Insect Pests of Field Crops, Stored Produce and Horticultural Crops
Insect pests of field crops, stored produce and horticultural crops tests recognition, damage symptoms, host range, life cycle and integrated pest management (IPM).
Core rules
- Field crops: rice stem borer Scirpophaga incertulas causes dead heart in vegetative stage and white ear at flowering; brown planthopper Nilaparvata lugens causes hopper burn; cotton bollworm Helicoverpa armigera bores squares and bolls; sugarcane top borer Scirpophaga excerptalis kills top shoots.
- Stored produce: Sitophilus oryzae (rice weevil) adults and grubs tunnel grain; Trogoderma granarium (khapra beetle) is a serious quarantine pest; Tribolium castaneum (red flour beetle) infests flour; Corcyra cephalonica (rice moth) webs grain.
- Horticulture: Bactrocera dorsalis (mango fruit fly) maggots pulp fruit; Idioscopus spp. mango hoppers suck sap and cause sooty mould; Diaphorina citri citrus psylla vectors greening; Plutella xylostella diamondback moth defoliates crucifers.
- IPM: monitoring and economic threshold level, resistant varieties, sanitation, crop rotation, mechanical trapping, biological control, judicious need-based insecticide.
Worked example
Paddy shows hollow, dead central shoots; pull one: a caterpillar is inside. This is dead heart from Scirpophaga incertulas. Scout for egg masses, avoid excess nitrogen, conserve Trichogramma, and spray only at ETL.
Traps
White ear and dead heart are the same pest at different stages. Khapra beetle is not a flour beetle. Fruit fly damage is internal, so surface spraying at harvest is ineffective and residue-prone.