Simsim gall midge or gall fly (Asphondylia sesami)
The adult is a 5 mm long red-bodied midge (mosquito-like fly). Female midges lay eggs along the veins of terminal leaves. The larvae are typical maggots; they are whitish to orange in colour, legless and with body tapering exteriorly and grow up to 3 to 4 mm in length. Maggots feed inside the floral buds and young capsules leading to formation of galls of up to 6 mm in diameter. They pupate inside the galls. Attacked flower buds wither and drop, or become twisted and stunted and do not develop in to flower/capsules. The simsim gall midge is usually a minor pest, but occasionally high infestations occur resulting in considerable crop losses. Generally plants with green capsules appear to be more susceptible to attack than plants with black capsules.
- Monitor plants at the time of bud initiation.
- Use resistant or tolerant varieties where available (The following varieties are recommended in India: "RT-46", "Swetha Til", "RT-103", "RT-108", "RT-125" and "RT-127")
- Intercrop with mungbean, pearl millet or groundnut.
- Clip the galls, pick and burn the shed buds.
- Conserve natural enemies. Parasitic wasps, like species of Eurytoma, parasitise maggots of the gall fly.
- Use neem products when necessary. They help reducing capsule damage by gall flies, and providing higher seed yield. In trials in India the commercial products "Neemgold" and "Neembicidine" were found more effective than neem leaf extract, neem seed kernel extract, neem oil, "NNG-4", "Neemark" and "Neemax" (AHUJA and KALYAN, 2001).