Brinjal (Solanum melongena L.), also called aubergine or egg plant, is one of the top ten vegetables grown in the world. Incidence of insect pests is one of the prime factors in reduction of yield. The major pests of brinjal fruit and shoot borer, leaf hopper, whitefly, thrips, aphid, spotted beetles, leaf roller, stem borer, blister beetle, red spider mite, and disease like little leaf of brinjal.
1. Brinjal shoot and fruit borer:
Lucinodes orbonalis Guen
Family: – Pyralidae
Order: -Lepidoptera
- Economic Importance
This pest is widely distributed all over India and is found associated with a number of host plants. It is one of the most serious pests of brinjal fruits and plants. The infestation on brinjal can be as high as 70 per cent.
- Marks of Identification
The moths are medium sized. The wings are whitish with large brown patches all over. Wings expanse 22-26mm. Full grown larva is light pink measuring about 12mm long.
- Nature of damage
Infestation starts after few weeks of transplantation. The caterpillars bore into the growing shoots or petioles large leaves and feed on internal tissues. As a result of damage, affected shoots wither and plants exhibit the symptoms of drooping. After fruit formation larva make their entry under the calyx when they are young. The holes later plugged with excreta leaving no visible sign of infestation. Large holes seen on the fruits are the exit holes.
- Life history
A female lays on an average 250 eggs on leaves, shoots or sometimes on fruits. Incubation period is 3-5 days, larva become full grown in 7-13 days. The full grown larva comes out and pupation takes place in boat shaped cocoons on the plant itself. The pupal period lasts about 7-10 days. Adults live for 2-3 days. The pest is active throughout the year.
- Host plants
Besides brinjal, the pest is also known to infest potato, bitter gourd, pea pods, cucurbits etc.
- Control measures
1. Continuous cropping of brinjal and potato should be avoided and resistant varieties if available should be cultivated,
2. Removal and destruction of affected shoot and fruits alongwith larvae
3. Spraying with 0.05% monocrotophos 36 WSC or 0.2% carbaryl or dusting with 10% carbaryl 3-4 weeks after transplantation subsequent application 15 days thereafter controls the pest effectively.
4. Use of Resistant/Tolerant varieties in endemic zones.
2. Brinjal leaf roller
Antoba olivacea M.
Family: – Noctuidae
Order: – Lepidoptera
- Economic Importance
It is a minor pest but occasionally assumes a serious form.
- Marks of Identification
Moths are medium sized having wing expanses 25-35mm. Fore wing are green in colour. They always found in the leaf folds. As a result of damage the folded leaves wither and dry up.
- Host plants
It feeds on brinjal and other salanaceous plants only.
- Control measures:
Removal and destruction of leaf folds alongwith caterpillars help in minimising the infestation.
Dusting with 10% carbaryl at the rate of 20-25 kg/ha.
3. Brinjal lace wing
Urentius echinus D. and Urentius sentis D.
Family: -Tingidae
Order: – Hemiptera
- Economic Importance
It is minor pest of brinjal in the State of Maharashtra.
- Marks of Identification:
Adults are oval in shape, straw coloured dorsaly and black on the ventral side. They measure about 3mm long. Nymphs are oval, greenish yellow with few black dots.
- Nature of damage
It is specific pest of brinjal. Nymphs and adults suck the cell sap from leaves, affected leaves become yellowish and lower surface are found covered with black insect excreta. The summer crop suffers comparatively more.
- Life history
Eggs is laid on lower surface of the leaves. A single female lays about 35-45 eggs, which hatch within 4-12 days. Nymph moult 5 times in a period of 10-21 days. Adults’ longevity is 30-40 days. There are 8 overlapping generations in a year.
- Control measures
Sulphur dusting or 0.2% sulphur or Dicofol 0.04% or formothion 0.05% spray controls mites effectively.
4. Aphids
Myzus persicae Sulz
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 aphds. The loss caused on this account is far more severe than by their feeding and devitalizing the plant.
- Life history
Adults and apterous forms reproduce parthenogenitically. Single female produces 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. Jassids
Amrasca biguttula bigutula Ishida
Family: – Jassidae
Order: -Homoptrera
- Economic importance
The adults are greenish yellow tith front wings having a black spot on each, at the apical margin and two black spots on the vertex of the head. The nymphs are also green. They walk diagonally.
- Nature of damage
Both nymphs and adult suck the sap from the lower surface of the leaves. The damaged leaves curl upwards along the margins. Which may turn yellowish and show burnt patches. This affect adversely plant growth and yield.
- Life history
Whitish eggs are laid along leaf veins, which hatch about a week. Nymph moults 5 times and become adults within weeks. A generation is completed in a period of one month.
- Host plants
Cotton, bhendi and other malvaceous plants.
- Control measures
Spraying with 0.05% endosulfan, 0.03% Dimethoate or thiometon and 0.02% phosphamidon control the pest effectively.
5.Leaf Eating Beetle
Epilachana vigintioctopunctata
- Nature of damage
The yellowish coloured grubs and adults feed voraciously on the leaves and tender parts of the plant and often cause serious damage when they appear in numbers. As a result, the leaves are completely skeletonized leaving only a network of veins.
Control: Collection and destruction of infested leaves along with the grubs, adult and eggs reduces the pest incidence. Spraying the crop with Malathion (2ml/litre of water) or Carbaryl (2-4 g/litre of water) effectively controls the pest.
6.Red Spidermite
Tetranychus neocaledonicus, Tetranychus cinnabarinus,Paratetranychus indicus
- Nature of damage
The mite is a pest of brinjal. Low relative humidity favours mite multiplication. Different stages of mites are found in colonies covered by white-silky webs on lower surface of leaves. Nymphs and adults suck cell sap and white patches appear on leaves. Affected leaves become mottled, turn brown and fall.
Control: During egg stage and the resting stages, most miticides are ineffective. At high temperatures, it may be necessary to apply these at an interval of two days. Acaricides like Dicofol (0.05%) and Wettable Sulphur (0.3%) gives effective control of mites. Collection and burning of severely infested plant parts reduces further multiplication of mites. Proper irrigation and clean cultivation are essential to keep the pest population under control.
7.Mealy Bug
Centrocccus insolitus
- Nature of damage
Nymphs and adults of mealy bugs suck sap from the leaves, tender shoots, and the fruits. Leaves show characteristic curling symptoms similar to that of a virus. A heavy black sooty mould may develop on the honeydew like droplets secreted by mealy bugs. If the flower blooms are attacked, the fruit set is affected. When the fruits are infested, they can be entirely covered with the mealy bug. The infestation may lead to fruit drop or the fruits remain on the shoots in a dried and shriveled condition.
Control: Unlike the adults, the crawlers are free from waxy coating and therefore the crawler stage is the most effective for spraying pesticides. Spraying of insecticides like Dichlorvos (0.02%) or Chlorpyriphos (0.05%) with fish oil rosin soap was found to control the insect population.
8.Root-Knot Nematodes
Meloidogyne incognita and Meloidogyne javanica
- Nature of damage
The root-knot nematode damage is more harmful to seedlings than to older plants. The affected plants show the development of galls on the roots. The plants become stunted and the leaves show chlorotic symptoms. Fruiting is adversely affected.
Control: Crop rotation with root knot nematode resistant crops like marigold etc. help in the reduction of nematode population. Treating the nursery beds with Aldicarb or Carbofuran @ 2g a.i./m2 is effective in increasing the seedling growth and reducing the nematode population. Application of Aldicarb or Carbofuran @1-2 kg a.i. /ha effectively reduces the nematode population in the field.
