Citrus

Citrus aphids Black aphid

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 appear cup shaped and crinkled

Growth of the plants is hindered

Crinkling of leaves

Adult wingless forms (apterae)

Adult winged forms (alatae)

Management

Use yellow sticky trap

Spray with methyl demeton (Metasystox) or dimethoate (Rogar) 2ml /lit

Use some concinellid beetles and syrphid flies

Citrus Black fly

Symptoms of damage

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

Identification of pest

Nymphs: Are flattened, oval in shape and scale like in appearance

Adult: Minute insect, shiny black with grey dusting on the body. Wings are extending beyond the tip of the abdomen.

Black flies on leaf

Close-up of Black flies

Black fly on leaves

Management

Collect and destroy the damaged plant parts along with nymphs, pupa and adults

Spray with 2 ml of chloropyriphos per litre of water

The entire plant canopy should be drenched with the solution.

Encourage activity of parasitoids, Encarsia sp., Eretomocerus serius and chlysoperla sp

Citrus psyllid

Symptoms of damage

Both nymphs and adults suck sap from the plants and injection of toxic saliva

Nymphs - are more destructive, crowd on the terminal shoots, buds and tender leaves

Excrete honeydew- growth of sooty moulds

Affected plant parts dry and die away

It is transmits the "Greening" virus

Psyllid infested plants

Sooty mould on leaves

Identification of pest

Nymphs: Are flattened, oval in shape with orange colour

Adult: Minute insect, shiny black with grey dusting on the body, wings are extending beyond the tip of the abdomen

Egg

Nymphs

Adult

Management

Collect and destroy the damaged plant parts

Spraying with systemic insecticides at flush growth periods

Spray malathion 0.05% or carbaryl 0.1%

Encourage the activities natural enemies such as Syrphids and Chrysopids

Mealy bug

Symptoms of damage

Both nymphs and adults suck the sap from the cells of tender branches and fruits

Turn pale colour

Affected plant parts - wilt and dry up

Large amounts of honey dew excrete - sooty mould fungus

Fungus covers the foliage and fruits

In severe infestation the flowers do not form fruits

Identification of pest

Eggs: Are laid in clusters, protective cottony mass

Nymphs: Are amber coloured with white waxy coating with filaments

Adult: Male is winged, long antenna and without mouth parts. Female is wingless, flat body and short, waxy filaments along the margins

Egg mass

Adult female and crawlers

Mealy bug on fruits

Management

Collect and destroy the damaged leaves, twigs and stems

Use sticky trap (5cm length) on fruit bearing shoots

Spray dichlorvas 0.2% in combination with fish oil rosin soap 25g/lit

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

Fruit sucking moth

Symptoms of damage

Adult pierce the fruit, sucks the juice causing rottening and dropping

Female

Male

Affected fruit

Identification of pest

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

Management

Destroy the weed host Tinospora cardifolia and coccules pendules

Use light trap or food lure to attract moths

Apply smoke to prevent adult moth

Bag the fruit with polythene bag (500 gauge)

Trap crop – growing tomato crop in orchards to attract the adult moth

dilute suspension of fermented molasses and malathion 0.05% (50 EC at 1ml/lit)

Citrus thrips

Symptoms 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

Identification of pest

Adult: Yellowish, fringed wing

Scarring on Fruit

Shoot damage

Leaf damage

Egg mass

Management

Collect and destroy the damaged plant parts

Spraying with systemic insecticides at flush growth periods

Spray malathion 0.05% or carbaryl 0.1%

Encourage the activities natural enemies such as Syrphids and Chrysopid

Cottony cushion scale

Symptoms of damage

Nymphs and adults suck the sap from leaves

Honey dew excretion

Development of sooty mould fungus

Identification of pest

Egg: White, ribbed masses that hold up to 800 red eggs

Nymphs: Are red with black legs and antennae

Adults: Are covered in white hair

Management

Spray dormant oil in late winter before spring

Spray horticultural oil, if needed, year round

Apply mixture of manure compost tea, molasses, citrus oil

Garlic-pepper tea also helps

Natural predators usually keep this insect in check

Control ants and dust which can give the scale a competitive advantage

Field release of vedalia and Australian ladybugs

Citrus leaf miner

Symptoms of damage

Caterpillars are attacked tender leaves and feed on the epidermis

Making silvery appearance presence on the lower surface of leaves

Leaves-distorted and crinkled

Severe attack caused defoliation

Encourage the incidence of citrus canker

Identification of 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

Serpentine larva

Crinkled leaves

Management

Spraying of fenvalerate 0.2ml or dimethoate [Rogor] 2ml/l

Spray application of NSKE 5%

Citrus butterfly

Symptoms of damage

Caterpillars prefers on light green tender leaves feeding voraciously and leaving only the mid-ribs

Severe infestation the entire tree gets defoliated

Identification of pest

Larva: Early stage larva resembles bird dropping. Grown up larva are cylindrical, stout, green and brown lateral bond

Adult: Dark brown swallowtail butterfly with numerous yellow marking

Management

Hand pick the larvae and destroy

First instar - Spraying of 1ml DDVP (Nuvan)

Field release of parasitoids Trichogramme evanescens and Telenomus sp on eggs of Brachymeria sp larvae and Pterolus sp pupae

Defoliation

First instar

Third instar

Larva feeding

Second instar

Fourth instar with osmotoria

Grown up larva

Adult

Source: https://tnau.ac.in/