''Agelastica alni'', the alder leaf beetle, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
leaf beetle
The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 (and probably at least 50,000) species in more than 2,500 genera, making up one of the largest and most commonly encountered of all beetle ...
(
Chrysomelidae
The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 (and probably at least 50,000) species in more than 2,500 genera, making up one of the largest and most commonly encountered of all beetle ...
) in the genus ''
Agelastica
''Agelastica'' is a genus of beetles in the family Chrysomelidae. It has two members, '' Agelastica alni'' and ''Agelastica coerulea
''Agelastica'' is a genus of beetles in the family Chrysomelidae. It has two members, '' Agelastica alni'' and ...
''.
''Agelastica alni'' is distributed in Europe, the Caucasus, Siberia, north-eastern Kazakhstan, and in the 19th century was introduced to the United States.
The beetle and the beetle's larval host is the grey or
speckled alder
''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'') and to a lesser extent black alder (''
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 ...
''), but it will also be found on
hazel
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
,
birch
A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...
or
hornbeam
Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere.
Origin of names
The common English name ''hornbeam' ...
if there is a shortage of food. It causes large holes and gaps in leaves from the end of April onwards, which are produced by the larvae in the first two stages, but the main damage is produced by larvae in the third stage.
Previously rare, and considered extinct in the UK, since being found in Manchester in 2004 it appears to be on the increase in the North West of England. Its range has been extending and it was found in Nottinghamshire and Hampshire in 2014 and in North Wales in 2018.
Description
The alder leaf beetle is a relatively small beetle, around 6–7 mm, black or metallic blue in colour. The winged adults overwinter and emerge in the spring. There is one generation each year. The larvae are normally black. Although the damage to alder trees can be unsightly, the trees will usually tolerate the damage.
Subspecies
There are two subspecies of ''Agelastica alni'':
* ''A. a. alni''
(Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
, 1758
Events
January–March
* January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of Systema Naturae, 10th edition of ''Systema Naturae'', the sta ...
)
* ''A. a. glabra''
(Fischer von Waldheim
Gotthelf Fischer von Waldheim (russian: Григо́рий Ива́нович Фи́шер фон Ва́льдгейм, translit=Grigórij Ivánovič Fíšer fon Vál'dgejm; 13 October 1771 – 18 October 1853) was a Saxon anatomist, entomol ...
, 1842) (formerly known as ''A. a. orientalis''
Baly, 1878 until 2015)
References
{{Taxonbar, from=Q882629
Galerucinae
Articles containing video clips
Beetles described in 1758
Beetles of Europe
Beetles of Asia
Taxa named by Carl Linnaeus