Crop Insect Pest : Plantation crops :Tea Weather Soil Water Seed Farm Enterprises Nutrition Post Harvest Technology Bio Technology Bio-Fuels Common name: Tea S.N: Camellia sinensis Family: Camelliaceae Major pests Major insect pests of Tea Tea mosquito bug, Helopeltis theivora Symptom s Identific ation Managemen t Looper cater pillar, Biston supressaria Symptom s Identific ation Managemen t
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Crop Insect Pest : Plantation crops :Tea
WeatherSoilWaterSeedFarm EnterprisesNutritionPost Harvest Technology Bio Technology Bio-Fuels
It is considered to be a serious pest of a tea. The damage more in most shaded areas.
Symptoms of damage
Adults and nymphs suck the sap from buds, young leaves and tender stems
Puncturing the plant tissues with their needle like rostrum and inject toxic saliva.
Punctures appear as reddish brown spots. Leaves curl up, badly deformed and shoots dry up.
Identification of the pest
Adult - black colour with red thorax, black and white abdomen and greenish brown wings.
Management
Spray endosulfan (or) phosalone (or) monocrotophos 2ml / lit of water for better control.
Adult
2. Looper cater pillar, Biston supressaria
Symptoms of damage
Young caterpillars feed on the tender leaves - making punctures Mature larvae prefer older leaves.
Grown up larvae feed entire leaf Severe infestation - tea bushes are completely denuded.
Identification of the pest
Larva - dark brown with pale yellowish white lines on the back and sides.
Adult - grey wings speckled with light brown or black markings and irregular wavy yellow lines.
LarvaManagement
Spray NSKE 5% (or) neem based oil formulations 3% Spray any one of the following insecticides endosulfan (or) phosalone (or) chlorpyriphos
(or) fenitrothion (or) malathion 2ml/lit.
3. Lobster Caterpillar, Neostauropus alternus Symptoms of damage
Two or three caterpillars can completely devour all the leaves from a small plant in two or three days.
Identification of the pest
Eggs are white and finely sculptured Larva – black colour, resembles on dry leave
Adult - Greyish white wings and reddish brown spots on the forewings.
Management
Hand collection and destruction Severe infestation - spray insecticide (endosufan 2ml/l).
4. Flush worm, Cydia leuocostoma Symptoms of damage
Caterpillar ties up the margin of tender leaves and forms a case enclosing the bud. Feed on the upper epidermis of leaves. Affected leaves - rough, crinkled and leathery. Bud - Shoot growth is arrested.
Identification of the pest
Eggs are pale yellow and lay singly on the under surface of mature leaves
Larva – brown in colour. Adult is very small moth, blackish brown in colour.
Adult
Management
Spray endosulfan or chlorpyriphos or fenitrothion 2 ml/lit.
5. Tea tortix, Homona coffeariaSymptoms of damage
Caterpillars make leaf nests by webbing the leaves using silken threads Feed from inside the leaf nest. Young larvae prefer tender leaves Older larvae are seen in mature leaves.
Identification of the pest
Larva - green in colour Pupae - initially green colour and turns to reddish
brown Adult - brown coloured and bell shaped in outline.
Management
Spray endosulfan or chlorpyriphos or fenitrothion 2 ml/lit.Adult, Tea tortix
6. Shot hole borer, Envallacea fornicatus Symptoms of damage
Presence of round shot holes in primary branches. The attack results in mortality of buds and dieback symptoms in branches. Presence of circular or longitudinal tunnels inside the stem.
Identification of the pest
Female - small, black colour and long beetle.
Male is half the size of female, devoid of wings.
Management
Remove and destroy affected twigs. Spray lindane 20 EC 2 ml/lit using hand sprayer immediately after pruning.
Infest the upper surface of mature leaves. Infestation starts along midrib and veins and spreads to
the entire upper surface of leaves. Affected leaves - bronzed, dry and crumpled.
Identification of the pest
Eggs are reddish in colour and spherical in shape Adult - female is elliptical in shape bright crimson
anteriorly and dark puplish brown posteriorly.
Adult,Red spider mite
b) Scarlet mite, Brevipalpus californicus
Symptoms of damage:
Mites congregate on the under surface of mature tea leaves
Feeding by scarlet mites leads to brown discolouration of leaves.
Identification of the pest
Eggs - are bright red colour and elliptical in shape
Adult - scarlet red in colour and ovate in shape.Adult, Scarlet mite
c) Purple mite, Calacarus carinatus
This is a major pest in South India.
Symptoms of damage
Mites feed on the under surface of mature leaves. Assam type of tea - more susceptible to purple mite. Damaged leaves - coppery brown discolouration
Coppery brown discolouration
Identification of the pest
Adult - very small, spindle shaped and dark puple in colour Five longitudinal white waxy ridges on the dorsal side.
Adult
d) Pink mite (or) Orange mite, Acaphylla theae
It is an important mite in India.
Symptoms of damage
Mites are found on the under surface (abaxial) of young leaves.
Affected leaves turn pale and upward curling. In severe infestation, leaves become leathery and brown. Damage - restricted to top 10 – 15 cm of tender leaves. Assam type of tea is susceptible.
Identification of the pest
Adult - very minute, orange coloured and carrot shaped.
e) Yellow mite, Polyphagotarsonemus latus
Yellow mite is a polyphagous pest attacking tomato, cinchona, cotton, pulses, potato, chillies etc.
Symptoms of attack and nature of damage
Mite is seen on young leaves especially the top two to three leaves and the bud.
Affected leaves become rough and brittle and corky lines
Downward curling Intermodes get shortened, Shoots - stunted and
deformed.Downward curling of leaves
Identification of the pest
Male mites are small and white to pale yellow in colour. Females are yellowish and bigger than the males. Yellow mites are active and fast moving mite.
Eggs AdultManagement
Spray dicofol 18EC 2 ml/lit or ethion 50 EC 2 ml/lit or monocrotophos 1ml/lit Application of wettable sulphur 80 WP 2g/lit using hand operated sprayer.
8. Thrips, Scirtothrips bispinosus Symptoms of damage
Thrips prefer young leaves and buds. Leaf surface becomes uneven, curled and matty. Feeding marks on the unopened buds - parallel brown lines on the leaves.
Pruning - colonies of aphids are seen on tender shoots of tea immidiately after pruningLeaves curl up and shoot growth is stunted.
Aphids are attended by ants. Honey dew secreted development of sooty moulds.
Identification of the pest
Dark brown aphids
Management
Collect and destroy the infested plant parts Spray dimethoate 30 EC (or) chlorpyriphos 20 EC 2 ml/lit. Spray endosulfan (or) phosalone 2 ml/lit.
Source
Pest management of horticultural crops
The tea growing environment in the North East India is conducive to a large number of pests and diseases. Detail studies have been made at Tocklai on the biology and control of tea pests during the last decades. Adequate and timely measures are to be taken to reduce crop loss due to pests and diseases. Pesticides invariably leave residues and their indiscriminate use may render the teas unsuitable for consumption and trade. With ever growing concern over pesticide residues and the rising costs of the pesticides, the concept of pest control has undergone radical changes. Therefore, monitoring of pests for their early detection, integrated management of pests (IPM) and discretion on the choice of pesticides to be used on tea is of utmost importance.
The major pests, their site of attack on the tea plant, the period of occurrence in North East India, their mode of dispersal and some of the alternate hosts are shown in the following table.
Major tea pests, site of attack and time of occurrence
PestsSite of attack / nature of damage
Life stages / time of occurrence
A) Chewing pestsBunch caterpillar(Andraca bipunctata)
Young larva : Small holes on margins of young leaf
MothsFeb-Mar/May/ Jul/Aug-Oct
CaterpillarMar-Apr/May-Jun/Jul -Aug - Sep- Oct
Mature larva : Whole leaf eaten away. Defoliation
PupaApr-May/Jul-Aug-Sep/Oct- Nov
Red slug caterpillar(Eterusia magnifica)
Under surface of mature leaf, bark of young stem eaten away. Defoliation
MothFeb-Mar/May/ Jul/Aug-Oct
CaterpillarMar-Apr/May- Jun/Jul- Aug/Sep-Oct
Flush worm (Lespeyrasia leucostoma)
Pluckable shoots /leaves tied up in nestformation
CaterpillarMoth
Jan - May
B) Sucking Pests
Helopeltis(Helopeltis theivora)
Young leaves/buds/tender stems; Develop light to dark brown transluscentirregular sucking spots/shoot growth retarded
AdultNymphsEgg
Feb-Nov
Jassid(Empoasca flavescence)
Young leaves/tender stems;Develop dark brown discoloration of leaf margin(Rim blight)/leaf curve inwardmid rib and veins turn brownish/Shoot growth retarded.
AdultNymphsEgg
Feb-Jul
Thrips(Scirtothrips dorsalis)
Unopened or partly opened buds/young succulent leaves;
AdultNymphsEgg
Jan-Jul
Aphids(Toxoptera aurantil)
Buds/tender stems/young leaves
Adult/nymph Jan-Apr
C. Mite PestsRed spider mite(Oligonychus coffeae)
Upper surface of young/ mature leaves. Brownishdiscoloration/defoliation.
Whole year
Scarlet mite(Brevipalpus phoenicis)
Under surface of leaf.Brownish discoloration along the mid rib/veins/petiole of leaf/splits on bark / defoliation of young tea.
Feb-Nov
Pink and Purple mite(Acaphylla theae andCalacarus carinatus)
Upper surface of leaf.Pinkish/ copperish discoloration onleaf/veins
Feb-Nov
Mode of dispersal of some major tea pests
Mode of dispersalRed spider mite Wind, Pluckers, Cattles, Weed hostScarlet mite Weed hostBunch caterpillar Bush to bush migration of caterpillar, Migration of mothsLooper caterpillar Migration from shade trees, Migration of moths
Red slug caterpillarMigration of caterpillar through ground, Migration of moths
Nettle grub Bush to bush migration of caterpillar, Migration of mothsFlush worm Shoot to shoot migration of caterpillar, Migration of mothsThrips Migration of adultsHelopeltis Migration of adults
Important weed hosts of tea pests in North East India
Weed hosts PestsAgeratum conizoides Root knot nematodeBorreria hispida Root knot nematode and scarlet miteCommelina bengalensis Root knot nematode and scarlet miteClerodendron infortunatum Scarlet miteMalastoma malabethricum Helopeltis, Scarlet mite and Red spider mite
Mikania micrantha HelopeltisPouzolzia indica Root knot nematode and scarlet miteUrena lohata Red spider miteOxalis corymbosa Root knot nematodeO. acetocella Helopeltis
Helopeltis Adult Hand collection in morning and evening.Nymphs
EggHand plucking and removal of infested shoots.
Cockchafer Adult Hand collectionThrips Pupa & Soil stirring /caustic washing
Nymphs Removing lichens & mossesEgg Hard plucking
AphidsAdult &Nymph
Removal of infested shoots
Tea seed bugsAdult &Nymphs
Hand collection
TermitesQueens andworkers/nest
Digging out/killing/ destruction by usinginsecticides
Regulatory Methods :
Only healthy, pest and disease free planting materials should be procured/used.
Biological methods :
Biological methods of control involve the conservation, preservation and introduction of natural enemies of tea pests, like predators, parasitoids and pathogens for suppression of pests within tolerable levels. More than one hundred indigenous natural enemies (predators, parasitoids and pathogens) have been recorded against various tea pests. A list the identified natural
enemies against their respective hosts are given in the table below:
Some common indigenous natural enemies of major tea pests
Tea pests Natural enemies
Red spider miteStethorus gilvifrons, Agistemus hystrixChrysoperla carnea (P)
Pesticide can have detrimental effects on natural enemies thereby disturbing the bio-diversity and the balance in natural ecosystem. It is therefore necessary that the indigenous predators, parasitoids and pathogens are adequately preserved.
Less toxic, selective pesticides should be preferred as much as possible, to keep the natural enemies active in tea areas.
Chemical control & Choice of Pesticides
Different groups of synthetic organic insecticides have been recommended against major and minor pests in tea after regular bioassay tests and multilocation field screenings for efficacy and residues. The maximum permissible residue limits for pesticides in tea fixed by different international regulatory bodies have restricted the choice of pesticides.
TRA has organized awareness campaigns among the tea planters of this region through seminars and conferences highlighting the need for safer plant protection schedules for minimizing residues so that tea continues to be a health drink. TRA has also generated data on residues of commonly used pesticides in tea through extensive supervised field trials. A number of invoice
tea samples have also been monitored for pesticide residues recently, which reveals that most of the samples have residues well below the MRL limits.
Steps to minimize pesticide residues in tea
Monitoring and early detection of pests Integrated pest management Use of safer pesticides, botanicals and bioagents Avoid repeated spraying of the same pesticide Allow sufficient waiting period between spraying of pesticides and plucking Spot treatment
Pesticides approved for use in flushing and non-flushing seasons
Season Pesticides Mode of actionFlushing/ Plucking Season
Endosulfan Contact and stomach
(Mid February to November)
Dicofol Contact
Sulphur ProtectiveAlphamethrin Contact and stomachNeem formulations Disrupt insect moulting/growth(Azadirachtin) antifeedant actionEtofenprox Contact and stomachCartap hydrochloride Systemic with contact and stomach
Non- flushing season Thiometon Systemic with contact and stomach(December to Mid February)
*Acephate Systemic with contact and stomach
Dimethoate Systemic with contact and stomachFenitrothion Contact and stomachFenvalerate Contact and stomachFluvalinate Contact and stomach*Chlorpyriphos Contact and stomach and vapourCypermethrin Systemic with contact and stomach*Quinalphos Contact and stomachFormothion Contact and stomach