• It is paradoxical that tobacco, which yields nicotine-a very effective insecticide, suffers from damage by many insect pests right from sowing to the leaf kept in storage.
• This is because of either selective feeding in phloem as in aphids or efficient excretory mechanism as in tobacco hornworm or capacity to metabolise nicotine to nontoxic cotinine and other alkaloids.
• The ants carry away the seeds from the nursery beds. Earthworms damage tiny seedlings by uprooting them and covering them with the soil.
• Caterpillars of various types including borers and grass-hoppers invade the nurseries as well as the fields.
• The ground beetles cut the young transplants causing gaps in the fields, aphids infest plants in the growth stage and suck juice from the leaves, and by secreting honey-dew on which sooty mould develops, makes the leaves unfit for curing.
• Capsule borers attack capsules and sometimes also climb down to feed on leaves.
• Apart from these, there are other pests such as crickets, white flies, thrips and stink bugs which cause damage.
• On the stored tobacco, cigarette beetle commonly known as cigarette weevil is a major pest.

• There are four cut worms that attack tobacco
  • Spodoptera litura F.
  • laphygma exigua Hb.
  • Agrotis ypsilon Rott.,
  • Plusia signata Fab.
• These are known to infest tobacco nurseries. The first 3 species are also called cutworms as they cut the tender seedlings.
• They feed on leaves during the night and hide during daytime. Plusia sp. feeds on the leaves while Scrobipalpa (Gnorimoschema) heliopa inhabits the stem, so it is known as stem borer. Of these five species, Spodoptera litura F. is the most important.

a) Spodoptera litura F.

Order: Lepidoptera

Family: Noctuidae

• Commonly known as tobacco caterpillar or tobacco cutworm, it is the worst enemy of tobacco nurseries, sometimes causes damage in the field also.
• It enjoys wide distribution and besides India it is present in countries like Vietnam, Indonesia, Australia, China and Fiji.
• It is extremely polyphagous and is known to feed on lucerne, Potato, castor, cabbage and cauliflower besides tobacco in our country

Life-history

• The adult lives for 8-10 days. Pairing takes place within 1 to 2 days after emergence, generally in the early morning or after dusk.
• A single female can lay on an average 2000 eggs.
• As they grow the cater pillar start spreading out in the seedbeds. Before growing fully the caterpillars pass through 5 growth stages (instars).
• The pupae are brown during early period but later on before emergence of adult moths they become dark brown or often black. It takes between 20-30 days to complete caterpillar stage and become pupa. In about 7- 14 days the moths emerge from pupae. The entire life history is completed in 30 to 50 days.

Nature of Damage

When the seedlings are small they cut the seedlings They voraciously feed on the leaves when the seedlings are grown up.

Third and fourth instar larvae are particularly voracious feeders and if no measures are taken entire seedbeds will be defoliated within a week.

b) Laphygma exigua Hb.

Order: Lepldoptera.

Family: Noctuidae

• The caterpillars of Laphygma exigua Hb. are sometimes found in the seedbeds in some parts of Alidhra Pradesh.

Nature of Damage

• Like larvae of Spodoptera litura F. these caterpillars also feed mostly by night. They cause defoliation as well as cutting off of the tender shoots of young seedlings.

c) Agrotis ypsilon Rott.

Order: Lepidoptera

Family: Noctuidae

• The full-grown catepillar is black or dark-brown in colour and is about 3-4 cm in length. It coils with the slightest touch.

Nature of Damage

• Pest is active during the night. It cuts the seedlings at ground level. The destruction caused by them far exceeds their feeding requirements.

d) Plusia signata F.

Order: Lepidoptera

Family: Noctuidae

• The Caterpillar is green in colour with looping movement and is about 3cm when fully grown. It is specific to nursery area.

Nature of Damage

Feeds on tender leaves and remains on underside of the leaves.

Control for cutworms

• Deep ploughing of nursery area during April - May will facilitate the exposure of pupae to high temperature and thus destroy them.

Sow castor around tobacco nursery 15 days before sowing of tobacco so that the castor puts up sufficient foliage by the time Spodoptera infestation builds up.

• The castor seedlings attract female moths of Spodoptera for egg laying. Clip leaves having egg masses and tiny caterpillars and destroy them.

Install 4 liture pheromone traps (loaded with 2.5 mg pheromone per vial) per acre two weeks after germination.

• If the catch of male Spodoptera moths is more than 5 per trap spray 1 percent neem seed kernel suspension (NSKS) in water on 3 weeks old seedlings and 2% NSKS on 4 weeks old seedlings. .
• Fifteen days should lapse between spraying and harvesting of leaf for curing is needed.
• If spraying is to be done repeatedly the insecticide has to be changed every time so as to avoid build up of residues of any single pesticide in the cured leaf.
• Some work has also been done recently on the use of indigenous plant products for control of this pest. Neem (Azadirachta indica) pesticide can used .
• Use of neem kernel suspension on 20-day-old seedlings and subsequently 3 sprays of 2% with an interval of 10 days effectively controls the pest.

Order: Lepidoptera

Family: Gelechiidae

• The tobacco stem-borer is an important pest in many parts of India especially of FCV tobacco and Natu tobacco in Andhra Pradesh, FCV tobacco in Karnataka State and biditobacco in Gujarat.
• It has been reported from various countries such as Malaya, Indonesia, Australia, New Guinea, Philippines.

Life cycle

• In bidi tobacco the female moth lays cylindrical eggs singly more on the upper surface than on lower and prefers laying towards the distal half of the upper surface and basal half of the lower surface.
• A female, on an average, lays 50- 80 eggs. In 4 days, eggs hatch and the tiny caterpillars mine along the leaf stalk into the stem and feed on the internal tissues.
• In 15-22 days the larvae fully grow and pupate. The full grown larva is pale white in colour, with head and thorax dark brown. When the larva is about to pupate it forms an exit tunnel in the gall.
• The tunnel is so prepared that a thin membrane of a stem tissue remains intact, which can be easily broken by the emerging adult. The adults after emergence survive for 2-14 days.
• The total life-cycle extends over 4-5 weeks.

Nature of Damage

Larvae bore inside the stem to form a swelling. It causes stunting and unusual branching of the seedlings.

Control measures

• Stem borer affected seedlings should be removed and destroyed.
• In tobacco nurseries when stem borer is a serious problem, spray Quinalphos 25% E.C at 0.05% (20 ml in 10 litres of water at 30 abd 40 days after germination. Final spray should be given before pulling outseedlings.
• In planted crop spray in above insecticide at20 and 30 days after planting. After completion of harvestings the stem borer affected plants should be uprooted and burnt to prevent carry over of the past to the next season.

Order: Homoptera

Family: Aleurodidae

• The importance of whitefly is that it as a vector of leaf curl disease of tobacco in India

Life cycle

• The adult female differs from male in having stouter abdomen and longer wings and pupa is bigger than male pupa.
• A single female lays between 43 and 243 eggs on the underside of the leaves.
• In 4-7 days the eggs hatch and the nymphs come out. After about 7-11 days the nymphs pupate, with in 7 days the adult fly emerges out.

Nature of Damage

• Whitefly transmits leaf curl disease.

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

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

Control

• Remove alternate weed hosts around nursery area and destry
• instal yellow-sticky traps (20 cm x 15 cm size galvanized iron sheet) coated with castor oil @ 5 per acre
• If the population of white fly is heavy, give the following spray schedule of insectidies at weekly interval commencing from 4 weeks after germination.

• 1^st spray Chlorpyrifos 20% E C @ 25 ml in 10 litres of water
• 2^nd spray Monocrotophos 36% WSC @ 15 ml in 10 lit. of water
• 3^rd spray Accephate 25% S P @ 10 gm in 10 litres of water
• 4^th spray Demeton-s-methyl 25% E.C. @ 15 ml in 10 litres of water

Order:Orthoptera

Family: Acrididae

• These green or greyish insects with cryptic colouration remain in grass or weeds around nurseries or fields.

Nature of Damage

• Cut holes in the leaves

Control

• Cultural practices like keeping the nursery area clean, free of weeds and grass helps to keep away the grass hoppers.
• Spray the surrounding vegetation with endosulfan 35% E.C @ 15 ml. or chlorpyrifos 20% E.C @ 25 ml. in 10 litres of water or dust the area with endosulfan 4% dust @ 40 grams per 10 sq.area.

Order:

Coleoptera

Family:

Tenebrionidae

Life cycle

• The egg and pupal periods are of only 2-10 days duration.
• The larval and adult periods are long being 30 to 150 and 2 to 190 days respectively.
• The total life period varies from 61 to 280 days.
• The female lays from 1 to l00 white oval eggs singly on the surface of the soil, under grass weeds near moist area.
• Within a week they hatch and white grubs come out. The grubs feed on the organic matter.
• A full-grown grub is about 25 mm in length and 1.2 mm in diameter. Nearing pupation, the grubs become sluggish and slimy to touch, go into the soil at the depth of 15 to 30, cm and pupate.
• The adult emerges out within a week.Eggs and larvae mainly occur in October-December , pupae only in December-May.

Nature of Damage

• These grey-black insects inhabiting soil generally feed on organic matter though tender tobacco transplants hold some special attraction for them.
• When the seedlings are transplanted they invade the fields from surrounding bunds and attack them
• The beetles attack freshly transplanted seedlings. When the cut is deep the seedlings die causing gaps in the field.
• In some years the damage is so heavy that replanting becomes necessary.

Control

• It is enough to protect the transplants for 4 weeks as by that time the plants establish, stems get hardened and thus the beetles are unable to cause any damage.
• Use endosulfan 35% E.C @ 14 ml or chlorpyrifos 20% E.C @ 16 ml in 10 litres of water @ 75 ml solution per plant in planting hole.
• Pongamia cake is safe to handle and does not leave any residue in the soil. Powder the cake and mix in fine sand. Apply 5g of cake powder mixed in handful of sand (20-25g) at the base of seedling immediately after transplanting.
• For treating one acre, 30 kg of Pongamia is sufficient.
• The efficiency of Pongamia cake is improved when 2 g of rice bran, an attractant, is added to it.
• Apart from controlling beetles the cake has some manurial value also helps the transplants to grow better.
• Keeping heaps of grass in between crop rows after sprinkling water on the soil at a distance of 6 m apart to attract the beetles and dusting with 5% carbaryl @ 10 kg/ha next day offers good control.

Order: Coleoptera

Family: Melolonthidae

• In recent years a new pest has been causing damage to tobacco plants in the field. It is commonly known as white grub

Life cycle

• A female lays between 24 and 92 eggs.
• The eggs hatch in 8-13 days.
• The grubs pass through 3 instars.
• Fully-grown grub is creamy white, measures about 45 mm in length and 11 mm in width.
• When fully grown it ceases feeding, digs down to 15-20 cm and constructs a small cell in the earth, tends to shrivel up in preparation for a change to pupal stage, sheds the skin and pupates.
• In all, the grub takes about 148 days to pupate. The pupa is creamy- white when fresh but becomes brown as transformation to adult beetle proceeds.
• In about 11 days it hatches and adult beetle comes out. The adult lives from 78 to 266 days. The total life cycle is completed in about 170 days.

Nature of injury

The grubs cut and feed on roots of well established plants resulting in their wilting and drooping.

Control

• Application of pongamia cake @ 75 kg/ha is effective
• Endosulfan dust 4% @ 60 kg/ha applied to soil before planting will also be effective.

Order: Homoptera

Family: Aphididae

Aphids are pinkish to brown or green small louse-like insects infesting the planted crop. If the infestation is heavy, hundreds of them can be seen on the underside of the leaves. Apart from tobacco, they also infest potatos, crucifers, peach etc.

• Among different tobaccos, Lanka and Natu tobaccos of East Godavari and Guntur districts respectively are highly susceptible and subjected to heavy aphid infestation every year. It has become a serious problem on FCV tobacco also.

Life cycle

• Both apterous (wingless) and alatae (winged) forms pass through 4-5 nymphal instars in their development and the nymphal period ranges from 5-7 days.
• Both the forms mate within a day or two after the final moult and start reproducing young ones.
• The apterous forms produce significantly more number of young ones than alatae but their life-period is shorter than that of alatae.
• In the field generally viviparous apterous forms are observed in slarge number.
• The winged forms are black or reddish with transparent wings.
• They are responsible for spreading the infestation from plant to plant and establish new colonies.
• Incidence of aphids depends upon the time of setting in of winter. Generally they appear by the end of November or first week of December multiplying and reaching peak from December and to first week of January.
• This period is a critical period for tobacco plant, because it is during this period that the plant puts up its maximum efforts for growth and leaves get ready for priming.
• From January end or first week of February, they start declining due to rise in temperature.

Nature of injury

• In addition to their being vector for various diseases, such as, rosette or bushy top the damage caused by aphids is two-fold.

Firstly by constant sucking of the sap through their tiny beaks.

	Aphids make the plants pale, sickly and thereby retard the growth Secondly the growth of black sooty mould which is by the sugary secretions (honey-dew) of aphids
	sugary secretions on leaves, makes them unfit for curing if cured the quality of leaf gets reduced considerably.

Control

• As the aphid infestation generally becomes severe when the crop is getting ready for priming, the choice of insecticides has to be made with great care, otherwise the cured leaves will carry excess of insecticide residue.
• During early winter, for control of aphids give one prophylactic spraying with any one of the following insecticides.
• Thiometon 25% E.C @ 10 ml in 10 litres of water
• Demeton-s-methyl 25% EC @ 10 ml in 10 litres of water
• Dimethoate W/V 30% E.C @ 6 ml in 10 litres of water
• Phosphamidan 100 @ 2.5 ml in 10 litres of water
• If the infestation is observed later, spray the infested plants only. Leave one week gap between last spray and harvesting of leaf.
• If more than one insecticide is required change the inscticide spraying should be done preferably in the evening hours
• The first spray has to be given as soon as the aphids are seen in the field. It helps to check the infestation in the initial stage.
• Subsequent sprays can be carried out with 10- 15 days interval on the top 4-5 leaves of the infested plants only.
• It is necessary to leave a gap of two weeks between last spray and priming, otherwise the leaves will carry excess of insecticidal residues to the cured leaves.
• If the spraying is done repeatedly, insecticide has to be changed every time so as to avoid build up of residue of a single insecticide.
• Aphids on Lanka tobacco can be effectively controlled for more than a month by soil application of Thiodemeton 5 G @ 2 g/ plant.
• The insecticide has to be applied in 5-8 cm deep furrow around the base of the plant than closing the furrow, one month after planting before first irrigation.
• However, Lanka tobacco so treated should be pit-cured invariably so as to avoid excess residues in the cured leaf.
• This treatment fits well in the new strategy of integrated control as it spares the beneficial insects and does not affect the environment.

Order:

Lepidoptera

Family:

Noctuidae

• Apart from tobacco, the capsule-borer damages many low-growing plants like pulses, maize, tomato, linseed, etc.

Life-history

• Female lays dull-white eggs singly on tender shoots and inflorescence.
• The eggs hatch in 3-4-days. The caterpillars fully grow within 20-40 days and measure 3-5 cm in length.
• It is greenish or pale-brown in colour with broken dark-brown stripes along the body.
• When young, it is generally green. It pupates in soil, within 17-24 days the adult moth comes out.
• The total life-cycle is completed in 43-63 days.

Nature of injury

After December, particularly after heavy rains, heavy infestation develops and 10-20 borers can be seen on a plant.

The caterpillars bore the capsules and destroy the seeds. When the infestation is heavy they come down and feed on the leaves also.

Control

• Monitoring the pest from four weeks after transplanting by pheremone traps/light traps.
• Growing chickpea/ N.rustica as ovipositional trap crop arround tobacco
• Topping in inflorescence helps to bring down the incidence considerably.
• The pest can be effectively controlled by spraying NPV @ 250 LE in 1125 l of water /ha or Bacillus thuringiensis var.kurstaki @ 1.5 Kg in 1125 l of water /ha
• Monocrotophos 40% E.C. @ 30 ml or Fenvalerate 20% E.C@10 ml or Endosulfan @ 20 ml/10 l of water on inflorsenses in seed plots.

Order: Coleoptera

Family: Ptinidae.

• The cigarette beetle, L serrlcorne F also commonly known as cigarette weevil, it is a serious pest of stored tobacco.
• It is associated with tobacco after it is cured.
• It attacks the principal types of cigarette, cigar, chewing and snuff tobaccos as well as most forms of manufactured tobaccos.
• In the flue-cured tobacco, the beetle prefers bright grades over medium or low grades.
• The beetle is cosmopolitan in distribution. It is more common in countries of tropics and near tropics.

Life-history

This beetle is a small dark -brown insect about 2-3 mm in length. A single female lays between 14-104 eggs in the folds and midribs of tobacco. The type of tobacco affects the oviposition also. Cigarette beetle laid more eggs in flue-cured tobacco than in Lanka tobacco. Ability of cigarette beetle to grow on stored tobacco depends upon.

1. Nicotine content
2. Adequacy of nutrients
3. Materials which enhance the toxicity of nicotine

• The beetle is a strong flier and readily flies half a mile and under favourable conditions it may fly even more than a mile.
• The flight is generally from 7 p.m. to mid-night. In the godowns the flight activity takes place throughout the year.
• It is least in April, starts increasing in August and reaches peak in October. Sepetember to November is the most destructive period.
• The degree of infestation depends upon the temperature, relative humidity, type and grade of tobacco and other conditions in storage.

Nature of injury

The larvae feed on the leaves making large galleries and when the infestation is heavy turn the leaf into powder. The damage occurs in the following ways Shortage in tobacco by quantity actually consumed by the larvae. Holes cut in the high-grade tobacco reduces its quality. Lowering the value of tobacco by the increase in the waste material such as dead bodies, dust and refuse. Loss of good will as customer may turn away after once buying infested tobacco.

Control

• Keep the godown and surroundings clean by removing tobacco bits and dust to avoid breeding of the pest Cover doors and windows with wire mesh (20 mesh screen to 2.54 cm) to prevent entry of beetles into the godown.
• Redry FCV tobacco at 77°C Spray the godown with malathion 50 EC @ 20 ml /10 l of water before storing of tobacco as prophylactic treatment Store tobacco at 16-18°C in the warehouse
• Fumigate heavily infested tobacco with aluminium phosphate tablets @ 1 tablet/ 1 cu.m for 96 hours exposure and then 72 hours aeration.
• Treat the tobacco with insect growth regulator methroprene @ 10 ppm Treat the tobacco seed with malathion 50% EC @ 1 litre per 1 tonne of seed for protecting it from cigarette beetle