Caloptilia robustella (commonly known as new oak slender)[2] is a moth of the family Gracillariidae. It is known from all of Europe, except the Balkan Peninsula.
| New oak slender | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Lepidoptera |
| Family: | Gracillariidae |
| Genus: | Caloptilia |
| Species: | C. robustella |
| Binomial name | |
| Caloptilia robustella Jäckh, 1972[1] | |
The wingspan is 10–13 millimetres (0.39–0.51 in). There are multiple generations per year, with adults on wing between April and November.[3]
The larvae feed on Fagus sylvatica and Quercus robur. They mine the leaves of their host plant. The mine starts as a narrow lower-surface epidermal gallery, regularly intersecting itself. Later, the mine becomes full depth. It remains a small mine, either rectangular or (more frequently) a triangle in a vein axle, with frass along the sides. Older larvae leave the mine and continue feeding in a leaf roll. Pupation takes place in a white cocoon.[4]