Taxonomy
A holly leaf showing the characteristic blotch mines of Phytomyza ilicis (the holly leaf-miner).
Morphology
The mining larva is typical of other flies - it is a legless maggot without a head capsule. The mouthparts comprise a uniquely Diptera cephalo-pharyngeal skeleton.
The larval and pupal anterior spiracles are elongated and unbranched at the tip.
The posterior spiracles have numerous spiracular bulbs not organized in a circle or semicircle.
Look-alikes
The species is similar to the exclusively Nearctic American holly leaf miner, Phytomyza ilicicola, the adult of which is larger and with the mesonotum less densely covered with fine hairs.
Glossary
Frass
Debris produced by burrowing insects.
Mesonotum
The upper surface of the middle segment of the thorax.
Petiole
The stalk of a leaf.
Spiracles
Openings that allow gas exchange in insects.
