Integrated ManagementIntegrated Managementofof

Hibiscus PestsHibiscus Pests

Edwin Duke, Ph.DEdwin Duke, Ph.DUniversity of Florida, IFAS and

Broward County Cooperative Extension Service

Tom Weissling, Ph.DTom Weissling, Ph.DUniversity of Florida, IFAS

Fort Lauderdale Research & Education Center

Biology and IdentificationBiology and Identificationof Pests and Beneficialsof Pests and Beneficials

PreventativePreventativePracticesPractices

Monitor PestMonitor PestPopulationsPopulations

Action ThresholdAction Threshold

Make ActionMake ActionDecisionDecision

Evaluation &Evaluation &Follow-upFollow-up

IPMIPMProgramProgram

• Aphids

• Scale insects

• Whiteflies

• Spider mites

• Hibiscus gall midge

• Mealybugs

• An unidentified worm

Identification and BiologyIdentification and Biology

The Pests:The Pests:

AphidsAphids

CorniclesCornicles

DamageDamage

HoneydewHoneydew

Sooty MoldSooty Mold

Scale InsectsScale Insects

• Oriental scaleOriental scale• Ivy scaleIvy scale• Florida red scaleFlorida red scale• Tesserata scaleTesserata scale• Cyanophyllum scaleCyanophyllum scale• Latania scaleLatania scale• Fern scaleFern scale• Quohog-shaped scaleQuohog-shaped scale• White peach scaleWhite peach scale• False parlatoria scaleFalse parlatoria scale• and othersand others

White Peach ScaleWhite Peach Scale

Infestations are unsightlyInfestations are unsightly

Damage typically is not this severeDamage typically is not this severe

WhitefliesWhiteflies

AdultAdult

NymphsNymphs

Greenhouse whiteflyGreenhouse whitefly

DamageDamage

Spider MitesSpider Mites

Webbing

DamageDamage

Prior to arriving in Florida, it was known from Prior to arriving in Florida, it was known from Hawaii where it attacked buds of many plants, Hawaii where it attacked buds of many plants, including hibiscus, tomato and jasmine. including hibiscus, tomato and jasmine.

Contarinia maculipennisContarinia maculipennis is a small fly that was first is a small fly that was first found attacking found attacking DendrobiumDendrobium spp. in Apopka spp. in Apopka (collected: November 1992) and Miami (collected: (collected: November 1992) and Miami (collected: August 1993).August 1993).

Since that time the number of people reporting Since that time the number of people reporting problems with hibiscus bud drop has greatly problems with hibiscus bud drop has greatly increased. increased.

Hibiscus Gall MidgeHibiscus Gall Midge

When infested buds are dissected, several small, white, fly larvae (maggots) may be found.

Once the larvae are fully developed they drop to the soil were they eventually burrow into the soil and pupate.

Adults emerge in about 3 weeks depending on temperature.

When infested hibiscus buds are placed in a plastic When infested hibiscus buds are placed in a plastic vegetable storage bag, fully developed larvae begin to vegetable storage bag, fully developed larvae begin to emerge within a day. When the larvae are removed emerge within a day. When the larvae are removed from the bag and placed on a dark flat surface you will from the bag and placed on a dark flat surface you will notice they begin to "flip" themselves significant notice they begin to "flip" themselves significant distances. distances.

One interesting behavior the helps in this pests One interesting behavior the helps in this pests identification is their ability to jump or spring several identification is their ability to jump or spring several centimeters.centimeters.

DamageDamage(and an example of Tom’s inability to take a good photo)

Mealybugs: Mealybugs: Pink Hibiscus MealybugPink Hibiscus Mealybug

The pink hibiscus mealybug, The pink hibiscus mealybug, Maconellicoccus Maconellicoccus hirsutushirsutus, is a serious pest of many plants. , is a serious pest of many plants.

It was found in the Caribbean in 1994. It was found in the Caribbean in 1994.

The pink hibiscus mealybug has not yet been found The pink hibiscus mealybug has not yet been found in Florida. in Florida.

If this mealybug becomes established in Florida, it is If this mealybug becomes established in Florida, it is expected to attack many crops and ornamental plants expected to attack many crops and ornamental plants

Pink mealybug on hibiscus.

Nymphs and adults before

egg-laying are clearly

visible in large numbers on

the twigs.

The insects injecttheir saliva into theplant…which is toxic.

Results in growthabnormalities

Early Defoliation of HibiscusEarly Defoliation of Hibiscus

Pink mealybug damage on hibiscus. Early stage of Pink mealybug damage on hibiscus. Early stage of infestation. Note the rosetting already beginning to infestation. Note the rosetting already beginning to show in some terminals. Leaf distortion and show in some terminals. Leaf distortion and shortening internodes are the result of toxin injection.shortening internodes are the result of toxin injection.

Pink mealybug on hibiscus. Close-up of a terminal in Pink mealybug on hibiscus. Close-up of a terminal in which the shortening of the internodes and the which the shortening of the internodes and the deformed leaves and flower buds are already visible. deformed leaves and flower buds are already visible.

Pink mealybug damage on hibiscus. Very heavily Pink mealybug damage on hibiscus. Very heavily damaged hibiscus shrubs. damaged hibiscus shrubs.

A recent search through the state for pink hibiscus A recent search through the state for pink hibiscus mealybug turned up a new pest…the mealybug turned up a new pest…the Papaya Papaya mealybugmealybug (but no phmb’s) (but no phmb’s)

The papaya mealybug is native to Mexico and Central The papaya mealybug is native to Mexico and Central America. America.

So far, the papaya mealybug has been found in PalmSo far, the papaya mealybug has been found in PalmBeach, Brevard, Manatee, and Hillsborough counties Beach, Brevard, Manatee, and Hillsborough counties

Damage is the same as described for the phmbDamage is the same as described for the phmb

In Florida, it has been found hibiscus, papaya, In Florida, it has been found hibiscus, papaya, cassava, and a few other species cassava, and a few other species

Prevention of Pest ProblemsPrevention of Pest Problems

Growing a healthy plantGrowing a healthy plant

Inspect plants or cuttings brought into the Inspect plants or cuttings brought into the landscapelandscape

Close inspection of imported plantsClose inspection of imported plants

Insect InvasionInsect Invasion

• Fly-ins

– Southern Florida’s close proximity to Caribbean regions

– Tropical Storms and Hurricanes

– Floating driftwood

Insect InvasionInsect Invasion

• Stowaways

– More than 500 million plants legally imported into the US each year• 16 US plant introduction facilities• 2 in Florida• Miami handles approximately 80% of the

total

Insect InvasionInsect Invasion

• Stowaways

– Legally imported cut flowers and foliage imported from around the world

– Illegal plant and plant product introductions

Insect InvasionInsect Invasion

• Commerce importation– Industry-related introductions– Pets, educational purposes, fishing bait

• Importation by government and universities

Recent Example:Recent Example:

The Cycad Aulacaspis Scale InsectThe Cycad Aulacaspis Scale Insect

Growing a healthy plantGrowing a healthy plant

Inspect plants or cuttings brought into the landscape...

Avoid SurprisesAvoid Surprises

Monitor Pest PopulationsMonitor Pest Populations

Value? To determine if population needs to be managed

Random Sampling:

The most commonly used method in IPM.

Used to determine pest numbers and/or damage per sample unit (i.e. leaf)

Counts of pest numbers, damage, and/or natural enemies are taken at random locations in the managed area

Sampling Methods:Sampling Methods:

Visual is most common

Counting number/leaf, terminal, plant

Counting number per square foot

Assessing damage per unit area

Can sometimes use trapsCan sometimes use traps

2) Signs of the pest (damage,

frass, cast skins)3) The actual

pest4) Beneficial

organisms5) Note condition or health of plant (does

it need water

or fertilizer?)

1) Conditions that favor a pest or

pest outbreak

When monitoring, look for:When monitoring, look for:

What to do with information? Keep Records!What to do with information? Keep Records!

0

20

40

60

80

30-Jun 14-Jul 28-Jul 12-Aug

Weekly monitoring is recommendedWeekly monitoring is recommended

Management Tools:Management Tools:

• Cultural MethodsCultural Methods• Biological ControlBiological Control• Chemical ControlChemical Control

Cultural MethodsCultural Methods

- - Modification or management practices that make the Modification or management practices that make the habitat less favorable to pest reproduction, dispersal, habitat less favorable to pest reproduction, dispersal, and survivaland survival

A) A) Host plant resistanceHost plant resistance. Heritable plant . Heritable plant characteristics that decrease damage due to characteristics that decrease damage due to pest feedingpest feeding

B) B) Plant RotationPlant Rotation. Rotate host and non-. Rotate host and non-host plantshost plants

C) C) Plant refuse destructionPlant refuse destruction..

D) D) Pruning & thinningPruning & thinning. Can increase . Can increase plant vigorplant vigor

E) E) FertilizationFertilization. Rate of fertilizer can . Rate of fertilizer can affectaffect

attractiveness of host plantattractiveness of host plant

F)F) SanitationSanitation. Keep leaf litter, etc. picked . Keep leaf litter, etc. picked upup

G) G) Water managementWater management..

Biological ControlBiological Control

Protection and enhancement of Protection and enhancement of natural enemies (use most natural enemies (use most selective management tool)selective management tool)

Introduction of natural enemiesIntroduction of natural enemies

Use of microbial controlsUse of microbial controls

Predators

Parasites

Nematodes

Disease

Lady BirdLady BirdBeetleBeetle

They love aphids!

Cryptolaemus Cryptolaemus adult and larvaadult and larva

Green LacewingGreen Lacewing

They also love aphids

Lacewing LarvaLacewing Larva

USDA - ARS

Predacious Gall Midge LarvaePredacious Gall Midge Larvae

UF - Entomology/Nematology

UF - Entomology/Nematology

Predatory MitePredatory Mite

Aphid MummiesAphid Mummies

Parasitized Pink Hibiscus MealybugsParasitized Pink Hibiscus Mealybugs

IchneumonidIchneumonidWaspWasp

PasitizingPasitizingCaterpillarCaterpillar

Parasitized CaterpillarParasitized Caterpillar

UF - Entomology/Nematology

Parasitized ScalesParasitized Scales

UF - Entomology/Nematology

Pathogens (especially fungi…botaniguard, Pathogens (especially fungi…botaniguard, avid, spinosad)avid, spinosad)

If using biocontrol

watch for ants…

They are the ranchers of theinsect world

Sticky bands canSticky bands canhelp keep thesehelp keep theselittle suckers offlittle suckers offthe plantthe plant

Chemical MethodsChemical Methods

- Insecticides

- Sterilants

- Insect Growth Regulators

- Attractants

- Repellents

Soaps and oilsSoaps and oils

Systemic products (merit/marathon)Systemic products (merit/marathon)

Contact products (conserve)Contact products (conserve)

Soil drenchesSoil drenches

Evaluation and Follow-UpEvaluation and Follow-Up

- Requires monitoring?- Requires monitoring?

- Were methods effective?- Were methods effective?

- Is re-treatment required?- Is re-treatment required?

Your help is needed to keep track of Your help is needed to keep track of new pests new pests

If you find anything unusual, report it to your county cooperative extension office

Questions & DiscussionQuestions & Discussion

How about…How about…

What’s Next?What’s Next?

Authors: Tom Weissling & Edwin Duke,University of Florida

Photos: University of Florida University of the Virgin Islands University of California University of Hawaii

Entomology And Nematology Department Copyright University of Florida 2000

For more detailed information see the Featured Creatures WWW site at

http://creatures.ifas.ufl.edu/