Catharine Mannion
UF/IFAS Tropical Research and Education Center
April 2014
Photos: H. Glenn, UF/IFAS
Current Insect Problems on Landscape
Woody Ornamentals
The Landscape
A Reservoir of Pests
Also a reservoir of natural enemies
Proper identification of
 The problem
 The pest
CRITICAL
for successful management
Invasive Pests
are one of our
biggest pest
problems
• Due to mild climate
and diversity of plants,
new insects become
easily established
• Approximately 1-2 new
pests introduced each
month
Pest Damage
Photos by Glenn, UF
Do not always
blame insects
for damage.
Other critters
can also
cause
damage!
Photos by Glenn, UF
Who did
this?
Photos: H. Glenn, UF/IFAS
Eggs
Pupae/cocoons
Cast skins
Webs
Frass
Secretions
Galls
Same insect ?
YES
Scale – females and males
Photos: H. Glenn, UF/IFAS
Photos: H. Glenn, UF/IFAS
Same insect ?
YES
Whiteflies
PUPA (NYMPH)
Photo: H. Glenn, UF/IFAS
Photos: H. Glenn, UF/IFAS
ADULT
Same insect ?
YES
YES
Photos: H. Glenn, UF/IFAS
All the same insect – Lobate lac scale
Photos: H. Glenn, UF/IFAS
What is this?
In addition to recognizing pests,
you need to recognize the “good guys”
Pest ?
YES
NO
Photos: H. Glenn, UF/IFAS
Pest ?
YES
NO
Pest ?
YES
NO
Photos: H. Glenn, UF/IFAS
Pest ?
YES
NO
Photos: H. Glenn, UF/IFAS
Stock Island tree snail
Which snail is
the pest?
Which snail is
endangered?
Giant African land snail
Photos: Bill Frank, www.jaxshells.org, D. G. Robinson, APHIS, Amy Roda, USDA APHIS
Is it a Pest ?
• No physical characteristics that define
a pest
• Need to look at where it is and what it
is doing
• Need to be familiar with the common
pests/natural enemies
• Invasive pests are difficult
– When in doubt – send to a proper
authority
Awareness of new
pests is very
important. Of 150
species introduced
into Florida during
1986-2002, 57%
were first found in
Monroe, MiamiDade, Broward, or
Palm Beach
Counties.
27 new pests were
reported for 2009-2010
The Biggest Invaders
• Hemiptera (Suborder Sternorrhyncha)
Photos: H. Glenn, UF/IFAS
– Psyllids, whiteflies, aphids, scales, mealybugs
– Often cover themselves in wax or froth
2012
2011
2010
2009
2008
2007
2002
1999
1996
Honeysuckle whitefly
Bondar’s nesting whitefly
Passionvine mealybug
Ash whitefly
Rugose spiraling whitefly
Nipaecoccus viridis (mealybug)
Croton scale
Ficus whitefly
Pink hibiscus mealybug
Bamboo mealybug
Lobate lac scale
Cycad aulacaspis scale
Giant whitefly
The Biggest Invaders
• Coleoptera (beetles)
2012
2009
2005
2000
Asiatic garden beetle
Ambrosia beetle (Xyleborinus andrewesi)
Redbay ambrosia beetle
Sri Lankan weevil
P. Skelley, A. E. Mayfield III, M. C. Thomas, FDACS DPI; J. Hulcr, MSU, forestryimages.org; H. Glenn, UF/IFAS
The Biggest Invaders
• Thysanoptera (thrips)
2006
2005
2003
H. Glenn and L. Osborne, UF/IFAS
Holopothrips tabebuia
Chilli thrips
Weeping ficus thrips
The Biggest Invaders
• Mites
2013
2007
2001
Phyllocoptes fructiphilus
(vectors/associated with rose rosette
virus)
Red palm mite
Eutetranycus sp. (spider mite)
Hemipteran Pest Damage
(aphids, whiteflies, scales, mealybugs)
• Changes in foliage
– Discoloration, spots, stippling, yellowing,
bronzing)
• Defoliation and branch dieback
• Overall plant decline
• Plant death
– Prolonged infestations
– Secondary stress
Signs of Infestation by
Hemipteran Pests
• Cast skins
• Mummies
• Wax
• Tar spots
• Honeydew
• Sooty mold
Photos: H. Glenn, UF/IFAS
Management
Hemipteran Pests
• Early detection
– Often cryptic; not noticed until populations
are high
• Many have waxy secretions/coverings
that provide protection
• Wash with water
• Insecticidal soaps and oils – need good
coverage/repeat application
• Biological control
• Insecticides - systemic vs. contact
Management of Pests with
Systemic Insecticides
• Several application methods and
formulations
– Soil application (drench, granular, pellets,
injection)
– Trunk application (basal spray, injection)
– Foliar application
• Excellent tools for pest control
– Can provide long term control
– Prone to overuse
Drench
Injection
Granular
Trunk spray
Neonicotinoids (MOA 4A)
Whitefly Management
Active
Trade Names
Ficus, Rugose Spiraling and Bondar’s Nesting Whiteflies
Ingredient
Professional Use
Acetamiprid
TriStar (no soil application)
Clothianadin
Arena, (Aloft – no longer available
in Florida)
Dinotefuran
Safari, Zylam
Imidacloprid
Merit, Marathon, Coretect, Discus,
Allectus, several generic labels
Thiamethoxam
Flagship, Meridian
Pest Groups Targeted
• Hemiptera
– Adelgids
– Aphids
– Bugs
– Leafhoppers
– Mealybugs
– Psyllids
– Scales
– Whiteflies
• Coleoptera
– Beetles
– Weevils
• Others
– Ants
– Fungus gnats
– Craneflies
– Leafminers
– Thrips
Using Neonicotinoid
Insecticides
• There is no “best” a.i. or method - take
advantage of the different methods and
formulations
• Fit the method(s) of application for the site
• The site and method needs to be on the
label
• Consider the methods that gets the
needed result with the least negative
impact on the environment/non-targets
Neonicotinoid Applications
Applied to the foliage
Applied to the trunk
Applied to the soil
Movement of the insecticide is upwards
Neonicotinoid Insecticides
• Application to coconuts (or fruits)
– Landscape: ornamental vs edible plant
• Effects on pollinators (particularly bees)
– Toxic to bees
– Systemic applications –use lowest effective dose
– Avoid use on tree species highly attractive to
pollinators; Use after bloom
– Impact of other types of insecticides
• EDIS ENY-162 Minimizing Honey Bee
Exposure to Pesticides
Honey Bee Health
USDA and EPA 2013
• There are multiple factors playing a role in
honey bee colony decline
• Forces impacting honey bee health are
complex
– Parasitic Varroa mite – major factor
– Bee viruses – major factor
– Poor genetic diversity
– Poor nutrition among honey bee colonies
– Need to determine actual pesticide exposure
and effects to bees in the field
Insecticide Resistance
• Resistance to insecticides - not a new problem
• Ongoing efforts with pyrethroids and
neonicotinoids, the two biggest selling classes of
insecticides
• Repeat application (particularly in multiple
generations)
• Exposure to sublethal (less than optimal)
pesticide rates
• How does systemic use affect resistance?
Arthropods Prone to
Resistance Development
• Mites, aphids, whiteflies, and thrips
– Many generations per year
– Exposure of multiple generations to a
pesticide
– Produce many offspring
– Limited dispersal
– Exposure to sublethal (less than optimal)
pesticide rates
Resources on Insecticide
Resistance
• Managing Insecticide and Miticide Resistance in
Florida Landscapes - http://edis.ifas.ufl.edu/in714
• Management of Insect and Mite Resistance in
Ornamental Crops - http://edis.ifas.ufl.edu/in715
• A Dresser Drawer Method of Managing Insect and
Mite Resistance in Ornamentals http://edis.ifas.ufl.edu/in773
• IRAC’s Insecticide Mode of Action classification http://edis.ifas.ufl.edu/pi121
Biological Control
• Natural first line of defense
• Conservation of natural enemies
– Everything you do has some impact
– Reduce negative impact
• Release natural enemies
– Requires knowledge of both the pest
and natural enemy
Pest Group
Natural Enemies
Aphids
Aphid midge, lady beetles, lacewings, minute
pirate bug, parasitic wasps, microbial
insecticides
Broad mites
Predaceous mites
Mealybugs
Wasp parasites, lacewings, beetle predators
(mealybug destroyer)
Scale insects
Lady beetles, wasp parasites
Spider mites
Lacewings, predatory mites
Thrips
Wasp parasites, lacewings, microbial
insecticides, minute pirate bug; predatory mites
Whiteflies
Lacewings, wasp parasites, predaceous beetle
larvae, microbial insecticides
Integration of Biological
Control and Pesticides
• Most broad spectrum insecticides are toxic
to arthropod natural enemies
• Fungicides are toxic to many
entomopathogens
• Acaracides and pyrethroids – most harmful
to predatory mites
• Pyrethroids – selective on most lacewings;
mixed results on other predators and
parasites
Integration of Biological
Control and Pesticides
• Organophosphates – toxic to most
arthropod natural enemies
• Botanicals – mixed effect on natural
enemies; some selection
• Growth regulators – usually more
specific; some selection
• Neonicotinoids – low to moderate
(depends on application)
Impact of “Lower Risk” Pests
•
•
•
•
Risk of spreading into production areas
High visual or local impact
Public, press and politic pressure
Yet, not considered national risk (lack of
funding or resources)
• Could be more problematic in isolated
areas
• Reliance on pesticides
Established Pest Populations
• These pests are not going away
• Expect populations to go down (takes
years)
• May always have “hot spots”
• Diverse landscapes
– Overplanting anything (including native plants)
can create a problem
• Select trees with less problems (but this is
dynamic and can change; i.e. ficus)
• Strive for biologically based, long-term pest
management
Web Resources
• http://trec.ifas.ufl.edu/mannion
• http://mrec.ifas.ufl.edu/lso/IAWG/
• http://edis.ifas.ufl.edu/
• http://creatures.ifas.ufl.edu/
• Pest Alerts
– University of Florida
(http://extlab7.entnem.ufl.edu/pestalert/)
– DOACS (http://doacs.state.fl.us/~pi/enpp/pipest-alert.html)
Whitefly Update
Photos: H. Glenn, UF/IFAS
Ficus
Whitefly
Photo: H. Glenn,, UF/IFAS
Ficus Whitefly
•
•
Only feeds on ficus
Causes leaf yellowing,
leaf drop and branch
dieback
Photos: W. Schall, Palm Beach County Extension
A Word About Ficus
• Overplanted
• Increased problems
–
–
–
–
–
Plants not recovering
Planted in poor locations
Heavily pruned
Under/over maintained
Cumulative stress ?
• Many new pests
– Ficus thrips (2003); Leaf gall wasp (2003); Ficus
whitefly (2007); Fig wax scale outbreaks (2007); gall
midge (2008); Bondar’s nesting whitefly (2011) and
others (lobate lac scale, croton scale)
Ficus Whitefly Update
• Can be difficult to see
whitefly building up until
damage is apparent
• Damage is most obvious in
late summer and fall
• Typically populations go
down in the winter
• Appears to be getting worse
in many areas since last year.
Photos: H. Glenn, UF/IFAS
Rugose Spiraling
Whitefly
Photos: H. Glenn, UF/IFAS
Rugose Spiraling
Whitefly
•
•
Makes a big mess
Produces white, waxy
flocculent substance
Photo: H. Glenn, UF/IFAS
Rugose Spiraling
Whitefly
•
•
Excretes a sticky, clear
substance called
honeydew
Sooty mold grows on the
honeydew
Photos: H. Glenn, UF/IFAS
Rugose Spiraling Whitefly
• More than 90
different plant hosts
reported
• Favorites:
– Gumbo limbo
– Coconut
– Bird of Paradise
– Calophyllum spp.
– Various other palms
•
•
•
•
Christmas
Alexander
Montgomery
Adonidia
Photos: H. Glenn, UF/IFAS
Rugose Spiraling Whitefly Update
• Populations naturally go down in the winter
• Populations are decreasing overall
– Management
– Natural enemies – 3 parasitic wasps and one
predatory beetle identified but one is very active
(Encarsia noyesii)
– Martin, Miami-Dade, and
Broward Counties all
reporting decline of this
whitefly
Photo: S. Taravati, UF/IFAS
Bondar’s Nesting Whitefly
Photos: H. Glenn, UF/IFAS
Bondar’s Nesting
Whitefly
• Not known as
economic pest
• Often seen with
other whiteflies
• Other species known
in Florida
Photos: H. Glenn, UF/IFAS
Catharine Mannion
Research and Extension Specialist
Ornamental Entomology
University of Florida, IFAS
Tropical Research and Education Center
18905 SW 280th Street
Homestead, FL 33031
305-246-7000
cmannion@ifas.ufl.edu
http://trec.ifas.ufl.edu/mannion