Identification of Insect Pests of Cotton(Cond.)andSunhemp and their damage symptoms

Defoliators

Cotton leaf roller : Sylepta derogata ( Pyralidae : Lepidoptra )

Adult is a medium sized moth with yellowish wings and brown wavy markings on both the wings

Host range : Cotton, Bhendi, Abutilon indicum and other Malvaceous plants

Life cycle of the pestEggs : are laid singly on under surface of the leaves Eggs are smooth, flat, pale white in colour Fecundity- 200-300 eggs/ female, I.P-3-6 days

Larva: there are 5 larval instars and measures 2.5-3cm in length, shinning smooth body green in colour with dark brown head and prothorax L.P – 15-35 days

Pupa : pupation takes place in leaf fold or within rolled leaf P.P – 6-12 days

Nature and symptoms of damage Initial instars scrape the leaf tissue and later roll the leaf like a trumpet and feed on them and thus defoliate the plant A single larva can damage several leaves

More than one larva can be seen inside the roll

It is fastened by silken threads on marginal portion

Rolled leaves in the form of trumpet Larva

Larva can be seen inside the leaf roll

More than one larva can be seen inside the leaf roll Control measures Clipping of folded leaves

Spray any contact insecticides

Cotton semilooper : Anomis flava ( Noctuidae : Lepidoptera )

Adult is a medium sized moth and measures 2.5 to 3 cm in wing expanse and brown in colour

Fore wings are dark brown or reddish brown with dark coloured zigzag bands

Hind wings are pale white or buff coloured.

It is a sporadic pest of Cotton

Life cycle of the pestEgg: are laid singly on the upper surface of the leaf Fecundity- 600 eggs/female I.P- 4-5 daysLarva: green in colour with 5 white longitudinal lines on the body and red coloured prolegs L.P – 20 days

Pupa : Its pupates within leaf folds P.P – 9-10 days

Nature of damageLarva feeds on leaves thus defoliates the plant Control measures

Spray any contact insecticides

Ash weevil: Myllocerus spp. ( Curculionidae : Coleoptera )

Adults are grey coloured weevil with or without markings on the elytra and measuring 3-6 mm long

Eggs : are white, laid in the rhizosphere Each female lays about 300 eggs I.P – 3 - 5 daysGrubs : are white apodous L. P – 30 31 daysPupa – It pupates in an earthen cell in soil P.P – 7-9 days

Nature of damageAdults feeds on leaf margin in “U” shaped manner and thus reduce the leaf area.Weevil also feed on the flower buds and flowers

Grubs remain under ground and feed on the root system and attacked plants wilt and dry up

Cotton grass hopper : Cyrtocathacris tatarica ( Acrididae : Orthoptera )

Adults are active and measuring 10 cm in length, bigger in size, pale brown coloured short horned grass hopper

The brown patches on the wings with fine marks on the pronotum.

Eggs : are laid in egg pod in the soil in the month of Nov – Dec It hatch in 15 days in summer and more than 150 days in winter

Egg pods

Nymphs : Nymphs have broad yellowish stripes on the prothorax and emerge during monsoon showers and passes 5-7 nymphal instars N.P – 10-170 days

Nature of damage

Young ones will feed on grasses / weeds initially and later move on to cotton Nymphs and adults feeds on cotyledons and growing plants and mainly feeds on leaves

Control measures Dusting of bunds with methyl parathion 2 %D

Tobacco cut worm: Spodoptera litura ( Noctuidae : Lepidoptera )

Adult is a medium sized moth with fore wings are greyish- brown and bearing white zigzag markings and hind wings are white in colour

Nature of damage

The first instar larvae feed gregariously on the leaf, on which the egg mass is laid by Scrapping the epidermal layer, leaving the skeleton of veins.

The skeletonized leaf may dry up Then, the larvae move to other leaves and feed by making small holes. In later stages, they consume most of these leaf tissues and because of severe attack,

only the stem and side shoots will be standing in the field without any leaf or bolls. Once squares, flowers and bolls develop, they prefer these better than leaves. They bore into them, feed on the internal content completely and cause shedding

of squares and young bolls

Egg Mass and Early instar gregarious larvae

Feeding on flower & leavesAdult

This type of feeding is seen only during early morning hours and night, and during hot sunny hours the caterpillars will be hiding in the flowers or in the cracks of the soil.

This pest is found to cause damage in all stages of crop growth, but fleshy green leaves should be present for egg laying

(Detailed refer under Tobacco)

Serpentine leaf miner: Liriomyza trifolii ( Agromyzidae : Diptera )

Adult is small beautifully coloured fly, head is yellowish with dark brown eyes and ocelluar triangle and back of the head are black in colour and mesoscutellum and abdominal sterna yellow and terga brown in colour and legs are yellow in colour

An introduced pest becoming serious in the recent years

(Detailed refer under Tomato)

Larva will mine the leaf and will feed on mesophyll tissues as a result tunnels will produced. As the maggot grow the tunnel become enlarged

Management practicesSpray the crop with 5 % NSKE orSpray the crop with triazophos 40 EC @ 0.05 % or deltamethrin 2.8 EC @ 0.0028 %Spray the area below the plant to eliminate the pupa

Root / Stem feeders orBorer pests of Cotton

Stem weevil: Pempherulus affinis (Curculionidae: Coleoptera)

The adult weevils are small and measures 3 mm long, dirty brown in colour with two small white patches on the elytra and a conspicuous down curved snout.

Eggs : It lays globular or oval shaped eggs singly in the cavities scooped out by the female weevil at the tender nodal region of the plants. The cavities are sealed with a gummy secretions   A female weevil lays an average of 50 eggs with a maximum of 121 eggs.  I.P - 6-10 days.Grub: white, apodous. The grub feeds on stem tissues internally.  The larval period lasts 35-37 days.  Pupa : It pupates in pupal chamber with in the stem

The adult may live for 25 - 30 days Nature and symptoms of damage :

The damage to cotton starts when plants are young and are about three weeks old.

The grubs bite into the region between the bark and the main stem feed on soft tissues, resulting in swellings on the stem just above the ground level.

Young plants are invariably killed on account of the attack of the pest and the older plants that survive, lack of vigour and strength, and when strong winds blow, these plants break at the nodes.

Stem gall Stem galls Grub Symptoms of damage Swellings on the stem just above the ground level. Young plants are invariably killed Older plants that survive, lack of vigor and strength, and when strong winds blow, these plants sometimes break at the nodes. Control measures

Removal and destruction of plants showing symptoms of attack Earthing up along the rows of seedlings and close spacing are the measures

recommended for the control Soil application of carbofuran 3G @ 12.5kg / acre on 20 days after sowing before

earthing up Basal application of FYM @ 10 tonns / acre or 100kg neem cake / acre Application of chlorpyriphos @ 2 ml / lit. of water at 15 days interval from 3 weeks

after sowing

Cotton shoot weevil: Alcidodes affaber ( Curculionidae : Coleoptera )

Adult is a dark greyish brown weevil with pale coloured cross bands on the elytraEggs : are laid singly in the tissuesGrubs : are creamy yellow, ApodousPupa : Pupation inside the stem

It is more common in South India

Adults feed on leaves, buds and tender terminal shoots

Nature and symptoms of damage Both adults and grubs injure the top shoots and leaf stalks

Terminal shoots with galls

Bored holes are surrounded by raised margins

The affected shoots dies up and growth will be effected symptoms Terminal shoots with galls Bored holes surrounded by raised markings

(Control measures refer under stem weevil)

Cotton stem borer: Sphenoptera gossypii ( Buprestidae : Coleoptera)

Adult is a shiny coppery brown beetle, measuring 8-10 mm long

It is a minor pest

Eggs : are laid singly on the stem, especially collar region

Grubs : are apodous and measures 2.5 cm long

Pupa : It pupates within the larval gallery

The grubs burrows into the stem feeding on the internal tissues and swelling at the region of feeding and plant will break at the point of swelling usually when the crop is in boll producing stage.

Symptoms Plants with drooping of leaves Plants wilting in patches

Infested plants  Control measures

Take out the affected shoots Plants with galls should be eliminated Spray any contact insecticides or Soil application of carbofuran 3G @ 12.5kg / acre on 20 days after sowing before earthing up Basal application of FYM @ 10 tonns / acre or 100kg neem cake / acre

Affected stem

Non Insect pests of Cotton

Cotton mite :Tetranychus urticae ( Tetranychidae : Acarina )

Adult mite Eggs

T. urticae is the most numerous mite species on cotton

Other species that may occur are Bean spider mite Strawberry spider mite

The mites lives under web on the upper surface / lower surface of the leaves by sucking sap. The grown up leaves suffer more as a result affected leaves turn brown and dry up.

Nature of damage The first sign of damage is bronzing of the upper leaf surface near the

petiole or leaf fold

As the numbers increase, the leaves turn red and become in the webbing and affected leaves may dry and fall off

High mite populations can significantly affect yield and quality of cotton

The earlier in the season that infestations develop the greater the potential of yield loss and quality decreases

Affected leaves turn brown and later dry up

The woolly mites : 1. Aceria gossypii (Eriophyidae : Acarina )

This is commonly found infesting the herbaceum variety of cotton in Gurjat, MH and Karnataka

The mite lives under the epidermis of the leaves and causes irritation resulting in the growth of dense whitish hairs on both sides of the leaves

The infested leaves become stunted, crinkled, hard and crisp and in severe cases of attack shedding of bolls

2. Aceria putturudriahi It occurs in Karnataka and induces felt like out growths of white hairs

on tender cotton shoots including squares and leaves Attacked plants may become stunted with boll formation suppressed

Management practices Mite infestations increase after the application of some broad- spectrum insecticides for control of other pests Control of weeds with in fields and along field boundaries that serve as over wintering sites for mites Spray the crop with dicofol @ 2.5ml/ lit. of water or propargite @ 2 ml / lit. of water

Indentification of Insect pests of Sunnhemp and their damage symptoms

Sunn hemp is one of the most important fibre crop, next only to cotton and jute

Unlike cotton and jute, It is a valuable green manuring crop

Sunhemp is attacked by a dozen of insects but only the hairy caterpillars and Capsid bugs are important and cause considerable damage

1.Sunnhemp hairy caterpillar: Utethesia pulchella (Arctiidae: Lepidoptera)

Adult is a medium sized moth and has pale white fore wings with red and black spots and black marginal blotches on the hind wings

Eggs : The female moths lay 80-100 small whitish eggs on the tender leaves and shoots. I.P : 3-4 days

It is the most seriou sand specific pest of sun hemp in TN, AP, WB, Orissa, Bihar, UP, and MH

Larva : Caterpillar hairy with brown head and yellow lines on the dorsal, dorso-lateral side with black stripes and orange patches Body has long brownish hairs arising on warts.  L.P : 18-21 days

Pupa : Pupation takes place either in the leaf folds or in the soil.The life cycle is completed in about 5 weeks and a number of generations are completed in a year. P.P : 6-8 days Nature of damage The hatching larva either defoliates during vegetative stage and the caterpillars feed by thrusting the head in to the pod and the rest of the body exposed and feed on the seed thus cause a decrease in seed production Symptoms Defoliation of plants Bored seed capsules

2. Hairy caterpillar: Argina cribraria / Argina syringa (Arctiidae: Lepidoptera)

A. A. cribraria adult has black spots on yellowish wings whereas B. A. syringa has black spots on reddish brown wingsEggs : Yellowish eggs laid in clusters on the undersurface of the leaves.  Larva : Caterpillar hairy with black transverse markings and white spots. Pupa : It pupates on the plant or the surface of the soil. Larvae feed on the leaves and cause defoliation. Control measures Larval parasitoids - Bracon brevicornis suppress the population naturally The pest can be suppressed by hand picking and killing the caterpillars Foliar spray with methyl parathion @ 2 ml / lit. of water or dusting methyl parathion 2 % D @ 10-12 kgs / acre are the effective measures

3. Sunhemp mirid/capsid: Ragmus importunitas (Miridae : Hemíptera)

This is a small, active, green coloured bug, which sucks plant sap and when present in large swarms, causes appreciable damage

The pest is widely distributed in Southern India

Life cycle of the pestEggs : The bugs lay white cylindrical eggs singly in the plant tissue, generally under the surface layer of leavesNymphs : The young nymphs on emergence, begin to feed on the plants All the stages of the insect may be found simultaneouslyWhen the population is high and attack severe, the plant become pale and appear unhealthy Damage symptoms Nymphs and adults suck the sap from tender leaves and shoots

Minute chlorotic spots, later coalesce to cause yellowing of leaves

In severe attack, cause death of plants Control measures The population of the pest can be suppressed by collecting the bugs with nets or sticky traps Spray the crop with 625 ml of malathion 50EC in 625 lit. of water per ha.

Adult is a 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

4. Flea beetle : Longitarsus belgaumensis ( Chrysomelidae : Coleoptera)

5. Spiny pod borer : Etiella zinckenella ( Pyralidae :Lepidoptera )

Adult is a medium sized moth, grayish brown with a white line on the anterior margin and transverse yellow band in the fore wing

Hind wings are pale coloured

(Refer pulses)

Nature of damage The larvae consume floral parts, newly formed pods and seeds inside the developing pods The reduction in yield may be up to 5 %  

6. Whitefly: Bemisia tabaci (Aleyrodidae: Hemiptera)

Adult is a minute insect with yellow body covered with a white waxy bloom.

Damage symptoms

Nymphs and adults suck the sap from the under surface of leaves.  Severe infestation results in premature defoliation, development of

sooty mould,