Grass seed-Leafminer

Phytomyza nigra

Pest description and crop damage This pest is most commonly in young stands. Very localized damage within a field may result in some seedling die-out. Larvae (small, white maggots) mine between the epidermal layers of grass blades. Moisture stress coupled with the chlorotic symptoms produced by the miner can kill seedling grasses.

Management-biological control

Parasitic wasps often prey heavily on leafminer larvae. As a result, leafminer populations crash-a good biological control that suppresses quite a few future generations of the fly.

Management-chemical control

Chemical control usually is not recommended. Dimethoate applied to control other pests on the grass seed label has been observed to give good control.