Green Peach Aphid
Myzus persicae (Sulzer)
(Hemiptera; Aphididae)
- During winter and spring season, the potato is attacked
by various aphid species like M.persicae,
Aphids gossyppi and A. fabae.
Out of them m. persicae causes serious damage to potato
crop by transmitting various viral diseases
Identification
Winged Adult
- It has black body with transparent wings.
- The abdomen has one or two transverse bands and four
lateral dark spots.
Wingless Adult
- It is shining green in colour.
- The cornicles are medium in length, slender and slightly
swollen in the middle.
Nymph
- It resembles wingless adult but the size is small.
Life-history
- The pest passes winter in egg stage on the bark of
Prunun Spp. (Peach, plum, apricot etc.)
Seasonal-History
- During spring season wingless forms are produced within
a few days from over wintering eggs.
- Partheno genetic females give rise to two similar
generations.
- In December, winged germs appear on potato crop.
- Apterous females are formed on potato, till end of
March.
- With rise of temperature, winged forms are produced
which migrate to hill areas again to primary hosts.
- Thus this pest appears in plain areas in winter while
in the hills it appears in summer and autumn season.
Ecology
- A relative humidity of 66 + 2.8% and 11 -140
C temperature are ideal for development of this aphid.
- Its population sharply decreases with increase in
RH over 73 percent.
- The build up of aphid population on potato in plain
area, is governed by arrival of winged forms and availability
of host and suitable environment.
Nature and symptom of damage
- Aphids suck sap of plants, as a result of which leaves
turn pale and dry up.
- This pest also transit various viral diseases like
leaf roll, virus Y and virus A to potato plants.
- These viruses cause heavy reduction in the yield besides
the degeneration of the seed stocks.
Control Measures
- Spray 300 ml of Metasystox 25EC (Methyl demeton) or
200 ml of Rogar 30EC (Dimethoate) or 75 ml of Dimecran
85SL ( phosphamidon) in 100 liters of water.
- In case of seed crop, apply 5 kg of Thimet 10G (phorate)
to the soil at the time of the first earthing up.
Top
Hadda Beetles
Epilachna duodecastigma (mulsant)
E. Vigintioctata (Fabricius)
(Caleoptera; coccinallidae)
- Two species of hadda beetles attack different solanaceous
vegetables, like brinjal, tomato and potato.
Identification
Adults
- Beetle of Epilachna viginatioctopunctata is
about 8-9 mm in length and 5-6 mm in width. Its colour
is deep red and usually has 7-14 black spots on each
elytron whose tip is some what pointed.
- Beetle of E. dudodecastigma is deep copper-coloured
and has six black spots on each elytron whose tip is
more rounded.
Egg
- Yellow, cigar shaped eggs, mostly laid in batches
(5-40) each on the underside of leaves.
Grubs
- Grubs of both the species are about 6mm long, yellowish
in colour and have six rows of long branched spines.
Pupa
- The pupae are darker and , are found fixed on the
leaves, stems and most commonly, at the base of the
plants.
Life-history
- A female beetle lays about 300 small cigar-shaped
yellow eggs in clusters of 10 to 50 on the under surface
of potato leaves.
- Eggs hatch in about 5 days into small, yellow grubs,
covered with hairy spines.
- The grubs feed on the lower epidermis of leaves are
full grown in 7 to 18 days.
- The pupal stage lasts 5 to 14 days.
Seasonal-Occurrence
- It passes the winter as a hibernating adult among
heaps of dry plants or in cracks and crevices in the
soil.
- The pest passes through several broods from March
to October and its population is at a maximum at the
end of April or in early May.
- During the hot and dry months, the number declines
greatly but the population again builds up in August.
Nature and Symptoms of damage
- Both the adults and grubs cause damage by feeding
on the upper surface of leaves.
- The leaves present a lace-like appearance.
- The infected leaves turn brown, dry up and fall off
and completely skeletonize the plants.
- A severe infestation may cause up to 75 percent loss
in yield.
Control Measures
Both adults beetle and grubs can be killed
by the following management practices
- On a small scale, hand collection of grubs and adults
should be done.
- Conservation and augmentation of natural parasitoids
viz. Pediobius foveolatus, Pleunotrogrus faveolatus
and Tetrastichus sp.
- Use of Bacillus thuringensis is effective.
- Application of Neem, Mahua, ground nut cakes are efficient
in suppressing the pest population.
- Spray of Malathion 50 EC in 200 liters of water per
acre provides up to 82 percent kill of this pest.
Top
Greasy Cutworm
Agrotis ypsilon Rott (Lepidoptera ;
Noctuidoe)
- The greasy cutworm has been reported from almost all the
potato-growing regions of Northern India.
- This polyphagous has been reported feeding on potato,
tobacco, peas, wheat, lentil, mustard, linseed, maize,
sugarcane, cucurbits, vegetable seedlings and several weeds.
Identification
Adult Moth
- It measures about 25 mm from the head to the tip of the
abdomen.
- And looks dark with some grayish patches on the back and
dark streaks on the forewings.
Eggs
- Creamy white, dome-shaped eggs
Larvae
- Newly emerged young larva is yellow in colour, 1.5 mm
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.
Pupa
- Dark brown pupae are found in earthen cells lying
underground in the potato fields.
Life-Cycle
- Moths come out at dusk and lay eggs (200-350) in
clusters of about 30 each, either on the under surface of
the leaves of host plants or in the soil.
- The larval stage varies from 30-34 days, in
February-April.
- Pupation takes place underground in a earthen chamber is
completed in 10 to 30 days.
- The moths usually emerge at night.
- The life cycle is completed in 48 to 77 days.
- This pest generally completes three generations in a
year.
Seasonal Occurrence
- This pest is active from October to April in plain area
of Punjab and probably migrates to the mountains for further
breeding during summer.
- The moths appear in plains in October & start
breeding on number of host plants till March.
- It suddenly disappears with the onset of summer during
April.
Ecology
- It is a pest of winter season.
- Both adults caterpillars become active at night.
- Caterpillars during the daytime, hide in crack and
crevices in the soil.
- Persistent dry weather with lesser or no rainfall,
reduced humidity & 16 deg-23deg C temperatures favor the
development of cutworm.
Nature and Symptoms of Damage
- The young larvae feed on the epidermis of the leaves.
- Older larvae come out at night and fell the young plants
by cutting their stems, either below the surface or above
the ground and thus affect their growth, vigor and yield.
- They also damage the tubers by eating away part of them.
Up to 40% of the tubers, in badly affected fields may be
damaged by this pest.
Control Measure
Following measures will help in minimizing the
infestation this pest
- Break the sods in the fields.
- Flood the infested fields.
- On a small area, collection of caterpillars from soil
around the plants can be done.
- Collection of moths in the light traps.
- Use of chlorpyriphos 20 EC @ 2 l / ha to the soil before
planting potato tubers.
Top
Tobacco Caterpillar
Scientific Name : Spodoptera litura
(Fabricius)
- This polyphagous feeds on tobacco, potato, tomato,
cabbage, cauliflower, peas, cowpea, and castor.
Identification
Moth
- It is dark-coloured and has certain patterns and
white-wavy markings on the fore wings.
- It measures about 22mm in length.
Egg
- Dark green and circular shaped eggs are laid under side
of leaves.
Caterpillar
- It is velvety black with yellowish-green dorsal stripes
and lateral white bands.
Pupa
- Dark-brown pupae are found in silken bodies.
Life-history
- The moths are active at night.
- After mating female moth lays eggs (300) in clusters,
which are covered over by brown hairs.
- The eggs hatch in 3-5 days.
- The larvae are full-fed in 15-30 days.
- The full-grown larvae enter the soil and complete pupil
stage in 7 to 15 days.
- Moths on emergence live for 7-10 days.
- The whole-life-cycle is completed in 32-60 days.
- The pest has eight generations in a year
Seasonal-history
- This pest breeds throughout the year on different host
plants.
- During winter, its development is considerably retarded.
Ecology
- Moderate temperature and humidity is quite favorable for
its multiplication.
Nature and Symptoms of damage
- The young larvae first feed gregariously and scrape the
leaves.
- Older larvae spread out and may completely devour the
leaves resulting in poor growth of plants.
Control-measures
- The leaves, which have egg masses and young larvae in
the gregarious phase, should be plucked and destroyed.
- The pest can be killed by spraying 300-400 ml of Ekalux
2 S EC (quinalphos) or Thiodan 35 EC (endosulfan or Diptrex
50 E C (tri chlorphon) in 100 liters of water per acre.
Top
Potato Tuber Moth
Gnorimoschema opercullella
(Zeller) (Lepidopterab ; Gelechiidae)
- This native of South America and was introduced in India
in the beginning of the 20th century.
- It is distributed in Bihar, Karnatak, Maharashtra,
Himachal Pradesh, Kumaon hills of west Bengal, Nilgiris
(Tamil Nadu), Maharashtra and submountainous areas of
Punjab.
- This pest occurs especially in hot and dry climates.
- It is destructive to potatoes and also attacks tomato,
egg-plant (brinjal), tobacco and Solanaceous weeds.
Identification
Moth
- The adult is a very small narrow-winged nocturnal moth,
about 12 mm across the wings when spread.
- It is grayish brown with mottling of dark brown.
Eggs
- The eggs are pale white in color, spherical in shape.
Larva
- Pinkish white or greenish caterpillars with dark-brown
heads. It is about 20 mm in length.
Pupa
- It pupates in a grayish silken dirt-covered cocoon,
which is about 13mm in length.
Life history
- The pest is active through out the year in the plains of
northern India.
- A female moth lays from 50 to 200 eggs on the underside
of leaves or on the eyes of exposed tubers.
- The eggs hatch in 3 to 4 days. The young larvae first
produce blotch mines on leaves but subsequently, they work
their way into the stems and exposed tubers.
- The larval stage is completed in 2 to 3 weeks during
summer season.
- The mature larva pupates in a silken cocoon and the moth
emerges in 7-10 days.
- The whole life cycle is completed in about one month and
they are usually 8-13 generations of this pest in a year.
Control
- Construct potato stores away from the fields
- Cover tubers lying in stores with a thin (2.5-5.0 cm)
layer of dry sand. The surface of sand cover of the potatoes
should be dusted with one percent malathion dust.
- Carry out disposal of infested potatoes.
Top
Whitefly
Bemisia tabaci genn
(Hemiptera; Abyrodidae)
- Apart from cotton, this pest also feeds on potato,
brinjal, okra, cabbage, cauliflower and some weeds.
Identification
Adult:
- It is small winged insect having light yellow body
of 1.0-1.5mm length dusted with a white waxy powder.
- Wings are pure white and has prominent long legs.
Nymph
- It is louse like, sluggish creature having pale-yellow
body.
Pupa
- Convex in shape and possesses deep yellow patches
on the abdomen.
Egg
- It is smooth, sub elliptical, stalked at broader basal
end.
- Its colour is light yellow, when freshly laid, turn
dark brown later on.
Life history
- The female white flies lay eggs singly on the underside
of the leaves.
- The eggs hatch in 5-17 days
- The nymphal stage lasts 14 to 81 days.
- In 2-8 days, the pupae change into white flies
- The life cycle is completed in 14-122 days
- Eleven generations of this pest are completed in a
year.
Seasonal history
- This pests breeds through the year and all the development
stages are noticed in different host plants.
- During cold season, most adult white flies are present
Ecology
- The temperature of 28-360 C and 62-92%
relative humidity and scanty rainfall during August
to January are quite favorable for this pest.
Nature and symptoms of damage
- Nymphs suck sap from the leaves and lower their vitality.
- Sooty mould develops on affected leaves and the affected
plants look sick.
- The growth of the whitefly heavily attacked potato
crop is arrested
Control measures
- This pest can be controlled by spraying 300 ml of
rogor 30EC (dimethoate) or metasystox 25EC (methyl-demeton)
or 75 ml of dimecran 85SL ( phosphamidon) in 80-100
liters of water per acre.
|