Tiêu đề pests of horti crops- theory notes.pdf ✅

1 1. Pests of Brinjal, Bhendi and Tomato Borers Leaf feeders Sap feeders Shoot and fruit borer Stem borer Bud worm Spotted leaf beetle Brown leafhopper Leaf roller Mealybug Plume moth Aphids Ash weevil Whitefly Leaf Webber Cotton leafhopper Sphingid Coreid bug Hairy caterpillars Lace wing bug Leaf miner Thrips Grasshoppers Scales Ants Red spider mite Shoot and fruit borer, Leucinodes orbonalis Pyraustidae, Lepidoptera Symptoms of damage • Withering of terminal shoots/ dead hearts • Bore holes on shoots and fruits plugged with excreta • Shedding of flower buds • Withering and drying of leaves ✓ It is the most important and destructive pest of brinjal in India. ✓ Sometimes, it also seriously infests potatoes ✓ The pest can cause 70 to 100% damage to the brinjal crops and up to 40% damage to the potato crops Biology • Eggs - Creamy white eggs EP – 3-5 days lay about 250 eggs within two to five days of their emergence. The eggs are laid singly on the surface of the tender leaves, shoot or fruits of the host plant during March-April • Larva - pink in colour LP 10-15 days • Pupa- greyish boat shaped cocoon among the fallen leaves or on the surface of stem and fruits of the host plant. • Adult- a medium sized moth Forewings- having black and brown patches and dots on white colour. Hind wings – opalescent with black dots
2 Management • Remove the affected terminal shoot showing boreholes. • Remove the affected fruits and destroy. • Avoid continuous cropping of brinjal crop • Grow the varieties with long and narrow fruits in endemic areas • Install pheromone trap@12/ha • Encourage the activity of larval parasitoids: ▪ Pristomerus testaceus ▪ Cremastus flavoorbitalis • Avoid use of synthetic pyrethroids • Avoid using insecticides at the time of fruit maturation and harvest • Neem seed kernel extract (NSKE) 5 % or any one of the following chemicals starting from one month after planting at 15 days interval Stem borer: Euzophera perticella, Phycitidae, Lepidoptera Symptoms of damage • Top shoots of young plants droop and wither. • Older plants become stunted. • Fruit bearing is affected Identification of pest • Egg- Cream, scale-like • Larva - Fully grown larva is creamy white • Adult - Greyish brown, • Forewings- with transverse line and hind wings - white in colour Biology  The female lays the eggs which last about 3 to 7 days on the leaf surface or stem.  On hatching, the larvae bore into the stem where they feed. Infested plants present a stunted growth.  The larvae remain active for 26 to 58 days.  The full-grown larvae measure 17.0 mm in length and they pupate for 9 to 10 days.  Pupa is dark brown and measures 12.0 mm in length.  There are 3 to 4 generations in a year. Management • Collect and destroy the damaged and dead plants • Light trap @ 1/ha to attract and kill adults • Spray neem oil 2ml/lit • Avoid using synthetic pyrethriods causing resurgence Bud worm: Scrobipalpa blapsigona, Gelechiidae, Lepidoptera Symptoms of damage • Shriveling and shedding of flower buds Identification of pest • Larvae - pale whitish with pink tinge • Adult - small with fringed wings. Management : Spray neem oil 2ml/lit
3 Hadda / spotted beetle: Henosepilachna.vigintioctopunctata, Coccinellidae,Coleoptera Symptoms of damage • Scrapping of chlorophyll • Skeletonization and drying of leaves Identification of pest • Eggs- Cigar shaped, yellow in colour • Grub: Yellowish bearing six rows of longitudinal spines. • Pupa: Yellowish with spines on posterior part and anterior portion being devoid of spines. • Adult: H. vigintioctopunctata: 14 spots on each elytra, deep red. Biology • The female ladybird may produce 300 to 400 eggs. • The development stages are completed in four to six weeks under optimal conditions. • Only adults are capable of over-wintering. They usually hibernate under fallen leaves in bushes or under plant residues in fields. Management • Collect damaged leaves with grubs and egg masses and destroy them • Shake plants to dislodge grubs, pupae and adults and destroy • Conserve natural enemies in brinjal ecosystem • Spray any one of the insecticides o Carbaryl 50 WP @ 3g/lit Ash weevils: Myllocerus subfasciatus, M. discolor, M. viridanus,Curculionidae,Coleoptera Symptoms of damage • Notching of leaf margins • Grubs feed on roots - wilting of plants Identification of pest • Larva: grub - small and apodous • Pupa: Pupates in soil in earthern cocoons Adult : M. maculosus: greenish white with dark lines on elytra • M. subfasciatus: Brown • M. discolor: Brown and white spots • M. viridanus: Small light green weevil Management • Collect and destroy adults • Apply Neem cake @ 500 kg / ha at the time of last ploughing • In endemic areas, apply carbofuran 3 G @ 15 kg/ ha – 15 days after planting • Spray carbaryl 50 WP @ 3g + wettable sulphur 2.5g/l Brown leaf hopper: Cestius phycitis, Cicadellidae, Hemiptera Symptoms of damage • Reduction in size of leaves • Shortened petioles, • Excessive growth of branches general stunting of plants, • Conversion of floral parts into leafy structures and • Plants become bushy