused on the sample area chosen. Or you can use a piece of wire bent into a square foot placed at your feet to help train your eye. Once the area is set, walk slowly toward it and determine the number of grasshoppers by counting the grasshoppers as they flush out of the visualized sample area.

Do not count individuals that hop into the sample area while conducting the sample count. When you reach the spot, probe the area with the handle of your insect net or other suitable object to make sure all individuals have flushed and been counted.

Record the number counted and repeat the process at 17 more sample areas. The total number of grasshoppers counted in the 18 one-square-foot sample areas, divided by 2, gives you the number of grasshoppers per square yard.

Grasshoppers develop through four immature stages, or instars, prior to becoming winged adults. For optimal results, delay treatment until you begin to spot third and fourth instars. For help with staging grasshoppers, see the Department of Entomology Grasshopper Web site at entomology.unl.edu/grasshoppers. This site also has more information on grasshoppers, grasshopper management, and a list of compounds that can be used to control grasshoppers in Nebraska.

Treatment is warranted when grasshopper nymphs at the third and fourth instar are spotted and the total number averages 25 to 30 per square yard.

Note that some areas of Nebraska may have restrictions on pesticide applications due to deleterious impacts to state or federally protected species.

However, producers and landowners can request a site specific survey to be conducted by APHIS. Contact your local Extension Office or call USDA-APHIS directly at 402-434-2345.

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