Onion is grown across most of India as a staple kitchen crop, but the crop is vulnerable to insect pests both above and below the soil surface. Left unmanaged, these pests can stunt growth, reduce bulb size, and cut significantly into yield by the time of harvest. This guide covers the two insect pests that most commonly affect onion, how to identify each one in the field, and the insecticide solutions available to manage them. 1. Thrips Thrips rasp and feed on onion leaves and the neck of the plant, scraping the surface and feeding on the sap that oozes out. This causes silvering, curling, and browning of leaf tips, and heavy infestation stunts plant growth and reduces bulb size, especially during hot, dry spells. How to Spot It Look for tiny, slender, pale yellow to brown insects hiding in the leaf folds and near the base of the plant. Affected leaves show silvery-white streaks or patches, tips that turn brown and curl inward, and overall stunted growth in badly infested patches. Solutions to Manage/Control It ProductActive Ingredient Bayer Jump InsecticideFipronil 80% WG PI Industries Keefun InsecticideTolfenpyrad 15% EC Syngenta Curacron InsecticideProfenofos 50% EC 2. Root Grub Root grubs are soil-dwelling larvae that feed on the root system of onion plants, weakening or killing the roots. This disrupts water and nutrient uptake, causing affected plants to wilt, yellow, and produce poor, undersized bulbs. How to Spot It Look for patches of wilting or yellowing onion plants scattered through an otherwise healthy field. Affected plants pull out of the soil with very little resistance since the roots have been chewed away, and digging around the base often reveals creamy white, C-shaped grubs in the soil. Solutions to Manage/Control It ProductActive Ingredient Dhanuka Dhanvan-20 InsecticideChlorpyriphos 20% EC Frequently Asked Questions Why are onion thrips so hard to control once they appear? Thrips hide deep in the leaf folds where sprays don't always reach easily, and they breed very quickly in hot, dry weather, so infestations can build up fast if not caught early. How can I tell root grub damage apart from a nutrient deficiency? Root grub damage shows up as patches of wilting plants that pull out of the soil very easily because the roots are gone, and digging near the base usually reveals the grubs themselves in the soil. When should spraying for onion thrips begin? Spraying is most effective when started at the first sign of silvering or curling on the leaves, particularly during hot, dry periods when thrips populations build up quickly. Does root grub need to be managed before planting or can it be treated later? A soil application before or at planting works best since the grubs live and feed below ground, but treating at the first sign of wilting patches can still help limit further spread in a standing crop. Always confirm the current label registration, approved dosage, and pre-harvest interval (PHI) for your state before using any product, as labels are periodically revised by regulatory authorities. This is general advisory content. Please do your own research and verify with a local agronomist or dealer before making any purchase, spray, or crop-management decision. "