Leafhoppers in Citrus

Sean Moore

Citrus leafhopper (brown)

Penthimiola bella

Green citrus leafhopper

Empoasca distinguenda

Other leafhoppers

• Epignoma natalensis

• Theronopus spp.

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

Life cycle

X 5

Other hosts

• Potatoes

• Cowpeas

• Sugarbeans

• Olieboom

• Hondebossie

• Other legumes

• Lucerne

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

Leaf damage symptoms

Early leafhopper damage(usually brown leafhopper)

Early leafhopper damage(usually brown leafhopper)

Early leafhopper damage once the fruit have coloured

Late leafhopper damage, darkened(usually green leafhopper)

Damage: sooty mould

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

Monitoring: thresholds on sticky traps

Brown: 90-120/trap/week Green: 5-8/trap/week

Cultivar sensitivity?

• Especially Valley Gold mandarins (B17) seem to be at particularly high risk

• Need to change trap thresholds for sensitive cultivars?

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

Biological control

Anagrus sp. egg parasitoid

Factors influencing leafhopper outbreaks

• Rain

• Temp

• Parasitism

• Flushing

• Inter-row vegetation

• Lucerne nearbyH.D. Catling (1972)

Leafhopper control

PRODUCT DOSE COMMENTS

Green leafhopper Brown leafhopper

Xterminator 500 ml - 2 d PHI for most markets

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

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

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

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

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

Efficacy of treatments against green leafhopperMarble Hall, Mpumalanga (2017)

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7 DAT 14 DAT

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Control Xterminator Kangroshield Phosdrin

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Grout & Stephen, 2017

Efficacy of treatments against brown leafhopperMarble Hall, Mpumalanga (2017)

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7 DAT 14 DAT

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Control Xterminator Kangroshield Phosdrin

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Grout & Stephen, 2017

Efficacy of treatments against green leafhopperCFB, E Cape (1998); 4 WAT

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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?