New Insecticide Chemistries for Management of Silverleaf Whitefly

New Insecticide Chemistries for Management of

Silverleaf WhiteflyAlton N. Sparks, Jr.

Extension EntomologistUniversity of Georgia, Tifton Campus

New Insecticides for Whiteflies

• Movento (spirotetramat)• Coragen (chlorantraniliprole) • First impressions and current view• Understanding of a products

capabilities is necessary for incorporation into IPM programs and evaluation.

Silverleaf Whitefly

• Bemisia tabaci, (B. argentifolii) • Silverleaf/Sweet potato/Poinsettia • Wide host range• Likes hot dry weather• Primarily summer/fall pest in Ga.• Damage:

– Feeding, honeydew, sooty mold– Plant disorders, virus vector

Silverleaf Whitefly

Whitefly Management• Do not overwinter populations• Start fields clean (clean transplants)• Separate hosts crops when possible• Avoid susceptible crops in fall if

possible• Insecticides

– Soil applied systemic– Foliar insecticides

Systemic Insecticides for SLWF

• Neonicotinoid insecticides–Admire Pro (generics)–Platinum–Venom

• Coragen• Durivo (Coragen+Platinum)

Foliar Insecticides for SLWF• Pyrethroids + organophosphates• Endosulfan• Neonicotinoids (Actara, Assail, Venom)

• Knack• Courier• Rimon• Oberon, Movento• Coragen (Voliam)

Movento• A.I. – spirotetramat (Group 23)• Bayer CropScience• Movento

–Highly systemic–Foliar applications only–Adjuvant necessary (on label)–Aphids, whiteflies

PhloemUpward and downwardtransport

XylemUpwardtransport

Spirotetramat application sites

Artificial caged infestation of Green Peach Aphid was controlled 3 days after application

Behavior within the Plant

Mealy Plum Aphid Fresno, CA – 2006 on French

Prune

0

10

20

30

40

50

60

70

80

90

100

7 14 21 29 36 42

Untreated

PROVADO - 6 fl oz

MOVENTO - 5 fl oz

MOVENTO - 5 fl oz +0.25% Succeed

MOVENTO - 5 fl oz +0.834% Induce

MOVENTO - 5 fl oz +0.21% Silwet

ID06NARSKHURW1. Dr. Richard Warner – Bayer CropScience.

% In

fest

ed T

erm

inal

s

DATWith surfactants

Surfactant Impact:

Coragen• A.I. – chlorantraniliprole (rynaxypyr)• DuPont• Coragen (also in Durivo and Voliam)

– Excellent control of caterpillars– Systemic activity (soil applications)– Adjuvants help foliar applications

(not on all crop labels)– Whitefly activity debatable

Chlorantraniliprole for SLWF

• Vegetable Entomologist Workshop Monterey, California, May 2008

• Best Management Practices for Pest Control in Vegetables

• “Not consistent for whitefly control; suppression at best”

Movento - First Experience• Activity on whitefly (no specifics)• Threw it in a squash test in fall of 2007• Foliar applications at first signs of

silvering• Extreme pest pressure• NOTHING WORKED very well• Had doubts about its activity on SLWF

• Bayer requested greenhouse work

Coragen – First experience

First Impressions

• Movento– Little or no activity on SLWF

• Coragen– Excellent activity on SLWF– Possible replacement for Admire

Greenhouse Studies

• At time of application– Two non-treated plants monitored– Oldest infestation – even mix of small

and large nymphs– Middle infestation – small nymphs +

few eggs– Youngest infestation – recently

hatched nymphs + few eggs

Whitefly per leaf (snap beans) Earliest (oldest) infestation

0

2

4

6

8

10

12

14

Check

Synap

seS+S

ilwet

S+Induce

S+MSO

Movento

Venom

PupaeL. nymphsS. nymphs

Evaluated at 7 DAT

Whitefly per leaf (snap beans) Second infestation

0

2

4

6

8

10

12

Check

Synap

seS+S

ilwet

S+Induce

S+MSO

Movento

Venom

L. nymphsS. nymphs

Evaluated at 10 DAT

SLWF greenhouse Cucumber Test 2 Oldest leaf

0

5

10

15

20

25

Check

Synap

seSun+

MSO

Coragen

Cor+MSO

Movento

Emerged PLar. Nym.Sm. Nym.

SLWF greenhouse Cucumber Test 2Youngest leaf

0

5

10

15

20

25

30

Check

Synap

seSun+

MSO

Coragen

Cor+MSO

Movento

Emerged PLar. Nym.Sm. Nym.

Number of plants with silverleafDrench Treatments - 2006

0123456789

1012

DA

T

14 D

AT

21 D

AT

29 D

AT

33 D

AT

47 D

AT

CheckVenomAdmireCoragen

Transplant drench (Oct. 31, one true leaf); pest pressure light to moderate

Silverleaf RatingsSoil and Foliar Treatments - 2007

0

1

2

3

4

5

6

7

8

13/7 DAT 17/11 DAT 23/17 DAT 31/26 DAT

CheckVenom (s)Venom (f)Coragen (s)Coragen+ (f)

Soil app. at cotyledon stage, first foliar 6 days later. Bif+Ort 3 times.

Silverleaf RatingsFoliar Treatments - 2008

0

1

2

3

4

5

6

3 DAT-1

6 DAT-1

3 DAT-2

1 DAT-3

6 DAT-3

4 DAT-4

7 DAT-4

CheckAssailCoragenCoragen+

Four weekly applications, minor silverleaf at first application.

Squash Silverleaf Ratings (0 to 6)Drench Treatments - 2008

0

1

2

3

4

5

6

9/2/

2008

9/4/

2008

9/6/

2008

9/8/

2008

9/10

/200

8

9/12

/200

8

9/14

/200

8

9/16

/200

8

9/18

/200

8

9/20

/200

8

9/22

/200

8

9/24

/200

8

CoragenVenom1013Check

Treatments applied 8/15/08 and 9/3/08

Current Views• Movento provides excellent control of

early instar whitefly nymphs• Coragen activity may be similar

– Addition of surfactant significantly increases efficacy of foliar treatments (label restrictions)

– Efficacy much better as preventive treatment

– Soil application longer residual

Current Views• Movento and Coragen provide excellent control

of early instar whitefly nymphs– Should be considered in

• product selection• application timing• product evaluation

– Probably not suitable for rescue treatment or stand alone on siesitive crops

– Excellent preventive or rotation partner (unique MOA, highly systemic, long residual)