There has been a recent change in the pest status of a related species, L. huidobrensis. This species has suddenly become dominant on other vegetable crops in California, and appears to be spreading southward through the state from the Salinas Valley where it first appeared. Reports are incomplete at this time on its status as a pest on tomatoes in California, but other parts of the world report significant losses on fresh market tomatoes. The three leafminer species are similar in life history. At high population levels, entire leaves may be covered with mines.
Mature larvae leave the mines, dropping to the ground to pupate.
If it occurs early in the fruiting period, defoliation can reduce yield and fruit size, and expose fruit to sunburn. Pole tomatoes, which have a long fruiting period, are more vulnerable than other tomato crops. In southern California, leafminers are normally a pest of late summer tomatoes and can reach high numbers. Mature larvae that drop from foliage accumulate on the trays and pupate there, providing a measure of leafminer activity. In all areas, do not treat unless pupae are present.