Ana's notes: It is important to differentiate leafmining flies and leafmining caterpillars, since the management of the two groups of pests is different. The leafminers attacking coffee, cotton, groundnut, soybean and citrus are caterpillars, not leafmining flies. Some work was done on neem for control of leafminers on tomatoes some years back, but it was not published. I am looking for it; it should be added when available.
Leafmining flies (Lyriomiza brassicae)
Leafmining flies are small about 1.3-1.6 mm in length. Maggots of leafmining flies cause mines while feeding within the leaf. Small, individual leafminers do not produce much damage, but when larvae occur in large numbers, entire leaves can be eaten out. Heavy attacks weaken seedlings and may result in dying off the young plants.
- Conserve natural enemies. Parasitic wasps normally control leafminers. However, the widespread indiscriminate use of persistent broad-spectrum insecticides, to control this and other pests, disrupt the natural control, leading to leafminer outbreaks.
- Rotate with non-host crops and plan the arrangement of fields so that old infested fields do not provide a reservoir of infestation for subsequent crops.
- Destroy leafminer pupae in the soil. This can be done by ploughing and tilling, by solarisation, and, on heavy soils, by flood irrigation.
- Monitor the crop by checking foliage for the presence of stipples caused by the adults while feeding and laying eggs, and for mines and larvae. Trap adult flies with yellow sticky or water traps. For more information on Traps click here.
- If necessary spray with neem-based pesticides. For more information on Neem-based pesticides click here.
