The Holly Leaf Miner

Prepare yourself for an adventure to an unimaginable place. This is not a Harry Potter adventure. Neither is it far away but it does have a tiny secret chamber.

To go there you have to imagine you are becoming smaller and smaller and now you are ready to visit the home of the Holly Leaf Miner.

Mother Holly Leaf Miner is a tiny fly that lays her eggs on the underside of the soft, new holly leaves of the Holly tree. The older, tougher leaves are much too hard for her very delicate mouth parts. Ten days later, her eggs hatch into tiny larvae and enter the holly leaf through small slits in the mid-rib.

They travel on to mine their way to the inside of the leaf where they feed for the entire winter. This constant feeding creates a chamber in the palisade parenchyma of the holly leaf. It is best not to say these words with your mouth full!

The palisade parenchyma of the leaf is where the plant makes its own food. The yellow larvae, when fully grown measure about 1.5mm in length. Within the chamber the larvae pupate and develop into tiny flies.

When spring comes, they emerge through little holes in the leaf and fly away to begin the cycle all over again.

Christmas is almost upon us and we are looking forward to presents and school holidays. Many of us still bring holly into our homes for decoration and Christmas wreaths.

If you do, have a look among the leaves for the holly leaf miner or better still go outside in search of the holly leaf miner. All of God’s creation will be there for you to explore and who knows you might find some secret chambers or make some other magical discoveries.

Elizabeth McArdle