1. Grasshopper Control in Forages
Brian Pugh
NE Area Agronomist
Oklahoma State University

2. Question #1
What 3 stages do grasshoppers go through?

3. Adults can survive another 2-12 weeks, lower pop. = longer life
Question #2
How long is the avg. maturation process?
40-55 Days
(egg to adult)
Adults can survive another 2-12 weeks, lower pop. = longer life

4. Question #3
How many generations/year are observed for most species? 1

5. Differential Grasshopper
Question #4
What is the common name of this species?
Differential Grasshopper
(Melanoplus differentialis)

6. Question #5
Approximately what % of BW will an adult consume in one day?
50%
Male = 1.5g BW

7. Pasture = 8 Range = 12 Question #6
At what threshold is control recommended in pastures?
Pasture = 8
Range = 12

8. In nursery areas; ditches and field borders.
Question #7
Where is the ideal place to initiate control?
In nursery areas; ditches and field borders.

9. Earlier the better! Ideally 2-3rd instar Question #8
What stage of growth?
Earlier the better!
Ideally 2-3rd instar

10. Question #9 Name a labeled insecticide with 0 day grazing withdrawl.
Beta Cyfluthrin – Baythroid
Diflubenzuron – Dimilin
Zeta Cypermethrin – Mustang Max
Lambda Cyhalothrin – Karate, Warrior
Chlorantraniliprole – Prevathon, Rynaxypyr
Lambda Cy + Ctp – Besiege
In Range: Malathion as well

11. Reduced Agent & Area Treatment
Bonus Question
What does RAAT stand for?
Reduced Agent & Area Treatment

12. Bonus Question
What chemical is labeled for this type of use?
Dimilin

13. 50-60% over standard treatments
Bonus Question
How much could this reduce costs?
50-60% over standard treatments

14. How much damage to our forage resource is occurring?
Scenario
Stocking Rate:
lb. cow / 4 acre stocking unit (SU)
30 lbs. forage DM /day
(2.5% of BW)
8 mature hoppers / yd2 
0.25 g forage DM /day
(50% of BW)
How much damage to our forage resource is occurring?

15. Scenario 8 hoppers/yd2 = 38,720 hoppers/ acre
Consuming 9,680 g forage DM/day
This threshold level of hoppers consumes and wastes 21 lbs/acre/day!
On our 4 acres they consume 85 lbs./day
Daily forage consumption from SU
Cow = 30 lbs.
Hoppers = 85 lbs.
We go from a 160 day to a 70 day availability

16. Scenario
So, for every 1 adult hopper per yd2 we lose 2.66 lbs forage/acre/day
This does not account for the 11.8 lbs/acre over the first 25 days of instar development
The larger the acreage needed for 1 cow the greater the loss to insect damage

17. Thresholds in Pasture? OSU Agents Handbook: Damage potential (#/ yd2 )
Small > 0.5” = per sq. yard
Large < 0.5 = 8-40 per sq. yard
Damage potential (#/ yd2 )
0-2 = noneconomic
3-7 = light
8-14 = moderate
15-30 = severe
30+ = very severe
8-12 per square yard!

18. Grasshopper Management in Pasture
Registered Insecticides: Post Plant
Baythroid to 2.9 fl oz/A
Besiege fl oz
Dimilin 2L 2 fl oz/A
Karate Z / Warrior II to 3.84 fl oz/A
Mustang MAX fl oz/A
Sevin XLR pts/Acre
Baythroid: (beta-cyfluthrin)
Besiege: (mix of lambda cyhalothrin and chlorantraniliprole [Rynaxypyr])
Dimilin: (diflubenzuron)
Karate/Warrior: (lambda cyhalothrin)
Mustang MAX: (zeta cypermethrin)
Sevin: (carbaryl)
Oklahoma State University

19. Oklahoma State University

20. Grasshopper Control Trial, 2012
Product Rate %Control
3 days 7 days
Endigo 2.06 ZC 4 fl oz/A 94% 45%
Endigo 2.71 ZC 4 fl oz/A 80% 50%
Centric 40WG 3.5 fl oz/A 80% 61%
Besiege 1.25ZC 9 fl oz/A 98% 80%
Baythroid XL 2.8 fl oz/A 60% 0%
Untreated
Treatments applied on 29 20gal/per acre , Adair County
Besiege: (mix of lambda cyhalothrin and chlorantraniliprole [Rynaxypyr])
Endigo: (mix of lambda cyhalothrin and thiamethoxam)
Baythroid (beta-cyfluthrin)
Centric: (thiamethoxam)
Oklahoma State University

21. Grasshopper Control number per 5 sweeps @ 28 DAT d $11.70/A d $16.41/A
oz/A d
$11.70/A d
$16.41/A c
$2.96/A b
$2.61/A a
Philip Shackelford, CEA & Roy Parker, EE
Texas A&M University, Austin County, 2012

22. Grasshopper Control number per 5 sweeps @ 42 DAT cd d bc b a oz/A
Philip Shackelford, CEA & Roy Parker, EE
Texas A&M University, Austin County, 2012

23. Things to consider! Grasshopper populations are dynamic
It is difficult to say exactly how much impact they have at any one time:
Variety of growth stages
Larger hoppers consume more
But, as they grow they become less dense
We must consider timing, weather, potential population, forage damage, etc.

24. Summary!
Practice good sanitation around roadsides, ditches and known wintering (nursery) areas
Consider spraying these areas early while nymphs are small and easy to control
Assess size and density of grasshopper outbreaks to determine control strategy
Scout effectively on field edges and interiors and use one of the square yard methods (EPP-7196)
Use RAAT treatments when possible to reduce costs
Mature grasshoppers pose a serious threat to forage producers
More difficult to control with insecticides
Consume large amounts of forage daily

25. Questions?

26. 21 lbs.
42 lbs.
210 lbs.
30 lbs.
58.8% utilization
12.5% utilization
0.66 days of grazing/ day
7 days of grazing/day
Notice that as stocking rate decreases, forage removal increases (per stocking unit/day)

27. Questions What 3 stages do grasshoppers go through?
How long is the avg. maturation process?
How many generations/year are observed for most species?
What is the common name of this species?

28. Questions Approximately what % of BW will an adult consume in one day?
At what threshold is control recommended in pastures?
Where is the ideal place to initiate control?
What stage of growth?
Name a labeled insecticide with 0 day grazing withdrawl.

29. Questions BONUS What does RAAT stand for?
What chemical is labeled for this type of use?
How much could this reduce costs?