Pin-sized puncture made by an agromyzid female with her ovipositor in the surface of leaf. She subsequently drinks from the extruding sap. Males, not having an ovipositor, drink from the punctures that the females have made.
A single female can make many tens of punctures in a leaf. When Agromyzidae are a pest it often is not because the mines made by the larva, but because of water loss of the leaves caused by the feeding punctures. Next to Agromyzidae also Scaptomyza (Drosophilidae) species use their ovipositor to make feeding punctures.
Phytomyza podagrariae: feeding punctures