Insect pests of citrus
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Common name: Citrus
S.N: Citrus spp
Family:Rutaceae
Pests |
Major pests of Citrus
| I. Sap feeders |
Citrus aphids Black aphid: Toxoptera aurantii,
Brown aphid: Toxoptera citricida |
Symptoms |
Identification |
Management |
| Citrus Black fly, Aleurocanthus woglumi |
Symptoms |
Identification |
Management |
| Citrus psyllid, Diaphorina citri |
Symptoms |
Identification |
Management |
| Mealy bug, Planoccus citri |
Symptoms |
Identification |
Management |
| Fruit sucking moth, Otheris materna, O. ancilla, O. fullonica |
Symptoms |
Identification |
Management |
| Citrus thrips, Thrips nilgiriensis |
Symptoms |
Identification |
Management |
| Cottony cushion scale, Icerya purchasi |
Symptoms |
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Management |
| II. Leaf feeders |
| Citrus leaf miner, Phyllocnistic citrella |
Symptoms |
Identification |
Management |
| Citrus butterfly , Papilio demolious, P. Polytes, P.helenus |
Symptoms |
Identification |
Management |
1. Sap feeders
1. Citrus aphids
Black aphid: Toxoptera aurantii,
Brown aphid: Toxoptera citricida
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Symptoms of damage
- Feed on tender foliage and flowers.
- Transmit tristeza virus disease.
- Nymphs and adults suck the sap of leaves
- Wilting and flower dropping
- Infested leaves - cup shaped and crinkled
- Growth of the plants is hindered.
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Crinkling of leaves |
Identification of the pest
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| Adult wingless forms (apterae) |
Adult winged forms (alatae) |
Management
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2. Citrus Black fly, Aleurocanthus woglumi
Symptoms of damage
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- The cell sap is sucked from the leaves - piercing stylet
- Leaf curling.
- Leaves fall off immaturely.
- Honey dew secrecation development of sooty mould fungus.
- Leaf turns to black in colour and affects photosynthetic activity of the leaves.
- Affected trees produce - few blossoms which develop into inspid fruits.
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| Black flies on leaf |
Close-up of Black flies |
Identification of the pest
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Nymphs - are flattened, oval in shape and scale like in appearance.
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Adult - minute insect, shiny black with grey dusting on the body.
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Wings are extending beyond the tip of the abdomen.
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Black fly on leaves |
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Management
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Collect and destroy the damaged plant parts along with nymphs, pupa and adults
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Spray with 2 ml of chloropyriphos per litre of water
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followed by a second spray after 15 days with 1.5ml of monocrotophos
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Ffemale lays eggs on lower surface of leaves in a form of three (15-22 eggs/whorl) whorls
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The entire plant canopy should be drenched with the solution.
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Encourage activity of parasitoids, Encarsia sp., Eretomocerus serius and chlysoperla sp.
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3. Citrus psyllid, Diaphorina citri
Symptoms of damage
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Both nymphs and adults suck sap from the plants and injection of toxic saliva.
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Nymphs - are more destructive, crowd on the terminal shoots, buds and tender leaves
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Excrete honeydew - growth of sooty moulds.
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Affected plant parts dry and die away
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It is transmits the "Greening" virus
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| Psyllid infested plants |
Sooty mould on leaves |
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Identification of the pest
- Eggs – are almond shaped yellow colour eggs, present on the bolds of half opened leaves
- Nymphs – are flattish, oval in shape and light orange colour.
- Adult – small, brown in colour and brown colour band present on the half of fore wing
Management
- Collect and destroy the damaged plant parts
- Spraying with systemic insecticides at flush growth periods
- Spray malathion 0.05% or monocrotophos 0.036% or carbaryl 0.1% or methyl parathion 0.05%.
- Encourage the activities natural enemies such as Syrphids and Chrysopids
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4. Mealy bug, Planoccus citri
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Symptoms of damage |
Mealy bug on fruits |
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Large amounts of honey dew excrete - sooty mould fungus.
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Fungus covers the foliage and fruits
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In severe infestation the flowers do not form fruits.
Identification of the pest
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Eggs – are laid in clusters, protective cottony mass
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Nymphs – are amber coloured with white waxy coating with filaments
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Adult - Male is winged, long antenna and without mouth parts.
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Female is wingless, flat body and short, waxy filaments along the margins
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Egg mass |
Adult female and crawlers |
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Management
- Collect and destroy the damaged leaves, twigs and stems
- Debark branches and apply methyl parathion paste
- Use sticky trap (5cm length) on fruit bearing shoots
- Spray dichlorvas 0.2% in combination with fish oil rosin soap 25g/lit
- Single soil application of aldicarb 10G at 50g/tree at the time of pruning
- Spraying of trees with methyl parathion 2ml or monocrotophos 1.5ml per /lit of water
- Soil treatment with chlorophyriphos apply on the near the tree trunk
- Spraying of trees with acephate, methomyl, or chlorpyriphos.
- Field release of Australian lady bird beetle Cryptoleamus montrouizeri 10 per tree
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5. Fruit sucking moth, Otheris materna, O. ancilla, O. fullonica
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Symptom of damage
- Adult pierce the fruit and suck the juice
- Rottening at the feeding site
- Fruit dropping
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| Affected fruit |
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Identification of the pest
O. fullonica
- Larva – orange blue and yellow spots on velvety dark speckled on the body
- Adult – stout moth and orange coloured wing
- Otheris materna – three black spots on the fore wing
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Female |
Male
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- O. ancilla – white colour band in the middle fore wing
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Management
- Destroy the weed host Tinospora cardifolia and coccules pendules
- Bag the fruit with polythene bag (500 gauge)
- Apply smoke to prevent adult moth
- Trap crop – growing tomato crop in orchards to attract the adult moth
- Poison bait
- dilute suspension of fermented molasses and malathion 0.05% (50 EC at 1ml/lit)
- Use light trap or food lure to attract moths
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6. Citrus thrips, Thrips nilgiriensis
Symptom of damage
- Nymphs and adults lacerate the leaf tissue and suck the sap from fruits
- Leaf curling
- Ring like appearance on the fruit
- Irregular mottled patches on rind
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| Scarring on Fruit |
Shoot damage |
leaf damage |
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Identification of the pest
Adult – yellowish, fringed wing
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| Adult - Thrips |
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Management
- Collect and destroy the damaged plant parts
- Spraying with systemic insecticides at flush growth periods
- Spray malathion 0.05% or monocrotophos 0.036% or carbaryl 0.1% .
- Encourage the activities natural enemies such as Syrphids and Chrysopid
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7. Cottony cushion scale, Icerya purchasi
Symptoms of damage
- Nymphs and adults suck the sap from leaves
- Honey dew excretion
- Development of sooty mould fungus
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Identification of the pest
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White, ribbed masses that hold up to 800 red eggs.
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Nymphs are red with black legs and antennae.
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Adults are covered in white hair.
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| Cottony cushion scale, Icerya purchasi |
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Management
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Spray dormant oil in late winter before spring.
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Spray horticultural oil, if needed, year round.
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Apply mixture of manure compost tea, molasses, citrus oil.
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Garlic-pepper tea also helps.
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Natural predators usually keep this insect in check.
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Control ants and dust which can give the scale a competitive advantage.
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Field release of vedalia and Australian ladybugs.
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II. Leaf feeder
8. Citrus leaf miner, Phyllocnistic citrella
Symptom of damage
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Caterpillars are attacked tender leaves and feed on the epidermis
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Making silvery appearance presence on the lower surface of leaves
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Leaves – distorted and crinkled
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Severe attack caused defoliation
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Encourage the incidence of citrus canker
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Serpentine larva |
crinkled leaves |
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Identification of the pest
- Eggs – are minute, flattened presence on the lower side of the midrib
- Larvae – minute, yellowish or reddish and apodous.
- Settled down on the edge of the folded leaves
- Adult – minute moth, black spot at the tip of the fore wing
Top
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Spraying of monocrotophos [Nuvacron] 1.5ml, fenvalerate 0.2ml or dimethoate [Rogor] 2ml
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mixed in a litre of water at weekly intervals at the time of emergence of new flush.
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9. Citrus butterfly , Papilio demolious, P. Polytes, P.helenus
Symptom of damage
- Caterpillars prefers on light green tender leaves
- Feeding voraciously and leaving only the mid-ribs
- Severe infestation the entire tree gets defoliated.
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Defoliation |
Larva feeding |
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Identification of the pest
Larvae
- Early stage larva resembles bird dropping
- Grown up larva – cylindrical, stout, green and brown lateral bond
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First instar |
Second instar |
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Third instar |
Fourth instar with osmotoria |
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Life cycle |
Grown up larva |
Adult
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Papilio demolious |
Papilio polytes |
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Management
- Hand pick the larvae and destroy
- First instar - Spraying of 1.5ml monocrotophos (Nuvacron), 1ml DDVP (Nuvan)
- Field release of parasitoids Trichogramme evanescens and Telenomus sp on eggs
- Brachymeria sp on larvae and Pterolus sp. on pupae.
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