PEST PROFILES: MISCELLANEOUS CHEWING PESTS
Picture of Leafminer
Leafminer Larva and Adult

Picture of Leafminer Damage
Leafminer Damage

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Leafminers

Description:
Adult Liriomyza trifolii leafminer flies are small (1/16 inch), with bodies overall gray-black with yellow markings. Maggots are 1/16 inch long are whitish yellow while pupae are yellow-brown, oval and seed-like. Mines appear snake-like, narrow in width towards oviposition site, and become progressively wider or blotch-like towards the end produced by larger, mature maggots.

Damage:
mmature larvae tunnel through leaf tissue causing whitish winding tunnels which can reduce yield and look unsightly. Other common species include chrysanthemum leafminer, serpentine leafminer, and vegetable leafminer.

Life cycle:
Mated leafminer females produce stipples on leaves with their ovipositor to insert an egg into the leaf. Larvae hatch in 2 days, and develop through 3 instars while producing the mine over a period of 7 to 8 days. The last stage emerges from the leaf and drops to the ground where is inflates its last skin for the pupa or puparium. Adult flies emerge from the puparium in 7 to 11 days. Duration of the life cycle varies with temperature and time of year. In the greenhouse, leafminers can breed throughout the year.