Polyphagous shot hole borer and Fusarium dieback: A...
Transcript of Polyphagous shot hole borer and Fusarium dieback: A...
Akif Eskalen, R. Stouthamer, P. Rugman-Jones, G. Douhan,
M. Twizeyimana, S. Lynch, D. Wang, J. Mayorquin, A. Gonzalez,
F. Na, L. Yeung
Department of Plant Pathology and Microbiology & Department of Entomology
University of California, Riverside
Polyphagous shot hole borer and Fusarium dieback: A generalist pest/disease complex threatening
avocado and landscapes trees in California
Southern California Forest Pest Council, April 23, 2013
Polyphagous Shot hole borer (Euwallacea sp.)
Female
0.1 inch long
Male 0.05 inch long
Beetle and fungi have symbiotic relationship
Fusarium sp.
Euwallacea sp.
Mycangium
Graphium sp.
Acremonium sp.
Beetle gallery and Fungal colony on the gallery wall
Beetle eggs and larvae in the gallery
Vascular discoloration caused by fungi
Situation in Israel, Oct. 2012
Calculating colony forming units of fungal species associated with PSHB
Head Larvae Abdomen
0
200
400
600
800
1000
1200
Female Head Female Abdomen Male Head Male Abdomen Larvae
Fusarium sp.
Graphium sp.
# of Colony Forming Unit per beetle
Pathogenicity test on Hass
Fusarium sp. Graphium sp. Control
02468
101214
Fusarium sp. control
Lesi
on
le
ngh
t (c
m)
Legend&Posi+ve&finding&Fusarium&sp./Polyphagous&Shot&Hole&Borer&Nega+ve<Fusarium&sp./Polyphagous&Shot&Hole&Borer&
Known&distribu+on&of&Fusarium&&dieback/&Polyphagous&shot&hole&borer&in&southern&California&12/18/2012&
Data*source:*Eskalen*lab.,*Dept.*of*Plant*Pathology*and*Microbiology,*University*of*California,*Riverside.**www.eskalenlab.ucr.edu****
Known distribution of PSHB/FD in Southern California 2/6/2013
Determine the plant host range of the beetle/fungus complex in California
Number of tree species
observed
Number of tree species attacked by
beetle
Number of tree species colonized by
fungus
Number of tree family
attacked
Number of reproductive
host
335 213 108 58 21
Eskalen et al. 2013. Host Range of Fusarium Dieback and its Ambrosia Beetle (Coleoptera: Scolytinae) Vector in Southern California. Plant Disease. In Press.
Reproductive / Suitable Hosts
1. Box Elder (Acer negundo) 2. Castor bean (Ricinus communis) 3. Avocado (Persea americanaI) 4. English oak (Quercus robur) 5. Coast live oak (Q. agrifolia) 6. Silk tree (Albizia julibrissin) 7. California sycamore (Platanus racemosa) 8. Coral tree (Erythrina corallodendron) 9. Chenese holly (Ilex cornuta) 10.Big leaf maple (Acer macrophyllum) 11.Japanese maple (Acer palmatum) 12.Black bean (Castanospermum australe) 13.Palo verde (Parkinsonia aculeata) 14.Blue palo verde (Cercidium floridium) 15.Liquidambar (Liquidambar styraciflua)
Symptoms of PSHB/FD on avocado
Symptoms of PSHB/FD on different hosts
Red Willow (Salix laevigata)
Box Elder
Symptoms of PSHB/FD on different hosts
Coast live oak Liquidambar California Sycamore Excelsa
Coast live oak Avocado English Oak Castor bean
Quercus robur
100 years old English oak in Huntington Botanical Garden
Similar symptoms caused by other factors
Woodpeckers Bacterial canker Avocado trunk canker Phosphorous acid Injection
Symptoms of PSHB/FD on different hosts
Alice Maple (Acer pectinatum)
Detection of Fusarium sp. directly from plant material using Quantitative Real Time PCR
Lad
der
Wat
er C
on
tro
l
Fusa
riu
m s
p.
Fusa
riu
m s
p.
Fusa
riu
m s
ola
ni
Forward: ACGTGATTGACCACAAAC
Reverse: CAGCGACATACCAATGAC
188 bp
EF-1α
What to do:
•Look for a single entry hole with surrounding either white powdery exudate, staining, gumming or frass
•Scrape off the bark layer around the infected area to see the canker
•Follow the gallery to look for the beetle (may or may not be present)
•Avoid movement of infested wood out of the infested area
•Look for the other hosts (Box elder, Castor bean, Coast live oak, California sycamore
Control strategies
What to do
Control strategies of PSHB using Entomopathogen Fungi
Treatment % of beetle alive
Control 100
Metarhizium 50
Beauvaria bassiana (Mycotrol)
0
Spiral gradient dilution fungicide screening
Spiral gradient dilution fungicide screening
Control Fungicide
Active
ingredient Trade Name
EC50 for inhibition of mycelial
growth (μg/ml)a
Metconazole Quash 0.031 a
Pyraclostrobin Cabrio 0.044 a
Tebuconazole Folicur 3.6F 0.057 a
Thiabendazole Arbotect 20-S 0.193 ab
Propiconazole Alamo 0.487 ab
Triflumizole Procure 0.714 b
Fluopyram Luna Privelage 2.080 c
Myclobutanil Rally 2.432 c
Pyrimethanil Scala 4.911 d
Fluxapyroxad Xemium NIb
Trifloxystrobin Flint NI
Triadimefon Bayleton Flo NI
Azoxystrobin Abound NI
LSD0.05 - 0.64
Collaborators Tim Thibault, Huntington Botanical Garden Frank McDonogh, LA Arboretum Tim Paine, Entomology, UC Riverside Gevork Arakelian, County Ag. Commissioner in LA Tom Coleman, USDA Forest Service, Southern California Jiri Hulcr, Univ. of Florida Kerry O’Donnell, NCUR-ARS-USDA Ben Faber, Farm Advisor, Ventura County, CA Gary bender, Farm Advisor, San Diego County, CA Mary Bianchi, Farm Advisor, Santa Barbara County, CA Jim Downer, Farm Advisor, Santa Barbara County, CA Don Hodel, Farm Advisor, Los Angeles County, CA John Kabashima, Farm Advisor, Orange County, CA Reuben Hofshi, Hosfhi Foundation Mary Lu Arpaia, UC Riverside Zvi Mendel, Volcani Center, Israel Stanley Freeman, Volcani Center, Israel California Avocado Commission for funding