Phyllonorycter salicifoliella is a moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

 of the Gracillariidae

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, Cameraria ohridella....

 family. It is widespread across North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, from Mississippi

Mississippi

Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

 to Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

 in the east and from southern California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

 to northern British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 in the west.

The length of the forewings is 3-4 mm. Adults are on wing from July to mid August
And again from late August to November in two generations.

The larva

Larva

A larva 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 mostly feed on Salix species, including Salix alba, Salix amygdaloides, Salix babylonica, Salix bebbiana

Salix bebbiana

Salix bebbiana is a species of Willow that is indigenous to Canada and the northern United States, from Alaska and Yukon south to California and Arizona and north-east to Newfoundland and New England...

, Salix bonplandiana

Salix bonplandiana

Salix bonplandiana , , is a perennial species of willow tree native to southern and southwest Mexico and extending into central Guatemala; in western Mexico it is a tree of the Sierra Madre Occidental cordillera, but also occurring in other small locales, for example Baja California Sur, northern...

, Salix caroliniana

Salix caroliniana

Salix caroliniana, commonly known as the coastal plain willow, is a shrub or small tree native to the southeastern United States, Mexico and parts of Central America and the Caribbean. It is an obligate wetland species and grows as an emergent species in the Everglades. In the absence of fire, S....

, Salix eriocephala, Salix lasiolepis

Salix lasiolepis

Salix lasiolepis is a species of willow native to western and southwestern North America, in the United States from central and southern Washington and southwestern Idaho south to California and Texas, and in Mexico from the Baja California peninsula east to Coahuila and south to Jalisco. The name...

, Salix "longifolia", Salix lutea

Salix lutea

Salix lutea is a species of willow known by the common name yellow willow. It is native to North America, including central Canada and parts of the western and central United States, with the exception of the Great Basin. It can be found in moist and wet habitat types, such as riverbanks, meadows,...

, Salix monticola, Salix purpurea, Salix x rubens (Salix alba x Salix fragilis), Salix scouleriana

Salix scouleriana

Salix scouleriana Salix scouleriana Salix scouleriana (Scouler's Willow; syn. S. brachystachys Benth., S. capreoides Anderss., S. flavescens Nutt., S. nuttallii Sarg., S...

and Salix sericea

Salix sericea

Salix sericea, also known as silky willow, is a shrub in the Salicaceae family that grows in swamps and along rivers in eastern United States and Canada...

, but may also feed on Populus species, including Populus balsamifera

Populus balsamifera

Populus balsamifera, commonly called balsam poplar, bamtree, eastern balsam poplar, hackmatack, tacamahac poplar, tacamahaca,...

and Populus tremuloides

Populus tremuloides

Populus tremuloides is a deciduous tree native to cooler areas of North America, commonly called quaking aspen, trembling aspen, American aspen, and Quakies,. The trees have tall trunks, up to 25 metres, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden...

. They mine

Leaf miner

Leaf miner is a term used to describe the larvae of many different species of insect which live in and eat the leaf tissue of plants. The vast majority of leaf-mining insects are moths , sawflies and flies , though some beetles and wasps also exhibit this behavior.Like Woodboring beetles, leaf...

the leaves of their host plant.