''Psylla alni'' is a species of

psyllid Psyllidae, the jumping plant lice or psyllids, are a family of small plant-feeding insects that tend to be very host-specific, i.e. each plant-louse species only feeds on one plant species (monophagous) or feeds on a few closely related plants ...

, a plant-feeding hemipteran in the family

Psyllidae Psyllidae, the jumping plant lice or psyllids, are a family of small plant-feeding insects that tend to be very host-specific, i.e. each plant-louse species only feeds on one plant species (monophagous) or feeds on a few closely related plants ( ...

Distribution

This species is present in the

Palearctic realm The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Sibe ...

(from Europe to Siberia and Sakhalin, Kazakhstan, Caucasus) and in the

Nearctic realm The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface. The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America t ...

(

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and

United States of America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

).Fauna Europaea
/ref>

Description

''Psylla alni'' can reach a body length of about . These rather large psyllids have a green head, body, and legs, and rather long antennae. The costal marginal veins of the wings are green, while the other veins are brown. Adults are initially green, later becoming orange, brown, or reddish. The nymphs are usually covered by white waxy secretions.
/ref> In the 5th preimaginal stage nymphs can reach a length of about .

Biology

Adults can be found from June to October. This species has one generation a year (

univoltine Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. The term is most often applied to insects, and is particularly in use in sericulture, where silkworm varieties vary in their voltinism. ...

) and overwinters as an egg. It is monophagous on most

Betulaceae Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of the t ...

(''

Alnus glutinosa ''Alnus glutinosa'', the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations whe ...

'', ''

Alnus hirsuta ''Alnus incana'', the grey alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners ...

'', ''

Alnus incana ''Alnus incana'', the grey alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners ...

'', ''

Alnus japonica ''Alnus japonica'', known as Japanese alder, is a species of Alnus Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a la ...

'', ''

Alnus viridis ''Alnus alnobetula'' is a common tree widespread across much of Europe, Asia, and North America. Many sources refer to it as ''Alnus viridis'', the green alder, but botanically this is considered an illegitimate name synonymous with ''Alnus alno ...

''). Larvae feed on young shoots in the leaf axils.Plant Parasites of Europe

References

*Psyl'list: Psylloidea database. Ouvrard D., Psyllidae Hemiptera of Asia Hemiptera of Europe Hemiptera of North America Insects described in 1758 Taxa named by Carl Linnaeus {{sternorrhyncha-stub