|
|
|
In Florida and the Caribbean Region |
|
|
|
|
Females are fairly sedentary when feeding, and
form a ring of white wax around their bodies. |
|
Heavily infest young leaves and excrete honeydew
upon which sooty mold will grow. |
|
|
|
|
|
Always tended by ants |
|
Control: |
|
Dimethoate (Cygon) Bicontrol: Lady beetles |
|
Many other insecticides |
|
|
|
|
|
|
|
Chiefly a problem in greenhouse and shadehouse
production and in the interiorscape. |
|
In the landscape, often infest leaf axils where
they are not easily observed. |
|
|
|
|
|
Control: |
|
A broad range of effective chemicals will
control mealybugs on palms. |
|
Natural predator: Mealybug destroyer (Cryptolaemus
montrouzieri), a tropical lady beetle. |
|
|
|
|
|
Scales on palm leaves: |
|
Thread scale. |
|
Magnolia white scale. |
|
Coconut scale. |
|
Florida red scale. |
|
Oriental scale. |
|
|
|
|
|
Most severe in greenhouse production and
interiorscapes, but common in the landscape as well. |
|
Control:
Hard shell of scales and their unique biology reduces effectiveness
of many chemicals. |
|
Dimethoate (Cygon) works on a variety of these
pests. |
|
Merit or Marathon works systemically on some
species. |
|
Insect predators and parasitoids very effective
on some species in some situations. |
|
|
|
|
|
Problem for greenhouse grown indoor palms and on
many Chamaedorea species. |
|
Control: |
|
Predatory mite, Phytoseiules persimilis,
controls two-spotted mites (Tetranychus urticae) on palms in greenhouses
and interiorscapes |
|
Chemical miticides. |
|
|
|
|
Heliothrips haemorrhoidalis, the Greenhouse
thrips, is the most common. |
|
Primarily production/interior problem, but after
several mild winters, it can cause significant damage on landscape palms
and field grown material. |
|
|
|
|
Rasp feeding casues stippling and silvering on
leaves. |
|
Red (soon turning black) excrement a tell-tale
sign. |
|
Control: malathion, Cygon, Orthene. |
|
|
|
|
|
Usually not a terribly significant pest problem
on landscape palms. |
|
Can be a severe problem in conservatory
plantings. |
|
Keys whitefly (Aleurodicus dispersus) was once
common on many palms and other plants in south Florida but has abated,
probably due to natural control (Encarsia formosa). |
|
|
|
|
Feeds on husk of coconut fruits, causing mostly
cosmetic damage and sometimes premature fruit drop. |
|
No control advisable. |
|
|
|
|
Moth larvae destroy several palm species in
tropical areas, especially Chamaedorea species and arecas, by tunneling
through stems. |
|
|
|
|
|
Mostly a palm production pest, but has infested
landscape palms. |
|
Control: |
|
Lindane Dipel |
|
Sevin Parasitic nematodes (Steinernema
carpocapsae) |
|
|
|
|
First conspicuous sign of infestation is large
quantities of “frass” (fibrous excrement) produced by caterpillars of small
moth, feeding mostly on tissue between veins or ribs of lower leaf surfaces
of many palms; will also feed on leaf stems, disrupting vascular tissue and
causing death of entire leaf. |
|
|
|
|
|
Successive generations throughout warm season. |
|
Control (anecdotal success): |
|
Sevin |
|
Lindane |
|
Dipel 2X (biopesticide) |
|
|
|
|
Only known vector of the Lethal Yellowing
phytoplasma in Florida. |
|
So far, vector management has not proven a very
successful approach to controlling LY. |
|
|
|
|
Pest of royal palms (Roystonea spp.) in Florida
and Cuba. |
|
Infestations in south Florida increase in spring
following a particularly mild winter. |
|
Feeds on young leaves, getting in between folds
on emerging leaf; when leaf unfolds it appears scorched and brown and
usually fails to mature. |
|
Control:
foliar spray with dimethoate (Cygon) works well, but is difficult to
apply to very tall royal palms.
Drench treatment with imidacloprid. Allow several weeks for chemical to translocate to the crown |
|
Problem usually abates after June. |
|
|
|
|
|
|
Male weevils respond to a semiochemical signal
from a “stressed-out” host palm. |
|
Once on the palm, he releases his own attractant
pheromone which mixes with the palm odor. |
|
Other male and female weevils arrive on the host
palm and nature takes its course... |
|
|
|
|
… females lay eggs in leaf bases of the crown
and large larvae tunnel into heart, causing crowns to topple over or
“deadhead.” |
|
|
|
|
|
|
|
|
As many as 200+ larvae have been extracted from
crowns of field-grown Canary Island date palms. |
|
Feeding is audible in large infestations,
especially if stethoscope is placed on upper trunk. |
|
Once present, eradication is difficult if not
impossible. |
|
Main host in wild is probably Serenoa repens,
which can withstand attack since it branches. |
|
|
|
|
|
Control: |
|
Reduce transplant stress on susceptible species. |
|
Preventative spray of Lindane or Dursban applied
at installation and again a few weeks later, shows some success. |
|
Remove and destroy infested palms before adults
emerge (sanitation) |
|
|
|
|
|
|
Related species, R. palmarum, occurs in Central
and South America and Caribbean, spreads destructive nematode that causes
red ring disease in coconuts and African oil palms (more on that later). |
|
|
|
|
|
|
|
|
|
Just for the record: |
|
In Asia and Africa, Corypha and Borassus palms
are deliberately wounded to attract native species of Rhynchophorus to the
palms. |
|
|
|
|
|
|
Feed on leaves of palms |
|
Completely defoliate young palms in 1-2 days if
on palm foliage in force. |
|
Control |
|
Small infestations - mechanical. |
|
Dipel 2X biopesticide effective on wide variety
of young instar caterpillars. |
|
Dursban or Lindane controls grasshoppers if
applied when insects are young. |
|
Semaspore, Nosema loctustae protozoan in bait. |
|
|
|
|
|
|
|
|
Apparently attack otherwise healthy palms. |
|
Heavy infestations riddle leaf bases and
sometimes move into trunk or crownshaft, promoting secondary fungal
(bacterial?) rots. |
|
|
|
|
|
Canary Island date palm, Royal palms, Majesty
palm, Spindle palm are favored, but many other species are at risk. |
|
Control: |
|
many
broad spectrum and systemic insecticides are effective. |
|
parasitic nematodes, especially effective on larvae. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Symptoms:
stem bleeding from small holes; frass plug pushed out of gallery. |
|
Generally ambrosia beetles (e.g., Xyloborus, Platypus spp.). |
|
|
|
|
Secondary invaders. |
|
Look for other problems (trunk rots, bud rots). |
|
Treatment near entry holes may kill the insects. |
|
|
|
|
|
|
|
Root knot (Meloidogyne incognita) a minor
problem on palms. |
|
Chamaedorea most seriously affected. |
|
Burrowing nematode (Radopholus similis) can
seriously affect Chamaedorea but is rare. |
|
The main concern in Florida is presence of
nematodes, rather than damage, since detection in material shipped to
California will result in refusal. |
|
|
|
|
|
Red ring nematode (Bursaphelenchus cocophilus) |
|
Extremely serious problem in Central and South
America on coconuts and African oil palms (“red ring disease”). |
|
Vectored by the palm weevil Rhynchophorus
palmarum. |
|
Not a problem in Florida. |
|
|
|
|
|
|
|
|
The possibility of introduction of R.
palmarum infested with red ring nematode inside imported seed nuts make
monitoring imperative. |
|
|
|
|
We thank the following colleagues who graciously
provided images for this presentation: Robin Giblin-Davis, Forrest W.
Howard, Greg Erdos, James De Filippis, the UF Department of Entomology and
Nematology (mostly J. Castner), J. Peña; and F. W. Howard and Robin Giblin-Davis for their review of the
presentation. |
|
Notes