Pest Management of Jute_ Bangladesh

The intensive cultivation of high yielding varieties and fertilizer responsive cultivars

of jute create problems of insect, pests and mites. So all stages of growth of the crop

from seedlings to seed pod formation are subjected to attack by pests. Hairy

caterpillar, Spilosoma oblique (walker), which is considered as a sporadic pest on jute

has become a major threat to jute crop. Semilooper, Anomis sabulifera (guen), stem

weevil, Apion corchori (Marshall), Yellow mite, Polyphagtarsonemus latus (Banks)

and the indigo caterpillar, Spodoptera exigua (Hubner) are the major pest of jute.

Tossa (Corchorus olitorius) jute occupies 80% of the jute growing areas as agonist

20% by the white jute (C. capsularis), but unfortunately the incidence of major pests

is more on tossa than white jute.

Major insects and control measure:

Field Cricket (Brachytrypes portentosus)

The adult insect is blackish-brown in colour,

measure about 5 cm in length and the hind legs are

enlarged. It occurs in the field from the time of

sowing to late May and causes damage to seedling

of jute plants. As a result, the plants are lost in

Field Cricket

patches or the entire crop of the field is badly damaged. In such a situation re-sowing

becomes necessary. Damage increases when drought conditions prevail early in the

season but decreases after heavy rainfall. Seedling jute plants above 18 cm escape the

cricket attack.

Control measures:

• In localities where infestation occurs every year, higher seed rate may be used

thereby increasing the initial plant population to offset losses due to field cricket

attack. Thinning should be done when the plants attain about 20-25 cm tall.

• As and when field cricket burrows appear in the jute field, ‘hole treatment’ with

recommended insecticide (Dursban 20 EC 3ml/l or 3.5 lit/ha 40 WP 2g/l. Vitanon

60 EC 1.60 lit/ha) is advised.

• Wherever possible infested fields should be flooded with water.

• Late sowing is preferred where field infestation occurs every year.

Jute Hairy Caterpillar (Spilosoma obliqua)

It is a major pest of jute in Bangladesh. The adult insect

is a pale buff colored, medium sized with black spots on

the wings. The infestation starts from the middle of

May and continues up to the end of August. Eggs are

laid in clusters on the lower surface of the mature jute

leaf. The young caterpillars remain gregarious for about

6 days on the lower surface of the leaves. Afterwards,

they gradually disperse all over the field and defoliate

the plants. In case of serious infestations the top shoots

are also eaten up. Once the caterpillars have swarmed the field, nothing but bare stems

will remain. As a result of infestation, the plants become stunted growth and yield

reduced. The loss in fibre yield may vary from 75 to 200kg per acre depending on the

intensity of infestation.

Control measures:

• Hand picking of egg masses and early instar larvae when they remain in a

gregarious state and killing them by burning or in kerosinized water is considered

to be the easiest method of control.

• After harvest the land should be ploughed well so that the pupae which remain in

the soil or crevices are exposed to natural enemies.

• When the caterpillars are spread in the entire field, chemical control measures are

necessary using recommended insecticide Hayzinon 60% EC or karate 2.5 EC,

Riva 2.5 EC 1ml/L.

Jute Semilooper (Anomis sabulifera)

It is a serious pest of jute in Bangladesh. The adult moth is of dull brown colour

having darker spots and wavy lines on the forewings. Field infestation begins from

June Hairy caterpillar

middle of May when the plants are 60-90 cm tall and

continues up to the end of July. A full grown larva is

a typical semilooper and about 4 cm long. The female

moth lays eggs singly on the ventral surface of the

young leaves. Soon after hatching the larva becomes

active and feeds on young leaves. There are 2-3

generations of jute semilooper during the jute season.

As they grow the larvae feed on leaf buds and top shoots. As a result of infestation

growth is inhibited and side branches develop. The loss of fibre is about 75 to

100kg/acrc and the quality of fibre reduced. Control measures should be adopted

when the infestation reaches 20 per cent.

Control measures:

• If perches are provided for insectivorous birds, they will eat up large number of

semiloopers and help in controlling the pest considerably.

• A. Telinid fly (Tricholyga sorbilans) parasitizes jute semilooper larvae during June

and July. The larvae of the parasite feed on the internal tissue of the host. The

parasite is effective in reducing semilooper population.

• Spraying with any one of the recommended insecticides (Hayzinon 60 EC or

Nokon 60 EC or Ekalux 25% EC) can give satisfactory control.

Stem Weevil (Apion corchori)

It attacks jute plants at all stages of growth from seedling to

harvest. The adult insect is a small dull black weevil measuring

about 2 mm in length. The rostrum is short cylindrical and

gently curved. The female weevil bores on the stem and deposits

eggs singly. After hatching, the grub feeds on the bark internal

tissues of the stem. As a result of injury, mucilaginous and

gummy substances accumulate around the wound cementing the

larval excreta with the adjoining tissues. On retting it does not

dissolve and forms a ‘knot’ with black stain on the fibre which

causes lower fibre quality.

In the early growing period the weevil attacks the top shoot for laying eggs. The

activity of the grub damages the top shoot and causes development of side branches

and deterioration of fibre quality.

Control measures:

• Removal and destruction of infested plants during early season could give effective

control of the pest.

• Removal of Bon-okra (Triumfetia rhomboidea) and other shrubs and bushes during

winter offers a possible reduction of Apion population.

Semilooper

Stem weevil

• C. olitorius L. jute is less susceptible to Apion. An increase of this jute cultivation

will minimize jute weevil damage.

• A high percentage of jute weevil grubs are attacked by two important parasites

(Entedon sp. and Bracon greeni). The parasites are very useful in controlling the

pest as they cause a high mortality of the grubs.

• It is desirable not to stack the harvested jute for more than 3 days. Quick steeping

of harvested jute will destroy the immature stages.

• Infested C. capsularis L. plants should be sprayed with any of the recommended

insecticides (Metasystox 25 EC or Hayzinon 60% EC or Dimecron 60 EC). Mixing

of 18 ml pesticide with 12 litre water is recommended for spraying.

Jute Yellow Mite (Palyhagotarsonemus latus)

It is very small in size and cannot be seen by naked eye but

the symptom of its attack can easily be recognized.

Generally, mite infestation begins in mid May and

continues till the end of July. However, late infestation

may occur up to August. It attacks the apical leaves and

cause damage by sucking the plant sap. As a result of

infestation, the young leaves crinkle, dry up and fall down.

The vertical growth of the internodes gets suppressed and side branches develop. In

case of heavy infestation the top shoot dies and apical branches appear resulting in

great loss in yield and deterioration of fibre quality.

Control measures:

• Population of jute yellow mite is greatly reduced after heavy rainfall.

• Spraying with lime-sulphur in the ratio of 1:20 has been found to give satisfactory

control. A second spray within 40 hours after the first spray is recommended for

adequate control.

• Green neem leaf extract of Azadirachta indica in the ratio of 2:5 has been found to

give effective control against jute yellow mite. Dry leaf extract using boiling water

(100 gr + 1 litre water) for 15 minutes and spraying would inhibit mite activities.

However, a second spraying within 40 hour is recommended for a satisfactory control.

• Spray the infested fields using recommended miticide (Kelthan 42% EC or Torque

55% WSC or Nerot 50% EC) when the infestation become serious.

Mealy Bug (Pseudococcus virgatatus)

The infestation appears in mesta and kenaf field in July.

The adult is elongate to oval in shape and pink in colour.

They form colony and remain covered by waxy filaments.

Both adults and nymphs feed on plant sap causing

swelling of the terminal shoot. Such infestation reduces

the plant height and induces side branches. The injury

causes formation of “Witches broom”.

Jute yellow mite

Mealy bug

Control measures:

• At the beginning of attacks the tops of infested plants should be removed and destroyed.

• Infested fields should be sprayed with any of the recommended insecticides.

Spiral Borer (Agrillus acutus)

It is a key pest of kenaf (Hibiscus cannabinus L.) in Bangladesh.

It has recently been causing considerable concern in the

production of kenaf. In a normal season field infestation of spiral

borer starts in mid-July or more precisely 70-80 days after

planting. At the time of initial infestation, the plants are about

120-130 cm tall and continue till harvest. The larval stage causes

the damage. It burrows upward around the stem in a spiral

fashion leading to the reed becoming wiry, brittle or remains

attached to the stick during extraction of fibre, thus causing

deterioration of fibre quality. It has been observed that nearly 65 per cent of borer

attacks occur within the lower 1 meter and 92 per cent within 2 meters above soil

level. This information may conveniently be utilized for its economic control.

Control measures:

• The incidence of the pest can be reduced by varying the time of sowing. Its

infestation tends to decrease gradually with the shifting of sowing time beyond the

month of April.

• Spraying of any one of the recommended insecticides Hayzinon 60% EC or vitanon

60 EC or Eka 25% EC can be sprayed. Covering the lower portion of the plant

upto 2 cm above soil level will give effective and economic control.