PESTS OF SORGHUM :: Major Pests :: Sorghum Midge
6. Sorghum midge: Contarinia sorghicola (Cecidomyiidae: Diptera)
Distribution and status: India, Pakistan, Bangladesh, West Iran, Sri Lanka, Sudan, Java, Africa, South East Asia, South China, South America, West Indies, USA and Italy.
Hosts: Sorghum cultivated and wild species.
Damage symptoms: A maggot feeds on the developing grains and pupates there. White pupal cases protruding out from the grains and chaffy grains with holes are the damage symptoms.
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Bionomics: The adult fly is small, fragile with a bright orange abdomen and a pair of transparent wings. It lays eggs singly in developing florets resulting in pollen shedding. A female lays about 30-35 eggs at the rate of 6-10 in each floret. The incubation period is 3-4 days. The maggot has four instars with duration of 8-10 days. Larvae are colorless, but, when fully grown, they are dark orange. Larval period 9 - 11 days. The larval stage undergoes diapause in a cocoon during December - January within a spikelet. Pupates beneath the glume. The pupal period 3 days. When the adult emerges the white pupal skin remains at the tip of the spikelet. A generation is completed in 14-16 days. The insect's rapid developmental cycle permits 9-12 generations.
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Management
- Grow resistant cultivars like DJ 6541, AF 28, ICSV 197, ICSV 745, ICSV 88032
- Conserve larval parasitoids - Apanteles sp., Eupelones popa; Larval and pupal parasitoid - Tetrastichus spp.; Predators – Orius albidipennis; Tapinoma indicum
- Give first application at nearly 90% earhead emergence and repeat after 4 or 5 days. The insecticides recommended are spray endosulfan 35 EC 1.0 L (or) malathion 50 EC 1.0 L (or) carbaryl 50 WP 2 kg/ha or endosulfan 4 D or malathion 5 D or carbaryl 10 D or quinalphos 1.5 D at 25 kg/ha .
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