Asian Citrus Psyllid / Citrus Greening

1. Asian Citrus Psyllid / Citrus Greening America Trades Produce The U.S./Mexico Trade Conference March 22, 2012

2. Asian Citrus Psyllid / Citrus Greening • The disease is commonly referred to as Citrus Greening in the US, its official name is Huanglonbing(HLB), translated meaning: Yellow Dragon Disease. • Three species are currently recognized. Ca. Liberibacterafricanus - a heat sensitive African form. • Ca. Liberibacterasiaticus - a heat tolerant Asian form. Ca. Liberibacter americanus - a strain found in Brazil. • Ca. L. africanus expresses symptoms in cool conditions (20-25ºC). • Ca. L. asiaticus expresses symptoms in wide range of temps up to 35ºC.

3. Asian Citrus Psyllid Life Stages • During a lifetime that lasts several months, the female lays up to 800 eggs. • Eggs hatch 2-4 days after they are laid on the leaf surface. • There are 5 nymphal instars. • The complete life cycle ranges from 15 to 45 days depending upon environment conditions and nutrition. • In Florida, the psyllid is capable of producing as many as 30 overlapping generations per year. Asian Citrus Psyllid Catling, 1970. Adult Egg Nymphal instars IFAS Asian Citrus Psyllid Feeding Damage

4. Evidence of Psyllid Feeding • Many times psyllids will not be present, but evidence of the feeding can still be found. The notch is a result of prior feeding by the psyllid. Bove Mason

5. The Hosts • The HLB pathogen infects all citrus species, cultivars, and hybrids, as well as many closely related citrus species. The Most Tolerant Species: Trifoliate Orange and Hybrids Mexican Lime The Species Exhibiting Moderate Symptoms: Grapefruit Lemons Pummelos Calamondins Ranpur Lime The Species Exhibiting the Most Severe Symptoms: Mandarins and Hybrids Sweet Oranges

6. Symptom Expression • Symptom expression – • Anywhere from 3 months to 3 years. • Residential Over Commercial • More psyllids and more classical symptoms are found in residential citrus trees than in the Florida citrus groves. Nutrient Deficiency or HLB Symptoms ?

7. Visual Detection is Difficult If leaves were clean and healthy picking out symptoms would be easy, but this is not the case. There are many other disease symptoms on the leaves, as well as insect damage and effects to see through. Experience with viewing leaves will build ability. Examine both sides of leaf. Note some other conditions below. + Nutrient Deficiency Sooty Mold Mason Mason Mason Mason Leafminer Damage Mixed Effects Melanose Leafminer Damage Spider Mite Damage Mason Mason Mason Leafminer Damage Citrus Canker Nutrient Deficiencies Vary Greasy Spot

8. Catling Foliar Symptoms Sectored Yellowing Mason • Hard to distinguish from select mineral deficiencies. • Infected trees • Exhibit mottled and blotchy, green and yellow leaves. • Many will be reduced in size. • The best mottle symptoms are general across the leaf and mottle spots will cross the veins. Classical Symptoms of a Positive Sample Mason Healthy Leaf Infested Leaves

9. Current Pest Status and UpdateArizona • From August 2009 to Present • 11 Positive ACP Sites were found in Yuma County. • All sites were immediately treated and are being regularly monitored for ACP • 1 Positive ACP – Nogales • 1 Positive ACP – Pima County

10. Current Pest Status and Update • ACP Quarantine Map

11. Where Is HLB Now – An Update…. Survey Status of Citrus Greening Huanglongbing (Asian) -  Candidatus Liberibacter asiaticus

12. Where Is ACP Now – An Update…. Survey Status of Asiatic Citrus Psyllid -  Diaphorina citri

13. Mexico Pest Information

14. Potential Economic Impact

15. Potential Economic Impact

16. Potential Economic Impact

17. Citrus Production in US

18. PPQ Plans to Mitigate Economic Impact Screen houses for clean nurserystock • HLB free plants Biocontrol options • Tamarixiaradiata Research into potential GMO varieties • Modify the ACP or plant Other • Continued research

19. QUESTIONS?

20. Thank You!Contact Information • Jerry Levitt • State Plant Health Director - Arizona • 602-431-3201 • Jerald.L.Levitt@aphis.usda.gov