Phytomyza ranunculi

Eggs are laid on plants in the Ranunculaceae family. The larvae are, primarily, leaf-miners. They form a long, conspicuous white mine with the frass present in close strings. In 2018 the first confirmed adults were reared from stem-mines of meadow buttercup (Ranunculus acris). This is a rare example of 'organoxeny', where a phytophagous insect occurs on a different part of a plant from where it can normally be found . The larvae pupates into a greyish or brown puparium, with posterior spiracles each with about 18-20 bulbs. Adult flies are approximately 2 mm in length. Adults are highly variable in colour, with several named variants including a pale form (P. ranunculi var. flava) and dark forms (P. ranunculi var. flavoscutellata and var. islandica).