Molecular identification of predators of cucumber

Molly Dieterich Mabin Celeste Welty Mary M. Gardiner

Images: pesthoreca.com Cucumber beetles

Coleoptera: Chrysomelidae

Acalymma viatum Diabroca undecimpunctata howardi

M. Spring M. Spring Cucurbits

B. Carter J. Jemmo

bncc369 Cucumber beetles

bemerson C. Welty

Bacterial wilt (Erwinia tracheiphila)

R. Manley

Fleischer et al. 1999; Ellers-Kirk & Fleischer 2006; Smyth & Hoffmann 2010 insecmages.org Vegetable Producon

• High input systems – Pescides – Ferlizers – Water – Plasc mulch – Frequent lling

M. Dieterich Vegetable Producon

• High input systems – Pescides – Ferlizers – Water – Plasc mulch – Frequent lling

M. Dieterich Conservaon Biological Control

Increase acvity, abundance, & diversity of predatory natural enemies • Reduced llage • Crop rotaons • Cover crops • Refuge habitats • Natural areas • Fallow fields M. Dieterich Batra 1982; Wissinger 1997; Gardiner et al. 2009; Maisonhaute et al. 2010 Hummel et al. 2002; Lee et al. 2001; Werling & Graon 2008; Saska et al. 2007 Strip llage

• Reduced disturbance • Organic maer • Structural & species

M. Dieterich diversity of vegetaon Strip llage

• Reduced disturbance • Organic maer • Structural & species

M. Dieterich diversity of vegetaon

Natural enemies

Boenberg et al. 1999; Luna & Staben 2002; Brainard & Corey Noyes 2012 Snner & House 1990; Marino & Landis 1996; Bryant et al. 2013 • Does this increase in natural enemy abundance and diversity result in greater biological control?

Ant © M Marlow. Wolf spider © I Cret. Harvestmen © GR Sapcote. Ground © DH Kavanaugh. Rove beetle © E Gofreed. Lady beetle © L Ruth. Cricket © R Cohutta. Grasshopper © JP Michaud. Centipede © UNL Entomology. Cucumber beetles © M Spring. Hypothesis

Complex vegetave habitats

M. Dieterich

Abundant, diverse, & acve NE community

Greater biological control of cucumber beetles 2013 & 2014

M. Dieterich M. Dieterich Strip Tillage Plasc Mulch

• organic & convenonal management

• natural enemy community & biological control Experiments

1. Piall traps • Diversity 2. Sennel egg study • Predaon rates 3. Video surveillance • Who’s eang the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol Experiments

1. Piall traps • Abundance, richness, diversity 2. Sennel egg study • Predaon rates 3. Video surveillance • Who’s eang the eggs? www.danielharper.org 4. Molecular gut content analysis • Who contributes to biocontrol Experiments

1. Piall traps • Abundance, richness, diversity

2. Sennel egg study M. Dieterich • Predaon rates 3. Video surveillance • Who’s eang the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol Experiments

1. Piall traps • Abundance, richness, diversity 2. Sennel egg study • Predaon rates 3. Video surveillance • Who’s eang the eggs? M. Dieterich 4. Molecular gut content analysis • Who contributes to biocontrol Experiments

1. Piall traps • Abundance, richness, diversity 2. Sennel egg study • Predaon rates 3. Video surveillance • Who’s eang the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol M. Dieterich Field Sites Field Sites Field Sites Field Sites Field Sites Field Sites Field Sites 2013 Pialls & 2014 sennel eggs

2014 Sennel eggs Predator Abundance

• Expected: greater abundance in strip llage plots than in plasc mulch plots • Observed: greater abundance in strip llage 75% of the me & in plasc mulch 25% of the me Predator Abundance

• Expected: greater * abundance in strip llage plots than in plasc * * mulch plots • Observed: greater * abundance in strip llage 75% of the me & in plasc mulch 25% of the

2013 2014 me Predator Richness

• Expected: greater richness in strip llage plots than in plasc mulch plots • Observed: greater abundance in strip llage plots 75% of the me Predator Richness

• Expected: greater richness * * in strip llage plots than in plasc mulch plots

* • Observed: greater richness in strip llage plots 75% of the me

2013 2014 Predator Diversity

• Expected: greater diversity in strip llage plots than in plasc mulch plots • Observed: greater abundance in strip llage plots 75% of the me Predator Diversity

• Expected: greater

* diversity in strip llage plots than in plasc mulch plots • Observed: greater diversity in strip llage plots 25% of the me

2013 2014 Non-metric Muldimensional Scaling (NMDS) Analysis

p=0.0004 Ohio 2014 Convenonal Squash Organic Squash p=0.0019 p=0.0004

Convenonal Melons Organic Melons p=0.0003 p=0.0001 Experiments

1. Piall traps • Abundance, richness, & diversity ! greater in ST • Community ! different between ST and PM 2. Sennel egg study • Predaon rates 3. Video surveillance • Who’s eang the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol 2. Sennel Egg Study

4 sites: Ohio, Kentucky, Iowa, Pennsylvania • 24 hours

M. Dieterich

M. Dieterich Egg Consumpon

• Greater egg consumpon in plasc mulch (2/6 sites) & below ground Experiments

1. Piall traps

2. Sennel egg study • Egg predaon rates ! generally greater in PM 3. Video surveillance • Who’s eang the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol 3. Video Surveillance

• Who is eang cucumber beetle eggs? – Video surveillance of above ground sennel egg cards

M. Dieterich 3. Video Surveillance

• Ants & beetles • Harvestmen, flies, & crickets

• Spiders, wasps, grasshoppers, slugs, & a mouse 3. Video Surveillance Formicidae

All predators

Coleoptera Experiments

1. Piall traps

2. Sennel egg study

3. Video surveillance • Who’s eang the eggs? ! ants & beetles 4. Molecular gut content analysis • Who contributes to biocontrol Molecular gut content analysis

M. Spring M. Spring

M. Spring

M. Spring

J. Gross Molecular gut content analysis

Collect NEs DNA extracon Develop primers (CO1 gene) M. Dieterich

M. Spring

M. Dieterich

Chisholm et al. 2014, Rougerie et al. 2011, Harwood et al. 2009, Lundgren et al. 2009, Harwood et al. 2007, Schmidt et al. 2014 Molecular gut content analysis

PCR & gel electrophoresis

M. Dieterich Molecular gut content analysis

• 204 wolf spiders (Araneae: Lycosidae)

M. Spring M. Dieterich

Pardosa milvina Pardosa pauxilla (n=133) (n=21) Immature Pardosa spp. (n=50) Molecular gut content analysis

• 204 wolf spiders ! 12.25%

M. Spring

Pardosa milvina Pardosa pauxilla (n=133) (n=21) Immature Pardosa spp. (n=50) Molecular gut content analysis

• 88 harvestmen (Opiliones)

G.R. Sapcote

eakringbirds.com discoverlife.org hp://mknhs.org.uk/

Phalangium opilio Opilio parienus Leiobunum spp. Mitopus morio (n=59) (n=22) (n=4) (n=3) Molecular gut content analysis

• 88 harvestmen ! 12.5%

G.R. Sapcote

eakringbirds.com discoverlife.org hp://mknhs.org.uk/

Phalangium opilio Opilio parienus Leiobunum spp. Mitopus morio (n=59) (n=22) (n=4) (n=3) Molecular gut content analysis

• 72 ground beetles (Coleoptera: Carabidae)

T. Murray

B. Betros Anisodactylus sanctaecrucis comma Harpalus pensylvanicus (n=36) (n=26) (n=3) Anisodactylus spp. Stenolophus spp. Harpalus spp. (n=1) (n=7) (n=5) Molecular gut content analysis

• 72 ground beetles ! 5.5%

T. Murray

B. Betros Anisodactylus sanctaecrucis Stenolophus comma Harpalus pensylvanicus (n=36) (n=26) (n=3) Anisodactylus spp. Stenolophus spp. Harpalus spp. (n=1) (n=7) (n=5) Molecular gut content analysis

• 72 ants (Formicidae)

T. Murray

Lasius neoniger (n=72) Molecular gut content analysis

• 72 ants ! 5.5%

T. Murray

Lasius neoniger (n=72) Digeson Rate Assay - Methods

starved for 3 days M. Spring G.R. Sapcote

+ cucumber beetle larvae

starved for: 0, 12, 24, 36, 48, 60, 72 hrs Digeson Rate Assay - Results

• Wolf spiders & harvestmen M. Spring G.R. Sapcote

• DNA is detectable for 72 hours – Cucumber beetles appear to metabolize slowly in arachnids

• In future: – added me points so we can start to compare – evaluang other species (beetles & ants) Digeson Rate Assay - Results

• Wolf spiders & harvestmen M. Spring G.R. Sapcote

• DNA is detectable for 72 hours – Cucumber beetles appear to metabolize slowly in arachnids

• In future: – added me points so we can start to compare – evaluang other species (beetles & ants) Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are oen greater in strip llage than in plasc mulch – We would expect to see increased biocontrol with increased natural enemy abundance & richness (Letourneau et al. 2009) Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are oen greater in strip llage than in plasc mulch – But, biological control was generally greater in plasc mulch Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are oen greater in strip llage than in plasc mulch – But, biological control was generally greater in plasc mulch • Perhaps the difference in community composion between strip llage & plasc mulch is driving this paern Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are oen greater in strip llage than in plasc mulch – But, biological control was generally greater in plasc mulch • Which predators consume cucumber beetles? – Ants & beetles are common egg predators – Wolf spiders & harvestmen consume CB in the field • Ground beetles & ants Implicaons

extension.org

calflora.net Chaplin-Kramer et al. 2011, Tscharntke et al. 2007, Crowder & Jabbour 2014 Thank you! • Welty Lab Funding: – Field work Specialty Crop Research Iniave grant number: • Ag-Urban Landscape 2012-51181-20295 Ecology Lab

• Dr. Andy Michel OARDC SEEDS Graduate Student Grant • Dr. Susan Jones

– Lab space

Graduate Research Grant Quesons?

M. Spring