Grasshopper ManagementStrategies for Crop

ProtectionScott P. Schell & Alexandre V. Latchininsky

UW Extension EntomologistsLas Cruces, NM April 11, 2006

Grasshopper Crop PestsThe major pest species

Migratory Differential

Twostriped Redlegged

Grasshopper Crop Pest Nymphsnote the “swoosh” on their body

MigratoryMigratory Differential

Twostriped RedleggedRedlegged

11

2233

44

55

Clear-Winged Grasshopper in NW NMClear-Winged Grasshopper in NW NM

AdultAdult

Nymphal development: 26-40 days (~ 1 wk/instar)Nymphal development: 26-40 days (~ 1 wk/instar)

How much do they eat?

Ten adult two-striped grasshoppers per sq. yd can defoliate a corn crop.

Most grasshoppers can eat and destroy about 6 times its own weight of vegetation daily.

Thirty adult two-striped grasshoppers per square yard equals 200 lbs of grasshopper per acre!

Grasshoppers

Adult twostriped females ganging up on a sunflower plant

Crop Pest GrasshopperReproduction

Redleggedegg pods avg.

20-26 eggs

Density 40/yd2

20 females out of 40Each female – 1 egg-pod

= 460 eggs/yd2

Egg density in field borders can be VERY HIGH!

Pest grasshoppers often lay their eggs in un-tilled field borders

Protect the crop before grasshoppers get into it by treating these areas early!

Diflubenzuron (Dimilin® 2L)

• Labeled for non-crop areas

• Long Residual >28 days (matches the extended hatch for some species) Treat Early

• Lower impact on non-targets and bees!

• Use maximum label rate for border areas

Benzoyl-Urea; IGR (chitin synthesis inhibitor)

Other Options: Carbaryl spray and baits

• Labeled for non-crop areas

• Will kill adults if label max. rates are used!

• Multiple applications of carbaryl baits may be necessary but safer for bees and non-target insects.

ATV Bait Application

Boomless nozzle spray pattern

New Version 4.0 with Crop Protection Module

Under the Consultation Menu Choose New

Take Grasshoppers on Cropland Option

A Guide to Grasshopper Control in Croplandbulletin NF97-328 included in your packet

Most up to date, May 2003, chemical control bulletin we could find.