Identification of insect pests of Mesta and Tobacco and their damage symptoms

Identification of insect pests of Mesta and their damage symptoms

It is an allied fibre crop extensively grown in Eastern IndiaMesta is attacked by a dozen of insect pests but only the hairy caterpillars are important and cause considerable damage

Mesta hairy caterpillar: Euproctis scintillans ( Lymantridae : Lepidoptera)

Adult is a medium sized yellowish coloured moth with reddish line and spots on edges of wings and tuff of hairs on dorsal side

Alternate hosts – It also infests Castor, Cotton,Pigeon pea,Mango, Sunnhemp etc.,

Life cycle of the pest

Eggs : are laid in masses on the under surface of leaves I.P – 5-9 days

Larva : Larvae are yellowish in colour and brown coloured head and yellow stripes with a mid dorsal red stripe There are tuft of black hairs dorsally on the first three abdominal segments L.P – 29-35 days

Pupa : It pupates in a cocoon of hairs on the leaves or leaf fold P. P – 10-12 days

Nature of damageThe early instar larvae feed gregariously on foliage and thus cause severe defoliation Control measures1.Timely sowing of the crop at the onset of monsoon rains

2. Foliar sprays with methyl demeton @ 2 ml / lit. or phosalone @ 2 ml / lit. of water were effective

Mesta stem weevil: Alcidodes affaber (Curculionidae : Coleoptaera)

Adults are a dark greyish- brown weevil with pale coloured cross bands on elytra.

This insect is a common pest on Malvaceous plants in India, infesting Bhendi, Bombax malabaricum, Althaea rosea, Ficus bengalensis etc.,

Nature of damageThe adult weevil feed on leaf buds, petiole and tender terminal portion However, serious damage is caused only by the grubs boring into the stem and petioles and causing gall like swellings

Frass is found through hole made on stems

The infested plants gets stunted

Their flowers and fruiting get retarded considerably

A single plant may harbour as many as 12 grubs This pest is active from September – December Control measures The grubs are parasitized by – Aphrastobracon alcidophagous Zoridescopus spp. Spray the crop with phosalone @ 2 ml / lit. of water are effective in management of this weevil

Bihar hairy caterpillar: Spilarctia obliqua (Arctidae:Lepidoptera)

Adult is a medium sized pale buff coloured moth with black spots on the wings.

The body is crimson coloured and black spotted. Caterpillar cause extensive defoliation. Control measureSpraying the crop with phosalone @ 2 ml / lit. of water

Adult female 2.5–4 mm long, soft-bodied, elongate oval and slightly flattened. Entire colony becoming covered by white, waxy ovisac material

Pink mealybug : Maconellicoccus hirsutus (Pseudococcidae : Hemiptera This pest occurs on mesta in AP and Bihar Besides Mesta, it also attacks Jute, Grapevine and Guava

Sac like pink coloured females are covered by milky white waxy coating The mealy bug lays eggs in masses and each female lays 52 – 543 eggs I. P – 4-11 days during different seasonsNymphs – The crawlers move to the succulent regions N. P – 18 – 31days The males are winged forms Nature of damage The mealy bugs infests the stem resulting in the formation of swellings and shortening of inter nodes The vertical growth of the stem is suppressed as the growing tips are damaged Bunchy top formation as secondary branches arises Control measures 1. Release of Cryptolaemus montrouzieri when peak infestation is noticed in Sept. – Octo. 2. Spray the crop with methyl demeton @ 2 ml/ lit. or dimethoate @ 1.5 ml / lit. of water is effectiveLeaf hopper : Amrasca biguttula biguttula (Cicadellidae :Hemiptera) Aphid : Aphis gossypii ( Aphididae : Hemiptera) ( Refer under Cotton)

Flea beetle : Longitarsus belgaumensis ( Chrysomelidae : Coleoptera)

Adults are small yellowish brown small beetle with enlarged hind femur Adult makes minute holes on leaves, grub feeds on the roots by mining Eggs are laid in soil   Yellowish grubs pupate in earthen cells in the soil

Identification of insect pests of Tobacco and their damage symptoms

The insect pests that infest in the nursery areCaterpillars

and Cut-worms

Spodoptera litura Laphygma exigua

Agrotis ipsilon Plusia signata

Noctuidae Lepidoptera

Stem borer Scrobipalpa heliopa Gelechiidae Lepidoptera Whitefly Bemisia tabaci Aleyrodidae Hemiptera

Grass hoppers Cyrtacanthacris tataricaAtroctomorpha

crenulata

Acrididae Orthoptera

Tobacco is the most important cash crop or narcotic crop in world’s agriculture and cultivated in more than 100 countries on 4. 02 million hectares 0.45 million hectares i.e. only 0.31% net cultivated area in the country India stands IInd in tobacco production and exports in the World

The insect pests in the planted crop areLeaf eating caterpillars

Spodoptera litura Noctuidae Lepidoptera

Whitefly Bemisia tabaci Aleyrodidae Hemiptera

Tobacco aphid / green peach aphid

Myzus nicotianae Myzus persicae

Aphididae Hemiptera

Capsule borer Helicoverpa armigera

Noctuidae Lepidoptera

Tobacco hornworm

Manduca sexta Sphingidae Lepidoptera

I. Caterpillars and Cut-worms

There are four species of caterpillars and cut worms

Spodoptera litura Laphygma exigua Agrotis ipsilon Plusia signata are known to infest tobacco nurseries. Of these four species Spodoptera litura commonly known as tobacco caterpillar is the most important pest

Tobacco leaf eating caterpillar : Spodoptera litura ( Noctuidae : Lepidoptera )

Adults are medium sized, stout bodied moths

FW : are dark brown colored with zigzag white markings

HW : are white in colour with out markings with a brown border

Eggs: Eggs are laid in batches and covered with brown coloured hairs on the tender leaves I.P- 7-10 days

Early instars Later instar

Life cycle of the pest

Larva: there are 5 larval instars The full grown caterpillar is about 3.5cm long and pale green to brown Colour with dark marks on the body L.P- 15-20 days

Pupa : it pupates in the soil P.P – 7-10 daysAdult moth

The full grown caterpillar is about3.5cm long and pale green to brownColour with dark marks on the body

Nature of damage

Early instars larvae feed gregariously and cause skeletonization

Later instars disperse and feed voraciously on foliage, only stalk is left, During day time hide under soil

The maximum damage is caused to the nursery and young plants not only feeds on leaves but also cuts the seedling at ground level

In severe case the plants are completely destroyed

Caterpillar Caterpillars feeds on leavesEarly instars larvae

Later instars disperse and feed voraciously on foliage

2. Cutworms: Agrotis ipsilon (Noctuidae: Lepidoptera)

Polyphagous pest. Refer under potato

The adult is fairly larger in size, with a wingspan of 40 to 55 mm Fore wing is pale brown with dark purplish brown along costal end. Hind wing is white with brown tinge. Male has bipectinate antenna and female has filiform antennaCaterpillar cuts the stalk of seedlings as well as transplanted plants at ground level. They feed only at night and may be found in the day time either just below soil level or under leaves.

Black cutworm (Agrostis ipsilon) damage on newly planted tobacco.

3. Beet Armyworm: Laphygma exigua (Noctuidae: Lepidoptera)

Young plants defoliated by larvae, older leaves with papery windows and irregular holes

4. Semilooper: Plusia signata (Noctuidae: Lepidoptera)

Adult – medium sized, brown coloured moth with white streaks on the forewingDue to larval feeding, tender leaves have large irregular holes and finally defoliated completely.   

Control measuresThese pests are controlled by spraying any one of the following insecticides Emamectin benzoate 5 SG @ 5 gm in 10 lit. of water or Novaluron 10 EC @ 10 ml in 10 lit. of water

Tobacco stem borer : Scrobipalpa heliopa ( Gelechiidae : Lepidoptea )

Adults very small active dark brown coloured moth with fringed wings

Distribution : Malaya, Indonesia, Australia, New Guinea, Philippines. In India especially of V F C tobacco and Natu tobacco in Andhra Pradesh, V F C tobacco in Karnataka State and bidi tobacco in Gujarat. Serious pest of both nursery and main field.

Life cycle of the pestEggs : are laid on the leaves of seedlings Fecundity – 50-80 eggs/ female I.P – 4-6 days

Larva : there are 4-5 larval instars

The caterpillar slender, measures 7-9 mm in length, pale greyish in colour with brown coloured head and prothoracic shield L.P – 15-20 days

Pupa : Pupation takes place within the swellings or galls after making exit hole, P.P- 9-10 days

Damaged seedlings of VFC tobacco (Virgin flue cured )

Nature and symptoms of damage Newly hatched caterpillar will mines the leaves for a while

later bore in the midrib, leaf stalk and finally reaches main stem, feed on internal tissues causing the formation of swellings on the stem.

The gall formation leads to stunting of the plants and unusual branching of the infested seedlings at the tip.

Tobacco stem borer, (Scrobipalpa heliopa Management practices

To remove infested seedlings and destroy them at the time of planting Split open the galls on the stem and crushed the larvae Treat the nursery with carbofuron 3 G before sowing @ 5gm / m2

In tobacco nurseries – chlorpyriphos 20 EC @ 0.05 % conc. ( 20 ml in 10lit. of water) at 30 and 40 days after germination Final spray should be given before pulling out seedlings

Deep ploughing of left over nursery beds and removing all crop stubbles in the field and burning them to prevent carry over of infestation

Tobacco white fly : Bemisia tabaci ( Aleyrodidae : Hemiptera )

A single female can lay 44-77 eggs on undersurface of leaves, I.P – 10 days

The importance of white fly is that it is a vector of leaf curl disease of tobacco in India It attacks the crop in nursery and main field

Nymphs : passes through 3 nymphal instars in 4-5 days

Pupae : freshly formed pupae are thin and flat, subeleptical and light yellow in colour and later they become yellow

N.P -16-39 days under laboratory condition Pest complete 12 generations / year

Sexual dimorphism is seen adults and pupae

Adult female- stouter abdomen and longer wings

Female pupae- are bigger in size

Parthenogenesis also occur in this pest resulting progeny from parthenogenesis are only males and these are smaller in size compared to sexually reproduced individuals

Alternate hosts- more than 100 host plants are recorded in India alone of which 12 shows disease symptoms similar to tomato leaf curl virus

Some important ones are- Crotolaria jucea, Ageratum conyziodes, Euphorbia hirta, Zinnia elegans, Solanum nigrum, Tomato etc.,

White fly is the important vector of “ leaf curl virus ”

Tomato leaf curl viruse diseases is cross infective among these hosts including tomato

Nature of damage Leaves of affected plants are curled, twisted, ruffled ( disturb smoothness) or

wrinkled, puctured, thickened with abnormal prominent veins The attacked plants are stunted, both yield and quality are reduced The diseased leaves are still suitable for chewing or snuff making but not

suitable for flue curing

Management practices Remove and destroy alternate hosts around nurseries and main field

Avoid leaf infected seedlings for transplantation

Remove and destroy leaf curl infected plants ( if there population is less than 2 % in transplanted crop)

Avoid cultivation of Brinjal and Sunflower in the vicinity of tobacco

Setting up of yellow sticky trap made out of GI sheet of 12cm X 15cm size and 2mm thickness coated with castor oil @ 12 traps / ha. for monitoring

When trap reach 100 white flies / trap adopt the following spray schedule commencing from 4th week after germination in nursery or 10 days after transplanting in main field at weekly intervals

Ist spray – Chlorpyriphos @ 25 ml in 10 lit. of water

IInd spray – Acephate @ 10gm in 10 lit. of water

IIIrd spray – Monocrotophos @ 15 ml in 10 lit. of water

IVth spray – Oxydemeton methyl @ 15 ml in 10 lit. of water

1000litres spray solution / ha

Grasshoppers: Cyrtacanthacris tatarica,  Atractomorpha crenulata (Acrididae : Orthoptera).

Cyrtacanthacris tatarica Atractomorpha crenulata

These are green or brown jumping insects commonly noticed in tobacco nurseries. Feed on leaves making circular holes. Control measures Cultural practices like keeping the nursery area clean, free of weeds and grasses helps to keep away the grass hoppers Spray the surrounding vegetation with chlorpyriphos 20 EC @ 25 ml in 10 lit. of water or dust the area with malathion 5 % D @ 40gm / 10m2 area

The insect pests in the planted crop areLeaf eating caterpillars

Spodoptera litura Noctuidae Lepidoptera

Whitefly Bemisia tabaci Aleyrodidae Hemiptera

Tobacco aphid / green peach aphid

Myzus nicotianae Myzus persicae

Aphididae Hemiptera

Capsule borer Helicoverpa armigera

Noctuidae Lepidoptera

Tobacco hornworm

Manduca sexta Sphingidae Lepidoptera

1.Tobacco leaf eating caterpillar : Spodoptera litura ( Noctuidae : Lepidoptera)

In the field crop the pest incidence is generally confined to few border rows Nature of damage A light green tiny caterpillars with black head feed on green matter of the leaf causing skeletonization and later turn to grey or dark grey or black in colour

The grown up larva feed voraciously on the tobacco leaf making lot of holes on the leaf causing damage to an extent of 10 to 15 % Control measures What were the control measures initiated in the nursery same control measures are adopted here

2. Tobacco white fly : Bemisia tabaci ( Aleyrodidae : Hemiptera )

These are tiny white flies cause leaf curl disease

The leaves of curled plants are twisted, puckered and thickened with abnormally prominent veins

The infested plants shows stunted growth

The incidence reduces the yield considerably The disease is more prevalent in tobacco cultivated in light soils than heavy black cotton soils

Control measures What were the control measures initiated in the nursery same control measures are adopted here

Tobacco Aphid : Myzus persicae ( Aphididae : Hemiptera )

Aphid was first reported in AP in the year 1990 – 91 with almost 80-90 %infestation

crop loss due to aphids - 513 kg / ha green leaf - 70 kg / ha bright leaf This pest reported from CTRI, Rajahmundry, AP

ETL for aphids is fixed less than 2 % infestation during epidemic year and 2 % infestation level during normal years

Aphid infestation results in reduction in quality

These are polyphagous insects found to feed on a number of host plants

Host range : More than 40 host plants have been identified. The important among them are Tobacco, Capsicum, Sesamum, Orobanche,Brassica , Brinjal, Cabbage, Mustard

Aphids are green coloured winged or wingless insects with cornicles on the abdomen

Cornicle

These aphids occurs in large numbers on the under surface of the leaves and shoots and their feeding causes curling and yellowing of leaves Excrete lot of honey dew and development of sooty mould and finally the attacked leaves are unfit for curing.

1. Tobacco mosaic disease2. Cucumber mosaic virus3. Rosette disease of tobacco

Aphids are the important vectors of viral diseases of tobacco

Management practices 1. Cultural practices1.Topping or removal of inflorescence / tender shoots coupled with usage of recommended dosage of nitrogen is useful for management2. Topping stimulates ( Increase vigour) – the accumulation of carbohydrates in leaf and also coincides with nicotine production in leaf which known to have insecticidal properties3. Mulching with aluminum foil ( Thin plate of metal ) of 61cm width and also using wheat straw as a mulch to reduce the aphid population by more than 50 % Using aluminum – because of reflection light 11. Biological control

Using green lace wing @ 6 larvae / plant and release 2nd instar larva to reduce the infestation by more than 50 % release should be at the beginning of infestation

Coccinella transvergatus @ 16 larvae / plant up to 54 % reduction under green house condition

Chelomenes sexmaculatus Syrphids – Ischiodon scutellaris SpidersFungal pathogens – Verticillium lecanii @ 30 X 106 spores / ml - Fusarium sp. @ 1 X 106 spores / ml III. Chemical control Prophylactic sprays with acephate during early winter @ 10 gms / 10 lit. of water or Oxydemeton methyl 25 EC @ 20ml in 10 lit. of waterSubsequent sprays should be given only on infested plants 10-15 days interval Do not spray 1 week before harvesting to avoid pesticide residues in cured leavesResistance : high levels of carboxyl esterase enzyme is responsible for insecticide resistance for almost all OP and Carbamate insecticide Higher enzymes activity in pink forms compared to green forms of aphidsAcephate and Methomyl are effective against these aphids

Tobacco bud worm or Capsule borer :Helicoverpa armigera ( Noctuidae : Lepidoptera )Adult is a medium sized stout bodied moth with fore wings light brown with black spots and hind wings are creamy white with black patch along the margin

Eggs : are laid singly on tender leaves, shoot and inflorescence I.P – 3-4 days

Larva : Larva passes 5-6 instars, measures 3.5 to 4.0cm in length, variously coloured / different colour morphs, pale green, dark green, pale brown, dark brown and can be recognized by a yellowish line on either side of the body L.P – 20-30 days

Bored capsules

The crop is 30 to 40 days old – The larva feed on tender shoots, leaves / buds Later bores in to the capsules and feeds on developing seeds The pest is active during early morning hours

While feeding on capsule it thrust head and thorax inside and remaining body outside

Pupa : They pupate in the earthen cocoon in the soil P.P – 17-24 days TLC – 43-63 days

Nature of damage

Bored capsules of tobacco

Management practices Setting of pheromone trap for monitoring pest population

Growing chick pea or Nicotiana rustica all around the plot as a ovipostional trap crop

Hand picking of caterpillars 30 – 50 days after transplanting and destroy

Spraying HaNPV @ 250LE / ha in 1125 lit. of water

Spray Bt formulations @ 1 kg / ha

Spray the crop with Monocrotophos 30 ml or fenvalerate 10 ml in 10 lit. of water on the inflorescence in seed production plots

The adults are large sized moths with stout, narrow wings, and a wing span of about 100 mm.

The forewings are much longer than the hind wings and are dull grayish or grayish brown in color

Though the sides of the abdomen usually are marked with six orange-yellow spots The hind wings , bear alternating light and dark bands.

Tobacco hornworm: Manduca sexta (Sphingidae : Lepidoptera)

Hornworms feed primarily on solanaceous plants (those in the potato family). They include tobacco,tomato, eggplant, pepper and some weedy plants. Tobacco and tomato plants are more preferred.

Caterpillars feeds on leaves causes severe defoliation

Control measures Spray the crop with contact insecticides