Transcript Invasive - UC Agriculture and Natural Resources

Invasive/Exotic Pests in the
Garden and Landscape
Mary Louise Flint, Ph.D.
Extension Entomologist Emerita
UC Davis
What’s an exotic invasive pest?
• Exotic—not native to the local
ecosystem
• Invasive—likely to unintentionally
spread within the ecosystem and
cause environmental or economic
harm
Forsythia-exotic but not invasive
NOT A PEST
Scotch broom—exotic AND invasive
A POTENTIAL PEST
Types of exotic/invasive pests
Plant pathogens—Dutch elm disease spread
by the European elm bark beetle
Weeds—including water
hyacinth and other aquatics
Shellfish and other aquatic
species: Quagga mussels
clog pipes & drains
Insects: Eucalyptus
lerp psyllid
Vertebrates can be
invasive pests too—think
of rats, wild pigs, carp
Why do we care about invasive pests?
• Threat to agricultural crops
with major economic
consequences
• Threat to landscape and
garden plants
• Threat to natural areas
• Threat to the environment:
More pesticides may be
required to manage them—
disrupt IPM programs and
ecosystems
Japanese beetles on a grape leaf
Starthistle invades rangelands and wild areas
How do invasive pests get here?
• Interstate and
international
commerce
• With luggage, cars,
movement of
household items
• Nursery stock
• Firewood
• Other
Chron.com
Gypsy moth egg
masses on wheel
What may happen when
a new invasive arrives?
• Invaded areas quarantined
• Eradication efforts carried out by
CDFA/USDA/Ag commissioners
• Infested plants and nearby areas
may be removed or sprayed with
pesticides
• Nurseries & other ag producers
may not be able to ship plants or
produce without special handling
• Inspected plants may be tagged at
retail stores
For many invasives, there are no
quarantine or eradication programs
• Cost of quarantine/eradication is
very high. Must be justified by
potential economic losses.
• Some pests are already too well
established in some parts of the
state.
• Some pests are not good
candidates.
• Nevertheless, gardeners and
farmers should still take
precautions to limit spread of
these pests to new areas.
Polyphagous shothole borer
Pampasgrass
How can Master Gardeners help?
• Become familiar with invasive
pests of concern.
• Encourage gardeners not to
plant invasive ornamental
species.
• Educate your community about
invasive pests, how to recognize
them, and how to prevent their
spread.
• When clients bring in plants
with pests you think might be
invasive—consult the county
Agricultural commissioner.
Some Invasives of Concern in CA
FOR FOOD CROPS
• Asian citrus psyllid and HLB disease
• Bagrada bug
• Brown marmorated stink bug
• European grapevine moth
• Glassy winged sharpshooter
• Spotted wing drosophila
• Vine mealybug
• Various exotic fruit flies
FOR LANDSCAPES AND WOODED AREAS
• Giant whitefly
• Goldspotted oak borer
• Ligurian leafhopper (rosemary & sage)
• Polyphagous shothole borer
• Sudden oak death
• Thousand cankers disease (walnuts)
INVASIVE ORNAMENTAL SPECIES
• Green fountain grass
• Pampasgrass
• Scotch broom
AQUATIC SPECIES
HEALTH CONCERNS*
• Water garden plants
• Quagga/zebra mussels
• Africanized bee
• Many others
• Killer algae
• Brown widow spider
• Red imported fire ant This is only a partial list—there are • New Zealand mud snail
many others already here or
• Water garden plants
*so far all in S. CA only
threatening to invade.
Asian Citrus Psyllid
• Psyllid, the size of an aphid,
spreads a bacteria that
causes Huanglongbing (HLB)
disease in citrus.
• Early HLB symptoms blotchy
yellow mottle of leaves
• Disease can kill a healthy
tree in as little as 5 years
Origin: Asia or India to Florida to Mexico
California: 2008 ACP/ 2012 HLB
Moves on its own or with citrus relatives
adult
ACP and HLB quarantines http://ucanr.edu/sites/ACP/Distribution_of_ACP_in_California/
nymphs
and waxy
tubules
Inspect citrus plants for ACP
• Look at young tissue for
nymphs
• Produce a lot of honeydew
• Waxy tubules
Adults feed at an angle.
Nymphs tucked in under
new leaves and buds.
If you find ACP: In an area where it is not established—report it.
In a quarantined area, manage it according to UC Guidelines.
More information: http://ucanr.edu/sites/ACP/
Bagrada Bug
• Damages broccoli,
cauliflower, cabbage, other
crucifers by feeding on buds
• Loves sweet alyssum, stock,
candy tuft, mustards
• Looks like harlequin bug
but 1/3 the size
Report: new areas but no
quarantine
Control: very difficult, remove
favored hosts, broad spectrum
Origin: Africa
California: 2008
Moves on its own
Bagrada Bug Identification
Harlequin bug
is much
bigger (left),
Bagrada
(right)
Bagrada bug adults and nymphs
Bagrada bug eggs
Bagrada bug (center) with lady beetle and
Say stink bug (right)
Remember, you are going to see Bagrada bugs primarily on mustard family or
Brassicaceae plants. Find more information at Pest Notes: Bagrada Bug
http://ipm.ucanr.edu/PMG/PESTNOTES/pn74166.html
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Brown Marmorated
Stink Bug
Damages fruit on vegetables and trees
and ornamentals. Many hosts.
Many occur in dense aggregations.
When feeding they inject enzymes that
cause spots of dead tissue
May be considered a nuisance when they
overwinter in large groups in buildings.
Report: new areas of
infestation, no quarantine
Control: traps, covers, difficult
to control with pesticides
Origin: E Asia to E USA to Oregon
California: 2005
Moves on its own
Brown marmorated stink bug (BMSB) ID
rough stink bug
BMSB
More info at Pest Notes: Brown
Marmorated Stink Bug
http://ipm.ucanr.edu/PMG/PES
TNOTES/pn74169.html
Glassy-Winged
Sharpshooter
Origin: SE U.S.
California: 1989
Moves on its on
• Adults are large (1/2 inch)
• Excrete lots of liquid honeydew
• Spreads various strains of the
bacterium Xylella fastidiosa that
cause several serious plant
diseases including:
– Pierce’s Disease of grapes
– oleander leaf scorch
– almond leaf scorch
– mulberry leaf scorch
Report: quarantine pest, report sightings
in new areas
Management: Insecticides can control
sharpshooter but often don’t prevent
disease spread. Biological control.
Oleander leaf scorch
Pierce’s Disease on grapes
Distribution of
GWSS 2016
Has not spread as rapidly in the last
10 years—likely due to strong
quarantine efforts and the release of
an effective parasite.
Ornamental Hosts Include:
• Bird of paradise
• Eucalyptus
• Euonymus
• Citrus
• Crepe myrtle
• Oleander
• Pittosporum
• Sunflower
• Hibiscus
• Xylosma
• cottonwood
Adult with egg mass
Glassywinged Sharpshooter:
What to look for
Adults on yellow
sticky trap
Nymphs feed on young
succulent stems
White residue from GWSS excrement
Light Brown Apple Moth
• Larvae are leafrollers, feeding inside leaves
of many ornamentals and fruit crops
including peaches, apples, citrus, berries,
grapes. May superficially injure fruit.
• Damage is not usually serious, but since it
is under quarantine, it is a problem for
nursery and fruit growers.
Report: new areas of infestation
Control: Not needed in home gardens, for
farms: Bacillus thuringiensis, other insecticides,
pheromones.
Origin: Australia
California: 2007
Moths fly and spread
Spotted Wing Drosophila
• Attacks cherries, berries,
and occasionally soft
stone fruit
• Difficult to manage
because the eggs are
deposited inside the fruit
Also now in Kern Co.
and probably others
Report: no quarantine, now widespread
Control: insecticides (spinosad and others) on
fruit just before it ripens to limit egg laying. See
the Pest Note: Spotted Wing Drosophila for info.
Origin: SE Asia
California: 2009
Moves in fruit and flight
Ligurian Leafhopper
• Tiny mottled leafhopper
• Damages rosemary, sage,
catnip, mint family plants
• Leaves stippled, plants
appear bleached, cast skins
from nymphs often present
• Distribution in California—
unknown but appears to be
wide from San Diego to Napa
to Sacramento.
Cast skins
Report: no quarantine
Control: Difficult. Inspect plants at nursery and
before planting and reject and destroy infested
ones. Oils and other insecticides may suppress.
Origin: Europe
California: 1990s?
Movement: on plants
Giant Whitefly
• Large whitefly (adults 3/16 inch)
• Attacks a wide range of
ornamentals such as hibiscus, bird
of paradise, mulberry
• Hairlike filaments of wax cover
leaves
• Has moved north from San Diego
to the SF Bay area and is still
spreading.
Report: Not a quarantined pest
Control: Difficult. Consider plant removal, water sprays.
Plant less susceptible species.
Origin: Mexico
California: 1992
Transported on plants
Goldspotted Oakborer
• Larval mining kills red oaks
• > 80,000 native oak trees
have been killed
• Concentrated in San Diego
county but could move north
• Moves with firewood or wood
Report: new areas of
infestation
Control: prevent spread
Origin: SE Arizona
California: 2002
Moves in firewood
Our forests are threatened by nonnative insects and diseases
that can kill large numbers of trees. Goldspotted oak borer,
sudden oak death, pitch canker, emer ald ash borer, and Asian
longhorned beetle can be transpor ted long distances on
diseases can become established and kill trees.
f
.org
Sudden Oak Death (SOD)
Kills California live oak,
California black oak,
Canyon live oak,
Shreve’s oak as well as
tan oak. (Trunk hosts)
Origin: unknown
California: mid-1990s
Movement: on plant material
Leaves of affected
oaks turn brown
suddenly—within
2-4 weeks.
Also infects Bay trees,
rhododendron,
camellia (and many
other species), but
does not kill these
plants. (Foliar hosts—
not trunk hosts. Help in
spread of disease.)
Report: if found in new
areas--quarantine pest
Control: infected trees
cannot be cured
Brown diseased tissue and
healthy tissue separated by
black zone line
bleeding
Sudden Oak Death Infestation Map
Limited to coastal areas,
probably limited by
moisture, temperature.
Quarantines in effect. Still
many areas in CA that are
free from disease that could
become infected.
Limit movement of infected
material.
More information:
www.suddenoakdeath.org/
0
50
100km
Confirmed isolation of Phytophthora ramorum
Community submitted incidents of Phytophthora ramorum
Data sources:
- Confirmed isolations of Phytophthora ramorum provided by UC Davis,
UC Berkeley, and CDFA. Nursery confirmations are not depicted.
Produced on 02/10/13 by UCB GIF
http://www.suddenoakdeath.org/
http://www.oakmapper.org/
Invasive weeds can escape from garden
plantings
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Pampas grass
Cotoneasters
Scotch broom
Russian olive
Edible fig
Fennel
English ivy
Myoporum
Mexican feathergrass
Green fountain grass
Big periwinkle
Many retail nurseries are removing these plants.
See PlantRight and Cal-IPC web sites and Invasive Plants Pest Note
Invasive weeds escaping from
water gardens and aquariums
Some species escape from backyard
ponds and aquariums—avoid:
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Water hyacinth
Hydrilla
Purple loosestrife
Giant salvinia
Eurasian watermilfoil
giant reed (Arundo)
Parrotfeather
Yellowflag iris
Water-primose (Ludwigia spp.)
Resource: Master Gardener Tip Sheet
http://anrcatalog.ucanr.edu/pdf/8369.pdf
Water hyacinth (David Chang)
Eurasian watermilfoil
Summary
• Become familiar with invasive pests, how to
identify them, and where to find information.
• Get suspicious organisms identified by experts.
• Inspect new plants carefully before planting.
• Don’t purchase invasive plant species.
• Don’t move firewood far from its source.
• Don’t bring plants or fresh produce into
California.
• Educate your community about the problem.
Resources
• Your local county agricultural commissioner
• CA Dept Food & Agriculture
www.cdfa.ca.gov/plant/
• UCR Invasives web site cisr.ucr.edu
• UC IPM web site ipm.ucanr.edu/EXOTIC
• UC IPM Pest Notes for many of these pests
• Cal-IPC cal-ipc.org
• PlantRight plantright.org
• USDA National Invasive Species Info Center
invasivespeciesinfo.gov