INTEGRATED PEST
MANAGEMENT
PALM TREES
IN
SOUTH FLORIDA
PALMETTO WEEVILS
• Drawn to stressed
palms in sub-tropical
deep south (mostly
cabbage & Canary
Island Date palms).
• Some species spread
nematode in Central
and South America
and Caribbean.
Palm weevils
Symptoms & Treatment
• Adult females lay eggs in leaf
bases of crown, larvae tunnel
into heart, destroying the
palm.
• Crowns of affected palms
topple over or “deadhead”.
• Reduce transplant stress
• Preventative spray of Lindane
or Dursban applied at and a
few weeks after transplant.
Reducing Transplant Stress
• Transplant early spring or summer - soil
below 65C discourages new root growth.
• Remove 1/2 or more of leaves at time of
digging to reduce water loss from
transpiration.
• Optimal drainage.
• Avoid transplanting deeper than originally
grown.
• Micronutrient foliar spray since root
absorption is limited.
ROYAL PALM BUG
• Troublesome pest in
Florida and Caribbean.
• Infestations increase in
Spring and Summer
after a mild winter.
• Feeds on young leaves
getting in between
folds of emerging leaf.
Treatment
• Three species of spiders have been found to
prey on royal palm bugs, and suggested that
they, along with heavy rains, are major
factors in the natural control of the species.
• whether populations of these prolific bugs
are regulated by spiders and rain alone is
still open to question. Tactic not in use.
Treatment
• A relatively new insecticide discovered by
Bayer, imidacloprid, shows promise. It can
be applied without a special use permit.
• low mammalian toxicity - oral LD50 rates
as 1858-2591 mg/kg and the dermal LD50
rate as >2000.
• Long term effectiveness due to stability in
soil, but may take weeks for root drench to
take effect.
PALM APHID
• Female becomes
sedentary like a scale
forming a distinctive
waxy ring around it.
• Heavily infest young
leaves and secrete
honeydew upon which
sooty mold will grow.
Sooty Mold
• Fungus that feeds
upon “honeydew”
from aphid, scale,
mealybugs.
• Interferes with
photosynthesis.
• Control honeydew
producing insects.
Leaf Spots
• Helminthosporium,
Anthracnose,
Stigmina,
Pestalotiopsis
• All cause spots, some
merge and form
blighted areas.
• Easily spread by use
of overhead irrigation.
False Smut
• Significant problem of
landscape palms
during heavy rainfall.
• Grayish-black fruiting
bodies on both sides of
leaf.
• Copper based
fungicides and maneb
or mancozeb effective
if applied in early
stages.
Phytophthora root rot
• Also causes leaf spots
and bud rots.
• Drenching soil with
metylaxyl reduce
populations of this
fungus.
• Foliar applied fosetyl
aluminum will
translocate to roots of
palm.
• Prevent overwatering.
Ganoderma Butt Rot
• Serious and incurable
disease of older palms.
• Progresses from older
leaves upward which
turn brown and droop
from the trunk.
• Wounds on lower
trunk allow entry of
fungus.
Ganoderma butt rot
• Fruiting body a
conspicuous bracket or
conch.
• Rapid spread and
persistent in soil.
• Remove and destroy
effected palms and
conchs.
• Fumigate soil and
replant broad-leafed
trees (not susceptible).
Fusarium wilt
• Frequent in California
and starting in Florida.
• Uneven decline in
canopy.
• Transferred from tree
to tree by pruning
tools, so they should
be sterilized between
uses.
Coconut Lethal Yellowing
• Incurable disease
caused by a
mycoplasma-like
organism.
• Vector - Leaf hopper.
• Yellowing and dying
of leaves.
• Avoid by planting
resistant varieties.
• Decline temporarily
suspended by
antibiotic injections.
Spider Mites
• Biggest problem in
greenhouse production.
• Chemical controls
diminishing.
• Best controlled by
predatory mites:
Phytoseiulus persimilus
Neoseiulus californicus
Spider Mites
• persimilus is a quickacting parasite and is
usually released ititially.
• californicus is slower
moving “bat clean up”
and released later.
• These tactics work better
in greenhouse where
plants are tip to tip.
Pest Management Approaches
• City of Hollywood, Florida, Alice Cohen greenhouse palm production.
• Central Florida extension agent for
University of Florida, Liz Felter
• South Florida extension agent for
University of Florida, Bill Schaal greenhouse and field grown palms.
City of Hollywood
• Palms in landscape, medians, parks, etc.
• Palm weevil occasionally a problem - only treat when they
see damage. Must spray in crown.
• Safe soaps and oils.
• Resistant varieties (lethal yellowing)
• Stopped planting impatients around trees because water
req. is high - promotes fungal pathogens.
• Unfortunately, plants are selected by non-horticulturalists
for aesthetic value. Some are tropical, req. lot of water
which promotes disease.
• No biological control used.
Central Florida Greenhouse
Production
• Predatory mites for spider mites. #1 pest.
• Scale, #2 pest - no biocontrol. Use
Dimethoate or Marathon (systemic).
Residue up to 60d, so cannot release
biocontrols during this time.
• Scouting and record keeping of juvenile
sitings. Use calendar documentation in dz.
forecasting.
• Companies such as Glades Crop Care
provide a scouting service, but charge about
600/mo. not seen as cost-effective by most.
• Most scouting companies specialize in
agronomic crops, not ornamentals.
• IPM consultants rare.
• Florikan, supplier of growing supplies,
focus on IPM products. Pheremone
attractants, Opogona (catarpillers for
nematode control), pred. mites, etc.
Credits
• Pictures and info. on : Palm aphid, scale,
royal palm bug, palmetto weevils, leaf
spots, sooty mold, phytophthera root rot,
Fusarium wilt, Ganoderma butt rot, lethal
yellowing - Betrodk’s guide to landscape
PALMS, Alan Meerow.
• Pictures and info on palm weevil/nematode
life cycle and spider mites - Palm
Production and Culture Resources t the Ft.
Lauderdale REC (UFL/IFAS) web site:
http://www.ftld.ufl.edu/palm.htm
Credits cont’d
• Alice Cohen, City of Hollywood, Florida.
• Liz Felter, Central Florida Extension Agent.
University of Florida, IFAS.
• Bill Schaal, South Florida Extension Agent.
University of Florida, IFAS.