Stalk-eyed fly (Diopsis thoracica) Management Strategies • It prefers an aquatic habitat. 1. Cultural control • The flies have a distinct black • Field sanitation, clipping the tip of seedlings thorax and reddish brown prior to transplantation to eliminate egg . masses. • Female flies lays eggs singly on • Use lures to trap adults flies. the upper surface of young leaves on mid rib. 2. Biological control Fig 1. Adult Stalk eyed Fig 2. Symptoms on • On older plants, eggs are placed fly (Rahab Magoti) growing tips (Rahab • Inspect regularly for presence of pest. in the leaf sheath. Magoti) • Destroy and discard infested plants to prevent • Peak oviposition occurs about 30 spread. days after transplanting, while • Timely control weeds that may act as reservoirs oviposition in the leaf sheath for the pest occurs about 10 days later. • Encourage conservation of natural enemies of • Eggs are boat-shaped, striated the pest. with a characteristic anterior 3. Chemical control • In nursery , spray with systemic projection, attached to the leaf Fig 3. of stalk Fig 4. Dead heart on before transplanting when the economic with a glue like substance. eyed fly (Rahab rice plant (Rahab Magoti) Magoti) threshold of 10% dead hearts of rice • Each female lays 30 eggs over a Damage on rice crop seedling is observed. 20-day period which hatch after • Damage occurs from seedling to maximum • Dip roots of seedlings root treatment for 12 or 2-4 days into maggots that infest tillering. The maggots bore through the leaf 14 hours before transplanting in recommended Factsheets for Rice Production, East Production, Rice Factsheetsfor Africa the crop causing dead hearts. sheath to the stem. (PCPB, 2015).. Vegetative stage at Geographical Distribution • Growth is stunted and plants eventually die. 15 DAT; At panicle initiation, presence of 1 • The stalk-eyed fly occurs in all • The presence of drying central shoot called moth or 1 egg mass/m2. rice growing areas. ‘dead heart’ in young plant or drying of the panicle called ‘white head’ in older plants.

Contact experts: Otipa, M ([email protected]); Kirigua, V; Ngari, B.M; Kega, V; Wasilwa, L . Kimani, J.M; Ochieng, V; Wandera, F; Mugambi, C; Wasike, V; Mutiga, S (BeCA ILRI); Nyongesa. O (IRRI); Zhou, B (IRRI)); Mitchell, T. (OSU); Wang, G. L (OSU); Were, V (TSL); Ouedraogo, I (INERA); Rotich, F (UoEm); Correll, J. C. (UARK) and Talbot, N. J (TSL). E-Guide for Rice Production in East Africa (2019)