Asian Citrus Psyllid and Huanglongbing

Transcription

1 Asian Citrus Psyllid and Huanglongbing Neil McRoberts & Carrie Teiken, UC Davis Beth GraftonCardwell, UC Riverside Tim Gottwald & Weiqi Luo, USDAARS Ft Pierce, FL Paul Mitchell, UW Madison, WI Len Coop, OSU, Corvallis, OR

2 Overview Introduction to pest and pathogen Indication of California situation Industry, State and federal responses to HLB threat

3 Asian Citrus Psyllid (Diaphorina citri) and HLB (Candidatus Liberibacter asiaticus)

4 /HLB situation in California first discovered in 2008 Now widespread in much of southern California In 2013 detections in southern San Joaquin Valley became more frequent To date only 1 confirmed case of HLB: tree in residential neighborhood of greater LA.

5 Incursion of into the San Joaquin Valley CA 99 CA 198 detections in 2013 CA 65 Source: CDFA CA Quarantine areas; web interface

6 IRCHLB III: Riskbased Residential HLB/ Survey for California, Texas, and Arizona Tim Gottwald Weiqi Luo Neil McRoberts

7 Purpose of a CA Residential Survey Justification: Early detection of HLB to: Maximize regulatory intervention and disease control. Minimize disease incidence, spread, and impact to commercial citrus industry. The recent finds of HLB underscore the urgency Los Angeles basin (residential) Texas (Commercial planting) Requisites and Goals: A statistically accurate and justifiable survey protocol to be used pre and postdiscovery for early detection across all citrus industries within the US that: Incorporates all HLB/ biological and epidemiological factors. Can be applied across residential areas and commercial citrus. Has high probability for early detection of both HLB and. Maximizes targeting of control/mitigation efforts. Maximizes fiscal and manpower resources.

8 Integration Model framework Original Census tract Filtering Elevation Water Land cover Military Indian Reservation Risk modeling Resulting residential area Weather Population & race Citrus transport (Nursery & Big box store Citrus green waste) + Final risk mapping and survey protocol

9 2. Risk Modeling Determining risk variables and their effects

10 Formula & algorithm Estimate total risk in residential area, including: Potential HLB risk Known HLB risk Output variables 1. Residential citrus population and distribution Residential citrus: 2. Residential Asian population risk 3. + location risk Residential Asian risk: R Asian 4. Citrus production related transport corridors + risk: R 5. Potential spread risk from commercial Transportation risk: R nursery, green waste facility, military Road installation, packing house and flea market Potential risk: R 6. Distance to MexicoTX border crossing LAS+ risk R LAS 7. HLB and LAS+ locations risk Border crossing risk: R 8. Proximity to commercial citrus groves Border (adjustment for sampling intensity) No prior preference for each risk factor, so equal weight is applied. The suitable weighting to be determined later from survey results. Total risk= Residential citrus *{([Asian] + [+] + [Road]+ []+[Border])/5+[LAS+]} = log( Pop citrus )* ( R Asian R R Road 5 R R Border ) R LAS Pop citrus Total risk Proximity to commercial citrus groves Sampling intensity

11 Formula & algorithm 4. Estimate risk from citrus fruit transport corridor (to packinghouse and juice plants) Apply HLB/ spread curve determined from Florida data Major routes with strong effects on HLB Major routes with strong effects on Full information available: Gottwald & Luo, An investigation of transport network on HLB/ spread.

12 Distance to commercial citrus groves Not Risk but affects sampling intensity Proposed new sampling scheme Linked with dispersal curve determined from FL data Southern California Rio Grande Valley, TX

13 3. Risk Mapping Integrating filtering and risk variables with GIS data to develop survey design and intensity

14 Total risk map (Considers all variables and filtering) Rio Grande Valley, TX Southern California

15 Incursion of into the San Joaquin Valley CA 99 CA 198 detections in 2013 CA 65 Source: CDFA CA Quarantine areas; web interface

16 Manpower and number of survey cycles/year 1 cycle/year 1 cycle/year 2 cycles/year 2 cycles/year 2 cycles/yr does not detect disease at as low an incidence

17 Riskbased sampling (1or 2 cycles/year) 1 cycle/year 2830 STR grids selected based on risk 2 cycles/year Cycle 1: 1393 STR grids Extra assurance = Includes random selection of a small proportion of low risk STR areas. In case we are totally wrong!!!! 2 cycles/year Cycle 2: 1464 STR grids

18 For more information on risk assessment A webcast by Dr Gottwald describing the process of building and deploying the risk model, mapping, and survey protocols is available at:

19 Medium to longterm solutions Organize growers into neighborhood (areawide) response groups (learn from unfortunate FL experience). Breed and release an altered Psyllid which is not competent as a vector for Clas. Subject of $15M USDA/Industry CAP grant

20 Where would Psyllid sit in the spectrum of opinion about GM traits? Human health benefit Corn Papaya Mosquito Ecological risk Technology dread Genetic pollution Corporate greed/monopolies Unnatural technology Genetic pollution Unnatural technology For Neutral Against Scientific merits Agricultural sustainability Editorializing Division of Google ranked pages on page 1 of searches for GM corn, GM papaya and GM mosquito.

21 Crossing the Rubicon Adopting a biotech solution moves the industry to a qualitatively different place in public perception Does it have to?

22 Simple causal model: a first look at Psyllid deployment Use of Public thinks is harmful Public thinks is dangerous Industry see as useful Industry backs Decrease insecticide use developed Political support for

23 Demonstrating benefit and avoiding antagonism could lead to sustainable Psyllid use Growers perceive nu_ as E+ beneficial E+ Adoption of nupsyllid E+ Decrease in pesticide use Industry promotes nu_ E+ technology E+ Nu_ developed Political support for nu_ E+ technology Public perceives nu_ as dangerous Public perceives nu_ crops as harmful It may even be possible at low direct cost to the industry Growers perceive nu_ as beneficial Adoption of nupsyllid Decrease in pesticide use E E E Industry promotes GM technology E+ Industry develops GM technology Political support for GM E+ technology Public perceives GM technology as dangerous Public perceives GM crops as harmful

24 What happens if public opinion is strengthened by industry promotion? Use of Public thinks is harmful Public thinks is dangerous Industry see as useful Industry backs Decrease insecticide use developed Political support for

25 With feedback between industry PR and public opinion things get messy Growers perceive nu_ as beneficial Adoption of nupsyllid Decrease in pesticide use Industry promotes nu_ technology Nu_ developed Political support for nu_ technology Public perceives nu_ as dangerous Public perceives nu_ crops as harmful E+ 06 8E+ 05 4E+ 05 3E+ 06 4E+ 06

26 What happens if public opinion is strengthened by industry promotion? Use of Public thinks is harmful Public thinks is dangerous Industry see as useful Industry backs Decrease insecticide use developed Political support for

27 With negative feedback between industry PR and skeptical public opinion there is hope Growers perceive nu_ as E+ beneficial E+ Adoption of nupsyllid E+ Decrease in pesticide use E+ Industry promotes GM technology E+ Industry develops GM technology E+ Political support for GM technology Public perceives GM technology as dangerous Public perceives GM crops as harmful

28 Acknowledgements USDA Citrus Research & Development Foundation (FL) Citrus Research Board (CA)