INSECT PESTS OF CRUCIFER

R. RegmiAssistant professor

Department of entomology

INSECT PESTS OF CRUCIFER

• Cabbage, cauliflower, broccoli, radish, mustard etc are major crucifer crops.

• Many insect pests infect the crucifer crops reducing the productivity and quality of product.

Major insect pests• Cabbage butterfly, Pieris brassicae / Pieris brassicae

nepalensis (Lepidoptera : Pieridae)• Diamond Back Moth, Plutella xylostella (Lepidoptera:

Plutellidae)• Flea Beetle, Phyllotreta cruciferae/Monalepta signata

(Coleoptera; Chyrosmelidae)• Mustard Sawfly, Athalia lugens (Hymenoptera:

Tenthredinidae)• Mustard Aphid, Lipaphis erysimi (Homoptera: Aphididae)• Cabbage Aphid, Brevicoryne brassicae (Homoptera:

Aphididae)• Cutworms, Agrotis segetum/ Agrotis ipsilon (Lepidoptera:

Noctuidae)

Cabbage butterfly Diamond back moth Flea beetle

Mustard sawfly Cabbage aphid cutworm

Minor insect pests• Tobacco Caterpillar, Spodoptera litura (Lepidoptera: Noctuidae)

• Soyabean Hairy Caterpillar, Spilarctia casigneta (Lepidoptera: Arctiidae)

• Semilooper, Thysanoplusia orichalcea/ Chrysodeixis chalcites (Lepidoptera: Noctuidae)

• Leaf Webber, Crocidolomia binotalis (Lepidoptera: Pyralidae)

• Rice Grasshopper, Attractomorpha crenulata (Orthoptera: Acrididae)

• Painted Bug, Bagrada hilaris (Hemiptera: Pentatomidae)

• Green Stink Bug, Nezara antennata (Hemiptera: Pentatomidae)

• Leaf Miner, Phytomyza horticola (Diptera: Agromyzidae)

• Red Ant, Dorylus orientalis/ D. labiatus (Hymenoptera: Formicidae)

• White Grub, Phyllophaga rugosa (Coleoptera : Scarabaeidae)

Tobbaco caterpillar Soybean hairy caterpillar

Cabbage semilooper Grasshopper

Red ant white grub

Flea beetle Leaf miner damage Leaf miner adult

Life cycle of painted bug

Cabbage butterfly, Pieris brassicae (Lepidoptera: Pieridae)

• It is serious pest of cabbage, cauliflower, knol khol & also attack turnip, radish, sarsoo, mustard and other cruciferous crops.

• Damage is caused by caterpillars only, when full grown measure 40-50 mm in length.

• The young larvae are pale yellow and become greenish yellow later on. The head is black and the dorsum is marked with black spots. The body is decorated with short hairs.

• The butterflies are pale white and have a smoky shade on the dorsal side of the body.

• The wings are pale white, with a black patch on the apical angle of each forewing and black spot on the costal margin of each hind wing.

• The females measure 6.5 cm across the spread wings and have two conspicuous black circular dots on the dorsal side of each forewing.

• Males are smaller than the females and have two black spots on the underside of each forewing.

Life cycle: • This pest appears on cruciferous vegetables at the beginning of October and

remains active up to the end of April. • From May to September, the pest is not found in the plain but breeding

takes place in the mountains. • The butterfly very active in the field and lay, on an average, 164 yellowish

conical eggs in clusters of 50-90 on the upper or lower sides of the leaves. • The eggs hatch in 11-17 days in November- February & 3-7 days in March –

May. • The caterpillars feed gregariously during the early instars & disperse as they

approach maturity.• They pass through five stages & are full fed in 15-22 days during March –

April and 30-40 days during November –February. • Pupation generally takes place in cocoon hanging in wall, branches and other

plant parts.• The pupal stage lasts 7.7- 14.4 days in March – April and 20-28 days in

November –February. • The butterflies live for 2.5 -12.5 days.

Damage:• The caterpillar alone cause damage. • The first instars caterpillar just scrap the leaf

surface• Whereas the subsequent instars eat up leaves

form the margin inwards, leaving intact the main veins.

• Often entire plants are eaten.

Management:

• Hand picking and mechanical destruction of caterpillar during early stage of attack can reduce infestation.

• Conservation of natural enemies like Assasian bugs, paper wasps etc.

• Release of Trichogramma, Apanteles glomeratus etc.

• Spray commercial formulation of Bacillus thuringiensis @1-2 g/liter of water

• Spray 1 liter of malathion 50EC in 250 liters of water per ha & Repeat spraying at 10- day interval if necessary.

Diamond Back Moth, Plutella xylostella (Lepidoptera: Plutellidae)

• Serious pest of cauliflower & cabbage, but also feeds on many other cruciferous crops, solanaceous and liliaceous crops.

• Damage is caused by the caterpillars

• Earlier stages feed in mines on the lower side of cabbage leaves.

• When full grown, the larvae measure about 8-12 mm in length and are pale yellowish green with fine black hair scattered all over the body.

• The moth measure about 8-12 mm in length and are brown or grey with conspicuous white spots on the forewings, which appears like diamond patterns when the wings lie flat over the body.

Life cycle: • This insect is active throughout the year.

• Yellowish eggs of pin-heads size are laid singly or in batches of 2-40 on the underside of leaves.

• A female may lay 18-356 eggs on her life time.

• The eggs hatch in 2.5-9 days .

• The newly hatched caterpillar bore into the tissue from the underside of leaves and feed in these tunnels.

• At first, their presence is detected by only from the blackish excreta that appear at the mouth of each tunnel, but in second instar, the mines become more prominent.

• In the third instar, the caterpillar usually feed outside the tunnels.

• The larvae of the fourth instar feed from the undersides of leaves, leaving intact a parchment like transparent cuticular laryer on the dorsal surface.

Continue life cycle

• The larvae are very sensitive to touch, wind or other physical disturbances and readily feign death.

• They become fully grown in 16.6-8.6 days

• Before pupating, the larva constructs a barrel shaped silken cocoon, which is open at both ends and is attached to the leaf surface.

• The pupal stage lasts 4-5 days at 17-25 ºC

• The moths may live for as long as 20 days.

• The life cycle is completed in 15-18 days during September- October and there are several generation in a year.

Damage:

• Caterpillar damages the leaves of cauliflower, cabbage and rape-seed particularly in the heart of the first two.

• Central leaves of cabbage or cauliflower may riddled and the vegetables rendered unfit for human consumption.

• The pest is serious when it appears on the early crop in August-September.

•

Management:

• Remove and destroy all the remnants, stubble, debris etc after the harvest of the crop and plough the fields

• Tomato intercropped with cabbage inhibit or reduces egg laying by diamond back moth

• Mustard can be used as trap crops. Two rows of mustard for every 25 rows of cabbage.

• Release larval parsitiod, Cotesia plutellae @200 pupae per ropani

• Spray commercial formulation of Bacillus thuringiensis @1-2 g/liter of water

• Spray 0.05% solution of malathion 50%EC to manage

Cabbage flea beetle, Phyllotreta cruciferae (Coleoptera; Chyrosmelidae)

• The flea beetles attack almost all the cruciferous plants.

• The common fields crops like mustard, Broad leaf mustard, radish, turnip, cabbage, cauliflower and Knol-khol and some winter flowering plants namely dahlia, sweet pea, antirrhinum etc.

• The dorsum of the adult beetle P. cruciferae is metallic blue in color with greenish hue.

• The body is elongated narrow in front but broad distally.

• The beetle is round at the anal end.

• The head is finely punctate and the antennae extend beyond the middle of elytra.

• The female beetle measures 2.0 mm in length while the male beetle measures 1.8 mm.

• The larva is dirty white in colour with pale white head measures about 5 mm in length.

Phyllotreta cruciferae

Monalepta signata

Life cycle: • This pest is active throughout the year except during the winter months,

when it hibernates in the soil or among plant debris.

• The over wintered adult beetles emerge in the last weeks of February or in the beginning of March & settle on the growing cruciferous plants.

• The female beetle laid 50-80 creamy white eggs singly in the soil around the host plants, during the oviposition period of 25-30 days.

• The incubation period ranges between 5-10 days.

• The larva is very active and feeds on the tender roots of the host plant, which moult thrice during a total larval period of 9-15 days.

• The larva before entering into the prepupal stage wriggles out of the mined roots & prepares an earthen cell, 0.5 mm long, in the vicinity of the infested plants where it pupate.

• The pre pupal period is 2-4 days and the pupal stage lasts 8-14 days.

• There are 7-8 generation of this pest in a year.

Damage: • The adult mostly feed on the leaves by making in-

numerable round holes in the host plants.

• The stem, the flower & even pods may also be attacked.

• The old eaten away leaves dry up, while the young leaves are rendered unfit for consumption.

• A special kind of decaying odour is emitted by the cabbage plants attacked by this pest.

Management:

• Field sanitation, Deep ploughing and removal of alternate hosts.

• Lacewing larvae and Big eyed bug are predator for management of flea beetle.

• Use of chemical pesticides like Malathion or cypermetrin @2-3 ml/lit of water.

Mustard Sawfly, Athalia lugens (Hymenoptera: Tenthredinidae)

• The mustard sawfly is widely distributed in Indian subcontinent.

• It feeds on mustard, rapeseed, cabbage, cauliflower, Knol khol, turnip, radish etc.

• Damage is done by the larva, which are dark in color and have 8 pairs of prolegs.

• There are five black stripes on the back and the body has wrinkled appearance.

• A full grown larva measures 16-18 mm in length.

• The adult are small orange yellow insect with black marking on the body & have smoky wings with black veins.

Larva Adult

Life Cycle: • The mustard sawfly breeds from October to March and the larvae rest

in their pupal cocoons in the ground during summer. • The adult emerge from these cocoons early in October. • Adult live for 2-8 days and lay 30-35 eggs singly, in slits made with saw

like ovipositors along the underside of the leaf margins. • The egg hatch in 4-8 days and the larvae feed exposed in groups of 3-6

on the leaves during morning and evening. • They remain hidden during the day time and, when disturbed, fall to the

ground and feign death. • They pass through seven stages and are full grown in 16-35 days. • The full fed larvae descend the plant and enter the soil to a depth of 25-

30 mm. • There, they pupate in water proof oval cocoon made of silk and emerge

from them as adults in 11-31 days. • Thus, the life cycle is completed in 31-34days and pest completes 2-3

generation from October to March

Damage:

• The grubs alone are destructive.

• They bite hole into leaves preferring the young growth & skeletonize the leaves completely.

• Sometime, even the epidermis of the shoot is eaten up.

• The older plants, when attacked, do not bear seed.

Management:

• Applying irrigation in seedling stage

• Collection and destruction of larva at evening and morning.

• Field sanitation, deep polughing

• Perilissus cingulator Morely, parsitiod of grub and bacteria Serratia marcescens Bizio infect the larvae of sawfly.

• Use of bio pesticide like margosom, Annosom show significant effect on management of this pest.

• Spray one liter of malathion 50 EC per ha in 150-200 liters of water.

Mustard Aphid, Lipaphis erysimi (Homoptera: Aphididae)

• The mustard aphid is a serious pest of cruciferous crops mustard, sarson, cabbage, cauliflower, Knol-khol etc.

• The damage is caused by both nymphs and adults, which are pale greenish insects.

• They are seen feeding in large number, often covering the entire surface of flower buds, shoots, pods etc.

Life cycle: • This insect is most abundant form December to march when it

infests various cruciferous oilseeds and vegetables.

• During summer, it is migrate to hills and there is some evidence that aphids also survive on abandoned stray plants of cabbage and on cruciferous weeds in the plains.

• The pest breeds parthenogenetically and the females give birth to 26- 133 nymphs.

• They grow very fast and are full fed in 7-10 days.

• About 45 generation are completed in a year.

• Cloudy and cold weather (20°C or below) is very favorable for the multiplication of this pest.

• The winged forms are produced in autumn and spring, and they spread from field to field and from locality to locality.

Cabbage Aphid, Brevicoryne brassicae (Homoptera: Aphididae)

• Cabbage aphid are 1.6- 2.8 mm in body length.

• They have short siphunculi and triangular cauda, their body is covered with grayish- white mealy wax, which is also secreted to the surface of plant & extends throughout the colony.

• They are commonly occurs in dense colonies, often covered with wax droplets.

• It is serious pest of cauliflower, cabbage, brocauli, radish, mustard etc.

Damage: • Both Nymph and adults suck cell sap from

leaves, stem, inflorescence, or the developing pods.

• Due to the very high population of the pest the vitality of plants is greatly reduced.

• The leaves acquire a curly appearance, the flower fail to form pods and the developing pods do not produce healthy seeds.

• The yield of an infested crop is greatly reduced.

Management:

• Early sowing the crop, preferably up to third week of October.

• Use of balance dose of fertilizer.

• Releasing and rearing of predator like ladybird beetle.

• Spray Rogor (dimethoate) 30 EC @1ml/liter of water.

Cutworms, Agrotis segetum/ Agrotis ipsilon (Lepidoptera: Noctuidae)

• This is important pest of worldwide occurrence.

• This is polyphagus pest reported from potato, tobacco, peas, wheat, lentil, mustard, linseed, maize, sugarcane, cucurbits, bhang etc.

• The damage caused by caterpillar only.

• The slightly yellowish caterpillar on emergence is 1.5mm long with a shiny, black head and a black shield on the prothorax.

• The full grown larva is about 42-45 mm long and is dark or dark brown with a plump and greasy body.

• The adult moth measures about 25 mm from the head to the tip of the abdomen and looks dark or blackish with some greyish patches on the back and dark streaks on the fore wings.

• A. ipsilon is more darker than A. Segetum.

Life Cycle: • The pest is active from October to April and probably migrates

to the mountains for further breeding during summer. • The moths appear in the plains in October and come out at

dusk and fly about until darkness sets in. • They oviposit at night & lay creamy-white, dome shaped eggs

in clusters of about 30 each, either on the undersurface of leaves of food plants or in the soil.

• The number of eggs laid by female varies from 199 to 344. • Oviposition continues from 5 to 11 days and the duration of

the egg stage varies from 2 days in summer to 8-13 days in winter.

• The newly hatched larvae feed on their egg- shells and move like a semilooper.

• The larval stage varies from 30 to 34 days in February-April.

Continue life cycle• The advanced stage larvae may become cannibalistic. • The caterpillars are found throughout the winter and become active at

night when they cut off and fell the young plants.• During the day, they hide in cracks and crevices in the soil. • When full- grown, they make earthen chambers in the soil & pupate

underground. • The pupal stage varies from 10 days in summer to 30 days in winter. • The moths usually emerge at night. • The life cycle is completed in 48-77 days and generally, 3 generation is

completed in a year. • It is cold weathered pest and is active from October to March in the

plains. • It suddenly disappears with the onset of summer during April and is not

traceable during the off-season from April to August-September.

Damage: • The young larvae feed on the epidermis of the leaves.

• As they grow, their habit changes.

• During the day time they live in cracks and holes in the ground and come out at night and fell the plants by cutting their stems, either below the surface or above the ground.

• The cut branches are sometimes seen to have been dragged into the holes where the leaves are eaten at leisure.

• The larvae may also bore into cabbage.

Management: • Collect and destroy caterpillar mechanically as they may be curled near the base of

young plants or just a few inches into the soil.

• Encourage predatory birds to visit on the field by placing birdbaths and feeder near the planting beds.

• Expose hibernating stages of the cutworm into scorching sunlight and predatory birds.

• Place piles of weeds in the crop field as caterpillars hide inside the piles of weeds to remain protected from day light & Collect and destroy the hidden caterpillar at morning.

• Irrigates field regularly.

• Broadcast Bt mixed bait (2gm Bacillus thuringiensis formulation with 1 kg of wheat bran)@ 10 kg of bait per ha.

• Broadcast pesticide mixed bait (mixing @2g Malathion 5%dust with 1 kg of wheat bran.)@10 kg bait/ha

• Treat soil with Dursban 10%G (Chloropyrifos) @20 kg per ha before planting.

• Spray cypermethrin (10% EC) or deltamethrin (10% EC) @1.5 ml per liter of water to manage moth and early instars of cutworms.

• Drench the soil around the plants with cholorpyriphos 20 EC @ 2.5 Liter in 1000 liters of of water/ha.

Tobbaco caterpillar, Spodoptera litura (Lepidoptera: Noctuidae)

• The tobacco caterpillar is found throughout the tropical and subtropical parts of the worlds.

• It is widespread and polyphagous, feeds on cabbage, cauliflower, tomato, cowpea, sunflower, groundnut, etc.

• The damage is done only by the caterpillars, which measure 35-40 mm in length at maturity.

• They are velvety black with yellowish green dorsal stripes and lateral white bands.

• The moth are about 22mm long and measure 40 mm across the spread wings.

• The fore wings have beautiful golden and greyish brown pattern.

♀ ♂

LARVA SPODOPTERA LITURA

Life cycle: • This pest breeds throughout the year, although its development is

considerably retarded during winter.

• The moths are active at night when they mate and the female lays about 300 eggs in clusters.

• These clusters are covered over by brown hair and they hatch in about 3-5 days.

• The larva feed gregariously form the first few days and then disperse to feed individually.

• They pass through 6 stages and are full fed in 15-30 days.

• The full grown larvae enter the soil where they pupate.

• The pupal stage lasts 7-15 days and the moths, on emergence, live for 7-10 days.

• The life cycle is completed in 32-60 days and the pest completes eight generations in a year.

Damage:

• The larvae feed on leaves and fresh growth. They are mostly active at night and cause extensive damage.

Management:

• Remove egg masses and clusters of larvae and destroy them.

• Spray commercial formulation of Bacillus thuringiensis @1-2 g/liter of water

• Spray 1 liter of malathion 50EC in 250 liters of water per ha. Repeat spraying at 10 day interval if necessary.

Thank you