Observations on the economic importance of tomato leaf miner (Liriomyza bryoniae) (agromyzidae)

Yield losses can occur as a result of leaf miner infestation, but are not dependent on severity of damage alone; proximity to fruit at an early stage of development is very important. If damage on leaves adjacent to a truss reached 30 mines/leaf at the time fruit was half-swollen, a 10% loss of yield resulted. At three levels of infestation investigated, losses amounted to 5, 13 and 20% of monetary returns. Although it was found that growing soft plants and keeping de-leafing to the minimum would maximise yields, it appeared that the direct effect of these cultural practices on yield was more important than their indirect effects on leaf miner damage.