Transcript Biological Control of Invasive Plants in South Florida

Ask your doctor if
Biological Control
is right for you
Paul Pratt
USDA-ARS
Invasive Plant Research Laboratory
Fort Lauderdale, Florida
Australia
Pathogens
Insects
Koalas
Melaleuca
Suitable environment
Florida
Pathogens
Insects
Melaleuca
Suitable environment
Approach: The “pipeline”
Melaleuca Weevil:
Oxyops vitiosa
Melaleuca Weevil:
Oxyops vitiosa
Feed on tender flush
Eggs
Melaleuca Weevil:
Oxyops vitiosa
Larvae
Weevil damage
Oxyops vitiosa
– The first melaleuca
bioagent introduced
– Doesn’t thrive in
permanently flooded
sites
– Spreading at a rate of 1
km/yr
– Now released at >150
sites
Melaleuca Psyllid:
Boreioglycaspis melaleucae
Egg
Adults
Nymphs
Flocculence – white waxy byproduct
Psyllid feeding damage
Melaleuca psyllid
– The second melaleuca
bioagent introduced
– Not influenced by water
levels
– >700,000 redistributed
– Now released at >90
sites
– Spreading at a rate of 7
km/yr
Do I have bugs?
• Biological control agents are everywhere
Integrated Melaleuca Management
How to use the biological control agents
most effectively?
Flower Production per Tree
reduces flowering
12
A
10
8
6
4
2
B
B
B
0
Control Oxyops 1 Oxyops 2 Mechanical
Treatment
• Reduces seed bank
• Reduces recruitment
after herbicide
kills seedlings
•Limits follow-up treatments
Regional impacts
reduces regrowth from cut
stumps
reduces regrowth from cut
stumps
Combining herbivory with occasional mowing caused 80%
stump mortality
80
70
60
50
40
30
20
10
0
% Mortality
th
bo
ow
m
g
in
s
g
in
ct
se
in
th
no
stunts growth
increases vulnerability
Reduced canopy
+
Repeated defoliations
=
Depleted starch reserves
Vulnerable to:
• Mechanical controls
• Drought
• Frost (low temps)
Integrated Melaleuca Management
with Biological Control
• Gives managers more time and flexibility
– Reduces seed dispersal from neighboring
lands
– Reduced frequency of mechanical and
chemical treatments
– Longer time between initial and follow-up
treatments
– Allows managers to redirect limited funds to
emerging weed problems
Melaleuca rust – Puccinia cidii
• Introduced accidentally
through ornamental trade
• Attacks Myrtaceous plants
including melaleuca
• Attacks young leaves
Future biological control agents
in the pipeline. . .
Melaleuca Bud-Gall Fly
Fergusonina turneri (Fergusoninidae)
Melaleuca Gall Fly:
Ferg Damage
Galls Melaleuca Flower Buds
gall
flower
Ferg Damage
2
3
galls melaleuca
shoot buds, too!!
1
9
10
4
5
8
6
7
Melaleuca Stem-Gall Fly
Lophodiplosis trifida (Cecidomyiidae)
Cecid Damage
Galls Melaleuca Stems
Accelerating the Program: New
Quarantine Facility for Screening
Biological Control Agents