Coriander Shoot Fly

📖 Description

The Coriander Shoot Fly (Napomyza lateralis) is one of the most destructive yet under-diagnosed pests of coriander seed crops in India. The fly belongs to the Agromyzidae, a family of small dipterans whose larvae are obligate miners of plant tissue — most agromyzids mine leaves (the leaf-miner flies), but Napomyza species specialise in mining stems and growing points. The female fly uses her hardened ovipositor to puncture the tender apical meristem of the coriander seedling and lays a single egg inside. The emerging maggot tunnels downward through the soft pith, severing the vascular supply to the apical growing point, which then dies and produces the characteristic ‘dead-heart’ symptom. Because the damage is largely internal, the pest is often not detected until the central shoot has already been killed, by which point chemical control is futile. In Rajasthan — India’s largest coriander-producing state, accounting for over 60 % of national production — the pest has become increasingly important since 2010, partly due to the shift from single-crop to double-crop coriander systems made possible by expanded irrigation. The pest is particularly damaging in late-sown (November) coriander, where the seedling stage synchronises with the post-monsoon peak in adult fly activity. IPM packages developed by NRCSS Ajmer emphasise early sowing, soil application of neem cake at sowing, and roguing of infested plants as the core management tactics.