Steven Naranjo, USDA-ARS, Maricopa, AZ Peter Ellsworth, Univ. AZ, Maricopa, AZ

Impact of Lygus spp. on damage, yield and quality of lesquerella (Physaria fendleri), a

potential new oil-seed crop

Lesquerella - Physaria fendleri •  Family Brassicaceae •  Perennial, native to North

America •  Physaria fendleri native to

southwestern US and cultivated as an annual Oct through May

•  Seeds contain industrially-valuable hydroxy fatty acids

•  Commercial production pending

Native P. fendleri Range

The Lesquerella Plant

Silique (seed pod)

Seed

Replum

Trichome

Open pollinated Flower w/ anthers & stigma

Plant with inflorescences

Products from Lesquerella

Other New Crops Guayule Source of hypoallergenic latex and domestic rubber

Camelina Biofuel feedstock and source of omega3 fatty acids

Vernonia Source of epoxy fatty acids

Lygus feed on variety of new crops

Naranjo and Stefanek, Indus. Crop Prod. 2012

Lygus preferentially feed on reproductive tissues

Naranjo and Stefanek, Indus. Crop Prod. 2012

Lesquerella is a suitable host

Naranjo, unpublished

Lesquerella is a potential source crop for natural enemies

Spiders

1 Mar 21 Mar 10 Apr 30 Apr 20 May 9 Jun

0

5

10

15

20

25

30

200420052006

Predatory Beetles

1 Mar 21 Mar 10 Apr 30 Apr 20 May 9 Jun0

5

10

15

20

25

30

Num

bers

per

5 s

wee

ps

Naranjo, unpublished

Predatory Bugs

1 Mar 21 Mar 10 Apr 30 Apr 20 May 9 Jun

Num

bers

per

5 s

wee

ps

0

20

40

60

80

100

200420052006

Col 1 vs Beetles

Col 14 vs Beetle05

Hymenoptera

1 Mar 21 Mar 10 Apr 30 Apr 20 May 9 Jun

0

5

10

15

20

25

30

35

Lesquerella is a potential source crop for natural enemies

Naranjo, unpublished

Lesquerella is a breeding site for Lygus

1 Mar 21 Mar 10 Apr 30 Apr 20 May 9 Jun

0

10

20

30

40

50

60

70

Lygus spp. 2006

1 Mar 21 Mar 10 Apr 30 Apr 20 May 9 Jun

0

10

20

30

40

50

60

70

Num

bers

per

5 s

wee

ps

0

10

20

30

40

50

60

70

AdultsNymphs

Lygus spp. 2004 Lygus spp. 2005

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

Evaluation of Lygus impact on lesquerella

•  Field studies conducted in 2005, 2006, 2007 and 2009 •  Plots 150 m2 (2005); 300 m2 (2006, 2007, 2009) •  Lygus spp. density manipulated by insecticides

applied at –  Varying nominal thresholds (e.g. 0.5, 2, 4, 8 per

sweep – 2005, 2006) –  Weekly, bi-weekly or tri-weekly intervals (2007,

2009) –  Early, late and total season control in 2009

•  Bi-weekly plant damage assessment •  Yield and quality assessment

Lygus damage to lesquerella B A

D C

Variable pest density by treatment

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

Lygus species composition

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

L. hesperus

L. elisus

L. lineolaris

Nymphs associated with damage

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

Variable impact of Lygus on lesquerella yield

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

Nymphs Adults

Variable impact of Lygus on lesquerella seed quality

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

Nymphs Adults

Timing of damage not important

Naranjo, Ellsworth & Dierig, J. Econ. Entomol. 2011

Nymphs Adults

All regressions NS

Seasonal cycle of Lygus spp.

J F M A M J J A S O N D

Weeds Alfalfa

Vegetables

Cotton

Vegetables

J F M A M J J A S O N D

Seasonal cycle of Lygus spp.

Lesquerella

Weeds Alfalfa

Cotton

Guayule

Vegetables Vegetables

J F M A M J J A S O N D J F M A M J J A S O N D

Vernonia Camelina

Summary/Conclusions •  Lygus hesperus readily feeds on lesquerella and

prefers the flowering structures; development is fast and mortality is low.

•  Lesquerella harbors significant breeding populations of Lygus spp. (and natural enemies).

•  Lygus spp. effects on lesquerella were inconsistent –  Nymphs were primarily associated with plant damage

and with resulting effects on yield/quality

–  Yield/quality effects observed in association with agronomic issues; plant compensation to damage?

•  Lesquerella could significantly influence regional pest and natural enemy dynamics in all affected crops

USDA-ARS Arizona Pest Mgt. Center USDA-CSREES, RAMP YULEX

Thanks to

Kim Beimfohr Becci Burke Gail Dahlquist Jessica da Costa David Dierig Emilie Latxague Jose Partida Letticia Redarte Anna Sonoqui Melissa Stefanek Julianne Trejo