Research project about tomato potato psyllid and Liberibacter ecology.

1. biosecurity built on science
Tomato potato psyllid and Liberibacter ecology
Jessica Dohmen-Vereijssen
Senior Scientist at Plant & Food Research, NZ
Natasha Agnew, Anna-Marie Barnes, Ruth Butler, Kyla Finlay,
David Logan, Kevin Powell, Aleise Puketapu, Mano Sandanayaka,
Shirley Thompson, Isabel Valenzuela, Alan Yen
Plant Biosecurity Cooperative Research Centre

2. biosecurity built on science
What is the main message of this slide?
In memory of
Alan Yen

3. biosecurity built on science
What is the problem?
 Tomato potato psyllid (TPP, Bactericera cockerelli)
 TPP vectors Candidatus Liberibacter solanacearum (CLso)
 CLso is putative agent causing zebra chip disease in potato
 But tomato, capsicum, tamarillo, chili, eggplant are affected too

4. biosecurity built on science
Significant economic losses across NZ’s horticulture industry
 March 2006, Bactericera cockerelli (tomato potato psyllid, TPP)
found in tomato crop near Auckland
 April 2008, Candidatus Liberibacter solanacearum (CLso) – a new to
science pathogen - confirmed in glasshouse capsicum crop
 May 2008, CLso confirmed in potatoes showing zebra chip disease
near Auckland
 Potato and tamarillo industry most severely impacted (Ogden, 2012)
 Reduced yield and quality, increase management costs
Potato: NZ$47-56M losses in 2008-09
Tamarillo: 80 growers lost in 5 years
Greenhouse tomato: 4-6% yield loss
(Ogden, 2012)

5. biosecurity built on science
What other plant hosts for B. cockerelli are out there?
 TPP host plant in Solanaceae
– these are widespread in Australia and New Zealand: crops and weeds, cultural uses too
 Knowledge gap: ecology of TPP and CLso related to their non-crop host
plants (temporal & spatial dynamics, feeding, development)

6. biosecurity built on science
Key outputs for this project
 Knowledge
 Scientifically validated list of crop and non-crop alternative hosts in Australia and New Zealand
 Tool & training
 Targeted monitoring and weed management advice to growers, plant primary industries and
biosecurity agencies

7. biosecurity built on science
Host plant surveys around crops
 Host plants of TPP and CLso are not restricted to crop species, and
include weed species, which provides challenges for surveillance,
eradication and management
– All TPP life stages were present on non-crop host plants throughout the year
– So they are not alternative hosts, but hosts
– Jerusalem cherry and thorn-apple tested positive for CLso in Hawke’s Bay

8. biosecurity built on science
Spatiotemporal dynamics of TPP throughout the year
 There was a low background population of B. cockerelli flying
around in the environment
 When African boxthorn was present adjacent to a crop, there was
increased activity nearby and an edge effect may be observed in
the host crop
 B. cockerelli multiplied in the crop but did not disperse far
 A desiccated crop increased adult flight in B. cockerelli

9. biosecurity built on science
Feeding of B. cockerelli on tomato and boxthorn
 Host plant species alone was not decisive in determining the number
and duration of phloem salivation (E1) and ingestion (E2) events in B.
cockerelli
 CLso infection status of B. cockerelli was more important in determining
feeding behaviour
– CLso-positive B. cockerelli are more likely to salivate than CLso-negative ones
– CLso-negative B. cockerelli are more likely to ingest phloem sap than CLso-positive ones

10. biosecurity built on science
What is the main message of this slide?
TPP performed
best
TPP performed
worst
Days till first egg
laid
Potato Boxthorn Poroporo Tomato
Number of
eggs/female/day
of life
Poroporo Boxthorn Potato Tomato
Mortality overall Poroporo Potato Boxthorn Tomato
Days to female
death
Poroporo Potato Tomato Boxthorn
Days to male
death
Poroporo Potato Boxthorn Tomato
Development
time overall
Poroporo Potato Boxthorn Tomato
Development and fecundity of B. cockerelli on host plants

11. biosecurity built on science
Who will benefit from this research?
• Growers (potato, tamarillo, outdoor tomato, capsicum, chili, eggplant, tomato)
• Plant primary industries NZ & AU
• Biosecurity decision makers / Surveillance / Pest Risk Assessment / Diagnostics
• PHA, SPHD, SNPHS
• Internationally (especially for PRAs)
• PBCRC
• Researchers US, NZ, AU
• CRC2002/2156, CRC2146, NZ Govt funded TPP/CLso programme
• Government (state, federal & Norfolk Island)

12. biosecurity built on science
What is the main message of this slide?Non-crop host plants are important in the ecology of B. cockerelli
 This has implications for
- biosecurity preparedness plans and PRAs
- surveillance and monitoring (techniques and locations)
- incursion responses
- pest and disease management
 For more information, please email
Jessica.Dohmen-Vereijssen@plantandfood.co.nz
 Twitter: @JVereijssen