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

Question #1 What 3 stages do grasshoppers go through?

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

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

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

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

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

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

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

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

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

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

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

How much damage to our forage resource is occurring? Scenario Stocking Rate: 1 - 1200 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?

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

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

Thresholds in Pasture? OSU Agents Handbook: Damage potential (#/ yd2 ) Small > 0.5” = 24-100 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!

Grasshopper Management in Pasture Registered Insecticides: Post Plant Baythroid 2.6 to 2.9 fl oz/A Besiege 6-9 fl oz Dimilin 2L 2 fl oz/A Karate Z / Warrior II 2.56 to 3.84 fl oz/A Mustang MAX 3.4-4.3 fl oz/A Sevin XLR 2-3 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

Oklahoma State University

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 May @ 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

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

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

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.

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

Questions?

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)

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?

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.

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