Several parasitic wasps attack the rice leafminer. The most effective are Chorebus aquaticus and Opius hydrelliae. Normally a combination of parasites, predators, and high temperatures cause leafminer populations to drop rapidly by June. Use a monitoring ring or floating plastic tubing 1 square foot in diameter. Check the plants within the ring for unhatched leafminer eggs on upper leaf surfaces.
Unhatched eggs are opaque, while hatched eggs are clear and flat.
If infestation levels do not increase and the plant stand remains at 25 or more, no treatment is needed. If the infestation level stays this low, treatment will not be required. When most of the leaves of the rice plants are upright, the rice leafminer will no longer cause economic losses. Consider prevailing weather conditions in cases where the need to treat is not clear cut. Cool growing conditions may favor leafminer damage.