Asian Citrus Psyllid
Help Stop This Dangerous Pest
ASIAN CITRUS PSYLLID &
HUANGLONGBING
Save Our Citrus!
• California's $2 billion citrus industry is at risk.
• A devastating plant disease called Huanglongbing, also known
as HLB or citrus greening, has been found in Southern
California.
• HLB kills citrus trees and there is no cure.
• The disease is spread by the Asian citrus psyllid, which has
been found throughout southern and central California.
• We are calling on all facets of the citrus industry to join a
collaborative effort to help save our state’s citrus.
California Citrus Pest & Disease
Prevention Program
• A grower-funded program established to
combat the Asian citrus psyllid and HLB.
• Key responsibilities of the program:
–
–
–
–
–
Detection & delimitation trapping
Visual survey
Residential treatment
Quarantine
Educational outreach
CPDPP Collaborates With
• Federal
– USDA
• State
– California Department of Food & Agriculture
– Dept. of Pesticide Regulation
– Office of Health Hazard Assessment
– University of California - Cooperative Extension
• Local
– County Agricultural Commissioners
• Industry
– California Citrus Research Board
– Growers
• Residents
What is the Asian Citrus Psyllid?
• Psyllids are small insects
— about the size of an
aphid.
• Young psyllids are
yellow-orange and
produce a white waxy
substance.
• The Asian citrus psyllid
feeds on the leaves and
stems of citrus plants
and can transmit HLB.
What is HLB?
• A plant disease for which there is no cure.
― Diseased trees eventually die.
• The disease causes blotchy yellow leaves and
small, asymmetrical fruit with bitter juice.
• The best way to protect against the disease is
to find and stop the pest from spreading.
The Impact of HLB
• In Florida, the insect and disease have caused
the loss of more than 8,000 jobs, and the
industry and workers it supports are
struggling.
• In California, our commercial citrus industry
and the more than 20,000 jobs it supports is
at risk.
HLB & ACP Spread in North America
• ACP and HLB came to
California through the
artificial movement of
plant material.
• HLB has spread
throughout Florida and
is moving through
Mexico. It has also
infected trees in Texas.
• HLB has been found
once in a residential tree
in Southern California.
Asian citrus psyllid, but not the disease
Both the psyllid and HLB disease
Asian Citrus Psyllid Spread
in California
•
•
•
•
•
•
•
•
ACP detected in Tijuana in June 2008
CDFA increased trapping/ visual surveys
2008- San Diego and Imperial
2009- Los Angeles, Orange and Ventura
2010- Riverside and San Bernardino
2012- Santa Barbara and Tulare
2013- Kern and Fresno
2014- San Luis Obispo
WHERE DOES CALIFORNIA
STAND NOW?
http://ucanr.edu/sites/acp
Commercial citrus
Sections with psyllids (density)
Sections with HLB
Quarantine boundaries
Tamarixia releases
Current Quarantines
HLB Quarantine
ASIAN CITRUS PSYLLID
CONTROL AND DETECTION
How is the Disease Controlled?
• Eradicating or
suppressing ACP
populations reduces
the chance of the
insect picking up and
spreading the disease.
• Planting disease-free
citrus trees.
• Infected trees will
need to be destroyed
to reduce the
reservoir of disease.
Asian Citrus Psyllid Suppression
• Goal: Suppress the psyllid to buy time
for researchers to develop solutions to
the disease problem.
– Slow the spread of the psyllid to new areas.
– Prevent the psyllid from finding HLB-infected
trees.
– If it does find an infected tree, slow spread of
HLB by reducing the vector population.
Asian Citrus Psyllid Control is Important –
Even if HLB Becomes Widespread
• Infected psyllids create local bacterial
infection points when they feed on a tree.
• The more infection points a tree has:
― The faster the infection takes over and
destroys the tree; and
– The easier it is for the psyllid to spread the
disease.
• This is why Florida growers continue to treat
for psyllids even though nearly all orchards
are infected.
Detection Methods
Yellow Sticky Traps
• CDFA is placing 1
trap/0.5 mi of
perimeter (every 40
acres).
• Traps only adults.
• Weakly effective
because if a psyllid is
given a choice
between a card and
leaf flush, it prefers
the flush.
Detection Methods
•
•
•
•
Visual Surveys
Conducted during
periods of flush.
Detects all stages; eggs,
nymphs and adults.
Flush locations on each
tree are searched.
Varieties that flush
frequently and young
trees receive extra
attention.
Detection Methods
Tap Sampling
• Conducted any time
of the year.
• Useful for detecting or
monitoring adults.
• A moist white plastic
sheet is used on a
clipboard and PVC to
tap 3 times on four
locations of the tree.
Sweep Net Sampling
• Conducted any time
of the year.
• Useful for detecting
or monitoring adults.
• A large sweep net is
used to stuff a branch
into it and tap the
branch.
• More effective
method than tap
sampling onto a
sheet.
The Citrus Industry’s Role
• Be aggressive in sampling for the Asian citrus
psyllid:
― Don’t rely on yellow sticky cards alone
― Increase scouting
― Use tap or sweep, and visual surveys to check
orchards
• Sample regularly:
– Conventional orchards: sample monthly
– Organic orchards: sample every two weeks
ASIAN CITRUS PSYLLID
TREATMENT OPTIONS
ACP Insecticides
The UCIPM recommends the following chemical
groups be used:
Organophosphate
Carbamate
Pyrethroids
Neonicotinoid foliar
Neonicotinoid
systemic
• Mixtures
• Spinosyn
• Avermectin
•
•
•
•
•
•
•
•
•
•
•
•
•
Benzylurea
Meti insecticide
Tetronic acid
Ryanodine
Oils
Pyrethrins + oil
Isaria fumorsoroseus
Chromobacterium
subtsugae
Visit UCANR.edu/sites/ACP for more information.
Eradication Versus Areawide Management
Eradication Strategy
Management Strategy
• Trapping and visual
• Continuous areawide
surveys find a low
management program
density population of
starts when established
psyllids that is isolated
populations of psyllids are
from established
found in an area.
populations and
• Minimum of three ACP
protected from both
treatments per year
natural and artificial
focusing on flush and
movement of psyllids.
overwintering populations
• The combination of two
to suppress the psyllid
broad spectrum
below detectible levels.
insecticides applied to an
800 meter area
eliminates psyllids from
the area.
Why Areawide Treatment Works?
• Areawide treatment is designed to be implemented in
areas where the psyllid can no longer be eradicated.
• The psyllids are tiny and it’s hard to know exactly where
they are.
• Most pesticides residue break down after 4-6 weeks .
― If treatments occur in a patchwork fashion, the psyllids
move in when the residues break down and reinvade.
• If treatments occur over a large area over a two to three
week period of time, they have the biggest impact on
psyllids (no where to run, no where to hide).
• In California, the areawide control concept has already
successfully been done for glassy-winged sharpshooter
(GWSS).
• Treating for the Asian citrus psyllid is critical
for maintaining a vibrant citrus industry.
• Visit UCANR.edu/sites/ACP for information
on the treatment products, protocols and
standards that have proven most effective for
managing this pest.
HOW CAN GROWERS HELP?
Cooperate
• Work closely with your County Agricultural
Commissioner, local grower liaison, task force and
CDFA in the event of a new psyllid find.
• Report any suspected findings of the Asian citrus
psyllid. Please call your local agricultural
commissioners.
• Stay informed.
– Visit www.CitrusInsider.org regularly and sign up
for regional and statewide updates.
• Coordinate treatments with neighbor growers to
get effective area wide treatment.
Best Practices When Out in the Field
• Growers should employ best management
practices for the Asian citrus psyllid and
encourage all others who take part in their
operation — farm managers, farm labor
contractors, pesticide applicators, etc. — to do
the same.
Best Practices When Out in the Field
• Be careful not to transfer citrus plant material
from one work site to another.
– This could spread psyllids.
• Inspect all equipment and remove all citrus
leaves and stems before leaving a site.
– This means brushing off – including
underneath – all equipment such as sprayers,
tractors, ladders, trailers, flatbeds and bins.
• Inspect personal items carefully and brush
them off before leaving a site.
• Inspect trees often, especially when there is
new flush.
Industry Challenge: Abandoned Groves
• Uncared for orchards are a threat, as these trees
can serve as reservoirs for the psyllid and HLB.
• These orchards must be removed in order to
protect neighboring homeowner and commercial
trees.
– Abandoned orchards can be those with lack of
irrigation and pest control, and no harvest for an
extended period of time.
• If you have an orchard that you do not care for or
know of an abandoned grove in your area, contact
your local grower liaison who can work with you
on solutions to remove these hazards and protect
neighboring citrus trees.
BIOCONTROL UPDATE
The Natural Enemy
There is a tiny parasitic wasp that lays its egg inside the
psyllid nymph. The wasp develops and kills the nymph.
Tamarixia
radiata
The wasps are specific to the Asian
citrus psyllid and pose no risk to
people or the environment.
Tamarixia Releases
• The hope is that the parasitoid will reduce the
psyllid population in the urban areas and
help to delay the spread of the disease.
• Natural enemies will not stop disease spread
in commercial orchards because:
• Natural enemies do not control all of the
psyllids.
• It only takes a few psyllids to spread the
disease.
• Many of the treatments for other pests will
reduce the effectiveness of the natural
enemies.
Moving Forward
• Be aggressive
– Sample regularly.
– Control the Asian citrus psyllid to reduce the
risk of HLB.
• Act quickly when a psyllid is found.
• Assist the program
– Provide information about your orchards to
help map the area.
– Help identify areas that need help.
• Identify residents with 25 plus trees.
• Report unloved citrus.
Resources
• Citrus Insider (http://citrusinsider.org/)
– Materials, maps and other links and
information
– Sign up for e-newsletter and stay informed
• University of California, Division of
Agriculture and Natural Resources
(http://ucanr.edu/sites/ACP )
– For treatment products, protocols and
standards
We are in this together!
Enrico Ferro
Ferroe@inbox.com
951-334-7611