For Clean, Smart and Profitable Farming.
Ag. Technologies (Pest Management)
Pests of Bhendi
1. Spotted bollworm
Earias vitella stell.
Family: - Arctiidae
Earias insulana boisd
Family: - Lepidoptera
Economic importance
It is found to occur throughout the plains of India and Pakistan as a serious pest of cotton and bhendi.
Marks of identification
The moths of E.vitella have pale white upper wings with broad greenish band in the middle; while incase of E.insulana the fore wings are completely greenish in colour. The months measure about 10 mm. The caterpillars of both the species are brownish white with a dark head and prothorasic shield. They have number of black and brown spots on the body and hence name. A full fed larva measures 18 mm in length.
Nature of damage
The larvae bore into the tender shoots, flower buds and fruits. As a result, the shoots dry and flower buds and fruits drop prematurely. Fruits remaining on the plants are deformed and often show exit holes of the larvae.
Life history
Greenish eggs are laid on tender shoots, flowers, buds and young fruits. A single female lays about 60-432 eggs. Incubation period is 3-7 days. Larval period is 9-11 days in summer and 20 days in winter. The full-grown larva pupate in the tough silken cocoons either on host or in soil or among the fallen leaves an d 30-31 days in winter. There are as many 12 broods in a year.
Host plants
Cotton, ambadi, shoe flower, holly hock and several other malvaceous host plants.
Control measures
Removal and destruction of infested shoots, fruits and shed material helps in reducing the intensity of infestation and
Spraying with 0.2% carbaryl or 0.1% Malathion or 0.06% endosulfan or 0.01% cypermethrin or 0.01% fenvalerate, 0.25% detamethrin at 10-15 days interval
3. Use of Resistant/tolerant lines.
2. Leaf roller
Sylepta derogata Fb.
Family: - Pyralidae
Order: - Lepidoptera
Economic importance
Though it is minor pest occasionally assumes a serious form. It occurs throughout the India.
Marks of identification
Moths are medium sized having yellowish wings with brown waxy marking. It measures about 24 mm across the wings full grown caterpillar is 25 mm long and green in colour.
Nature of damage
The caterpillars roll up the leaves in funnel shape and feed from margin by remaining inside. In case of heavy infestation, the crop is completely defoliated.
Host plants
Cotton and other malveceous plants
Life history
Female lays about 200 eggs on the lower side of leaves. They hatch within (6-7) days. Larva undergoes 6 Earias moults in 15-20 days before pupation. Pupation takes place inside the rolled leaves and moths emerge after about 6-7 days.
Control measures
1. Removal of leaf rolls and destruction alongwith caterpillars in initial stage used for reducing the pest intensity
2. Dusting with 10% Carbaryl @ 20 kg/l.
3. Aphids: - (Aphis gossypii G.)
Family: - Aphididae
Order: - Hemiptera
Marks of identification
Aphids are tiny yellowish soft-bodied insects, the adult is along 1mm long and has two projections called cornicles on the dorsal side of abdomen.
Nature of damage
Aphids are found in large colonies on underside o leaves and tender shoots. The nymphs and adults suck the sap. Therefore, the affected leaves turn yellow, get wrinkled and destorted. The insect also exude honeydew on which fungus develops, rapidly covers the plant with sooty mould that interferes with the photosynthetic activity of the plant. As a result, the growth of plant is stunted and yield is affected adversely. Besides, they act as a vector for transmitting by aphids. The loss caused on this account is far more severe than by their feeding and devitalising the plant.
Life history
Adults and apterous forms reproduce parthenogenitically. Single female produce 8-22 nymphs/day. The nymphs are completed in 7 to 9 days and several generations are completed in a season.
Host plants
It is a polyphagous species have been recorded on cabbage, brinjal, radish, chilly, tomato, tobacco, sanhemp, sweet potato etc.
Control measures
Spraying with 0.05% endosulfan, 0.02% phosphamidon, 0.03% dimethoate, methyl demeton or thiometon control the pest effectively.
4. Thrips: - (Anephothrips dorsalis H.)
Family: -Thripidae
Order: - Thysanoptera
Marks of Identification
The adults are minute, delicate insects, less than 1mm long and are light yellow in colour. Wings have fringe or hairs throughout and hence they are called fringed, winged insects. The nymphs are still smaller, minute and wingless.
Nature of damage
The adults and nymphs feed on leaves. They scrape the epidermis and such the oozing sap. As a result, light brown patches appear on infested leaves. The affected leaves curl and become dry.
Life history
A female lays about 30-50 eggs in leaf tissues, which hatch in 4-5 days. Nymphal stage lasts for about 10-15 days. A generation is completed in one month.
Host plants
Cabbage, cauliflower, knolkhol, groundnut, ambadi, brinjal etc
Control measures
Spraying with 0.05% endosulfan, 0.02% phosphamidon, 0.03% dimethoate, methyl demeton or thiometon control the pest effectively.
Mites
(Leyranychus telarius L.)
Marks of Identification
Mites are not insects as they have four pair of legs and belong to the class – Arachnida. They are extremely minute with variable colour.
Nature of damage
They suck the cell sap from leaves. Badly attacked leaves show a peculiar bronzy and shiny appearance, ultimately wither and dry up.
Host plants
Chillies, cotton, cluster bean, brinjal, bhendi etc.
Control measures
Spray 0.2% sulphur or 0.03% dicofol,
Sulphur dusting at the rate of 20-25 kg/ha also gives satisfactory control of the pest.