Hessian Fly ID/Management in Wheat Jack Baldwin Fangneng Huang Rogers Leonard Steve Harrison Ed Twidwell Jack Baldwin Fangneng Huang Rogers Leonard Steve Harrison Ed Twidwell

Adults Hessian fly Mayetiola destructor There are 4-6 generations each year. A generation takes about 35 days at 75 º F, longer at cooler temperatures. Development occurs between º F

Hessian fly eggs

Hessian fly larvae 2nd stage (L) and 3 stage (R)

Hessian fly puparia

 puparia Larvae  R. Ratcliffe Photo

Hessian fly puparia

Hessian Fly In Wheat Fly damaged plants and/or tillers

More dead tillers, thin stand

Toxins in saliva cause stunting, plant death, yield and quality losses A thin stand of stunted plants (right) is a classic symptom of Hessian fly infestation

Hessian Fly In Wheat Fly damaged plants and/or tillers John Van Duyn - NC State Randy Weisz – NC State

Hessian fly damage looks different, depending on when the wheat was infested sometimes a wide leaf blade is a symptom. Often the wide blade has a blue-green hue.

Hessian fly damage looks different, depending on when the wheat was infested early infestation results in stunting so leaf blades only partially emerge from the ground

Infested tillers often die, particularly when subjected to cold stress in winter

Hessian fly puparia

infested in winter? infested in spring

Hessian fly yield loss in winter wheat Seedling early tiller stage: – 1 larva completely stunts and kills tiller – Cold injury Jointing / Heading / grain fill stage: – Multiple larva per stems at joints – Stunts stem – Weaken stem cause lodging. – Reduces grain filling / test weight. ↓

Hessian fly yield loss in winter wheat Seedling early tiller stage: – 5% - 8% infested tillers Heading / grain fill stage: – 15% - 20% infested stems – $7.00+/bu

Ryegrass /winter wheat are common for food plots in southern “green fields” K acres K acres

Winter Wheat Acreage and Losses to Hessian Fly in Georgia ( )       Hessian fly outbreak years $28M

Wheat Hessian Fly Management Summary for Georgia David Buntin Dept. of Entomology UGA – Griffin Campus 2008

Hessian ‘fly-free’ planting dates to avoid fall damage

Effect of Spring Tillage on Hessian Fly Emergence from Wheat Stubble (From Chapin et al J. Entomol. Sci. 27:293) a ab bc c d

Hessian fly Suppression (Wheat Stubble Management) Plant as far away from previous year’s wheat stubble as possible. Bury stubble to prevent emergence. No-till = burn alone > disking > plow. Burning stubble will not kill pupae. Plant resistant varieties in previous years field.

Control Volunteer Wheat Only important alternate host in GA is little barley, Hordeum pusillum No-till Soybeans with volunteer wheat DO NOT use susceptible wheat for wildlife plots or as a cover crop

Hessian Fly Parasitism in Winter Wheat in Georgia – 1986/1987 Sample Period Parasitoid Species % Parasitism North GASouth GA OctoberP. hiemalis90 JanuaryP. hiemalis274 MarchP. hiemalis574 MayH. destructor E. allynii 235

Plant Resistance for Hessian Fly Control

When a population of Hessian flies overcomes the host plant resistance, it is called a biotype. Numerous plant resistance genes have been identified for Hessian flies. As they are deployed, new biotypes emerge. It is important to know what biotypes are present in order to choose the right Hessian fly "resistant" variety

Hessian Fly Biotype Composition in Southern Georgia ( ) Sources: R. Ratcliffe et al., USDA-ARS, Purdue Univ. ?

Other Biotype L Biotype O Percent: Poplarville 1996 L, D, J Roger Ratcliffe, now retired from the USDA Hessian fly lab Hessian fly biotypes

Insecticides for Hessian Fly Gaucho 600 – 0.8 to 2.4 fl. oz. / 100 lb Gaucho XT – 3.4 oz/100 lbs seed – Raxil & Apron fungicides – Rate too low for HF Gaucho XT + Gaucho 1 oz/100 lb seed Commercial seed treater – Seed conditioner, dealer Cruiser 5FS (Wheat-Pak) – 1 oz/100 lb seed – Contains 3 fungicides – Rate too low for HF – Max oz/100 lb seed Karate Z (1.92 oz/A) 2-4 leaf stage. full tiller (early to mid March) – Suppression; Timing difficult Di-Syston 15G and Thimet/Phorate 20G are no long labeled for use on wheat.

Hessian Fly Control by Insecticide Treatments (Plains, GA) * * * * * * *Significantly different from Untreated, P = 0.05.

Early spring Hessian fly control with insecticide in fall infested wheat Treatments* Eggs/10 leaves** HF/5 plants*** Bu/acre oz 12.3 c 41.2 c 48.2 a 3.8 oz5.0 c 23.3 c 56.7 a oz 2X8.0 c 16.2 c 58.1 a Untreated 32.3 b a 17.7b * Sprayed 3/13; ** on 3/20; *** on 4/6 JVD

Hessian Fly Management Tactics Rotate wheat if possible. Control volunteer wheat. Do not use susceptible wheat as cover crops/wildlife plantings. Conventional tillage (fall and spring). Plant at recommended times. Variety selection. – Plant resistant varieties (if possible). – Plant susceptible varieties ‘only’ in new fields. Insecticides use strategies – Seed treatments – Lambda cyhalothrin - scouting for late winter suppression. For Grazing: only oats, rye, ryegrass.

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