4. Fruit fly
4. Fruit fly - Bactrocera (= Dacus) diversus Coq. ( Tephritidae : Diptera)
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Damage
- The maggot bores into the fruits and feeds on soft pulp.
- The infested fruits show small cavities with dark greenish punctures and when cut open, the wriggling maggots are seen inside.
- It infestation causes rotting and dropping of fruits.
Cut open fruit with maggots
Bionomics
- The adult fly is smoky brown with greenish black thorax having yellow marking.
- It is active throughout the year except severe cooler months.
- It lays the eggs on the soft skin offruits. The egg period is 1-4 days during July.
- The maggot is pale cream in colour, cylindrical in shape measuring 5-8 mm in length.
- The larval stage lasts for 4-5 days. It pupates in soil.
- The pupal period extends from 7 days in August to 13 days in November.
- The adult stage over winters in cooler months.
Adult
Management
- Collect and destroy fallen and infested fruits by dumping in a pit and cover with a thick layer of soil or apply lindane 1.3 D over them.
- Plough interspace to expose pupae.
- Encourage parasitoids Opius compensates and Spalangia philippinensis.
- Use methyl eugenol lure trap (25/ha) to monitor and kill adults or prepare methyl eugenol and malathion 50 EC mixture at 1:1 ratio and use 10 ml mixture / trap.
- Use polythene bag fish meal trap with 5 g of wet fish meal + 1 ml dichlorvos soaked in cotton at 50 traps/ha. Renew fish meal and dichlorvos soaked cotton once in 20 and 7 days respectively.
- Use bait spray combining molasses or jaggery 10g/ 1 and one of the insecticides, fenthion 100 EC 1 ml/, malathion 50 EC 2 ml/1, dimethoate 30 EC 1 ml/1, carbaryl 50 WP 4 g /1, two rounds at fortnight interval before ripening of the fruits.
- Spray hostothion 2ml /litre or malathion at 1 ml/1 four times at 15 days interval.
- Rake the soil around the tree during the pest incidence and apply lindane dust 1.3 % at 25 kg /ha.
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Last modified: Tuesday, 7 February 2012, 12:01 AM