''Gracillaria ussuriella'' is a

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

of the family

Gracillariidae Gracillariidae is an important family of insects in the order Lepidoptera and the principal family of leaf miners that includes several economic, horticultural or recently invasive pest species such as the horse-chestnut leaf miner, ''Camerar ...

. It is known from the islands of Hokkaidō, Honshū and Kyūshū in Japan and the

Russian Far East The Russian Far East (russian: Дальний Восток России, r=Dal'niy Vostok Rossii, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in Northeast Asia. It is the easternmost part of Russia and the Asian continent; and is admin ...

.Global Taxonomic Database of Gracillariidae (Lepidoptera)
/ref> The

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan o ...

is 9.8–12 mm. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e feed on '' Fraxinus'' species, including ''

Fraxinus americana ''Fraxinus americana'', the white ash or American ash, is a species of ''ash tree'' native to eastern and central North America. The species is native to mesophytic hardwood forests from Nova Scotia west to Minnesota, south to northern Florida, ...

'', ''

Fraxinus chinensis ''Fraxinus chinensis'', the Chinese ash, is a species of flowering trees. Its leaves are used in traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China ...

'', '' Fraxinus mandshurica'' and ''

Fraxinus pennsylvanica ''Fraxinus pennsylvanica'', the green ash or red ash, is a species of ash native to eastern and central North America, from Nova Scotia west to southeastern Alberta and eastern Colorado, south to northern Florida, and southwest to Oklahoma an ...

''. They

mine Mine, mines, miners or mining may refer to: Extraction or digging * Miner, a person engaged in mining or digging *Mining, extraction of mineral resources from the ground through a mine Grammar *Mine, a first-person English possessive pronoun ...

the leaves of their host plant. The mine made by the larva of the first three

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

s is large, lower-

parenchymal Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word ...

, and tentiformed. The leaf roll made by the larva of the late instars is conical, or often cigarette-formed when many larvae inhabit a single leaflet. The cocoons are ordinarily formed inside the leaf roll. They are shining white and spindle-shaped. The species probably hibernates in the adult stage.

References

Gracillariinae Moths of Japan Moths described in 1977 {{Gracillariinae-stub