Common Slender

<em>Gracillaria syringella</em>, commonly known as the Common Slender, is a small moth belonging to the family Gracillariidae within the order Lepidoptera. It is classified as Least Concern on the IUCN Red List, reflecting stable and widespread populations. This species is a leaf-mining moth whose larvae typically feed internally within the leaves of host plants, most commonly lilac (<em>Syringa</em>) and ash (<em>Fraxinus</em>) species, creating distinctive mines that are characteristic of the gracillariid life strategy. The geographic range of <em>Gracillaria syringella</em> spans much of Europe, including Belgium, Denmark, Italy, Norway, and other countries, as well as North America, where populations are established in Canada and the United States. It is typically found in virtually all terrestrial and freshwater-adjacent habitats where its host plants occur, including gardens, parks, hedgerows, and woodland edges. Adults are small, narrow-winged moths with a wingspan of approximately 11–15 mm. The larvae undergo hypermetamorphosis, beginning as flattened leaf miners before transitioning to a more typical caterpillar form inside rolled leaf margins. Precise data on average lifespan and body measurements are not comprehensively documented but are typical of small gracillariid moths.