The major insect pests of jute and with their appropriate control measures are given below:
1. Jute Semi-Looper:
The incidence of semi-looper starts from middle of June and continues up to the middle of August. The caterpillars are green in colour and their length ranges from 5-8 cm. They attack soft leaves of the apical region of a plant. They devoure apical leaves and cause retardation in growth in the apical region which reduces side branches.
Control Measures:
Spray Endusulfan 35EC at the rate of 1 litre in 1000 litres of water per hectare.
2. Jute Stem-Weevil:
The incidence of jute stem-weevil starts from seedling stage of the plant. The female makes a hole at the base of stalk of the leaf (petiole) with the help of its snout, turns and lays eggs singly in holes. After three days, the eggs hatch and the grub is inside the hole.
The grub being stationary takes food causing wounds from within the plant and grows old day by day. The mucilaginous substance of the plant oozes out from the wounds, get mixed with the excreta of the grubs and harden with adjoining tissues and from a knot. The quality of the fibre thus gets deteriorated.
Control Measures:
Spray crop with Endosulfan 35EC at the rate of 1.0 litre in 1000 litres of water per hectare.
3. Bihar Hairy Caterpillar:
The caterpillars in their young stages remain congregated. After two months they scatter themselves throughout the field. These caterpillars attack both capsularis as well as olitorius jute. At first, as a result of its attack, the skeleton of the leaf only remains, denuded of green colour. In the later stages of growth the whole leaf is eaten by them.
Control Measures:
Young caterpillars can be killed by dusting 2% Methyl parathion dust at the rate of 25-30 kg per hectare.
For full grown caterpillars spray 1.5 litres of Endosulfan 35EC in 1000 liters of water per hectare.
4. Tobacco Caterpillar:
Deep green caterpillars devoure upper leaves of the plant and thereby retard growth of the plant and induce side branches which are not desirable in jute crop.
Control Measures:
Spray Endosulfan 35EC at the rate of 1 litre in 1000 litres of water per hectare.
5. Indigo Caterpillar:
Indigo caterpillars damage the leaves of jute plant when its age is 25-30 days Yellowish-green caterpillars damage young leaves. They, of course, do not damage much. At the trim of thinning, the damaged plants may be uprooted.
Control Measures:
In case of severe damage spray Endosulfan 35EC at the rate of 1.25 litres per hectare in 1000 litres of water.
6. Yellow Mite:
Yellow mite mainly attacks olitorius jute. Light yellow coloured mites their immature stages (nymphal stages) collectively damage the apical leaves of jute plant by piercing their stylet and sucking of the leaf juice. As a result, the leaves crumple and ultimately turn coppery brown. The growth of the plant gets arrested. Thus the Jute plants become weak. They prefer to remain on the under surface of a leaf.
Control Measures:
Spray Endosulfan 35EC at the rate of 1.25 litres in 1000 litres of water per hectare or 2 litres of lime-sulphur in 500 litres of water per hectare.
7. Jute Girdler:
This pest attacks olitorius jute only. The female adult cuts two rings at the apical region of the plant and lay egg singly. The grubs grow inside the stem. The apical portion at its attack gets withered or gets detached at the gush of wind.
Control Measures:
Spray Oxydemeton methyl (Metasystox) 25 EC at the rate of 1.25 litres or dimethoate (Rogor) 30EC in 1000 litres of water per hectare.
8. Red Mite:
Red mite damages more in the month of May-June when hot humid weather is prevalent. They prefer to remain on the under surface of the leaf and pierce their stylets to take juice from the leaf. Yellow mites restrict its attack to upper tender leaves whereas red mites attack both younger as well as older leaves. As a result of injury the leaves appear to be white spotted. After this the leaves turn yellow and fall off prematurely.
Control Measures:
Apply Kelthane or Dicofol at the rate of 1100 milliliter or Morocid at the rate of 1.5 litre in 1000 litres of water per hectare.