Holly is evergreen, so the mines can be found all year.
| The Holly Leaf Gall Fly Phytomyza ilicis | ||
| The Holly Leaf Gall Fly Phytomyza ilicis is a tiny insect which develops inside the leaf of Holly, pupating inside the leaf and emerging in midsummer. It produces a characteristic blotch on the leaf - actually classed as a gall, as the presence of the larva causes the leaf to produce abnormal growth in the affected area. More information on its biology is available in this paper (.pdf file 440kB). It is much more widely distributed than the map suggests. If you see Holly in Highland, check the upper surface of the leaves for these unmistakeable marks, and report them via the 'Submitting records' page. This allows you to submit records on line. Most will be found in gardens, parks etc., but records from more remote areas (Holly often grows on crags and in mountain gullies and riverbanks) will be especially valuable. Holly is evergreen, so the mines can be found all year. | ||
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| Mature mines on a leaf. | The oviposition (egg-laying) scars on the mid rib on the underside of the leaf. | Close-up showing an exit hole from the mine (but from a wasp parasitic on the fly, not the fly itself). |
| Photos © Murdo Macdonald. | ||
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