Molecular identification of arthropod predators of cucumber beetles
Molly Dieterich Mabin Celeste Welty Mary M. Gardiner
Images: pesthoreca.com Cucumber beetles
Coleoptera: Chrysomelidae
Acalymma vi atum Diabro ca 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 insec mages.org Vegetable Produc on
• High input systems – Pes cides – Fer lizers – Water – Plas c mulch – Frequent lling
M. Dieterich Vegetable Produc on
• High input systems – Pes cides – Fer lizers – Water – Plas c mulch – Frequent lling
M. Dieterich Conserva on Biological Control
Increase ac vity, abundance, & diversity of predatory natural enemies • Reduced llage • Crop rota ons • 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 & Gra on 2008; Saska et al. 2007 Strip llage
• Reduced disturbance • Organic ma er • Structural & species
M. Dieterich diversity of vegeta on Strip llage
• Reduced disturbance • Organic ma er • Structural & species
M. Dieterich diversity of vegeta on
Natural enemies
Bo enberg et al. 1999; Luna & Staben 2002; Brainard & Corey Noyes 2012 S nner & 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 beetle © 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 vegeta ve habitats
M. Dieterich
Abundant, diverse, & ac ve NE community
Greater biological control of cucumber beetles 2013 & 2014
M. Dieterich M. Dieterich Strip Tillage Plas c Mulch
• organic & conven onal management
• natural enemy community & biological control Experiments
1. Pi all traps • Diversity 2. Sen nel egg study • Preda on rates 3. Video surveillance • Who’s ea ng the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol Experiments
1. Pi all traps • Abundance, richness, diversity 2. Sen nel egg study • Preda on rates 3. Video surveillance • Who’s ea ng the eggs? www.danielharper.org 4. Molecular gut content analysis • Who contributes to biocontrol Experiments
1. Pi all traps • Abundance, richness, diversity
2. Sen nel egg study M. Dieterich • Preda on rates 3. Video surveillance • Who’s ea ng the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol Experiments
1. Pi all traps • Abundance, richness, diversity 2. Sen nel egg study • Preda on rates 3. Video surveillance • Who’s ea ng the eggs? M. Dieterich 4. Molecular gut content analysis • Who contributes to biocontrol Experiments
1. Pi all traps • Abundance, richness, diversity 2. Sen nel egg study • Preda on rates 3. Video surveillance • Who’s ea ng 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 Pi alls & 2014 sen nel eggs
2014 Sen nel eggs Predator Abundance
• Expected: greater abundance in strip llage plots than in plas c mulch plots • Observed: greater abundance in strip llage 75% of the me & in plas c mulch 25% of the me Predator Abundance
• Expected: greater * abundance in strip llage plots than in plas c * * mulch plots • Observed: greater * abundance in strip llage 75% of the me & in plas c mulch 25% of the
2013 2014 me Predator Richness
• Expected: greater richness in strip llage plots than in plas c mulch plots • Observed: greater abundance in strip llage plots 75% of the me Predator Richness
• Expected: greater richness * * in strip llage plots than in plas c 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 plas c mulch plots • Observed: greater abundance in strip llage plots 75% of the me Predator Diversity
• Expected: greater
* diversity in strip llage plots than in plas c mulch plots • Observed: greater diversity in strip llage plots 25% of the me
2013 2014 Non-metric Mul dimensional Scaling (NMDS) Analysis
p=0.0004 Ohio 2014 Conven onal Squash Organic Squash p=0.0019 p=0.0004
Conven onal Melons Organic Melons p=0.0003 p=0.0001 Experiments
1. Pi all traps • Abundance, richness, & diversity ! greater in ST • Community ! different between ST and PM 2. Sen nel egg study • Preda on rates 3. Video surveillance • Who’s ea ng the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol 2. Sen nel Egg Study
4 sites: Ohio, Kentucky, Iowa, Pennsylvania • 24 hours
M. Dieterich
M. Dieterich Egg Consump on
• Greater egg consump on in plas c mulch (2/6 sites) & below ground Experiments
1. Pi all traps
2. Sen nel egg study • Egg preda on rates ! generally greater in PM 3. Video surveillance • Who’s ea ng the eggs? 4. Molecular gut content analysis • Who contributes to biocontrol 3. Video Surveillance
• Who is ea ng cucumber beetle eggs? – Video surveillance of above ground sen nel 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. Pi all traps
2. Sen nel egg study
3. Video surveillance • Who’s ea ng 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 extrac on 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 h p://mknhs.org.uk/
Phalangium opilio Opilio parie nus 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 h p://mknhs.org.uk/
Phalangium opilio Opilio parie nus 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 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 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) Diges on 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 Diges on 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 – evalua ng other species (beetles & ants) Diges on 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 – evalua ng other species (beetles & ants) Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are o en greater in strip llage than in plas c 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 o en greater in strip llage than in plas c mulch – But, biological control was generally greater in plas c mulch Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are o en greater in strip llage than in plas c mulch – But, biological control was generally greater in plas c mulch • Perhaps the difference in community composi on between strip llage & plas c mulch is driving this pa ern Summary • Does strip llage result in greater biocontrol? – Predator abundance & richness are o en greater in strip llage than in plas c mulch – But, biological control was generally greater in plas c mulch • Which predators consume cucumber beetles? – Ants & beetles are common egg predators – Wolf spiders & harvestmen consume CB in the field • Ground beetles & ants Implica ons
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 Ini a ve 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 Ques ons?
M. Spring