New Traits and Technology

for Corn Insect Management

Agent UpdateDr. Ric Bessin

Extension Entomologist

Southwestern Corn Borer

European Corn Borer

Overwinter SWCB Survival

Year SWCB Survival

SWCB/stalk

1999 10.1 3.64

2000 26.9 5.57

2001 9.7 3.92

2002 5.3 0.63

2003 4.3 1.13

2004 2.5 0.39

2005 5.3 0.30

Caldwell, Henderson, Davies, Hardin CountiesFour fields/county

Planting-Date Study

• UK REC Princeton Kentucky – R. Bessin, D. Johnson, J. Herbek

• Five planting dates, Early April thru early June (every 2 weeks)

A Bt corn hybrid and non-Bt isoline

Yield Benefit by Planting Date 7-Year Average

Planting Date Non-Bt Tunnelin

g (in)

Yield, non-Bt

(bu)

Yield, Diff.(bu)

Early – Mid April

3.2 189.7 3.2

Late April 4.0 198.8 2.7

Early –Mid May

4.1 182.3 6.2

Late May 5.2 160.2 9.2

Early – Mid June

6.3 112.3 21.1

Biotech Tools for Corn Pests

Bt Corn– YieldGard Corn Borer (Cry1Ab)

– YieldGard Rootworm (Cry3Bb1)

– YieldGard Plus (Cry1Ab+Cry3Bb1)

– Herculex I (Cry1F)

– Herculex RW (Cry34Ab1/Cry35Ab1)

– Herculex Xtra (Cry1F+Cry34Ab1/Cry35Ab1)

– Agrisure CB (Cry1Ab)

– Agrisure RW ? (Cry3A)

– Agrisure CB/RW ?

Insects Controlled by Bt Corn

ECBSWC

BBCW FAW CRW

YieldGard CB ++ ++ - + -

YieldGard RW - - - - ++

YieldGard Plus ++ ++ - + ++

Herculex 1 ++ ++ ++ ++ -

Herculex RW - - - - ++

Herculex Xtra ++ ++ ++ ++ ++

Traditional Corn Seed Treatments‘Hopperbox’

Agrox PremiereGermate Plus

Grain Guard PlusKernel Guard

Kernel Guard SupremeKickStart

Lorsban SL

Hopperbox Treatments

• Permethrin, lindane, chlorpyrifos, imidacloprid

• Cheapest treatments available

• Recommended when no soil insecticides used

• Effective against seedcorn maggot and wireworms (low populations)

• High exposure potential

True Seed Treatments

Seed Treatments (Ordered with seed)– Imidacloprid

Gaucho extra (0.6 mg/kernel)

Prescribe (1.34 mg/kernel)

– ThiamethoxamCruiser Extreme Pak (0.25 mg/ker)

Cruiser Extreme Pak CRW (1.25 mg/kernel)

– ClothianidinPoncho 250 (0.25 mg/kernel)

Poncho 1250 (1.25 mg/kernel)

Immediate Plant Back

30-Day Plant Back

120-Day Plant Back

12 Month Plant Back

Insects Controlled

WW WG FB SCM BCW

CRW

Gaucho ++ ++ + ++ - -Prescribe ++ ++ ++ ++ - +Cruiser Ex Pak ++ ++ ++ ++ + -Cruiser EP CRW

++ ++ ++ ++ + ++

Poncho 250 ++ ++ ++ ++ + -Poncho 1250 ++ ++ ++ ++ ++ ++

Common Wireworm species identified from corn fields in KY 2004-2005.

Aeolus mellillus Conoderus lividus

Melanotus depressus Melanotus communis-dietrichi

Herculex RW

• Received full EPA registration in 2005

• Cry34Ab1 + Cry35Ab1• Controls Western and Northern

corn rootworms• European and Japanese approval

pending• Limited marketing for 2006

BT RW IRM Requirements

Requirement

YieldGard RW Herculex RW

Minimum size of refuge

20 % of corn acreage

20 % of corn acreage

Arrangement

Same or adjacent field

Same or adjacent field

Minimum size of refuge strips

6 rows or more 4 rows or more

Rotational history

Refuge same as BT RW field

Refuge –Continuous

BT RW – Continuous or 1st

year

Larvacide? Yes in refuge Yes in refuge

Herculex Xtra

• Received full EPA registration Oct 31, 2005

• Cry34Ab1/Cry35Ab1 + Cry1F• Controls rootworms, corn

borers, cutworms, fall armyworm

• Japanese approval pending• Limited marketing for 2006

Making the Control Decision

• Rotation information– Corn after corn ? After pasture ?

• Planting Date – Very early - wireworms– Very late – corn borers

• Likelihood of Problems– Past problems ?

• Cost – Is rotation more cost effective?

• Equipment

Soybean Aphid Status

Seed Treatments on Soybeans

Agent UpdateDr. Doug Johnson

Extension Entomologist

Updates on Soybean aphid can be found at the KY-IPM home page. Just

click on the Soybean aphid icon

http://www.uky.edu/Agriculture/IPM/ipm.htm

Soybean Aphid Status

• 2005 Present but virtually unseen in KY

• Significant populations limited to northern portions of the mid-west

• Some populations over shadowed by outbreak of spider mites.

• Presence of the “White dwarf” aphid

Soybean Aphid StatusSampling

• MN speed sampling method tends to over estimate the need to spray.

• Will incorporate 05 data in to procedure

• Not useful for a repeat spray

Soybean Aphid StatusDecision

• 250 aphids per plant,• More than 80% plants infested,• With an INCREASING

population,• V through R5 (beginning seed

set) stages. • Provides 7 day lead time

Yield Loss Factors

• Flowering stages most sensitive

• Loss through seed abscission• Some recuperation through

increase in seed size

“White Dwarf” Soybean aphid

Cast Skins

Insecticide Seed Treatments for Soybean

Trials at UK-REC Princeton

• Three years of trials 2003-05• Included seed treatments, foliar

applications and combinations.• Focus on insecticides but some

treatments also contained fungicides.

• All seed treatments applied by professional seedtreaters.

Seed Treatment Test Results

• In NO trial did any treatment ever yield differently from the untreated check.

• In all cases insect populations were minimal.

• In no year was movement of plant virus important.

Recommendations?

• This does NOT indicate that seed treatments do not work.

• This DOES indicate that seed treatments were not needed.

• Recommendations remain the same.

Recommendations

• Use seed treatments in High risk areas.– Early planting, cool \ damp ground– History of significant soil pests

• Select the seed treatment which fits the situational risk e.g.– Seed corn maggot & seed corn beetle– Wireworm history

Seed Treatments in relation to Soybean Aphid• Will provide some control but

are not holding up economically in NC states.

• Are unlikely to be the main method of control if problem develops in KY because the populations will develop too late in the season.