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Introduction
- Of the several constraints that lower yields of brinjal,
insect pests take a major share of the accountable loss.
- The brinjal is severely affected by the attack of
several insect pests.
- Some of the insect- pests which are considered important
are discussed here under
Insect-Pests of Brinjal
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Stage
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Common name
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Scientific name
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Vegetative – Reproductive
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Shoot and Fruit borer
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Leucinodes orbonalis Guen.
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Vegetative – Reproductive
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Stemborer |
Euzophera perticella Rag.
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Vegetative – Reproductive
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Leaf roller |
Eublemma olivacea Walker
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Vegetative – Reproductive
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Epilachna beetle |
Epilachna vigintioctopunctata
Fab.
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Vegetative – Reproductive
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Root grub
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Holotrichia spp.
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Vegetative – Reproductive
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Leaf hopper
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Empoasca devastans Dist.
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Vegetative – Reproductive
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Brown leafhopper
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Cestius phycitis
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| Vegetative – Reproductive
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Aphid |
Myzus persicae (Sulzer)
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Vegetative – Reproductive
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Whitefly
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Bemisia tabaci Genn.
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| Vegetative – Reproductive
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Mealybug |
Coccidohystrix insulita
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| Vegetative – Reproductive
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Spider mite |
Tetranychus spp.
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Aphid, Myzus persicae
(Sulzer) (Aphididae: Homoptera)
Marks of identification
- The young aphids are pale yellowish, green in colour
with three dark lines on the back of the abdomen.
- The aphids that are found in great numbers on the
leaves are apterus (wingless) forms which can be either
oviparous or viviparous.
- The aphids can also occur in winged form and in these
cases they spread the infestation from plant to plant
and form new colonies.
Nature of damage
- By constant feeding on the sap, of the plants, the
leaves look sickly in appearance.
- The beginning of the infestation can be recognised
by the cast off skins of these insects on the underside
of the leaves as also by the occurrence of a few winged
aphids on them.
- The green peach aphids are outstanding among aphids
for transmission of diseases.
- They cause more than 50 kinds of virus diseases, mostly
the non-persistent type.
- The "Rosette disease" of tobacco is known to be transmitted
by them.
- Apart from direct damage they also excrete a sugary
liquid commonly known as 'honey dew' whose presence
on the leaves for a few days causes development of a
black mould called the "sooty mould".
- The presence of mould on the leaves also disturbs
the photosynthetic process of the leaves.
Alternate host
- Spinach, tobacco, peach, plum, cherry, many ornamental
shrubs and flowering plants.
Biology
- The winter is passed as black shining eggs on the
aerial parts of plants.
- As the brinjal blooms, the young aphids begin to hatch
from eggs.
- On becoming full-grown, they begin giving birth to
wingless nymphs.
- These remain on the peach for two to three generations,
after which most of the individuals acquire wings and
migrate to other garden plants in late springs.
- The fertilized females deposit their eggs on the back
of the fruit trees.
- The aphids have 4 nymphal instars and total nymphal
period lasts 6 to 11 days.
Management
- Remove the severely affected plants to prevent further
spread of this pest.
- Remove alternate weed host in and around the brinjal
field.
- Spray methyl demeton 25 EC 2 ml/litre or dimethoate
30 EC 2 ml/litre, malathion
50 EC 0.1 per cent, 2 ml/litre to the point of run-off
twice at 15 days interval.
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Brinjal Stem
borer : Euzophera perticella Rag. (Pyralididae: Lepidoptera)
Marks of identification
- The moth is medium-sized that measures 10.5 mm in
length and its wing-span is 22.0 mm.
- Antennae are long and the distinct dentate black line
on the forewing enables this species to be recognised.
- The hind wings are lighter than the forewings which
are brown with a characteristic pattern.
Nature of damage
- The infested plant withers up and presents a stunted
growth due to the feeding activities of the caterpillar
on the tissue of the stem.
Alternate host
- Chillies and many wild solanaceous plants.
Biology
- The female lays the eggs which last about 3 to 7 days
on the leaf surface or stem.
- On hatching, the larvae bore into the stem where they
feed. Infested plants present a stunted growth.
- The larvae remain active for 26 to 58 days.
- The full-grown larvae measure 17.0 mm in length and
they pupate for 9 to 10 days.
- Pupa is dark brown and measures 12.0 mm in length.
- There are 3 to 4 generations in a year.
Management
- Removal and destruction of affected parts of the plants
is the common method of control.
- Pruning should be done of all infested parts of the
plants.
- Spraying carbaryl 50 WP 0.1 per cent (@ 2g/litre)
at fortnightly intervals at vegetative to flowering
stage gives adequate control.
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Brown Leaf
Hopper, Cestius phycitis (Cicadellidae: Homoptera)
Marks of identification
- Adults are small light brown leafhopper, measuring
around 3 mm long.
- Males are little smaller in body length.
- Nymphs are creamy white, wingless and turn brownish
with the advancement of age.
- They are found between the veins of leaves on the
undersurface.
Nature of damage
- Nymphs and adults remain on the undersurface of leaves
and suck the sap.
- The leaves turn yellow, crinkle and curl backwards.
- Plants become stunted and may be killed in severe
cases.
- The hopper is a vector of little leaf disease.
Alternate host
- Mainly a pest of brinjal.
Biology
- The female hopper lays about 15-20 eggs.
- Eggs are laid preferably on under surface of young
leaves.
- The eggs are yellowish and hatch in 4-6 days.
- Nymphs feed on the lower surface of leaves.
- A nymph undergoes 4 moultings and attain maturity
in 10 days.
- Full grown nymph is cream-white and turn light brown
at maturity.
Management
- Remove the severely affected plants to prevent further
spread of the pest.
- Spray Methyl demeton 25 EC 2 ml/litre or Dimethoate
30 EC 2 ml/litre.
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Epilachna
Beetle, Epilachna vigintioctopunctata Fab. (Coccinellidae:Coleoptera)
Marks of identification
- The adult beetles are spherical, pale brown and mottled
with black spots.
- There are two species one having 12 spots, Epilachna
12-stigma and another having as many as 28 spots,
Epilachna 28-punctata.
- Their eggs are yellowish, cigar shaped and are deposited
on leaves in groups of 5-7.
- The grubs are yellowish in colour and stout bodied,
with short spine like hair on the body.
Nature of damage
- Both grubs and adults eat the chlorophyll of the leaf
in between the veins and cause characteristic skeletonized
patches on the leaves, which ultimately dry.
Alternate host
- It is a common pest of various cultivated plants,
including potato, brinjal, Luffa sp., Lagenaria
sp., and other cucurbitaceous plants.
Biology
- Yellowish, elongated cigar-shaped eggs are laid in
batches, generally on lower surface of leaves, with
their tips pointing upwards.
- A female lays as many as 120 to 180 eggs in batches
of 30 to 35 numbers.
- They hatch in 3 to 4 days and spiny, yellowish grubs
start feeding on the epidermis of leaves.
- The larval (grub) stage lasts for 11 to 15 days.
- Full-grown grubs pupate on the leaves. The pupae are
hemispherical in shape and pupal period lasts about
4 - 6 days.
- The entire life cycle is completed in 18 to 25 days
during hot season and it may be as long as 50 days in
winter.
- All the stages of the pest are found on the plants
only.
- The pest has 7 generations a year.
Management
- Hand picking of grubs and collection of beetles by
handnets in the early stages of attack is recommended
for small holdings.
- Spray Neem Seed Kernel Extract (NSKE) 5.0 per cent
or Neem oil 2.0 per cent at fortnightly intervals.
- In cases of wide spread attack, the crop may be sprayed
with Carbaryl 50 WP 0.1 per cent (@ 2g/litre).
Preparation of Neem Seed Kernel Extract (NSKE)
5 per cent
- Fifty grams of neem seed kernel powder is required
for use in one litre of water.
- The neem seed kernel is powdered gently, in such a
way that no oil comes out.
- The powdered kernel powder is gathered in a muslin
pouch and this is soaked overnight in water.
- The next morning, the pouch is squeezed and the extract
is taken out.
- To the extract, an emulsifier is added at the rate
of 1 ml/litre.
- Khadi soap solution is used as an emulsifier. Khadi
soap @ 1 gm per litre is soaked overnight in water and
the solution is used.
- The emulsifier helps the extract to stick well to
the foliage.
- Twenty five kilogram neem seed kernel powder is required
for preparation of 500 litres of seed kernel extract,
which can be used for one hectare.
Preparation of Neem Oil 2 per cent
- Twenty ml of neem oil is required for one litre of
water.
- The oil is added to the emulsifier at the rate of
1 ml per litre and stirred well.
- It is very essential to add the emulsifier and mix
properly. This enables the oil to mix with water well.
- Khadi soap solution is used as an emulsifier. Khadi
soap @ 1 gm per litre is soaked overnight in water and
the solution is used.
- To this, add one litre of water and stir well.
- The emulsion should be used immediately, otherwise,
oil droplets start floating.
- Five litres of neem oil is required for preparation
of 250 litres of oil spray which can be used for one
hectare.
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Leaf Hopper, Empoasca
devastans Dist. (Cicadellidae: Homoptera)
Marks of identification
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- The adult is wedge-shaped about 2 mm long
and pale green in colour.
- The forewings have a black spot on their posterior
parts.
- The nymphs are wingless, pale green in colour
and are found in large numbers on the lower
surface of the leaves.
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- They have a characteristic way of walking diagonally
in relation to their body.
Nature of damage
- The numphs and adults pierce the plant tissues and
suck the cell sap by their mouth parts.
- Initial damage is noticed curling up, followed by
the yellowing of the margins of leaves, while a continued
excessive infestation may result in etiolation of the
leaves and subsequently stunted growth of plants.
- Little-leaf, a virus disease is transmitted by E.devastans
from diseased to healthy brinjal.
Alternate host
- Cotton, lady's finger, potato, castor, hollyhock,
and sunflower.
Biology
- The adult female lays about 20 to 30 eggs in the leaf
tissues and the minute nymphs emerge out of the eggs
in 7 to 10 days.
- The nymphs moult five times. The life cycle is completed
in 14 to 30 days.
- About 11 generations have been observed in a year,
the duration of each varying form 15 to 36 days, but
there is considerable overlapping.
- The adults are generally long-living and can tide
over adverse climatic conditions.
Management
- Spraying endosulfan 35 EC 0.05 per cent (@ 1.5 ml/litre)
has given very satisfactory results against adults and
nymphs.
- Alternatively spray malathion 50 E.C 0.01 per cent
(@ 2 ml/litre) is very effective.
- A waiting period of 7-10 days is necessary for subsequent
harvest.
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Leaf
Roller, Eublemma olivacea Wlk. (Noctuidae: Lepidoptera)
Marks of identification
- The moths are medium-sized having a wing-span of 4.0 cm and the forewings are white with olive-green suffusion.
- The caterpillars when full grown, are stout, beautiful purple brown with yellow spots and hairs, and usually found in rolled-up leaves.
Nature of damage
- The caterpillars bore in the green shoots of the brinjal and eat the internal contents, resulting the plant to wither.
- The larvae also roll up the leaves and feed on the green matter while remaining inside the folds and thus lead a concealed life.
- Ultimately the folded leaves wither and dry up.
Alternate host
- Main host is brinjal but it attacks many other wild solanaceous weed plants.
Biology
- The female lays about 100-150 eggs on leaves.
- They hatch in 3-5 days. On hatching, the larvae fold the leaves from the tip upwards and feed on the green matter by remaining inside the folds for 15-18 days.
- Full grown caterpillars pupate inside the folds for 7-10 days and become adults.
- Life cycle is completed in 25-33 days.
Management
- Removal and destruction of the folded leaves along with the caterpillars inside the damaged shoots is a direct method.
- As the caterpillars remain inside the folds, spraying of contact insecticides does not reach them properly.
- Therefore, systemic insecticides like monocrotophos 36 WSE 0.05 per cent (@ 1.5 ml/litre) should be sprayed to the point of run-off to tackle the pest.
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Mealy Bug, Coccidohystrix
insolita (Pseudococcidae: Hemiptera)
Marks of identification
- The bugs are small, oval, soft-bodied insects measuring 3-4 mm long, covered with white mealy wax.
Nature of damage
- Both nymphs and adults suck the sap from leaves and tender shoots.
- Heavy clustering of mealy bugs usually seen under surface of leaves as a thick mat with waxy secretion.
- They also excrete copious amount of honey dew on which the fungus sooty mould grow.
- Affected plants appear sick and black, resulting reduced fruiting capacity.
Alternate host
- Polyphagous, feeding on variety of plants belonging to malvaceae, solanaceae and leguminaceae.
Biology
- Females have reproductive potential of laying 200-300 eggs, majority of which are female resulting in explosive outbreak.
- Eggs are incubated beneath their body cavity for about 4-5 days.
- There are three nymphal instars which lasts for 22-25 days.
- Total life period from egg to adult is 26-30 days under normal conditions.
Management
- Remove and burn the severely affected plants, to prevent further spread of the pest.
- Spray any one of the following insecticides at 15 days intervals Dichlorvas 75 WSC
1 ml/litre, Monocrotophos 36 WSC 1.5 ml/litre, Methyl demeton 25 EC 2 ml/litre.
- Thorough coverage is a must.
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Root Grub, Holotrichia
spp. (Melolonthidae: Coleoptera)
Marks of identification
- Adults are medium sized, reddish brown beetles with a dark tinge.
- Grubs are flesh, C-shaped creamy white with swollen dark abdominal segments.
Nature of damage
- The adult beetles feed on the foliage of the plants.
- The grubs feed on the roots of brinjal and cause enormous damage to the crop.
- As the grubs grow, they become voracious feeder.
- In case of heavy root damage, the whole plant is affected, while partial damage leads to poor growth of plants.
- A single grub is capable of destroying a number of young plants in its life time.
- In older crop, the plants are not directly killed but become yellow and their leaves are found to wither.
- Severely affected plants come off easily when pulled.
Alternate host
- The root grobs are polyphagous in nature and attack rice, sugarcane, cotton, pulses and vegetable crops.
Biology
- Female beetle lays pearl-like, whitish eggs in the moist soil at the base of the plants. Incubation period lasts for about 10-15 days.
- Larvae (grubs) are soft bodied and fleshy and C-shaped having well developed thoracic legs and lives for 50-60 days.
- Mature grub is about 25-40 mm in length depending upon the species.
- Pupation takes place in the soil in an earthern cocoon for 15-20 days.
- The insect may overwinter as grub or beetle also over winters in a state of diapause in colder climate.
- Life cycle is completed in 75 - 100 days in tropical climate. These beetles have only one generation in a year.
Management
- Ploughing of the fields especially after crop harvest is advisable to expose the grubs and pupae to predatory birds.
- Two to three repeated ploughings at 10 days interval may reduce the grubs population by 80 per cent.
- Collect and kill the adult beetles by operating electric or petromax light traps.
- Avoid using raw farm yard manure, as it attract the beetles to settle in the fields.
- Apply phorate 10 kg/ha or carbofuran 3G 33 kg/ha in furrows at the time of weeding and earthing up at 30 DAT.
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Shoot and Fruit Borer,
Leucinodes orbonalis (Guen.) (Pyralididae: Lepidoptera)
Marks of identification
- The moths measure about 10.0 mm in length, 20.0 mm wing-span and are medium sized, having whitish wings with large brown patches all over.
- The head and thorax are blackish brown.
- The caterpillars are pale white, smooth, almost hairless, about 13 mm long when full-grown.
Nature of damage
- The caterpillars bore into the stem and riddle it and eat the internal tissues and thus cause the plants to wither.
- When the infestation is on terminal shoots, they bend down and wither.
- The larvae also attack the fruits making their entry under the calyx when they are tender leaving no visible signs of infestation.
- The large holes seen on fruits are usually the exit holes of the caterpillars. The content of vitamin C in the fruits of the brinjal is found to be reduced.
Alternate host
- Potato and many wild or cultivated solanaceous plants.
Biology
- The female lays about 250 flat, whitish eggs which are scattered on the leaf surface.
- They hatch in 3 to 5 days. On hatching, the caterpillars start to bore into the tender, growing shoots of plants and when fruits are formed, they bore into them.
- They feed on the internal contents of the shoots or fruits and become full-grown in 7 to 13 days.
- Full grown caterpillars come out of their larval burrows and pupate in boat-shaped cocoons.
- Their pupal period lasts 7 to 11 days; adult longevity is 5-7 days.
Management
- Avoid continuous cultivation of brinjal.
- Removal and destruction of the affected shoots and fruits along with the caterpillar inside is an effective method.
- Brinjal with long, narrow fruits are less susceptible to attack and therefore, these varieties should be preferred than other varieties.
- Spray to the point of run-off either
| Carbaryl 50 WP |
@ 2 g / litre, |
| Endosulfan 35 EC |
@ 1.5 ml/litre. |
| Quimalphos 20EC |
@ 2 ml / litre |
| Neem oil |
@ 2 ml / litre |
| Neem seed kernel |
@ 50g / litre |
At 15 days interval from one month after planting.
- Spraying of neem seed kernel extract (NSKE) 5% at 10 days interval from flower initiation controls the fruit borer in brinjal.
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Spider Mites, Tetranychus
spp. (Tetranychidae: Acari)
Marks of identification
- Mites are tiny, spider-like creatures.
- They are elongated-oval, microscopic and deep orange in colour.
- Immature instars and adults grow under the leaves.
Nature of damage
- Both nymphs and adults imbibe sap from between the veins from under surface of leaves and produce soft profuse webbing.
- A multitude of pale speckles appear on tender leaves, which coalesce into pale or silvery patches as the population increases.
- This gives a chlorotic appearance and causes premature shedding of leaves and flowers.
Alternate host
- It attacks cotton, tomato, bhendi, chillies, gingelly and many field crops.
Biology
- Females lays white spherical eggs under the leaves which hatch into pale yellow hexapod larvae in 3-4 days.
- Larvae passes through two nymphal instars called protonymph and deutonymph before the adult stage.
- The protonymph has three pairs of legs. The deutonymph and adult have four pairs of legs.
- A fully grown mite lives for about 2 weeks and lays about 200 eggs during this time.
- The life cycle is completed in 20-25 days.
Management
- Infested plants must be rogued out from the fields, to prevent further spread.
- The infestation subsides after sharp showers.
- Spray to the point of runoff either
1.Phosalone 35 EC 2 ml/litre
2.Chlorpyriphos 20 EC 2.5 ml/litre
3.Dicofol 18 EC 2.5 ml/litre
- alternatively at 15 days interval from one month after planting.
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White Fly,
Bemisia tabaci (Aleyrodidae: Hemiptera)
Marks of identification
- Adults are minute insects with yellowish body covered with a white waxy bloom.
- Nymphs are greenish yellow, oval in outline, along with puparia on the undersurface of leaves.
Nature of damage
- Nymphs and adults suck the plant sap while remaining on lower surface of leaves.
- Chlorotic spots appear on the leaves which later coalesce forming irregular yellowing of leaf tissue which extends from veins to the outer edges of the leaves.
- If the plant is shaken, a cloud of tiny moth-like insects flutter out but rapidly resettle.
- Severely affected leaves dry and shed.
Alternate host
- Polyphagous, main hosts are cotton, tomato, tobacco, sweet potato, bhendi and cruciferous plants.
Biology
- The insect breeds throughout the year but the attack is more common during dry season.
- The adult female lays pear shaped eggs on the lower surface of leaves.
- Eggs are white but colour changes to brown before hatching.
- Incubation period lasts for 7-10 days.
- Nymphs after hatching move about and settle by fixing their mouth parts into the leaf tissue. Afterwards they do not move.
- Nymphs are scale-like, oval and greenish white in colour. Nymphal period is completed in 9-12 days
- Pupation taken place on the leaf itself. Pupal period lasts for 6-8 days.
Management
- In nature, the adults and grubs of Brumus sp.
and larvae of Chrysoperla are predacious on this
insect.
- Spray Methyl demeton 25 EC 2 ml/litre or Malathion 50 EC 2 ml/litre to the point of run-off at 15 days interval from 15 days after transplanting.
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