Overview of myrtle rust response in Australia; Impact on Rhodamnia rubescens and Rhodomyrtus psidioides. Angus J. Carnegie

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1 Overview of myrtle rust response in Australia; Impact on Rhodamnia rubescens and Rhodomyrtus psidioides Angus J. Carnegie

2 Guava rust Eucalyptus rust Ohia rust Myrtle rust

3 What s in a name? Austropuccinia psidii (Winter 1884): echinulate urediniospores Many synonyms (~25) novel species described from many hosts as Puccinia (sexual state) or Uredo (asexual state) In 2006 Simpson et al. described Uredo rangelii, based on tonsure on urediniospores (from only two herbarium specimens) Identified as Uredo rangelii when arrived in Australia Urediniospores & Teliospores J. Walker (1983) Now accepted as Austropuccinia psidii Single strain in Australia

4 Australia s Biosecurity System Emergency Plant Pest Response Deed ( the Deed ) Provides the framework for managing Exotic Plant Pest (EPP) incursions Cost-sharing (Government / Industry) PLANTPLAN Technical response plan used by jurisdictions and industry in responding to an EPP incident Provides nationally consistent guidelines for response procedures under the Deed Outlines the Phases of an incursion response Investigation, Alert, Response, Stand Down Key roles and responsibilities of industry and government

5 Australian myrtle rust Emergency Response - Stages Stages of myrtle rust response 1. Detection, initial surveys, stand down [1 week] 2. NSW Response (not under the Deed) [minimal resources] 3. National Response (under the Deed) [large resources] 4. Transitional Management (living with it) Stage 1 Stage 2 Stage 3 Stage 4 April May June July August September October November December January Carnegie & Cooper (2011) Australasian Plant Pathology 40:

6 Emergency Response Stage 1 Rust on Agonis flexuosa detected by grower 21 April Identified by national expert 23 April Surveys of IP1 24 April 1100 Agonis plants, Syncarpia glomulifera windbreak Consultative Committee EPP convened 27 April Require more information to make an informed decision Surveys continue 25 sites; nurseries, native bush, road-sides, gardens; 2 survey teams IP2 detected (nursery 8.5 km from IP1) CCEPP re-convened 30 April myrtle rust not technically feasible to eradicate National response stood down 30 April Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri IP1 IP2

7 Infected Premises (IP) 1

8 Emergency Response Stage 2 NSW land management agencies agree to continue containment and surveillance Outside of the Deed & cost-sharing arrangements May & June 2010 Minimal resources Interim Response Plan (CCEPP) Plant Health Australia request CCEPP to reconsider decision Decision to stand down too hasty Surveillance: 85 site visits; 55 sites (multiple visits, especially IPs) 5 Infected Premises detected 4 with small number of plants infected Containment: Informal quarantine on properties IP1: continued fungicide regime and surveys Infected plants & trees NOT destroyed IP2 to IP5: plants destroyed and fungicide regime Tracing: some track back and trace forward No indication of original source Some links between infected premises IP4 IP3 IP1 IP2 IP5

9 Emergency response Stage 3 Observations from Stage 2 indicated rust had not behaved as expected Limited spread, limited hosts, not spread to native bush, good containment on infected premises Decision to go into full-blown emergency response Under the PLANTPLAN & the DEED (costs covered) Quarantine (restrictions on movement of Myrtaceae) Tracing (>20,000 traces identified and processed) Surveillance (>1,600 sites surveyed) Containment & destruction (16,000 plants destroyed) Communication & education campaign Resources: 350+ staff

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11 Stand Down - final 2 nd December CCEPP reviewed status Increasing host range Spread beyond Central Coast: Large number of domestic, commercial, public & recreational sites Native vegetation and forests Wind-borne spread NMG 22 nd December: not technically feasible to eradicate

12 C u m u l a t i v e n u m b e r o f I P s Detection Stood Down Emergency response restarts Surveillance ramps up Austromyrtus Bushland - focus Weather changes Emergency response time-line Human-assisted transfer April May June July August September October November December 2010

13 Key lessons Surveillance and eradication procedures should be implemented immediately Coordinated and well resourced response protocols Speedy process & firm decisions Strong (pre-arranged) links with industry and peak interest groups Industry need to be prepared for emergency response Appropriate length for Investigation and Alert phase (before decision is made to proceed or stand down) Initial investigative stage need to be well resourced Uredo rangelii & myrtle rust caused confusion Staff need to be identified pre-incursion and accessible during incursion Pathologists, botanists, biosecurity/surveillance Training in emergency response procedures Assume all species of Myrtaceae are a host Don t assume myrtle rust symptoms are easy to detect Difficult to predict which species will be significantly impacted

14 Distribution in Australia Berthon et al. (under review) Biological Conservation

15 Number of host species Number Rapidly expanding host range Prior to reaching Australia ( ): 130 species, 33 genera, 9 tribes Australia ( ): 270 species, 51 genera, 15 tribes (naïve hosts) Field & laboratory NATIONAL FIELD Field - NATIONAL only Apr 2010 Nov 2010 July 2011 Dec 2011 Aug 2012 Date Acca Beaufortia Eremaea Agonis Callistemon Eucalyptus Allosyncarpia Calothamnus Eugenia Angophora Calycorectes Gossia Archirhodomyrtus Campomanesia Heteropyxis Astartea Chamelaucium Homoranthus Asteromyrtus Choricarpia Hypocalymma Austromyrtus Corymbia Kunzea Backhousia Darwinia Lenwebbia Barongia Decaspermum Leptospermum Lindsayomyrtus Osbornia Stockwellia Lithomyrtus Pericallyma Syncarpia Lophomyrtus Pilidiostigma Syzygium Lophostemon Pimenta Thryptomene Melaleuca Plinia Tristania Metrosideros Psidium Tristaniopsis Mitrantia Regelia Ugni Myrcia Rhodamnia Uromyrtus Myrcianthes Rhodomyrtus Verticordia Myrrhinium Ristantia Xanthostemon Myrtus Sphaerantia Worldwide combined host list: 450 species, 73 genera, 16 tribes Giblin F, Carnegie AJ (2014)

16 Impact on key Myrtaceae Rhodamnia rubescens Understory shrub to small tree (12 m) Highly susceptible AVH

17 1 m 1 m Unsprayed Sprayed

18 Rhodamnia rubescens 12% of trees surveyed were dead 2017: increase in mortality (up to 50%) Just listed as Critically Endangered

19 Rhodomyrtus psidioides K. Kupsch G. Pegg

20 Rhodomyrtus psidioides 50% of trees surveyed were dead Some 100% dead Just listed as Critically Endangered

21 Conservation model Start SUSCEPTIBLE N Y RANGE OVERLAPS? N Y > 80 % THREATENED < 80 % N Y NON-PRIORITY PRIORITY CAT. C PRIORITY CAT. B PRIORITY CAT. A Berthon et al. (under review) Biological Conservation

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