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Update on Bud Mites, Blueberry Gall
Midge & Chilli Thrips
Oscar E. Liburd
Professor of Small Fruits and Vegetable Entomology
University of Florida
Gainesville, FL 32611
Blueberry bud mite (BBM)
• Eriophyid mite
• 2 pairs of legs close to the head
• Microscopic (200 μm)
• Tapers toward the dorsal part of
the abdomen
• Transparent /colorless to whitish
• Attack primarily Vaccinium spp.
Life History & Description
• Mites overwinter under bud scales or in protected sites
near the host plant
• Adults emerge at bud break during spring
• Eggs, Protonymphs, Deutonymphs, & Adults
• A female can lay up to 200 eggs during its lifetime.
• In north-central Florida population peaks around
February-March
Symptoms of BBM Infestations
• Swollen bud scales
• Buds appear reddened &
rosetted
• Reduced fruit set
Symptoms of BBM Infestations
Cont’d
Evaluation of Post-harvest Acaricides for
Control of BBM
• Envidor® 2 CS (Spirodiclofen)
• Agri-Mek® 1.8 EC (Abamectin)
• Thionex® 3 EC (Endosulfan)
• Water (Control)
- Southern highbush cv Farthing
- RCBD with 4 reps
-CO2 sprayer, application date Oct 14
* Observation of flower bud damage & BBM density during 2009/10
season
Effect of Acaricides on the Percentage of Flower
buds Infected with BBM
control
Envidor
Agri-Mek
Thiodan
% flower buds infected
80
70
a
a
60
50
40
30
20
10
0
b
b
b
b
c
c
Effect of Acaricides on the Population of
BBM
Mean number of BBM per bud
14
control
Envidor
Agri-Mek
Thiodan
a
12
a
10
8
b
6
4
2
0
b
b
c
bc
c
Findings and Assessment of Miticides
• All of the miticides reduced the population of BBM and
the number of flower buds infected compared with the
control
• Overall Endosulfan was the most effective acaricide in
reducing the percentage of flower buds infected with
BBM
• Envidor was the second most effective acaricide in
reducing BBM infestation
• Agri-Mek performance was not significantly different to
Envidor in reducing BBM infestation
Management of BBM
• Pruning and removal of older infected branches
• Post-harvest application of acaricides - Endosulfan and
horticultural oils,
• Envidor was evaluated through the IR-4 program ~ 3-4
yrs ago and registration is pending.
• Endosulfan will be phased out globally 2015
• Portal (78) (fenpyroximate) is a miticide that will be
going through the IR-4 program during 2014-2015
[Nichino America Inc.]
Blueberry gall midge
• Dasineura oxycoccana
Johnson
• Pupae overwinter in soil
• Adult females lay eggs
in developing buds
• Up to 80% yield loss
Injury resulting from blueberry gall midge
New shoot damage
Ovary necrosis &
Larvae in flower bud
Monitoring for BGM
• Bucket emergence trap
• Clear panel trap
Cook et al. 2011
Modified panel trap
3
1
2.5
0.8
2
0.6
a
1.5
a
0.4
1
0.2
0.5
b
0
0
26-Jan
2-Feb
9-Feb
16-Feb 23-Feb 1-Mar
Sampling dates
Average BGM larvae per bud
Average BGM adults per trap
Mean Number of Blueberry Gall Midge per Trap
& Larvae per Bud (2012)
bucket
panel
mod
buds
Mean Number of Blueberry Gall Midge per Trap
& Larvae per Bud (2013)
bucket
panel
mod
buds
18
16
14
12
0.5
0.4
a
0.3
10
8
0.2
6
4
0.1
2
0
8-Feb
15-Feb
b
b
Sample date
0
22-Feb
Average BGM larvae per bud
Average BGM adults per trap
20
Captures of BGM in Bucket traps in Rabbiteye Blueberries
In rows
Number of adults captured in 3-4 weeks
50
a
2012
2013
40
30
ab
ab
bc
20
10
c
0
18-48
18-48
34-64
34-64
51-81
51-81
Lane
Between rowsIn lane
Distance from bush (cm)
Between rows
4-34
4-34
16-46
16-46
InRow
row
Management of BGM
• Weekly monitoring of BGM population in the field
• Application of Insecticides
- Delegate (Spinetoram)
- Malathion
- Entrust (Spinosad)
• Parasitoids
• Most common genera:
- Platygaster (flower buds)
- Aprostocetus (leaf buds)
Chilli Thrips (Adult & Larvae)
Adults are about 1.2 mm (0.05) inches long
Dark wings
Chilli
thrips
Flower
thrips
Symptoms of Chilli Thrips Infestation
• Severe leaf curling
in heavy
infestation
• Implicated in
transmission
of a few virus
diseases
• Tomato Spotted
Wilt Virus (TSWV )
and Yellow Spot
Virus in peanuts
Symptoms of Chilli Thrips Infestation
Bronzing
Shoot Die-back
Insecticide Management Program
Weekly monitoring (scouting of blueberry planting)
• Spinosyns
Delegate
Entrust (organic)
3.5
3.0
• Neonicotinoids
Assail (Acetamiprid)
4.0
Imidacloprid (Admire)
3.5 – 4.0
• Organophosphates
Malathion
Imidan (Phosmet)
2.5 – 3.0
2.5 – 3.0
Acknowledgements
• Florida Blueberry Growers Association
• Staff (post-Docs & Graduate Students)
• USDA-NIFA Pest Management Program
• Florida growers that allowed us to conduct research on
their farms
Oscar E. Liburd
http://liburd/fruitnvegipm/index.htm
[email protected]