Maize Planthopper (MRDV Vector)

📖 Description

Maize Planthopper (Peregrinus maidis), also called Corn Planthopper or Delphacid Planthopper, is the most important viral disease vector of maize across the Indian subcontinent, particularly severe in the major maize-growing belts of Karnataka (Davanagere, Haveri, Bellary, Chitradurga — India’s largest maize-producing state), Andhra Pradesh (Anantapur, Kurnool, Kadapa), Telangana (Mahabubnagar, Rangareddy), Maharashtra (Aurangabad, Jalgaon, Nashik), Tamil Nadu (Namakkal, Dindigul, Theni), Bihar (Khagaria, Begusarai), Madhya Pradesh (Ujjain, Dewas, Shajapur), Rajasthan (Kota, Bundi, Bharatpur) and Uttar Pradesh (Bulandshahr, Aligarh, Hathras) where India is the world’s seventh-largest producer of maize (over 9 million hectares cultivated, producing over 30 million tonnes annually for food, feed and industrial use). The pest is particularly damaging because (a) it is the most efficient known vector of Maize Stripe Virus (MStV) and Maize Rayado Fino Virus (MRFV) — devastating viral diseases of maize in India, (b) the pest has a very short life cycle (25-30 days) allowing rapid population buildup, (c) the pest prefers to feed inside maize whorls where contact insecticides cannot reach — only systemic insecticides are effective, (d) once a maize plant is infected with MStV or MRFV, it cannot be cured — the disease causes characteristic stripe symptoms on leaves, stunting, reduced cob size and yield loss of 30-70%, (e) the planthopper acquires MStV/MRFV in 1-3 hours of feeding on an infected plant and can transmit it for life (persistent transmission, circulative), (f) the pest has a wide host range allowing populations to persist between maize crops via weeds (Echinochloa, Sorghum halepense, Cynodon) and other cereals (sorghum, bajra, finger millet, sugarcane), and (g) the pest is most severe in continuous maize cropping and in areas with high weed pressure. IPM with certified virus-free seed (most critical preventive measure), yellow sticky trap monitoring, biological control (Anagrus egg parasitoid, conservation of native predators), roguing of virus-infected plants (prevents secondary spread), reflective mulches (silver mulch repels planthoppers), and need-based systemic insecticide rotation (systemic insecticides are required because planthoppers hide inside whorls) provides effective and sustainable control. The pest is most severe in continuous maize cropping and in areas where weed hosts serve as virus reservoirs. Climate change is expanding the range of the planthopper into previously cooler maize-growing regions, making the pest an increasing concern. The pest is a particular concern for maize growers because MStV/MRFV outbreaks can devastate entire crops, with no curative treatment available once plants are infected — prevention through planthopper management and weed control is the only effective strategy.