Long distance natural (wind-assisted) dispersal of exotic plant pests and pathogens into Australia, is a very real and underestimated, biosecurity risk.

1. biosecurity built on science
Natural dispersal as a biosecurity risk - are we prepared?
1031: Understanding the significance of natural pathways for pest entry into Australia and
New Zealand &
2153: Enhanced surveillance strategies in horticultural industries based on knowledge of
natural dispersal pathways
Dr John Weiss
Senior Research Scientist, Vic DEDJTR
Plant Biosecurity Cooperative Research Centre

2. biosecurity built on science
What problem is your research addressing?
Long distance natural (wind-assisted) dispersal of exotic pests and pathogens into Australia
is a very real and underestimated biosecurity risk

3. biosecurity built on science
Aim - Enhanced surveillance of natural dispersal pathways.
Focus on the what, where, when and how.
(normal wind trajectories, severe weather events)

4. biosecurity built on science
Focus on the what, where, when and how.
Review of long distance natural dispersal wind patterns – wind trajectory analysis,
synoptic charts, collaboration with BOM
Monthly % of winds from Indonesia that crossed the Aust mainland 1994 -1998

5. biosecurity built on science
Focus on the what, where, when and how.
Asiatic citrus psyllid
Citrus greening/HLB – Asian Strain
Fruit fly
Citrus fruit borer
Black mildew
Cacao mealybug
GWSS?
Oriental Fruit Fly
Bean thrips
Mexican Fruit Fly ?
African citrus psyllid
Citrus greening/HLB- African Strain
Citrus scale?
Asiatic citrus psyllid
Citrus greening/HLB – Asian Strain
Fruit fly
Citrus fruit borer
Mango mealybug
Fruit tree mealybug
Potential wind-borne biosecurity risks for Citrus?

6. biosecurity built on science
Comparison of passive suction/ interception Insect Traps for remote locations
Existing Traps New Designs
Zellot modified Macquarie
Island
Farrow and Greenslade (2013)
Focus on the what, where, when and how.

7. biosecurity built on science
Focus on the what, where, when and how.
Processing bulk samples using next generation
sequencing for rapid DNA species
identification of priority plant pests
Pilot studies on;
Tomato Potato Psyllid
Russian Wheat aphid
But this means – lots more samples
How do we filter out what we are interested in?

8. biosecurity built on science
What key outputs will your research produce? (E.g. Tool, new
knowledge, training/capacity)
1. Risk Calendar – What, When and Where
2. Review Industry Biosecurity plans
3. A new passive wind suction trap ?
and next gen sequencing for priority plant pests.

9. biosecurity built on science
What is the expected outcome / benefit of this research?
Filling the gaps that the wind blows through.
Improved surveillance for long distance wind dispersed pests
Risk calendar – What, Where and When - Fed and state biosecurity
agencies - NAQS, BV, TAS DPIWE
Industry Biosecurity plans including risk of wind borne pests
- PHA, Industry
How - Traps and next gen sequencing – diagnostics for bulk samples

10. biosecurity built on science
What are the next steps? (What is required to realise these benefits?)
1 more year
Traps and diagnostics - Verification & validation
Finalise frequency of wind trajectories
Further engage with industry & PHA and
develop template for risk of LDD for IBPs.

11. biosecurity built on science
What is the main message of this slide?
 For more information, please email
john.weiss@ecodev.vic.gov.au
 Alan Yen, John Weiss, Paul Cunningham, Kyla Finlay, Mark Blackett
(DEDJTR Vic), Alison Saunders (PHA), Alan Wain (BOM), James
Walker (NAQS) & Les Zeller (USQ)

12. biosecurity built on science
Common name Taxa Species Entry Overall risk Distribution
Huanglongbing/ citrus greening (African strain) BAC Candidatus Liberibacter africanus HIGH HIGH Africa
Huanglongbing/ citrus greening (American strain) BAC Candidatus Liberibacter americanus HIGH HIGH Americas
Huanglongbing/ citrus greening (Asiatic strain) BAC Candidatus Liberibacter asiaticus HIGH EXT
Asia
Citrus stubborn disease BAC Spiroplasma citri MED HIGH US, Mediterranean
Citrus canker BAC Xanthomonas citri subsp. citri HIGH HIGH worldwide
Citrus variegated chlorosis (CVC) BAC Xylella fastidiosa subsp. pauca HIGH HIGH
Central & South
America
Mexican fruit fly DIPT Anastrepha ludens MED HIGH Central America
Carambola fruit fly DIPT Bactrocera carambolae HIGH HIGH PNG, Indonesia
Oriental fruit fly DIPT Bactrocera dorsalis HIGH HIGH PNG, Indonesia
Fruit Fly DIPT Bactrocera kandiensis HIGH HIGH PNG, Indonesia
Fruit Fly DIPT Bactrocera occipitalis HIGH HIGH PNG, Indonesia
New Guinea fruit fly DIPT Bactrocera trivialis HIGH HIGH PNG, Indonesia
Asiatic/Asian citrus psyllid HEM Diaphorina citri HIGH EXT Asia
Glassy winged sharpshooter (GWSS) HEM Homalodisca coagulata MED
HIGH
America, Pacific
Islands, Hawaii
African citrus psyllid HEM Trioza erytreae MED EXT Africa
Citrus fruit borer LEP Citripestis sagittiferella HIGH
HIGH
Western Indonesia,
Asia
Bean thrips THYS Caliothrips fasciatus HIGH HIGH NZ
Florida flower thrips THYS Frankliniella bispinosa HIGH
HIGH US, Central America
Citrus leprosis VIR Citrus leprosis virus (Cilevirus) MED HIGH
Central & South
America
eg mandarin stem pitting, citrus tristeza VIR
Citrus tristeza virus (Closterovirus) exotic
strains (aphid vector)
HIGH HIGH worldwide
High priority citrus pests and pathogens
Distribution of D. citri (cabi.org)

13. biosecurity built on science
Who will benefit from this research?
 Fed and state biosecurity agencies - NAQS, BV, TAS DPIWE
• targeted and timely surveillance protocols
• proactive preparedness strategies
• NAQS - implementation of improved surveillance strategies based on plant biosecurity risks rather than the
animal risk zones.
• PHA, SNPHS –
 Improved strategic capability through increased awareness of natural dispersal pathways,
 opportunity to improve IBP (better risk assessment)
• Horticulture Industry–
 increase the chance of early detection
 better use of limited resources
 Natural dispersal risk maps for Potato , Sugarcane, Citrus

14. biosecurity built on science
End-User Advocate’s Perspective
“This project will certainly better inform biosecurity planning and surveillance for our
industries’ high priority pests that have wind dispersal as a significant pathway”.
”I also believe it may be possible to establish some general rules or models that can
assist us in estimating the significance of the wind dispersal pathways for the myriad of
the unknown pests we assess in biosecurity planning processes”.
“On the trap – I cant wait to see how this clever piece of engineering works out in the
field, particularly in our more remote locations.”