Tuberose Bulb Mite

📖 Description

Tuberose Bulb Mite (Rhizoglyphus echinopus), also called Bulb Mite or Root Mite, is an important microscopic mite pest of tuberose and many other bulbous ornamentals and vegetables across the Indian subcontinent, particularly severe in the major tuberose-growing belts of Tamil Nadu (Tirunelveli, Kanniyakumari, Madurai, Dindigul, Theni — India’s largest tuberose-producing state), Karnataka (Bangalore Rural, Tumakuru, Kolar, Hassan), Andhra Pradesh (Guntur, Krishna, West Godavari), Telangana (Hyderabad, Rangareddy), West Bengal (Purba Medinipur, Nadia), Maharashtra (Pune, Nashik, Ahmednagar) and Uttar Pradesh (Kannauj, Farrukhabad, Kanpur) where India is the world’s largest producer of tuberose (over 25,000 hectares cultivated, producing loose flowers and cut flowers for both domestic and export markets — tuberose is one of the most important commercial flower crops in India, especially for the perfumery industry and traditional flower markets). The pest is unusual among tuberose pests because (a) it is a soil-borne and storage pest — adults live between bulb scales, on the bulb plate and in the soil immediately around the bulb, making them invisible without digging up and inspecting bulbs, (b) the pest feeds both on bulb tissue AND on the fungi that cause bulb rot — meaning that bulb rot (from Pythium, Fusarium, Rhizoctonia, Sclerotium) and bulb mites are mutually reinforcing problems, with rot promoting mite buildup and mite feeding promoting rot, (c) the pest has a very short life cycle (7-14 days) allowing rapid population buildup in warm moist storage conditions — 15-20 overlapping generations per year, (d) the pest has a very wide host range (essentially any bulbous plant — tuberose, gladiolus, lily, narcissus, tulip, iris, onion, garlic) allowing populations to persist between tuberose crops via other bulbous crops and weeds, (e) the pest is most severe in storage when warm moist conditions promote both mite buildup and fungal rot, and in field plantings with poor drainage (waterlogged soils promote bulb rot and mite buildup), and (f) the mites are often inside bulb scales where contact miticides cannot reach — only systemic miticides or bulb dip treatments are effective. IPM with mite-free certified bulbs (most critical preventive measure), hot water treatment at 43-44°C for 60-90 minutes before planting (kills mites and eggs without damaging bulbs — most effective organic control), sulphur dusting before storage (deters mites), proper storage conditions (cool, dry, well-ventilated — avoid plastic bags which trap moisture and promote rot), Trichoderma bulb dip (suppresses the fungal rot that mites feed on), proper field drainage (waterlogged soils promote bulb rot), and need-based miticide rotation (bulb dip with systemic miticide most effective) provides effective and sustainable control. The pest is a particular concern for Indian tuberose growers because tuberose is propagated primarily through bulbs (not seeds) — meaning that mite-infested bulbs are the primary means of spreading the pest between fields and regions, and the long storage period (4-6 months between harvest and planting) provides ample time for mite populations to build up to damaging levels in storage. The pest is most severe in years with warm moist weather during the storage period (Jul-Oct in southern India) and in fields with poor drainage. Climate change with warmer more humid conditions is increasing the severity of this pest across all major tuberose-growing regions of India.