leafhoppers in citrus
TRANSCRIPT
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Leafhoppers in Citrus
Sean Moore
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Citrus leafhopper (brown)
Penthimiola bella
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Green citrus leafhopper
Empoasca distinguenda
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Other leafhoppers
• Epignoma natalensis
• Theronopus spp.
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Life cycle• Up to 30 eggs/female• Incubation – 9-19 days
• 5 nymphal instars• 35-63 days
• Live for 15-59 days• Pre-oviposition period: 7-15 days
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Life cycle
X 5
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Other hosts
• Potatoes
• Cowpeas
• Sugarbeans
• Olieboom
• Hondebossie
• Other legumes
• Lucerne
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Seasonality
• Brown leafhopper generally peaks in December and may be a problem until February
• Green leafhopper is usually only a problem once fruit starts to colour
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Leaf damage symptoms
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Early leafhopper damage(usually brown leafhopper)
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Early leafhopper damage(usually brown leafhopper)
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Early leafhopper damage once the fruit have coloured
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Late leafhopper damage, darkened(usually green leafhopper)
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Damage: sooty mould
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Monitoring
• Use sticky yellow traps:• Hang from November for Brown leafhopper• Hang just before colour-break for Green leafhopper
• 3 traps per orchard (approx 1 ha)
• Check traps weekly
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Monitoring: thresholds on sticky traps
Brown: 90-120/trap/week Green: 5-8/trap/week
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Cultivar sensitivity?
• Especially Valley Gold mandarins (B17) seem to be at particularly high risk
• Need to change trap thresholds for sensitive cultivars?
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Monitoring
• Visual inspections on new flush (Nov & Feb), and also after colour-break for green leafhopper• Can then also spray at presence of green leafhopper
and signs of damage
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Biological control
Anagrus sp. egg parasitoid
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Factors influencing leafhopper outbreaks
• Rain
• Temp
• Parasitism
• Flushing
• Inter-row vegetation
• Lucerne nearbyH.D. Catling (1972)
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Leafhopper control
PRODUCT DOSE COMMENTS
Green leafhopper Brown leafhopper
Xterminator 500 ml - 2 d PHI for most markets
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Leafhopper control
PRODUCT DOSE COMMENTS
Green leafhopper Brown leafhopper
Xterminator 500 ml - 2 d PHI for most markets
Chess 40 g 40 g 42 d PHI for most; 90% pd for some
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Leafhopper control
PRODUCT DOSE COMMENTS
Green leafhopper Brown leafhopper
Xterminator 500 ml - 2 d PHI for most markets
Chess 40 g 40 g 42 d PHI for most; 90% pd for some
![Page 25: Leafhoppers in Citrus](https://reader031.vdocuments.mx/reader031/viewer/2022012505/61806e0055bbe8777d28c6f9/html5/thumbnails/25.jpg)
Leafhopper control
PRODUCT DOSE COMMENTS
Green leafhopper Brown leafhopper
Xterminator 500 ml - 2 d PHI for most markets
Chess 40 g 40 g 42 d PHI for most; 90% pd for some
Phosdrin 40 ml 50 ml Not registered
Mevinphos 132 ml 165 ml Not registered
Methomyl WP 60 g 60 g Not registered
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Leafhopper control
PRODUCT DOSE COMMENTS
Green leafhopper Brown leafhopper
Xterminator 500 ml - 2 d PHI for most markets
Chess 40 g 40 g 42 d PHI for most; 90% pd for some
Phosdrin 40 ml 50 ml Not registered
Mevinphos 132 ml 165 ml Not registered
Methomyl WP 60 g 60 g Not registered
Kangroshield 100 500 ml - Not registered
![Page 27: Leafhoppers in Citrus](https://reader031.vdocuments.mx/reader031/viewer/2022012505/61806e0055bbe8777d28c6f9/html5/thumbnails/27.jpg)
Leafhopper control
PRODUCT DOSE COMMENTS
Green leafhopper Brown leafhopper
Xterminator 500 ml - 2 d PHI for most markets
Chess 40 g 40 g 42 d PHI for most; 90% pd for some
Phosdrin 40 ml 50 ml Not registered
Mevinphos 132 ml 165 ml Not registered
Methomyl WP 60 g 60 g Not registered
Kangroshield 100 500 ml - Not registered
Endosulfan WP 300 g - Not permitted
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Efficacy of treatments against green leafhopperMarble Hall, Mpumalanga (2017)
0
10
20
30
40
50
60
70
7 DAT 14 DAT
Nu
mb
er
of
leaf
ho
pp
ers
per
tra
p
Control Xterminator Kangroshield Phosdrin
a
b b b
a
b b b
Grout & Stephen, 2017
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Efficacy of treatments against brown leafhopperMarble Hall, Mpumalanga (2017)
0
5
10
15
20
25
7 DAT 14 DAT
Nu
mb
er
of
leaf
ho
pp
ers
per
tra
p
Control Xterminator Kangroshield Phosdrin
a
a
a
b
aa
a
b
Grout & Stephen, 2017
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Efficacy of treatments against green leafhopperCFB, E Cape (1998); 4 WAT
0
0.5
1
1.5
2
2.5
3
3.5
4N
um
be
r o
f le
afh
op
per
s p
er t
rap a
bb
bb
b
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Acknowledgment
• Tim Grout (CRI) for some of the data
• Some of the photos:
• Peter Stephen (CRI)
• Isabel Sparks (Katco)
• James Warrington
Questions?