In the Pacific it is present in Tahiti, Guam, New Caledonia, American and Western Samoa, Vanuatu, Cook Is. It is present on all major islands in Hawaii. Mines are linear and irregular, whitish or greenish in color, with conspicuous black thread-like strips of frass at alternate sides of the channel. In large numbers the feeding damage can severely weaken or even destroy both mature and young plants. Heavily damaged plants appear as if they have been scorched by fire.
Infested leaves are more susceptible to wind damage and possibly plant pathogen infection.
Adult female flies make tiny punctures in the upper sides of the leaf with their pointed ovipositor. The flies feed on about 8 out of 10 of these punctures, and deposit eggs in the remaining two. Males are unable to puncture leaves, but occasionally feed upon the food sources made available by female activity. Puncture wounds made my the adult females cause a stippled and yellowish appearance to the leaves and are easily seen in heavy infestations. On tomatoes, secondary problems of plant stress, moisture loss, or sun scald of fruit due to absence of shading foliage may occur.