Current Insect Problems on Landscape Woody Ornamentals Catharine Mannion UF/IFAS Tropical Research...

Current Insect Problems on Landscape Woody Ornamentals

Catharine MannionUF/IFAS Tropical Research and Education Center

April 2014

Pho

tos:

H. G

lenn

, UF

/IFA

S

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 ?

Scale – females and males

YES


Same insect ?

YES

Phot

os: H

. Gle

nn, U

F/IF

AS

ADULT

PUPA (NYMPH)

Whiteflies

Photo: H. Glenn, UF/IFAS Phot

os: H

. Gle

nn, U

F/IF

AS

Same insect ?YES

YES


What is this?

All the same insect – Lobate lac scale Phot

os: H

. Gle

nn, U

F/IF

AS

In addition to recognizing pests, you need to recognize the “good guys”

Pest ?

YES NOPhotos: H. Glenn, UF/IFAS

Pest ?

YES NO

Pest ?

YES NOPhotos: H. Glenn, UF/IFAS

Which snail is the pest?

Which snail is endangered?

Photos: Bill Frank, www.jaxshells.org, D. G. Robinson, APHIS, Amy Roda, USDA APHIS

Stock Island tree snail

Giant African land snail

http://www.jaxshells.org/

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, Miami-Dade, Broward, or Palm Beach Counties.

27 new pests were reported for 2009-

2010

The Biggest Invaders• Hemiptera (Suborder Sternorrhyncha)

– Psyllids, whiteflies, aphids, scales, mealybugs– Often cover themselves in wax or froth

Phot

os: H

. Gle

nn, U

F/IF

AS

2012 Honeysuckle whitefly2011 Bondar’s nesting whitefly2010 Passionvine mealybug

Ash whitefly

2009 Rugose spiraling whiteflyNipaecoccus viridis (mealybug)

2008 Croton scale2007 Ficus whitefly 2002 Pink hibiscus mealybug

Bamboo mealybug

1999 Lobate lac scale1996 Cycad aulacaspis scale

Giant whitefly

The Biggest Invaders• Coleoptera (beetles)

2012 Asiatic garden beetle2009 Ambrosia beetle (Xyleborinus andrewesi)2005 Redbay ambrosia beetle2000 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 Holopothrips tabebuia2005 Chilli thrips2003 Weeping ficus thrips

H. Glenn and L. Osborne, UF/IFAS

The Biggest Invaders• Mites

2013 Phyllocoptes fructiphilus (vectors/associated with rose rosette virus)

2007 Red palm mite2001 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


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

Whitefly Management Ficus, Rugose Spiraling and Bondar’s Nesting Whiteflies

Neonicotinoids (MOA 4A)

Active Ingredient

Trade NamesProfessional 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 soil

Applied to the trunk

Movement of the insecticide is upwards

Applied to the foliage

• 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

Neonicotinoid Insecticides

Honey Bee HealthUSDA 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

• 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/pi-pest-alert.html)

Web Resources

Whitefly Update


Ficus Whitefly

Photo: H. Glenn,, UF/IFAS

Photos: W. Schall, Palm Beach County Extension

Ficus Whitefly • Only feeds on ficus• Causes leaf yellowing,

leaf drop and branch dieback

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.


Rugose SpiralingWhitefly


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


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


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 WhiteflyPhotos: H. Glenn, UF/IFAS

Bondar’s Nesting Whitefly

• Not known as economic pest

• Often seen with other whiteflies

• Other species known in Florida


Catharine MannionResearch and Extension Specialist

Ornamental Entomology

University of Florida, IFASTropical Research and Education Center

18905 SW 280th StreetHomestead, FL 33031

[email protected]

http://trec.ifas.ufl.edu/mannion

Current Insect Problems on Landscape Woody Ornamentals Catharine Mannion UF/IFAS Tropical Research...

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